Patent Publication Number: US-2021169500-A1

Title: Devices and methods for excluding the left atrial appendage

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/782,871, filed Feb. 5, 2020, and titled “Devices and Methods for Excluding the left Atrial Appendage,” which claims the priority benefit of U.S. Provisional Patent Application No. 62/803,289, filed Feb. 8, 2019, the entire disclosure of each of which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Field 
     This development relates generally to systems, devices and methods for excluding the left atrial appendage (LAA). In particular, systems, devices and methods for excluding the LAA using an expandable foam implant with a deployable and compliant frame are described herein. 
     Description of the Related Art 
     Atrial fibrillation (Afib) is a condition in which the normal beating of the left atrium (LA) is chaotic and ineffective. The left atrial appendage (LAA) is a blind pouch off the LA. In patients with Afib, blood stagnates in the LAA facilitating clot formation. These clots (or clot fragments) have a tendency to embolize or leave the LAA and enter the systemic circulation. A stroke occurs when a clot/clot fragment embolizes and occludes one of the arteries perfusing the brain. Anticoagulants, e.g. Coumadin, have been shown to significantly reduce the stroke risk in Afib patients. These drugs reduce clot formation but also increase bleeding complications including hemorrhagic strokes, subdural hematoma, and bleeding in the gastrointestinal tract. 
     There are about eight million people in the US and EU with Afib. About 4.6 million of these patients are at a high risk for stroke and would benefit from anticoagulation. A large portion of these patients cannot take anticoagulants due to an increased bleeding risk, leaving their stroke risk unaddressed. The prevalence of Afib increases with age. 
     Existing devices for occluding the LAA have drawbacks. Existing devices are offered in many sizes and must be closely matched to the highly variable LAA anatomy. This is difficult to do using fluoroscopy and often requires adjunctive imaging in the form of transesophageal echocardiography (TEE), cardiac CT and MRI, all with three dimensional reconstructions. If the device is significantly oversized, the LAA ostium may become overstretched leading to tearing, resulting in bleeding into the pericardial space. If the device is too small, it will not adequately seal the ostium and may be prone to embolization. Even if sized correctly, the device forces the oval LAA ostium to take the round shape of the device, often resulting in residual leakage at the edges due to poor sealing. 
     Existing devices require sufficient spring force or stiffness to seal and anchor to surrounding tissue. If too stiff, these devices may lead to leaking of blood through the tissue into the pericardial space which may lead to cardiac tamponade. Furthermore, the geometry of these devices limits repositioning once the implant is fully expanded. Existing devices also complicate delivery by requiring positioning in the LAA coaxial to the axis of the LAA. 
     There is therefore a need for an improved LAA occlusion device. 
     SUMMARY 
     The embodiments disclosed herein each have several aspects no single one of which is solely responsible for the disclosure&#39;s desirable attributes. Without limiting the scope of this disclosure, its more prominent features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled “Detailed Description,” one will understand how the features of the embodiments described herein provide advantages over existing systems, devices and methods for left atrial appendage (LAA) occlusion. 
     The following disclosure describes non-limiting examples of some embodiments. For instance, other embodiments of the disclosed systems and methods may or may not include the features described herein. Moreover, disclosed advantages and benefits can apply only to certain embodiments and should not be used to limit the disclosure. 
     Devices and methods are described for occluding the LAA (LAA) to exclude the LAA from blood flow to prevent blood from clotting within the LAA and subsequently embolizing, particularly in patients with atrial fibrillation. An LAA occlusion device is delivered via transcatheter delivery into the LAA and anchored using a compliant frame and foam body. The device conforms to the oval shape of the LAA with superior sealing effect, does not require an excessive number of sizes and thus negates the need for extensive pre-procedure imaging, and can be delivered off-axis thereby allowing for simpler delivery procedure, among other advantages. 
     A foam body, which can be tubular in shape, and a compliant frame inside or within the foam body, are described that are collapsed for delivery and then expand in place within the LAA. The device is anchored by structural anchors of the frame and/or by tissue ingrowth from the left atrium (LA) and LAA into the foam. In one aspect, a conformable left atrial appendage occlusion device is described. The device comprises an expandable tubular body and a self-expandable support. The expandable tubular body has a compressible open cell foam sidewall, a proximal, occlusive end for facing a left atrium following implantation of the device in a left atrial appendage, a distal end for facing into the left atrial appendage following implantation of the device in the left atrial appendage, and a longitudinal axis extending therethrough, the tubular foam body having a mean diameter in an unconstrained expansion. The self-expandable support is carried within the expandable tubular body such that the foam sidewall provides a cushion between the support and the wall of the left atrial appendage following implantation, the support comprising a plurality of struts forming a plurality of apexes. Compression of the device from a diameter of about 35 mm to a diameter of about 20 mm along a minor axis transverse to the longitudinal axis causes no more than about a 5 mm reduction in the mean diameter. 
     There are various embodiments of the various aspects. For example, compression of the device from a diameter of about 35 mm to a diameter of about 20 mm along a minor axis transverse to the longitudinal axis may cause no more than about a 2 mm reduction in the mean diameter. The support may comprise a plurality of distally facing apexes, and the tubular foam body extends distally beyond the distal apexes to provide an atraumatic distal bumper. The conformable left atrial appendage occlusion device may further comprise at least one anchor. The expandable body may be compressed within a delivery catheter having an inside diameter of no more than about 20 F and self-expand to a diameter of at least about 35 mm when released from the delivery catheter. Application of 0.10 lbs compressive force along a minor axis transverse to the longitudinal axis may produce a compression of at least about 0.25 inches along the minor axis. Application of 0.20 lbs compressive force along the minor axis may produce a compression of at least about 0.5 inches along the minor axis. The side wall may have an uncompressed thickness of at least about 0.5 mm. The side wall may extend in a distal direction beyond a distal end of the support by at least about 2 mm in an unconstrained, expanded state. The foam sidewall may comprise a reticulated, cross linked matrix having at least about 90% void content, an average pore size within the range of from about 250-500 microns, a wall thickness of at least about 2 mm, and wherein a pressure required to compress the foam to 50% strain is at least about 1 psi. The pressure required to compress the foam to 50% strain may be within a range of from about 1 psi to about 2 psi. The self-expandable support may comprise one or more recapture struts extending radially in an unconstrained configuration. 
     In another aspect, a conformable left atrial appendage occlusion device is described. The device comprises an expandable tubular body and a self-expandable support. The expandable tubular body has a compressible open cell foam sidewall, a proximal, occlusive end for facing a left atrium following implantation of the device in a left atrial appendage, a distal end for facing into the left atrial appendage following implantation of the device in the left atrial appendage, and a longitudinal axis extending therethrough, the tubular foam body having a mean diameter in an unconstrained expansion. The self-expandable support is carried within the expandable tubular body such that the foam sidewall provides a cushion between the support and the wall of the left atrial appendage following implantation, the support comprising a plurality of struts forming a plurality of apexes. Compression of the device from a diameter of about 35 mm to a diameter of about 25 mm along a minor axis transverse to the longitudinal axis causes an elongation of at least about 6 mm along a major axis transverse to the minor axis. In some embodiments, compression of the device from a diameter of about 35 mm to a diameter of about 25 mm along the minor axis may cause an elongation of at least about 8 mm along the major axis. 
     In another aspect, a conformable left atrial appendage occlusion device is described. The device comprises an expandable tubular body and a self-expandable support. The expandable tubular body has a compressible open cell foam sidewall, a proximal, occlusive end for facing a left atrium following implantation of the device in a left atrial appendage, a distal end for facing into the left atrial appendage following implantation of the device in the left atrial appendage, and a longitudinal axis extending therethrough, the tubular foam body having a mean diameter in an unconstrained expansion. The self-expandable support is carried within the expandable tubular body such that the foam sidewall provides a cushion between the support and the wall of the left atrial appendage following implantation, the support comprising a plurality of struts forming a plurality of apexes. Application of 0.10 lbs compressive force along a minor axis transverse to the longitudinal axis produces a compression of at least about 0.2 inches along the minor axis. 
     There are various embodiments of the various aspects. For example, application of 0.20 lbs compressive force along the minor axis may produce a compression of at least about 0.5 inches along the minor axis. Application of no more than about 0.30 lbs compressive force along the minor axis may produce a compression of at least about 0.6 inches along the minor axis. The side wall may have an uncompressed thickness of at least about 0.5 mm. The side wall may have an uncompressed thickness of at least about 1.5 mm. The foam sidewall may comprise a reticulated, cross linked matrix having at least about 90% void content, an average pore size within the range of from about 250-500 microns, and a wall thickness of at least about 2 mm, and a pressure required to compress the foam to 50% strain may be at least about 1 psi. The pressure required to compress the foam to 50% strain may be within a range of from about 1 psi to about 2 psi. 
     In another aspect, a loading system for loading an expandable implant into a deployment catheter is described. The loading system comprises a delivery catheter having a proximal end and a distal end, a tapered chamber located at the distal end of the delivery catheter and having a small diameter proximal end and a large diameter distal end, and a hydraulic loader located at the proximal end of the delivery catheter. Actuation of the hydraulic loader causes the implant to advance proximally through the tapered chamber and into the distal end of the delivery catheter. 
     There are various embodiments of the various aspects. The hydraulic loader may comprise a first piston actuator configured to advance by applying a first force F 1 , a second piston actuator in fluid communication with the first piston actuator and configured to receive a second force F 2  in response to the applied force F 1 , and where F 1  is less than F 2 . The hydraulic loader may comprise a first piston actuator having a first cross-sectional area in fluid communication with a second piston actuator having a second cross-sectional area that is greater than the first cross-sectional area, where the second piston actuator is configured to advance proximally in response to manual activation of the first piston actuator. The first piston actuator may comprise a syringe configured to receive a first moveable plunger and the second piston actuator may comprise a barrel configured to couple with a second moveable plunger. The hydraulic loader may comprise a piston actuator having a distal end fixed relative to the delivery system and a proximal end configured to advance proximally relative to the delivery system in response to actuation. The loading system may further comprise an elongate, flexible pusher and a tether extending through the pusher and detachably connected to the implant. The loading system may further comprise a hand piece at a proximal end of the pusher, the hand piece having a control for moving between a first, transvascular navigation configuration in which the implant is held by the tether in close proximity to a distal end of the pusher, and a second, test configuration in which the distal end of the pusher may be moved a distance away from the implant without changing the orientation of the implant, while the tether is still attached to the implant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the drawing, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure. 
         FIG. 1  shows the anatomy of the left atrium (LA) and left atrial appendage (LAA). 
         FIG. 2  shows an LAA with an embodiment of an LAA occlusion device implanted in the LAA. 
         FIGS. 3A-3C  are proximal, distal and side views, respectively, of an embodiment of an LAA occlusion device having a compressible foam body, an expandable frame, and a proximal cover. 
         FIG. 3D  is a distal view of the embodiment of the LAA occlusion device of  FIGS. 3A-3C  additionally having an interior cover and proximal markers. 
         FIGS. 4A-4B  are side and cross-section views, respectively, of the compressible foam body of  FIGS. 3A-3C . 
         FIG. 4C  is a cross-section view of the foam body of  FIGS. 3A-3C  with the expandable frame. 
         FIGS. 5A-5C  are top perspective, side, and cross-section views of another embodiment of an LAA occlusion device. 
         FIGS. 5D-5E  are side cross-section views of various embodiments of the LAA occlusion device of  FIG. 3D . 
         FIG. 6A  is a top view of an embodiment of a proximal cover shown in a flat configuration that may be used with the various LAA occlusion devices described herein. 
         FIGS. 6B-6C  are top views of another embodiment of a proximal cover shown, respectively, in a flat configuration and assembled with an LAA occlusion device. 
         FIG. 6D-6E  are side and perspective views, respectively, of another embodiment of a proximal cover shown assembled with an LAA occlusion device. 
         FIGS. 7A and 7B  are side perspective and proximal perspective views, respectively, of the frame of  FIGS. 3B and 4C  shown in a deployed configuration. 
         FIGS. 8A-8C  are sequential proximal perspective views of an embodiment of a frame showing assembly of a cap and pin with the frame that may be used with the LAA occlusion devices of  FIGS. 3A-6E . 
         FIG. 8D  is a distal perspective view of the cap of  FIGS. 8A-8C . 
         FIG. 9  is a side view of an embodiment of a loading system for loading the device of  FIGS. 3A-6E  into a delivery catheter. 
         FIG. 10A  is a side view of a schematic of a transcatheter delivery system for delivering the device of  FIGS. 3A-6E  via an artery or vein. 
         FIGS. 10B-10C  are proximal and distal perspective views, respectively, of the delivery system of  FIG. 10A , showing an associated tether release mechanism and method. 
         FIGS. 11A and 11B  are proximal and distal perspective views respectively of another embodiment of a tether release system that may be used with the device of  FIGS. 3A-6E . 
         FIGS. 12A-12C  depict various embodiments of an anchor/foam interface that may be used with the LAA occlusion devices of  FIGS. 3A-6E . 
         FIG. 13A  is a schematic showing an embodiment of a profile of an ostium and an LAA. 
         FIG. 13B  is a schematic of the LAA occlusion devices of  FIGS. 3A-6E  as implanted in the ostium and LAA of  FIG. 13A , illustrating the conforming capabilities of the devices. 
         FIG. 14A  is a schematic of an LAA occlusion device illustrating the radial compression capabilities of the devices of  FIGS. 3A-6E . 
         FIG. 14B  is a schematic of an LAA occlusion device illustrating the axial compression capabilities of the device of  FIGS. 3A-6E . 
         FIG. 15  is a plan view of an embodiment a laser cut tube frame shown in a flat configuration that may be used as the frame for the LAA occlusion devices of  FIGS. 3A-6E . 
         FIGS. 16A-16C  are various detail views of the frame of  FIGS. 7A-8C  indicating some of the structural aspects contributing to the LAA occlusion device&#39;s conformable capabilities. 
         FIGS. 17A-17B  are top views of the device of  FIGS. 3A-6E  shown, respectively, in an uncompressed configuration and a compressed configuration. 
         FIGS. 18A-18C  are data plots of test results showing various structural characteristics for certain embodiments of the device of  FIGS. 3A-6E . 
         FIGS. 19A-19C  are data plots of test results showing various structural characteristics for certain other embodiments of the device of  FIGS. 3A-6E   
         FIG. 20  is a schematic of an embodiment of a test setup that may be used to perform a flat plate test to characterize the stiffness and other structural attributes of the device of  FIGS. 3A-6E . 
         FIG. 21  is a flow chart depicting an embodiment of a flat plate test method that may be performed with the test setup of  FIG. 20  and the device of  FIGS. 3A-6E . 
         FIGS. 22A and 22B  are perspective and cross-section views, respectively, of an embodiment of a loading tool having guides, a locking connection for securing a catheter, and configured to hold fluid. 
         FIGS. 23A-23D  are various views of an embodiment of a delivery catheter handle that may be used with the LAA implant and associated devices and systems described herein. 
         FIGS. 24A-24D  are various views of an embodiment of a tether control switch or components thereof that may be used with the various LAA implant delivery handles, such as the handle of  FIGS. 23A-23D , and associated devices and systems, described herein. 
         FIGS. 25A-25C  show various views of various embodiments of dual lumen delivery catheter pushers that may be used with the various delivery systems and implants described herein. 
         FIG. 26  is a side view of a catheter delivery system that may be used with the various occlusion devices described herein. 
         FIGS. 27A-27C  are side views of a hydraulic loading system that may be used to load the various occlusion devices into a delivery catheter. 
     
    
    
     While the above-identified drawings set forth presently disclosed embodiments, other embodiments are also contemplated, as noted in the discussion. This disclosure presents illustrative embodiments by way of representation and not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of the presently disclosed embodiments. 
     DETAILED DESCRIPTION 
     The following detailed description is directed to certain specific embodiments of the development. In this description, reference is made to the drawings wherein like parts or steps may be designated with like numerals throughout for clarity. Reference in this specification to “one embodiment,” “an embodiment,” or “in some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrases “one embodiment,” “an embodiment,” or “in some embodiments” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but may not be requirements for other embodiments. Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     The devices and related methods are described herein in connection with use in occluding, i.e. excluding, a left atrial appendage (LAA). The various figures show various embodiments of LAA occlusion devices, systems and methods for delivery of the LAA occlusion devices, and/or methods of using the device to occlude a LAA. The various systems, devices and methods described herein may include the same or similar features and/or functionalities as other LAA occlusion systems, devices and methods as described, for example, in U.S. application Ser. No. 14/203,187 entitled “DEVICES AND METHODS FOR EXCLUDING THE LAA” and filed on Mar. 10, 2014, and/or as described in U.S. Provisional Application No. 62/240,124 entitled “DEVICES AND METHODS FOR EXCLUDING THE LAA” and filed on Oct. 12, 2015, the entire disclosure of each of which is incorporated herein by reference for all purposes and forms a part of this specification. 
     Some embodiments of an LAA occlusion device  3000  include a foam body  3002 , a deployable and compliant frame  3040 , and a proximal cover  3100 , as primarily shown and described for example with respect to  FIGS. 3A-8D . Other features and functionalities that the device  3000  may include and employ are shown and described with respect to  FIGS. 1-23 and 30-11B . 
     The heart  100  is shown in  FIG. 1  with the left atrial appendage (LAA)  102 , which is a cavity emanating from the left atrium (LA)  104 . The LAA  102  is quite variable in shape in all dimensions. If the heart is not beating normally, a condition called atrial fibrillation, blood within the LAA becomes stagnant which promotes clot formation. If blood clots within the LAA, the clots may pass from the LAA  102  to the LA  104 , to the left ventricle  106  and out of the heart  100  into the aorta. Vessels that bring blood to the brain branch off the aorta. If the clot passes to the brain via these vessels, it may get stuck and occlude a small vessel in the brain which then causes an ischemic stroke. Strokes have severe morbidities associated with them. The opening of the LAA  102  to the LA  104  is called an ostium  110 . The ostium  110  is oval, highly variable and dependent on loading conditions, i.e., left atrial pressure. An object of the LAA occlusion devices described herein is to occlude the ostium  110  thereby sealing off the LA  104  from the LAA  102 . 
     One embodiment of an LAA occlusion device  204  is shown in  FIG. 2 . The occlusion device  204  is placed within the LAA  200  at its opening to the LA  202 . It is understood that the device  204  may have the same or similar features as other implantable “devices” or “implants” described herein, such as the implant  3000 , and vice versa. The device  204  may thus have an expandable foam body carrying a support structure or frame with anchors, as described herein, for example with respect to the implant  3000  and  FIGS. 3A-8D . 
     The device  204  may be cylindrical in shape in an unconstrained expansion, but it may also be conical for example with its distal end smaller than the proximal end or reversed. It could also be oval in cross section to better match the opening of the LAA. 
     The device  204  is oversized radially in an unconstrained expansion to fit snuggly into the LAA and may be 5-50 mm in diameter depending on the diameter of the target LAA. The compliance and thickness of the foam are designed to provide a good seal against the tissue with minimal compression. While other devices require significant oversizing relative to the width of the LAA to obtain a seal, the implants described herein may require only ≤1 mm of oversizing. In some embodiments, the implant may require only ≤2 mm, ≤3 mm, or ≤4 mm, or ≤5 mm. In a free, unconstrained state, the axial length “L” of the plug is less than its outer diameter “D” such that the L/D ratio is less than 1.0. In some embodiments, this ratio may be greater than 1.0. The compliance of the foam material is designed such that it pushes on the walls of the LAA with sufficient force to maintain the device  204  in place but without overly stretching the LAA wall. The foam and/or skin also conforms to the irregular surfaces of the LAA as it expands, to provide a complementary surface structure to the native LAA wall to further enhance anchoring and promote sealing. Thus, the expandable foam implant described herein conforms to the native configuration of the LAA. In one embodiment, the structure of the foam may be fabricated such that squeezing axially on the opposing ends of the foam causes the foam to increase in diameter. 
     An outer ePTFE layer may be formed as a sheet. The sheet may have a wall thickness between 0.0001″ and about 0.001″ thick and serves to allow one to collapse and pull on the device  204  without tearing the foam material. In other embodiments, an outer ePTFE layer may be formed from a tube with a diameter about the same diameter of the foam plug and a wall thickness between about 0.0001″ and about 0.001″ thick and serves to allow one to collapse and pull on the device  204  without tearing the foam material. The ePTFE material also serves as the blood contacting surface facing the LA  206  and has pores or nodes such that blood components coagulate on the surface and an intimal or neointimal covering of tissue grows across it and anchors tightly to the material. Pore sizes within the range of from about 4μ to about 110μ, ideally 5-35μ are useful for formation and adherence of a neointima. 
     The outer covering  206  may be constructed of materials other than ePTFE such as woven fabrics, meshes or perforated films made of FEP, polypropylene, polyethylene, polyester or nylon. The covering  206  should have a low compliance (non-elastic), at least longitudinally, be sufficiently strong as to permit removal of the plug, a low coefficient of friction, and be thromboresistant. The outer covering  206  serves as a matrix to permit plug removal as most foams are not sufficiently strong to resist tearing when pulled. The plug  204  can also be coated with or contain materials, such as PTFE. Such materials may enhance the plug&#39;s  204  ultrasonic echogenic profile, thromboresistance, and/or lubricity. The plug  204  can also be coated with or contain materials to facilitate echocardiographic visualization, promote cellular ingrowth and coverage. 
     The outer covering  206  has holes in it to permit contact of the LAA tissue with the device  204  to encourage ingrowth of tissue into the foam plug pores and/or allow blood flow therethrough. These holes may be 1 to 5 mm in diameter or may also be oval with their long axis aligned with the axis of the foam plug, the length of which may be 80% of the length of the foam plug and the width may be 1-5 mm. The holes may be as large as possible such that the outer covering maintains sufficient strength to transmit the tensile forces required for removal. The holes may be preferentially placed along the device. In one embodiment, holes are placed distally to enhance tissue ingrowth from the LAA wall. 
     The device  204  or  3000  (as described below) may be anchored and secured in place in the LAA by anchoring features. In some embodiments, the device  204  or  3000  may also be anchored by tissue ingrowth. 
     Deployment of the occlusion device may be via transvascular access. However, the implants may alternatively be deployed via direct surgical access, or various minimally invasive access pathways (e.g. jugular vein). For example, the area overlying the xiphoid and adjacent costal cartilage may be prepared and draped using standard techniques. A local anesthetic may be administered and skin incision may be made, typically about 2 cm in length. The percutaneous penetration passes beneath the costal cartilage, and a sheath may be introduced into the pericardial space. The pericardial space may be irrigated with saline, preferably with a saline-lidocaine solution to provide additional anesthesia and reduce the risk of irritating the heart. The occlusion device may thereafter be introduced through the sheath, and through an access pathway created through the wall of the LAA. Closure of the wall and access pathway may thereafter be accomplished using techniques understood in the art. 
     Various features for LAA occlusion may be included in the LAA occlusion devices, systems, and methods described herein, such as those described, for example, in U.S. patent application Ser. No. 15/290,692, filed Oct. 11, 2016 and titled DEVICES AND METHODS FOR EXCLUDING THE LAA, in U.S. patent application Ser. No. 14/203,187, filed Mar. 10, 2014 and titled DEVICES AND METHODS FOR EXCLUDING THE LAA, in European Patent Application no. EP 14779640.3, filed Aug. 24, 2015 and titled DEVICES AND METHODS FOR EXCLUDING THE LAA, and in PCT Patent Application no. PCT/US2014/022865, filed Mar. 10, 2014 and titled DEVICES AND METHODS FOR EXCLUDING THE LAA, the entire disclosure of each of which is hereby expressly incorporated by reference for all purposes and forms a part of this specification. Further additions and improvements to these and other concepts are described below. The embodiments described in the sections below may include the same or similar features and/or functionalities as the embodiments described above, and vice versa, except as otherwise noted or indicated by context. 
     A. LAA Occlusion Device Embodiments with Compressible Foam Body, Proximal Cover, and Compliant Frame Having Proximal Recapture Struts and Distal Tubular Body 
       FIGS. 3A-11B  show an embodiment of an LAA occlusion device  3000 . The device  3000  described herein may have the same or similar features and/or functionalities as other LAA occlusion devices described herein, and vice versa. Any of the features of the device  3000  described with respect to  FIGS. 3A-11B  may therefore apply to features of the devices described with respect to  FIG. 2 , such as the device  204 , and vice versa. 
       FIGS. 3A-3C  show the LAA occlusion device  3000  having a foam body  3002 , an expandable support or frame  3040 , and a proximal cover  3100 .  FIG. 3D  shows the LAA occlusion device  3000  additionally having an interior cover  3101  and proximal markers  3023 A.  FIGS. 4A-4C  show the foam body  3002 , with the body  3002  shown in cross-section in  FIGS. 4B and 4C .  FIG. 4C  additionally includes the full view (i.e. non-cross section) of the frame  3040 . The device  3000  is shown in an expanded configuration in these figures. The device  3000  has a longitudinal axis as shown, which may be defined by the foam body  3002 , as further described. 
     1. Compressible Foam Body 
     The body  3002  is formed from a compressible material, such as foam. The body  3002  may be a foam formed from reticulated (e.g. net-like) polycarbonate polyurethane-urea. The body  3002  may be cut, formed or assembled into a cup shape, as further described. The body  3002  may have a thickness and compressibility sufficient to engage the surrounding tissue and conform to the anatomic irregularities under radial force applied by the inner frame, as further described. The use of a compressible material such as foam for the body  3002  provides a complete seal of the LAA and superior performance for LAA occlusion over existing devices, as further described. The structure of the foam of the body  3002  comprises a three-dimensional network of interconnected reticulations, spaced apart to form a network of interconnected open pores, as further described. The reticulations can carry a coating, such as PTFE, while preserving the open pores, as further described. 
     The foam material of the body  3002  has a high porosity. “Porosity” as used herein has its usual and customary meaning and refers to open void content between the interconnected reticulations of the foam. The porosity of the body  3002  may be at least about 65%, at least about 70% at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95% or more. The porosity may be within the range of approximately 90-95%. The porosity may be approximately 90%. The porosity may be approximately 95%. The porosity may be 90%, 91%, 92%, 93%, 94%, or 95%. The high porosity promotes quick and tenacious tissue ingrowth, allows it to be compressed into a small catheter, and/or allows blood to pass if the implant embolizes, among other advantages. 
     The foam body  3002  has pores or cells formed between the interconnected reticulations of the foam material. The foam body  3002  has cells with sizes in the range of from about 250 μm to about 500 μm. The foam may have a cell size from about 125 μm to about 750 μm, from about 175 μm to about 650 μm, from about 200 μm to about 600 μm, from about 225 μm to about 550 μm, from about 275 μm to about 450 μm, less than 125 μm, or greater than 750 μm. These sizes may refer to the size of the cell prior to application of any coating, such as PTFE. The cell size may thus change, e.g. decrease, after application of the coating. The desired porosity and/or cell size may be determined based on allowing the passage of blood while blocking debris of a size capable of potentially causing ischemic stroke. The allowable size of such debris may drive the selection of the particular porosity and/or cell size. For example, the cell size from about 250 μm to about 500 μm may be based on prevention of debris of a particular size from passing through the body  3002 . 
     In an embodiment, the foam body  3002  is made from a non-resorbable, reticulated, cross-linked, polycarbonate polyurethane-urea matrix, structurally designed to support fibrovascular tissue ingrowth, with a fully interconnected, macroporous morphology with over 90-95% void content and cell sizes ranging from 250 to 500 μm. 
     The body  3002  has a proximal end  3004  and a distal end  3006 . In some embodiments, the axial length of the device  3000  from the proximal end to the distal end in a free, unconstrained state is 20 mm. As used herein, the “free, unconstrained” state, and the like, refers to a state of the device  3000  without any external forces applied to the device  3000  other than a normal or reactive force from a surface (e.g. table top) on which the device  3000  is placed. In some embodiments, this axial length may be from about 10 mm to about 30 mm, from about 12 mm to about 28 mm, from about 14 mm to about 26 mm, from about 16 mm to about 24 mm, from about 18 mm to about 22 mm, or about 20 mm. The body  3002  may have any of these lengths regardless of outer diameter of the body  3002 . 
     The proximal end  3004  of the body  3002  has a proximal end wall or face  3008 . The proximal face  3008  faces generally toward the LA when the device  3000  is implanted into the LAA. The device  3000  may be implanted off-axis, as further described, in which case the proximal face  3008  may not reside at a perpendicular to a longitudinal axis of the LA. The proximal face  3008  thus provides a closed proximal end  3004  of the body  3002 . The closed proximal end  3004  is configured to span the ostium but the porosity, as further described, is sufficient to permit the passage of blood while blocking debris of a size capable of potentially causing ischemic stroke. This membrane may be formed by the body  3002  and/or the cover  3100 . In some embodiments, the proximal face  3008  or portions thereof may be open. For example, there may not be a proximal face  3008 , there may be a partial proximal face  3008 , there may be a proximal face  3008  with portions removed, etc. In some embodiments, the proximal face  3008  or portions thereof is/are not included and any opening or openings is/are covered by the cover  3100 . The size of any such openings in the proximal face  3008  may be driven by the desired size of embolic debris to be prevented from escaping the LAA, as further described. 
     The proximal face  3008  is flat or generally flat and generally perpendicular to the longitudinal axis of the device  3000 . The proximal face  3008  has a circular or generally circular shape as viewed from the proximal end  3004  in an unconstrained expansion. In some embodiments, the proximal face  3008  may be flat, rounded, segmented, angled with respect to the longitudinal axis, other shapes, or combinations thereof. The proximal face  3008  may have a non-circular, polygonal, other rounded shape, other shapes, or combinations thereof, as viewed from the proximal end  3004 . 
     The proximal face  3008  has an outer surface  3010  and an opposite inner surface  3012 . The outer surface  3010  faces proximally away from the device  3000  and the inner surface  3012  faces distally toward the frame  3040 . The surfaces  3010 ,  3012  may define outer and inner sides of the proximal face  3008 . The thickness of the proximal face  3008  may be measured axially between the outer surface  3010  to the inner surface  3012 . This thickness in a free, unconstrained state (e.g. uncompressed and expanded) may be from about 0.5 mm to about 5 mm, from about 1 mm to about 4 mm, from about 2 mm to about 3 mm, about 2.5 mm, or 2.5 mm. In some embodiments, the thickness may be less than 0.5 mm or greater than 5 mm. The thickness of the proximal face  3008  may be uniform or non-uniform. Thus the thickness may be greater or smaller in different regions of the proximal face  3008 . 
     The body  3002  includes a sidewall  3014  extending distally from the proximal face  3008 . The sidewall  3014  extends circumferentially about a perimeter of the proximal face  3008  to form a closed cross-section (i.e. extends circumferentially 360 degrees about the axis). The sidewall  3014  extends axially to define a tubular body concentric about the longitudinal axis of the device  3000 . The longitudinal axis extends through a geometric center of the tubular body defined by sidewall  3014 . The sidewall  3014  is tubular or generally tubular, e.g. cylindrical, along the axis. In some embodiments, the sidewall  3014  may be conical or frustoconical, for example where the proximal end is wider than the distal end or vice versa. The sidewall  3014  may have an outer profile at the proximal end thereof, and as viewed from the proximal or distal end, to match that of the outer perimeter of the proximal face  3008 . 
     In some embodiments, the cross-section of the sidewall  3014  may not be closed, for example where there are openings in the sidewall  3014 . Thus cross-sections taken at various locations along the longitudinal axis may or may not show a closed section. In some embodiments, the sidewall  3014  may be non-tubular, non-cylindrical, non-circular, polygonal, other rounded shapes, other shapes, or combinations thereof. In some embodiments, as shown, the sidewall  3014  may extend continuously for the entire length from the proximal end  3004  to the distal end  3006 . In some embodiments, the sidewall  3014  may not extend continuously for the entire length from the proximal end  3004  to the distal end  3006 . For example, the sidewall  3014  may include a plurality of disconnected sections, such as annular portions of the sidewall, located and spaced along the longitudinal axis and connected to the frame  3040 . 
     The sidewall  3014  has an outer surface  3016  and an opposite inner surface  3018 . The outer surface  3016  faces radially outward from the axis. The inner surface  3018  faces radially inward toward the axis. The thickness of the sidewall  3014  may be measured radially between the outer surface  3016  to the inner surface  3018 . This thickness in a free, unconstrained state (e.g. uncompressed) may be from about 0.5 mm to about 5 mm, from about 1 mm to about 4 mm, from about 2 mm to about 3 mm, about 2.5 mm, or 2.5 mm. In some embodiments, the thickness may be less than 0.5 mm or greater than 5 mm. The thickness of the sidewall  3014  may be uniform or non-uniform. Thus the thickness may be greater or smaller in different regions of the sidewall  3014 . The thickness of the sidewall  3014  may be the same or different as the thickness of the proximal face  3008 . In some embodiments, the thickness of the proximal face  3008  is 2.5 mm and the thickness of the sidewall  3014  is 2.5 mm. In some embodiments, the thickness of the proximal face  3008  is about 2.5 mm and the thickness of the sidewall  3014  is about 2.5 mm. 
     The sidewall  3014  has a distal free end  3020  having a distal surface  3022 . The distal surface  3022  is flat or generally flat and perpendicular to the longitudinal axis of the device  3000 . In some embodiments, the distal surface  3022  is non-flat, angled with respect to the axis of the device  3000 , curved, rounded, segmented, other shapes, or combinations thereof. 
     The body  3002  may have a distal opening  3024 . The opening  3024  is formed by the distal free end  3020  of the sidewall  3014 . The opening  3024  is at a distal end of an internal central volume or cavity  3028  of the body  3002  that is formed at least partially by the sidewall  3014 , the proximal face  3008  and/or the shoulder  3030 . The frame  3040  may reside within the cavity  3028 , as further described. The distal opening  3024  may be completely open. In some embodiments, the distal opening  3024  may be mostly open, partially open, or closed, for example where the body  3002  has a distal face similar to the proximal face  3008  to enclose or partially enclose the cavity  3028 . 
     The body  3002  has a shoulder  3030 , shown as a bevel, that extends between the proximal face  3008  to the sidewall  3014 . The shoulder  3030  may be an intersection of a proximal end of the sidewall  3014  and the proximal face  3008 . The shoulder  3030  extends circumferentially about the entire perimeter of the intersection. The shoulder  3030  has an outer surface  3032 . The outer surface  3032  may be a beveled surface. The outer surface  3032  is flat or generally flat in an axial direction. The outer surface  3032  extends circumferentially about the entire perimeter of the shoulder  3030 . In some embodiments the shoulder  3030  and/or outer surface  3032  may be non-flat, rounded, other shapes in an axial direction, or combinations thereof. The shoulder  3030  and/or outer surface  3032  may extend circumferentially less than the entire perimeter of the shoulder  3030 . The thickness of the shoulder  3030  may be measured inward perpendicularly to the outer surface  3032 . The thickness of the shoulder  3030  may be the same as the thicknesses of the proximal face  3008  and/or the sidewall  3014 , as described herein. In some embodiments, the thickness of the shoulder  3030  may be different from the thicknesses of the proximal face  3008  and/or the sidewall  3014 . The shoulder  3030  may function as a recapture ramp, to facilitate drawing the implant proximally into the deployment catheter. 
     The compressibility of the body  3002  contributes to the superior sealing capability of the device  3000 . The foam may be compressible to provide a larger radial “footprint” and spread out the radial forces from struts on the frame  3040 , as further described. The foam body  3002  may have a compressive strength of at least 1 pound per square inch (psi) or within a range of about 1 psi to about 2 psi, or no more than about 2 psi. The “compressive strength” here refers to the pressure to compress the foam to 50% strain. With some foam materials for the body  3002 , the pressure may not change from 50% strain through at least 80% strain, and the relation of pressure versus strain may be flat or generally flat. Thus, even with thicker foams for the body  3002 , the body  3002  will not exert much more outward force on the tissue due to the increased thickness by itself. In an embodiment, the foam body  3002  is a reticulated, cross linked matrix having at least about 90% void content, an average cell size within the range of from about 250-500 microns, a wall thickness of at least about 2 mm and a compressive strength of at least about 1 psi. In an embodiment, the body  3002  is formed from a foam material having or substantially having the material properties indicated in Table 1. In some embodiments, the body  3002  is formed from materials described in, for example, U.S. Pat. No. 7,803,395, issued Sep. 28, 2010, and titled “Reticulated elastomeric matrices, their manufacture and use in implantable devices,” or U.S. Pat. No. 8,337,487, issued Dec. 25, 2012, and titled “Reticulated elastomeric matrices, their manufacture and use in implantable devices,” the entire disclosures of which are incorporated herein by reference. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Example material properties for an embodiment of foam 
               
               
                 material that may be used for the foam body 3002. 
               
            
           
           
               
               
               
            
               
                   
                 Material Property 
                 Value 
               
               
                   
                   
               
               
                   
                 Permeability 
                 311 Darcy 
               
               
                   
                 Average Cell Size 
                 377 μm 
               
               
                   
                 Density 
                 2.7 lb/ft 3   
               
               
                   
                 Compressive Strength 
                 1.1 psi 
               
               
                   
                 Tensile Strength Parallel 
                  68 psi 
               
               
                   
                 Tensile Strength 
                  32 psi 
               
               
                   
                 Perpendicular 
                   
               
               
                   
                 Elongation Parallel 
                 219% 
               
               
                   
                 Elongation Perpendicular 
                 243% 
               
               
                   
                   
               
            
           
         
       
     
     The device  3000  may include markers  3023  (see  FIGS. 3B and 5D ; for clarity only some of the markers  3023  are labelled in the figures) to facilitate visualization during delivery. The markers  3023  may be radiopaque marker bands sewn into the distal free end  3020  of the body  3002 . The markers  3023  may be for visualization using fluoroscopy imaging of the distal end  3006  of the device  3000  during delivery. There may be a series of the markers  3023  located circumferentially along the distal surface  3022  of the body  3002  (for clarity, only some of the markers  3023  are labelled in  FIG. 3B ). In some embodiments, the markers  3023  may additionally or alternatively be located in other areas of the body  3002  and/or on other parts of the device, such as the cover  3100  or frame  3040 . 
     In some embodiments, four platinum iridium (Ptlr) radiopaque (RO) tubular markers  3023  are sewn onto the distal end  3006  of the foam body  3002  to enable visualization of the distal edge of the device  3000  under fluoroscopy. In some embodiments, a Ptlr marker  3023  is attached to the foam body  3002  at the location of the proximal shoulder  3030  to use as a marker during recapture of the device  3000 . Visualization of the proximal and/or distal markers  3023  may facilitate with identifying the amount of recapture. If the device  3000  is recaptured up to but not including the anchors proximal  3090  inside the access sheath, the device  3000  can be redeployed and reused. If the proximal anchors  3090  are recaptured into the access sheath, the device  3000  may be removed and discarded due to permanent deformation of the anchors  3090 . In some embodiments, other materials may be used for the markers  3023 , such as gold or other suitable materials. 
     As shown in  FIGS. 3D and 5D , the device  3000  may include one or more markers  3023 A. As one example only, there are three markers  3023 A shown. In some embodiments, there may be one marker  3023 A. There may be two, four, five or more markers  3023 A. In some embodiments, there is one proximal marker  3023 A and ten of the distal markers  3023 . The markers  3023 A may have the same or similar features and/or functionalities as other markers described herein, for example the marker  3023 , and vice versa, except as otherwise noted. The markers  3023 A may be located at or near the proximal end of the device  3000 . As shown, the markers  3023 A are located on an inner surface  3012  of the proximal end  3004  of the foam body  3002 . The markers  3023 A may be located at or near an inner surface of a shoulder  3030  (see  FIG. 4B ) of the foam body  3002 . The markers  3023 A may be distributed circumferentially, for example equidistant or equiangular, relative to each other, or they may be at different relative distances from each other. They may be radially located at the same or different location relative to each other. In some embodiments, there is only one marker  3023 A. There may be one proximal marker  3023 A and four of the distal markers  3023 . The one or more markers  3023 A may be on the inside, outside, or within the foam body  3002 , or combinations thereof. The one or more markers  3023 A may be located on or at the distal surface  3022  of the foam body  3022 . The markers  3023 A may be elongated circumferentially as shown. In some embodiments, the markers  3023 A may be linear when the device  3000  is viewed from a particular angle, such as a side view. The markers  3023 A may be aligned or oriented in the same or similar orientation, or in different orientations. Some, none, or all of the markers  3023 A may be oriented circumferentially, laterally, axially (for example along an inner surface  3018  of the sidewall  3014 ), other orientations, or combinations thereof. 
     As further shown in  FIG. 5D , there may be one or more markers  3023 B. The one or more markers  3023 B may have the same or similar features and/or functionalities as the other markers described herein, such as the marker  3023  or  3023 A and vice versa, except as otherwise noted. The markers  3023 B may be located along the sidewall  3014  of the body  3002 . There may be one or more markers  3023 B located along an inner surface  3018  of the sidewall  3014 . 
     As shown, two markers  3023 B are visible on either side of the interior of the foam body  3002 . The markers  3023 B are attached through the foam and around the frame  3040 . The marker  3023 B may be attached, for example sutured, around a proximal face  3060  member of the frame  3040 , such as one of the struts  3061 . The marker  3023 B may be attached to the frame  3040  just proximally of one of the proximal apexes  3084  of the frame  3040 , for example at an outer curved portion  3066  of the strut  3061 . There may be only one marker  3023 B, or two, three, four or more markers  3023 B. There may be one of the markers  3023 B for each strut  3061 . The markers  3023 B may be used additionally to connect the frame  3040  with the foam body  3002 . The markers  3023 B may be sutures as described herein. 
     The one or more markers  3023 A and/or  3023 B at or near the proximal end of the device  3000  provide various desirable features. For instance, the marker  3023 A at the shoulder  3030  facilitates visualization of the device  3000  during and after implantation. The typically non-circular shape of the opening of the LAA (ostium) may compress the proximal end  3004  of the device and cause the proximal end  3004  to protrude slightly in the proximal direction. However, the shoulder  3030  may provide a location for the marker  3023 A where linear bulging of the foam body  3002  in the proximal direction is reduced or prevented. Thus, the marker  3023 A in that location can provide a more useful visualization of the positioning of the device  3000  and reduce complexity. For example, in some embodiments, the marker  3023 A at the shoulder  3030  (e.g. on an inner surface as shown) may be particularly useful during delivery, allowing for delivery using fluoroscopy imaging only without the need for echo or other ultrasound imaging. The one or more markers  3023 B may provide similar benefits. 
     As further shown in  FIGS. 3D and 5D , the device  3000  may include an inner cover  3101 . The inner cover  3101  may have the same or similar features and/or functionalities as the cover  3100  (described in further detail below, see section “Proximal Cover”), except as otherwise described. The inner cover  3101  may be a cover for the hub  3050  (see, e.g.,  FIGS. 4C and 7A-8C ). The inner cover  3101  may be formed from expanded Polytetrafluoroethylene (“ePTFE”). The inner cover  3101  may be a separate portion of the same material as the proximal cover  3100 . 
     The inner cover  3101  may be located between the foam body  3002  and the frame  3040 . As shown, the inner cover  3101  is located between the inner surface  3012  of the foam body  3002  and a proximal end of the hub  3050  of the frame  3040 . The inner cover  3101  may be circular or other shapes. The inner cover  3101  may have an area sufficient to provide a barrier in between the hub  3050  and the proximal end  3004  of the foam body  3002 . In some embodiments, the inner cover  3101  may extend radially to an outer circumference of the hub  3050 , or it may extend radially to the sidewall  3014  such as to an inner surface  3018  of the foam body  3002 , or to any radial locations in between. The inner cover  3101  may have a diameter from about 4 mm to about 22 mm, from about 5 mm to about 15 mm, from about 6 mm to about 10 mm, about 8 mm, or 8 mm. The inner cover  3101  may be flat or generally flat. The inner cover  3101  may have a thickness from about 0.0001″−0.0020″, from about 0.0002″-0.0010″, about 0.0005″, or 0.0005″ thick. The inner cover  3101  may include one or more openings  3103  such as holes therethrough. The inner cover  3101  may include two holes  3103  to receive therethrough a tether  3240  (see, e.g.,  FIGS. 10A-11B ). The two holes  3103  in the cover  3101  may align the tether  3240 , such as a suture, that extends distally into the hub  3050  through one hole  3103  in the inner cover  3101  and exits proximally back out of the hub  3050  through the other hole  3103  of the inner cover  3101 . 
     The inner cover  3101  may prevent the hub  3050  and/or other features of the frame  3040  from directly contacting the foam material. The cover  3101  may protect the integrity of the foam body  3002  from stresses that may be imparted by the hub  3050  on the foam material. This protection may be desirable for example during loading, deployment, retrieval, re-deployment, etc. of the device  3000 . The inner cover  3101  may prevent or reduce damage to the foam body  3002  from the hub  3050 . 
     The foam body  3002  may be attached to various features of the device  3000 . The body  3002  may be attached to the frame  3040  at numerous points, including for example the center of the proximal end of the frame  3040 , as further described herein. Attachment can be done using suture, such as polypropylene monofilament suture, although other methods known in the art such as adhesive bonding could be utilized. The proximal row of proximal anchors  3090  may be individually attached to (e.g. inserted through) the foam body  3002  to prevent relative movement between the foam body  3002  and the frame  3040 . In other embodiments, the foam body  3002  could be formed around the endoskeleton so that the metallic frame is within the foam body  3002 , eliminating the need for a secondary attachment step. Attachment of the body  3002  to the frame  3040  promotes retrieval without damage to the foam body  3002 , among other advantages. The attachment also ensures that a bumper  3026 , further described herein, extends beyond the frame  3040  at all times, including during initial exposure of the device  3000  upon proximal retraction of the delivery sheath. 
     As shown in  FIG. 5D , the device  3000  may include one or more attachments  3001 . The attachments  3001  may connect the frame  3040  with the foam body  3002 . The attachments  3001  may be sutures. Other suitable attachment structures may be used, including staples, ties, wires, components of the frame  3040 , other mechanical attachments, adhesives, other suitable means, or combinations thereof. The attachments  3001  may extend around the frame  3040  and through the foam body  3002 , for example through the sidewall  3014 . 
     As shown, four attachments  3001  are visible in  FIG. 5D . There are two proximal attachments  3001  and two distal attachments  3001  visible. The proximal attachments  3001  are each located at the base of a respective proximal anchor  3090 . The distal attachments  3001  are each located at the base of a respective distal anchor  3094 . There may be one, two, three, four, five, six, seven, eight, or more attachments  3001 . There may be twenty attachments  3001 . There may be one of the attachments  3001  for each anchor  3090 ,  3094  of the device  3000 . The attachments  3001  may each be located at a proximal apex  3084  or at a distal apex  3088  of the frame  3040 , as further described herein, for example with respect to  FIG. 7A . For example, the attachments  3001  may be wrapped around one or more of the struts  3082 ,  3086 , as further described herein. The attachments  3001  may locally compress the foam body  3002  at and/or around the location of attachment, as further described herein, for example with respect to  FIG. 12C . The attachment  3001 , such as a suture, may extend from within the cavity  3028 , through the foam body  3002 , exit the foam body  3002  and extend along the outer surface  3016  of the foam body  3002 , extend back into and through the foam body  3002  into the cavity  3028 , and be tied or otherwise connected together around the frame  3040 . In some embodiments a similar routing of the attachments  3001  may be used with the attachment  3001  tied or otherwise connected together around and outside the foam body  3002 . In some embodiments the attachments  3001  may also extend through the cover  3300 , or other covers as described herein. The attachments  3001  may extend through the material of the cover  3300 . The attachments  3001  may extend through openings in the cover  3300 , such as the side openings  3324 , or windows  3177  (see, e.g.,  FIGS. 6B-6E ). As shown, the proximal attachments  3001  may extend through the foam body  3002  and through openings in the cover  3300 , and the distal attachments  3001  may not extend through the cover  3300  but only through the foam body  3002 . 
     The foam body  3002  may include a coating. In some embodiments, there may not be a coating. In embodiments with a coating, the coating is applied to the interconnected reticulations of the foam material. The body  3002  may be coated with pure polytetrafluoroethylene (PTFE). The PTFE coating minimizes the thrombogenicity of the LA surface, while also reducing the friction of the foam body  3002  against the delivery system to facilitate ease of deployment and retrieval. The body  3002  may be coated with conformable, vacuum deposited, pure PTFE. In addition or alternatively, the body  3002  may be coated with a coating other than PTFE. The coating, whether PTFE or otherwise, may be about 0.5 μm thick, and covers at least a portion of the surface of the interconnected reticulations of the foam without occluding the pores. The coating may be applied to some or all of the foam body  3002 . The coating may be applied to some or all of the outer surfaces of the foam body  3002 . 
     In some embodiments, the thickness of the coating is from about 0.1 μm to about 1 μm, from about 0.2 μm to about 0.9 μm, from about 0.3 μm to about 0.8 μm, from about 0.4 μm to about 0.7 μm, about 0.4 μm to about 0.6 μm, or about 0.5 μm thick. In some embodiments, greater or smaller thicknesses of the coating may be applied. The coating has a uniform or substantially uniform thickness. In some embodiments, the coating may have a non-uniform thickness. For example, the portion of the body  3002  facing the LA when implanted, such as the proximal face  3008  and/or shoulder  3030 , may have a thicker coating relative to a coating along the sidewall  3014  of the body  3002 . In some embodiments, the outer surface  3010  of the proximal face  3008  has a PTFE coating and the proximal face  3008  also has a ePTFE cover  3100 . 
     The coating is applied using a vapor deposition process. In some embodiments, the coating is applied through coating, vapor deposition, plasma deposition, grafting, other suitable processes, or combinations thereof. The coating is applied to the outer surfaces  3010 ,  3032  and  3016  of, respectively, the proximal face  3008 , the shoulder  3030  and the sidewall  3014 . In some embodiments the coating is applied to the outer surfaces  3010 ,  3032  and only partially on the outer surface  3016 . In some embodiments the coating is applied to outer and inner surfaces of the body  3002 . 
     In some embodiments, other biocompatible, thromboresistant and/or lubricious materials could be applied to the surface(s) of the foam body  3002  and/or the cover  3100 . These materials may encourage tissue ingrowth. Such materials may include, for example, heparin, albumin, collage, polyethylene oxide (PEO), hydrogels, hyaluronic acid, materials that release nitric oxide, oxygen, nitrogen, amines, bioabsorbable polymers, and other biomaterials, pharmacologic agents, and surface modification materials. Additionally, the surface(s) of the body  3002  could be roughened, textured, or otherwise modified or coated to promote healing or to make it more echogenic. 
     2. Proximal Cover 
     The device  3000  may include a cover  3100 , which may be an ePTFE cover as further described. Other embodiments for this outer cover  3100  are described herein, for example the cover  3101 ,  3300 ,  3150 ,  3151 , etc. The various embodiments of the cover may have the same or similar features and/or functionalities as each other, except as otherwise noted. The cover  3100  may have a series of openings. In some embodiments, the cover  3100  may be solid and not have any openings. In some embodiments, the cover  3100  may only have openings to receive anchors and/or a tether therethrough, as further described herein. In some embodiments, the device  3000  may include an inner cover such as an inner cover  3101 , as shown and described with respect to  FIG. 3D . 
     The outer cover  3100  is a generally flat material applied over and covering at least a portion of the body  3002 . The cover  3100  is on the proximal end  3004  of the device  3000 . The cover  3100  covers the proximal face  3008  of the body  3002  and at least part of the sidewall  3014 . The cover  3100  covers a proximal portion of the sidewall  3014 . The cover  3100  has a proximal surface  3102  that at least partially faces the LA when implanted. The cover  3100  has an outer edge  3104  forming outer vertices  3106  (for clarity, only some of the outer edges  3104  and outer vertices  3106  are labelled in the figures). In some embodiments, the cover  3100  may cover only the proximal face  3008  or portions thereof. In some embodiments, the cover  3100  may extend over more of the sidewall  3014 , such as the middle or distal portion thereof, or the entire sidewall  3014 . 
     The cover  3100  may have a thickness measured perpendicularly from the proximal surface  3102  to an opposite distal surface of the cover  3100  that faces the body  3002 . The cover  3100  may have a thickness of 0.001″ (inches). In some embodiments, the cover  3100  may have a thickness from about 0.00025″ to about 0.005″, from about 0.0003″ to about 0.004″, from about 0.0004″ to about 0.003″, from about 0.0006″ to about 0.002″, from about 0.0008″ to about 0.0015″, or about 0.001″. In some embodiments, the cover  3100  may have a thickness of 0.0005″. In some embodiments, the cover  3100  may have a thickness from about 0.0002″ to about 0.0008″, from about 0.0003″ to about 0.0007″, from about 0.0004″ to about 0.0006″, or about 0.0005″. 
     The cover  3100  may be attached to the frame  3040  through the foam body  3002 . The cover  3100  may in addition or alternatively be attached to the body  3002 . The cover  3100  may be attached at least two or four or six or more of the outer vertices  3106 . The cover  3100  may be attached to the frame  3040  and/or body  3002  at various locations, including at the outer vertices  3106 , through the proximal surface  3100 , at the proximal face  3008  of the body  3002 , other locations, or combinations thereof. The cover  3100  is attached using mechanical attachments, such as sutures. In some embodiments, polypropylene 6-0 sutures are used throughout the device to attach the foam body  3002 , proximal cover  3100 , and RO markers  3023  to the foam body  3002  and/or frame  3040 . In some embodiments, the cover  3100  is attached to the frame  3040  via standard braided or monofilament suture material, such as polypropylene, ePTFE, or polyester. In some embodiments, a polypropylene monofilament is utilized. Proximal anchors  3090  of the frame  3040  (further described herein) may extend through the outer vertices  3106  of the cover  3100 . Such penetrating anchors  3090  may further secure the cover  3100  in place relative to the body  3002 . In some embodiments, the cover  3100  may be attached to the various parts of the device  3000  with mechanical attachments, fasteners, adhesives, chemical bonds, other suitable techniques, or combinations thereof. 
     As shown, the cover  3100  is formed from expanded Polytetrafluoroethylene (“ePTFE”). An ePTFE cover  3100  provides many advantages. For example, the ePTFE cover  3100  may enhance the ability to recapture the device  3000  in vivo by distributing the proximal retraction forces applied by the catheter. The cover  3100  may be an ePTFE material approximately 0.001″ thick, with the appropriate porosity to encourage healing and minimize thrombus formation, similar to the underlying PTFE coated foam. 
     An ePTFE cover  3100  may assist in recapture of the implant into the access sheath while providing a smooth, thromboresistant surface which encourages tissue coverage and integration. The ePTFE may cover the entire proximal face and partially covers the sides, as shown in  FIG. 3C . The ePTFE cover  3100  is fabricated from a previously laminated sheet comprised of two or more sheets of oriented material, offset to form a biaxially orientated material. Alternatively, one could use a tube, preferably biaxially oriented, that is then cut to form a sheet. The thickness of the final construct can be from 0.0005″- 0 . 005 ″ but is preferably about 0.001″. 
     In some embodiments, the cover  3100  is fabricated from other thromboresistant, high strength, biocompatible materials, such as knitted or woven polyester fabrics, polypropylene, polyethylene, non-woven vascular scaffolds, porous films, or bioabsorbable scaffolds such as polylactic acid, polyglycolic acid, and co-polymers. The shape of the cover prior to attachment with the device  3000 , such as shown in  FIGS. 6A and 6B , minimizes wrinkling and provides a smooth surface following attachment to the implant. This shape may be a star shape, an outer pointed shape, or other shapes. 
     The cover  3100  may be perforated with a series of openings  3120  (for clarity, only some of the openings  3120  are labelled in the figures). The openings  3120  are perforations or holes formed in the cover  3100  via laser or mechanical cutting. The openings  3120  include proximal openings  3122  and side openings  3124  (for clarity, only some of the proximal openings  3122  and side openings  3124  are labelled in the figures). When the cover  3100  is assembled with the body  3002 , the proximal openings  3122  are located over the proximal face  3008  and/or shoulder  3030 , and the side openings  3124  are located over the sidewall  3014 . In some embodiments, the cover  3100  includes forty proximal openings  3122 . In some embodiments, the cover  3100  includes forty side openings  3124 . The number of openings  3120  located over the proximal face  3008  and/or shoulder  3030  when assembled with the body  3002  may range from ten to eighty, from twenty to seventy, from thirty to sixty, from thirty five to fifty, or forty openings  3120 . The number of openings  3120  located over the sidewall  3014  may range from ten to eighty, from twenty to seventy, from thirty to sixty, from thirty five to fifty, or forty openings  3120 . 
     The openings  3120  may have a variety of sizes. The openings  3120  are 0.070″ in width, e.g. minor axis, or diameter for circular openings. The openings  3120  may have a width from about 0.010″ to about 0.200″, from about 0.020″ to about 0.150″, from about 0.030″ to about 0.110″, from about 0.040″ to about 0.100″, from about 0.050″ to about 0.090″, from about 0.060″ to about 0.080″, or about 0.070″. In some embodiments, the width may be less than 0.010″ or greater than 0.200″, such as 0.25″, 0.5″ or greater. These widths may apply to circular as well as non-circular shaped openings  3120 . 
     In some embodiments, the openings  3120  may be various shapes. The openings  3120  may be elongated slots. The openings  3120  may extend radially along the cover  3100  from or near a center portion of the proximal surface  3102  toward and/or to the outer edge  3104 . The openings  3120  may be annular openings extending circumferentially along the cover  3100  and having varying radial positions. The openings  3120  may be of uniform size and shape. Some of the openings  3120  may have varied sizes and/or shapes with respect to other of the openings  3120 . The openings  3120  may have various distributions or concentrations about the cover  3100 . For example, the openings  3120  may be more densely located in various areas, such as along the proximal surface  3102  that faces the LA, along the shoulder  3030 , etc. 
     The openings  3120  enable blood to flow through the device  3000 . The openings  3120  may allow blood to adequately flow through the device  3000  and thereby mitigate the risk of occlusion in the bloodstream should the device  3000  embolize within the vasculature system. In some embodiments, should the device  3000  embolize, it may act as a stationary filter at low pressures but may pass through the bloodstream at higher pressures. In some embodiments, the device  3000  allows for about two to about fourteen liters, from about four to about twelve liters, from about six to about ten liters, or from about eight liters per minute of blood to pass at &lt;30 mmHg pressure drop to prevent shock in the event of a device embolization. In some embodiments, there are forty circular openings  3120  each having a diameter of 0.070″, and allowing for approximately eight liters per minute of blood to pass at &lt;30 mmHg pressure drop. In some embodiments, the proximal end of the device  3000  may be a foam layer such as the foam proximal face  3008  or a membrane such as the cover  3100  or both, enclosing the cavity  3028  defined within the tubular side wall  3014  of the body  3002 . 
     In one implementation, having both the foam proximal face  3008  and the cover  3100 , the foam body  3002  has the open cell structure further discussed herein that can permit the passage of blood but block escape of embolic debris. The cover  3100  may be occlusive to blood flow, and is present to provide structural integrity and reduced friction for retracting the expanded body  3002  back into the deployment catheter. In one implementation, the cover  3100  is ePTFE in a form that is substantially occlusive to blood flow, as described. In this embodiment, the cover  3100  is therefore provided with a plurality of perfusion windows or openings  3120 , so that blood can pass through the open cell foam and cover  3100  but the device  3000  still benefits from the other properties of the cover  3100 . 
     In some embodiments, the device  3000  may allow for a particular flow rate of water at specified conditions, to test the perfusion performance of the device  3000 . The device  3000  may have the foam body  3002  and cover  3100  configured to allow for a flow rate of water axially through the device  3000  of at least 2.8 liters per minute. The water may be at sixty-eight degrees Fahrenheit (F) or about sixty-eight degrees F. and an upstream pressure of twenty-eight millimeters of Mercury (mmHg) or about twenty-eight mmHg. In some embodiments, the device  3000  may be configured to allow for flow rates under such conditions from about 2.8 liters to about 19.6 liters, from 4.2 liters to about 5.6 liters, from about 4.76 liters to about 5.6 liters, from about 5.6 liters to about 16.8 liters, from about 8.4 liters to about 14 liters, more than 2.8 liters, more than 5.6 liters, more than 8.4 liters, or more than 11.2 liters of water per minute. 
     In some embodiments, the foam and cover are configured to allow for a flow rate of water axially through the device of between 4.2 liters per minute and 5.6 liters per minute (for example, in embodiment of a 27 mm diameter implant), with the water at about sixty-eight degrees Fahrenheit (F) and an upstream pressure of about twenty-eight millimeters of Mercury (mmHg). In some embodiments, the foam and cover are configured to allow for a flow rate of water axially through the device of between 4.76 liters per minute and 5.6 liters per minute (for example, in embodiment of a 35 mm diameter implant), with the water at about sixty-eight degrees Fahrenheit (F) and an upstream pressure of about twenty-eight millimeters of Mercury (mmHg). 
     The particular flow rate may depend on the porosity of the foam body  3002  and the open area of the cover  3100 . The particular flow rate may depend on the inner cover  3101  features as well. The cover  3100  may have particular percentages of the cover area open with the series of openings, as further described herein, to attain a particular desired flow rate. The flow rate of water at the specified conditions may be used to extrapolate or otherwise calculate the corresponding expected flow rate of blood in the body through the device  3000  should it embolize, as described herein. In some embodiments, the device  3000  may be configured to allow for a flow rate of blood axially through the device  3000  of at least 1 liter per minute (for example, in embodiment of a 27 mm diameter implant at room temperature with an upstream pressure of about 15 inches of water head). The device  3000  may allow for a cardiac output from about 4.2 to 8 liters per minute. The average body surface area is 1.6 square meters for females and 1.9 square meters for males. The device  3000  may allow for a cardiac index from about 2.2 to 5 or from about 2.6 to 4.2 liters per minute per square meter. The device  3000  may have these and other flow rate capabilities either aligned or approximately aligned with the direction of flow of the fluid, or off-axis where the device  3000  is angled with respect to the direction of flow of the fluid (a flow axis), as further discussed herein for example in the section “Off-Axis Delivery and Deployment.” 
       FIGS. 5A-5C  depict an embodiment of the LAA occlusion device  3000  having another embodiment of a cover  3300 . The device  3000  includes the foam body  3002  and the frame  3040 , and features thereof, as described herein, and additionally includes the cover  3300 . The cover  3300  may have the same or similar features and/or functionalities as the cover  3100 , and vice versa. The cover  3300  is on the proximal end  3004  of the device  3000 . The cover  3300  covers the proximal face  3008  of the body  3002  and a proximal part of the sidewall  3014 . The cover  3300  has a proximal surface  3302 . The cover  3300  has an outer edge  3304  forming a plurality of at least two or four or six or eight or ten or more outer vertices  3306  (for clarity, only some of the outer vertices  3306  are labelled in the figures). The cover  3300  is attached to the body  3002  at the outer vertices  3306 . The proximal anchors  3090  extend through side openings  3324  in the outer vertices  3106  of the cover  3100 . 
     The cover  3300  includes a series of openings  3320 . The openings  3320  include proximal openings  3322 , shoulder openings  3323 , and the side openings  3324 . The proximal openings  3322  are located over the proximal end  3004  of the body  3002 . The shoulder openings  3323  are located over the shoulder  3030 , e.g. a bevel, of the body  3002 . The side openings  3324  are located over a proximal portion of the sidewall  3014  of the body  3002 . The proximal anchors  3090  may extend through the side openings  3324  that are located in the outer vertices  3106 . The openings  3320  may have the same or similar features and/or functionalities as the openings  3120 , and vice versa. In some embodiments, the proximal anchors  3090  may extend through the cover  3300  material at or near the outer vertices  3106 . 
       FIG. 6A  shows another embodiment of a cover  3150  that may be used with the device  3000 . The cover  3150  may have the same or similar features and/or functionalities as the cover  3100  and/or cover  3300 , and vice versa. The cover  3150  may be used to cover the proximal face  3008  of the body  3002  and part of the sidewall  3014 . The cover  3150  has a proximal surface  3152 . The cover  3150  has an outer edge  3154  forming outer vertices  3156 . The cover  3150  may be attached to the body  3002  at the outer vertices  3156 . The proximal anchors  3090  may extend through the outer vertices  3156  of the cover  3100 . The cover  3150  includes a series of openings  3170 . The openings  3170  include proximal openings  3172  and side openings  3174  (for clarity, only some of the openings  3170 ,  3172 ,  3174  are labelled in the figures). When the cover  3150  is assembled with the body  3002 , the proximal openings  3172  are located over the proximal end  3004  and the side openings  3174  are located over the sidewall  3014 . As shown, the openings  3174  may be substantially uniformly located along the cover  3150  except for a center region of the proximal surface  3152 . 
       FIG. 6B  is a top view of another embodiment of a proximal cover  3151  that may be used with the various LAA occlusion devices described herein.  FIG. 6C  is a top view showing the cover  3151  assembled with the device  3000 . The cover  3151  may have the same or similar features and/or functionalities as other covers described herein, such as the cover  3100  and/or cover  3300 , and vice versa, except as otherwise noted. For example, the cover  3151  may include the proximal surface  3152  and outer edge  3154  forming outer vertices  3156 . 
     The cover  3151  further includes another embodiment of a series of openings  3171 . The openings  3171  include smaller openings  3175  and larger openings  3173 . The openings  3175 ,  3173  may have the same or similar features and/or functionalities as other cover openings described herein, such as the openings  3120 ,  3122 ,  3124 ,  3320 ,  3322 ,  3324 ,  3170 ,  3172  and/or  3174 , and vice versa. The smaller openings  3175  may be relatively smaller, in width and/or area, than the larger openings  3173 . There may be openings with widths or areas smaller than that of the smaller openings  3175 , larger than that of the larger openings  3173 , or anywhere in between. As shown, the openings  3173 ,  3175  may be generally uniformly distributed about the proximal surface  3152  of the cover  3151 . The openings  3173 ,  3175  may be circumferentially evenly spaced or approximately evenly spaced about the cover  3151 . 
     There may be a variety of different quantities of each of the openings  3173 ,  3175 . There may be a total of ten, twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety, one hundred, one hundred fifty, two hundred, three hundred, four hundred, or more openings of the series of openings  3171 , or any lesser, greater or in between number of openings. The series of openings  3171  may be holes as shown. They may have circular shapes. They may have other shapes, including non-circular, segmented, other shapes, or combinations thereof. The openings  3171  may all have the same general shape or different shapes. In some embodiments, there may not be any holes in the cover  3151 . 
     When the cover  3151  is assembled with the foam body  3002 , the large and small openings  3173 ,  3175  may be located over the proximal end  3004  and/or the sidewall  3014  of the foam body  3002 . When assembled with the foam body  3002 , on the proximal-facing portion of the cover  3151 , there may be a collective total of one hundred forty or about one hundred forty openings  3173 ,  3175 . On this proximal-facing portion of the cover  3151 , there may be a collective total from about ten to about three-hundred, from about fifty to about two hundred fifteen, from about one hundred ten to about one hundred seventy, from about one hundred twenty to about one hundred sixty, from about one hundred thirty to about one hundred fifty, or from about one hundred thirty-five to about one hundred forty-five openings  3173 ,  3175 . On this proximal-facing portion of the cover  3151 , there may be from about thirty to about fifty, from about thirty-five to about forty-five, about forty, or forty of the larger openings  3173 . On this proximal-facing portion of the cover  3151 , there may be from about sixty to about one hundred forty, from about eighty to about one hundred twenty, from about ninety to about one hundred ten, about one hundred, or one hundred of the smaller openings  3175 . 
     When assembled with the foam body  3002 , on the portion of the cover  3151  located over and/or near the shoulder  3030 , such as over the outer surface  3032  of the foam body  3002  (see, e.g.,  FIG. 4B ), there may be from about five to about eighty, from about ten to about forty, from about fifteen to about thirty, about twenty, or twenty of the smaller openings  3175 . In some embodiments, at this same portion of the cover  3151 , there may be from about five to about eighty, from about ten to about forty, from about fifteen to about thirty, about twenty, or twenty of the larger openings  3173 . 
     When assembled with the foam body  3002 , on the portion of the cover  3151  located over and/or near the sidewall  3014 , such as over the outer surface  3016  of the foam body  3002  (see, e.g.,  FIG. 4B ), there may be from about five to about eighty, from about ten to about forty, from about fifteen to about thirty, about twenty, or twenty of the larger openings  3173 . In some embodiments, at this same portion of the cover  3151 , there may be from about five to about eighty, from about ten to about forty, from about fifteen to about thirty, about twenty, or twenty of the smaller openings  3175 . 
     The larger and smaller openings  3173 ,  3175  may have a variety of different sizes, for example as described herein with respect to the openings  3122 . In some embodiments, the openings  3173 ,  3175  may have diameters ranging from about 0.025 inches to about 0.040 inches. In some embodiments, the larger openings  3173  may be 0.040 inches or about 0.040 inches in diameter. The larger openings  3173  may be from about 0.030 inches to about 0.050 inches, or from about 0.035 inches to about 0.045 inches, in diameter. These values may also refer to the widths, for example maximum widths, of non-circular larger openings  3173 . In some embodiments, the smaller openings  3175  may be 0.025 inches or about 0.025 inches, in diameter. The smaller openings  3175  be from about 0.015 inches to about 0.035 inches, or from about 0.020 inches to about 0.030 inches, in diameter. These values may also refer to the widths, for example maximum widths, of non-circular smaller openings  3175 . 
     The series of openings  3171  may be configured to provide a desired amount of open area through the cover  3151 . This open area refers to the total area of certain openings in the cover  3151 . The cover  3151  may be covering a proximal face  3008  at the proximal end  3004  of the foam body  3002 . The open area may refer to openings through the portion of the cover that is over the proximal face  3008  of the foam body  3002  when assembled with the foam body  3002 . The series of openings in the various covers described herein may collectively provide the open area. For example, the series of openings  3171  in the cover  3151  over the proximal face of the foam may collectively provide an open area. This is the sum of the area of the openings in the cover  3151  over the proximal face. As further example, the open area may be the sum of the proximal openings  3122  of the cover  3100 . As further example, the open area may be the sum of the proximal openings  3322  of the cover  3300 . 
     The open area may be at least five percent of the area of the proximal face  3008  of the foam body  3002 . The open area may be at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen percent, at least fifteen, at least sixteen, at least seventeen, at least eighteen, at least nineteen, at least twenty, at least twenty-five, at least thirty, at least forty, or at least fifty percent, of the area of the proximal face  3008 . The open area may be from about one to about fifty percent, from about five to about twenty percent, from about eight to about fifteen percent, from about ten to about twelve percent, or about eleven percent, of the area of the proximal face  3008 . The “area” of the proximal face  3008  is understood here to refer to an area equal to Pi×R 2 , where R is the radius of the proximal face  3008  and extends perpendicularly from the longitudinal axis of the device  3000 . Further, “R” may be measured to the inner boundary of the shoulder  3030 , to the outer boundary of the shoulder  3030 , or to the outer surface  3016  of the sidewall  3014 . Further, as mentioned, some embodiments may not include a cover at all. 
     The cover  3151  may include one or more windows  3177 . As shown, there may be ten windows  3177 . There may be one window  3177  for each proximal anchor  3090 . There may be four, six, eight, twelve, fourteen or more windows  3177 , or any lesser or in between number. The windows  3177  may be openings in the cover  3151 . The windows  3177  may be located at or near the outer edge  3154  of the cover  3151 . The windows  3177  may be located along portions of the outer edge  3154 , for example at or near the outer vertices  3156 . The windows  3177  may have a shape conforming to the shape of the cover  3151  at the respective portions of the outer edge  3154 . As shown, the window  3177  may be diamond or generally diamond shaped. The window  3177  may be square, rectangular, triangular, rounded, circular, segmented, flattened diamond, other polygonal shapes, other shapes, or combinations thereof. The cover  3150  may be attached to the body  3002  at the outer vertices windows  3177 . The windows  3177  may have the same or similar feature and/or functionalities as the side openings  3324 , described and shown in  FIG. 5B . The proximal anchors  3090  may extend through the windows  3177  of the cover  3151  to retain the cover  3151  on the device  3000 . 
       FIG. 6D-6E  are side and perspective views, respectively, of another embodiment of a proximal cover  3153  shown assembled with the device  3000 , that may be used with the various LAA occlusion devices described herein. The cover  3153  may have the same or similar features and/or functionalities as other covers described herein, such as the cover  3100 ,  3151 , and/or cover  3300 , and vice versa, except as otherwise noted. For example, the cover  3151  may include the proximal surface  3152 , outer edge  3154  forming outer vertices  3156 , and windows  3177 . 
     The device  3000  with cover  3151  may have proximal anchors  3090  extending through the windows  3177 . The proximal anchor  3090  may extend through the opening of the respective window  3177 . The proximal anchor  3090  may extend through a distal portion of the window  3177 , for example to contribute to securing the cover  3153  on the device  3000 . The proximal anchors  3090  may extend through the window  3177  at a distal edge or distal vertex of the window  3177 . In some embodiments, the proximal anchor  3090  may extend through the cover  3151  material, for example through material adjacent (such as distal) to the window  3177 . In some embodiments, the proximal anchor  3090  may extend through various other locations within, adjacent or near the window  3177 . Some of the proximal anchors  3090  may extend through first locations and other of the proximal anchors  3090  may extend through second locations of the cover  3153  different from the first locations. For instance, one or more anchors  3090  may extend through a first region of the window  3177 , one or more other anchors  3090  may extend through a second region of the window  3177 , still one or more other anchors  3090  may extend through other regions, such as through the cover  3153  material, etc. 
     The cover  3153  may include proximal vertices  3155 . The proximal vertices  3155  may be formed by the outer edge  3154 . The proximal vertices  3155  may be indentations along the outer edge  3154  of the cover  3153 , for example angled as shown or other shapes, configurations, etc. The proximal vertices  3155  may define a region  3016 A of the outer surface  3016  of the sidewall  3014 . The region  3016 A may be partially enveloped by the outer edge  3154  of the cover  3153 . The region  3016 A may receive one or more of the distal anchors  3094  therethrough. The distal anchor  3094  may extend through a distal portion of the region  3016 A, or in other locations within, adjacent, or near the region  3016 A. In some embodiments, the distal anchor  3094  may not extend through or near the region  3016 . There may be multiple such regions  3016 A of the foam body  3002  defined circumferentially about the device  3000  by the cover  3153 . 
     The cover  3153  may include the series of openings  3320 , for example as described with respect to  FIG. 5A . The series of openings  3320  may include the proximal openings  3172 , the shoulder openings  3323 , and/or the side openings  3174 . The cover  3153  may include different patterns, sizes, distributions, etc. of the openings  3320 , for example as shown and described with respect to  FIGS. 6B-6C . 
     3. Compliant Frame 
     The expandable and compliant support or frame  3040  is shown, for example, in  FIGS. 3B, 3D, 4C and 5C -E. Further,  FIGS. 7A and 7B  are side and proximal perspective views, respectively, of the frame  3040  shown in a deployed configuration and in isolation from the rest of the device  3000 . The frame  3040  provides a compliant structure with anchors to facilitate delivery, anchoring, retrieval and to enable the foam body  3002  to compress against the LAA tissue to facilitate sealing, among other things, as further described. The frame  3040  is located inside the cavity  3028  formed by the foam body  3002 . In some embodiments, the frame  3040  may be located partially or entirely inside one or more portions of the body  3002 , e.g. within the proximal face  3008  and/or the sidewall  3014 , as further described. For example, the frame  3040  may be partially located within the sidewall  3014  as shown in  FIG. 5C . 
     The frame  3040  has a proximal end  3042  and an opposite distal end  3004 . The frame  3040  may be tubular, e.g. cylindrical, in a free, unconstrained state. Thus the width of the proximal end  3042  may be the same or similar to the width of the distal end  3004  in the free, unconstrained state. In some embodiments, the frame  3040  or portions thereof may be conical or frustoconical, e.g. where in the free, unconstrained state the width of the proximal end  3042  is greater than the width of the distal end  3004  or vice versa. 
     At the proximal end  3042 , the frame  3040  has a proximal hub  3050 , shown as a cylindrical nipple. The hub  3050  is a rounded, structural end piece. The hub  3050  may be tubular, e.g. circular and having the cylindrical shape as shown, or may be rounded, non-circular, segmented, other shapes, or combinations thereof. The hub  3050  extends axially and may have a central lumen. The hub  3050  may be wider than it is long, or vice versa. The hub  3050  is hollow and has a sidewall defining a space therethrough, such as a longitudinal opening. In some embodiments, the hub  3050  may be partially hollow, solid, or other configurations. The hub  3050  facilitates delivery and retrieval of the device  3000 , as further described. The hub  3050  may provide a central structural attachment, as further described herein. The hub  3050  may be located within the cavity  3028  at a proximal end thereof. In some embodiments, the hub  3050  may be located partially or entirely within the foam body  3002 , e.g. within the proximal face  3008 . 
     A pin  3051  is located within the hub  3050  (shown in  FIGS. 7A and 7B ). The pin  3051  is an elongated, rounded structural element extending laterally across the central lumen. “Lateral” here refers to a direction perpendicular or generally perpendicular to the longitudinal axis. The pin  3051  has a cylindrical shape. The pin  3051  provides a rounded outer surface configured to provide a smooth engagement surface with a tether, as further described. The pin  3051  provides a high strength connection with the frame  3040  to allow for pulling on the device  3000  with sufficient force to re-sheath the device  3000 . The pin  3051  may be formed from Nitinol. The pin  3051  is secured across the width, e.g. diameter, of the proximal hub  3050 . The pin  3050  may be secured at its two opposite ends with the sidewall of the hub. The pin  3051  is configured to be engaged by a tether  3240 , which is wrapped around the pin  3051  in sliding engagement for temporary attachment to a delivery catheter, as further described. In some embodiments, the pin  3051  is assembled with a cap  3180 , as further described herein, for example with respect to  FIGS. 8A-8C . 
     The frame  3040  at the proximal end  3042  includes a proximal face  3060 . The proximal face  3060  may be located within the cavity  3028  at a proximal end thereof. In some embodiments, the proximal face  3060  may be located partially or entirely within the foam body  3002 , e.g. within the proximal face  3008  and/or sidewall  3014 . The proximal face  3060  includes a series of recapture or reentry struts  3061 . The struts  3061  are located at a proximal end of the cavity  3028 . In some embodiments, the struts  3061  or portions thereof may be located partially or entirely within the foam body  3002 , e.g. within the proximal face  3008  and/or sidewall  3014 . 
     The struts  3061  are elongated structural members. The struts  3061  may have rectangular, circular or other shaped cross-sections. In some embodiments, the struts  3061  have a cross-section, e.g. rectangular, with a width that is greater than a thickness such that the struts  3061  are stiffer in one direction compared to another direction. This width may be in the lateral direction or a direction generally perpendicular to the longitudinal axis of the device  3000  when the device  3000  is in the expanded configuration, with the thickness perpendicular to the width. The struts  3061  may be less stiff in the direction of flexing or bending, for example to facilitate contraction and expansion of the device  3000  in the delivery and expanded configurations. The struts  3061  may be elongated pins. The struts  3061  may extend from the hub  3050 , for example, and incline radially outwardly in the distal direction from the hub  3050 . The struts  3061  may be attached inside, outside, and/or at the end of the sidewall of the hub  3050 . The struts  3061  may be separate parts that are then attached to the hub  3050 , for example welding, bonding, fastening, other suitable means, or combinations thereof. In some embodiments, some or all of the struts  3061  and the hub  3050  may be a single, continuous structure formed from the same raw material such as a laser cut hypotube. Some or all of the struts  3061  may be attached, e.g. with sutures as described herein, to the body  3002  and/or the cover  3100  at one or more attachment locations. 
     Each recapture strut  3061  may include an inner curved portion  3062  connected to a distal end of the hub  3050 , a middle straight portion  3064 , and/or an outer curved portion  3066  (for clarity, only some of the portions  3062 ,  3064 ,  3066  are labelled in the figures). In the deployed configuration, the inner curved portion  3062  extends from the hub  3050  primarily in a distal direction and then curves to face more outwardly radially. The middle straight portion  3064  extends from the inner curved portion  3062  primarily radially but also slightly distally. The outer curved portion  3066  extends from the middle straight portion  3064  primarily in the radial direction and then curves toward the distal direction. The portions may have different shapes in the delivery configuration inside a delivery catheter. In the delivery configuration, the portions may extend primarily distally. The portions may then take the deployed configuration as described upon deployment from the delivery catheter. In some embodiments, the struts  3061  may include fewer or more than the portions  3062 ,  3064 ,  3066 . 
     The device  3000  may include ten of the proximal recapture struts  3061 . Such configuration may accompany a device  3000  having a foam body  3002  with an outer diameter of 27 mm in the free, unconstrained state. Such configuration may accompany a device  3000  having a foam body  3002  with an outer diameter of 35 mm in the free, unconstrained state. In some embodiments, the device  3000  may have from about two to about thirty, from about four to about twenty, from about six to about eighteen, from about eight to about sixteen, from about ten to about fourteen, or other numbers of struts  3061 . In some embodiments, the device  3000  has twelve of the proximal recapture struts  3061 , for example for the 35 mm diameter device. 
     In the deployed configuration, each strut  3061  may extend radially outward and distally at an angle to the axis. This angle, measured relative to a portion of the axis that extends distally from the device  3000 , may be from about 60° to about 89.9°, from about 65° to about 88.5°, from about 70° to about 85°, from about 72.5° to about 82.5°, from about 75° to about 80°, or other angular amounts. This angle may be much smaller when the device  3000  is in the delivery catheter. The struts  3061  may bend or flex when transitioning between, or when positioned in, the delivery and expanded configurations. The struts  3061  may bend or flex at the inner curved portion  3062 , the middle straight portion  3064 , and/or the outer curved portion  3066 . 
     The proximal end  3042  of the frame  3040 , such as the proximal face  3060 , may therefore have a conical shape in the expanded configuration. The conical proximal face  3060  may facilitate with recapture of the device  3000  back into the delivery catheter. For example, the orientation of the struts  3061  inclining distally and radially outward from the hub  3050  in the expanded configuration provides an advantageous conical shape to the proximal face  3008  such that distal advance of the delivery sheath over the device  3000  will bias the struts  3061  inward and cause the device  3000  to stow back toward the delivery configuration and size for retrieval within the catheter. 
     The proximal face  3060  foreshortens considerably upon expansion of the device  3000  relative to the delivery configuration. “Foreshortening” here refers to the difference in axial length of the proximal face  3060  between the reduced delivery configuration and the expanded configuration (expanded either freely or as implanted). This length may be measured axially from the distal or proximal end of the hub  3050  to the distal ends of the outer curved portions  3066  of the recapture struts  3061 . The proximal face  3060  may foreshorten by 50%, 60%, 70%, 80%, 90% or more. The proximal face  3060  has significantly more foreshortening upon expansion than the tubular body  3080 , the latter of which may be referred to as the “working length” or “landing zone.” The landing zone is further described with respect to the tubular body  3080  herein. 
     As shown, the struts  3061  are angularly spaced about the axis in even angular increments. That is, looking at the frame  3040  from the distal or proximal end, the angles between the struts may be equal. In some embodiment, the struts  3061  may not be evenly angularly spaced about the axis as described. The struts  3061  may or may not be symmetrically disposed about the axis or about a plane that includes the axis. 
     In some embodiments, portions of the frame  3040  may be at various distances from the proximal end of the foam body  3002 , such as the proximal end wall having the proximal face  3008 . As shown in  FIG. 5D , there may be a gap of size Z in the axial direction between the proximal face  3060  of the frame  3040  and the inner surface  3012  of the proximal face  3008 . The length of Z may be one, two, three, four, five, six, seven, eight, nine, ten, or more millimeters. The length of Z may vary depending on the radial distance at which it is measured. For instance, the length of Z may decrease, increase, or combinations thereof, as measured along the length of the strut  3061 . In some embodiments, the length of Z may be zero at more or points along the length of the strut  3061 . As shown in  FIG. 5E , the proximal face  3060  or portions thereof may contact the proximal inner surface  3012  of the foam body  3002 . The inner curved portion  3062 , the straight portion  3064 , and/or the outer curved portion  3066  may contact the proximal end wall such as the inner surface  3012  and/or other portions of the foam body  3002 . The hub  3050  may compress the proximal face  3008  or proximal end wall of the foam body  3002  slightly in a proximal direction as shown. The proximal face  3008  may therefore have a smaller thickness in this compressed region as compared to other portions of the proximal face  3008 , for example portions adjacent to this compressed portion. The hub  3050  may be located based on the axial location of connection of the anchors  3090 ,  3094  to the sidewall  3014 , as described herein. In some embodiments, the hub  300  may not compress the foam body  3002  as shown. In some embodiments, the proximal face  3060  may extend radially outwardly as shown. For instance, the struts  3061 , or portions thereof for instance the straight portions  3064 , may extend radially outwardly perpendicularly or generally perpendicularly to the longitudinal axis of the device  3000 . The proximal face  3060  may extend radially outwardly and incline in a distal direction, as described herein, or it may incline in a proximal direction. The device  3000  may have any of these features in the constrained, unconstrained and/or implanted configurations. 
     The frame  3040  includes a tubular body  3080 . The body  3080  provides a mechanical base structure for the device  3000 , as further described. The tubular body  3080  is attached to a distal end of the proximal face  3060  of the frame  3040 . The tubular body  3080  extends to the distal end  3044  of the frame  3040 . The tubular body  3080  is attached at a proximal end to the outer curved portions  3066  of the recapture struts  3061 , as further described. The tubular body  3080  may be attached to other portions of the recapture struts  3061 . The tubular body  3080  of the frame  3040  may be attached to the body  3002  and/or the cover  3100 , e.g. with sutures as described herein, at one or more attachment locations, as further described. The tubular body  3080  may be located within the cavity  3028 . In some embodiments, the tubular body  3080  may be located partially or entirely within the foam body  3002 , e.g. within the sidewall  3014 . 
     The tubular body  3080  includes a series of proximal struts  3082  and distal struts  3086  (for clarity, only some of the struts  3082 ,  3086  are labelled in the figures). The proximal struts  3082  and/or distal struts  3086  may have rectangular, circular or other shaped cross-sections. In some embodiments, the proximal struts  3082  and/or distal struts  3086  have a cross-section, e.g. rectangular, with a width that is greater than a thickness, or vice versa, such that the struts  3061  are stiffer in one direction compared to another direction. The struts  3061  may be less stiff in the direction of flexing or bending, for example to facilitate contraction and expansion of the device  3000  in the delivery and expanded configurations. Proximal ends of pairs of adjacent proximal struts  3082  join at proximal apexes  3084 . Each proximal strut  3082  is connected at a respective proximal apex  3084  to a respective outer curved portion  3066  of one of the recapture struts  3061 . Each distal end of the proximal struts  3082  connects to a distal end of an adjacent proximal strut  3082  and to proximal ends of two distal struts  3086  at an intermediate vertex  3087 . Pairs of adjacent distal struts  3086  extend distally to join at a respective distal apex  3088 . A repeating pattern  3089 , shown as a diamond shape, may be formed by adjacent pairs of proximal struts  3082  and adjacent pairs of distal struts  3086 . Some or all of the proximal struts  3082  and/or distal struts  3086  may be attached, e.g. with sutures as described herein, to the body  3002  and/or the cover  3100  at one or more attachment locations. Some or all of the proximal struts  3082  and/or distal struts  3086  may be located within the cavity  3028 . In some embodiments, some or all of the proximal struts  3082  and/or distal struts  3086  may be located partially or entirely within the foam body  3002 , e.g. within the sidewall  3014 . 
     There are the same number of proximal apexes  3084  as distal apexes  3088 . As shown, there are eleven proximal apexes  3084  and eleven distal apexes  3088 . The number of proximal and distal apexes  3084 ,  3088  may each be at least seven, at least eight, at least nine, at least ten, at least eleven, at least twelve, at least thirteen, at least fourteen, at least fifteen, at least sixteen, or fewer or more apexes. In some embodiments, there may not be the same number of proximal apexes  3084  as distal apexes  3088 . In some embodiments, there may be more than one row of the pattern, e.g. diamond pattern, formed by the proximal struts  3082  and distal struts  3086 . There may be two, three, four or more rows of the pattern. Some or all of the proximal apexes  3084  and/or distal apexes  3088  may be attached, e.g. with sutures as described herein, to the body  3002  and/or the cover  3100  at one or more attachment locations. 
     The body  3080  may be tubular, e.g. cylindrical or generally cylindrical, in the expanded configuration. The tubular body  3080  may be cylindrical, rounded, segmented, polygonal, tube-like, other shapes, or combinations thereof, all of which are subsumed non-exhaustively under the category “tubular.” The tubular shape is formed by the proximal struts  3082  and distal struts  3086  in the expanded configuration. The tubular shape may also be formed by the outer curve portions  3066  of the recapture struts  3061  in the expanded configuration. The tubular shape may also be formed by the foam body  3002  exerting an outward radial force on the frame  3040 . The frame  3040  may therefore have a proximal conical section and a cylindrical working length. In some embodiments, the body  3080  may be conical or frustoconical, for example where the distal end is wider than the proximal end or vice versa. 
     The tubular body  3080  may be referred to as a “landing zone,” as described. This landing zone may refer to the axial length of the body  3080 , from a distal-most end to a proximal-most end at the transition to recapture struts  3061 , in the expanded configuration. The landing zone may have an axial length as measured from the proximal apex  3084  to the distal apex  3088 . The length of the landing zone may be 10 mm or about 10 mm. The landing zone may have a length from about 5 mm to about 15 mm, from about 6 mm to about 14 mm, from about 7 mm to about 13 mm, from about 8 mm to about 12 mm, from about 9 mm to about 11 mm, or other lengths. The tubular body  3080  may foreshorten slightly upon expansion of the device  3000  relative to the delivery configuration. The tubular body  3080  has significantly less foreshortening upon expansion than the length of the proximal face  3060 . The tubular body  3080  may foreshorten by no more than about 5%, 10%, 15%, 20% or 30%. 
     The frame  3040  self-expands upon delivery from the sheath. The proximal face  3060  and the tubular body  3080  will self-expand. Upon expansion, the radially outward portions of the tubular body  3080  will contact and compress the foam body  3002  against tissue of the LAA wall. The tubular body  3080 , for example the proximal struts  3082  and distal struts  3086 , will contact the inner surface  3018  of the sidewall  3014  and press against the sidewall  3014  so that the outer surface  3016  of the sidewall  3014  contacts and compresses against the LAA wall. 
     When compressed against the LAA wall, the foam body  3002  provides a larger “footprint” than the skeletal frame  3040  components and forms a complete seal. Thus, the sidewall  3014  acts as a force dissipation layer, spreading radial force out from the struts  3082 ,  3086  of the frame  3040  over a larger area than just the area of the individual struts  3082 ,  3086  (e.g. a larger area than just the area of the radially outer surfaces of the struts  3082 ,  3086 ). The use of the foam material in the body  3002  and the thickness of that foam, such as 2.5 mm, provide advantages in this regard over devices with thinner and less resilient materials than foam. For example, thin fabrics or similar materials that are pressed against the LAA wall with a skeletal frame will not spread the radial force out, and may even sag or otherwise bend, creating gaps and an unsealed portion of the LAA wall. The foam body  3002  as described herein will take the shape of the LAA wall to create a complete circumferential seal and will also spread out the radial forces from the frame  3040  to create a stronger seal and retention with the foam body  3002 . 
     Further, the device  3000  described herein with the compressible body  3002  allows for a structural frame  3040  that is compliant due to the smaller required radial force from the frame  3040 . For example, existing devices with a non-compressible fabric material will have a less effective seal, and so the structural elements of those devices must provide larger radial forces to compensate and ensure an effective seal, resulting in a less compliant device. In contrast, the current device  3000  provides advantages in this regard by having the compressible foam body  3002 , allowing for among other things smaller radial forces from, and thus better compliance of, the frame  3040 , while still providing an effective seal. This structural configuration has a cascading effect in terms of performance advantages. For instance, the compliance of the device  3000  allows for delivery off-axis while still providing an effective seal, among other advantages as further described herein. 
     The frame  3040  includes a series of proximal anchors  3090 . Each proximal anchor  3090  extends from a respective intermediate vertex  3087 . The proximal anchors  3090  may extend from other portions of the tubular body  3080 . As shown, in the deployed configuration, the proximal anchors  3090  extend from the tubular body  3080  radially and proximally. The proximal anchors  3090  may extend into an adjacent region of the sidewall  3014 . The proximal anchors  3090  may extend through the outer surface  3016  of the sidewall  3014  to penetrate tissue adjacent the device  3000 . 
     The frame  3040  includes a series of distal anchors  3094 . Each distal anchor  3094  extends from a respective distal apex  3088 . The distal anchors  3094  may extend from other portions of the tubular body  3080 . As shown, in the deployed configuration, the distal anchors  3094  extend from the tubular body  3080  radially and proximally. The distal anchors  3094  may extend into an adjacent region of the sidewall  3014 . The distal anchors  3094  may extend through the outer surface  3016  of the sidewall  3014  to penetrate tissue adjacent the device  3000 . The anchors  3090 ,  3094  may incline radially outward in a proximal direction to engage the tissue to resist proximal movement of the device  3000 . 
     The anchors  3090 ,  3094  are elongated structural members. The tips of the anchors  3090 ,  3094  may be sharpened to facilitate tissue engagement and penetration. The anchors  3090 ,  3094  may be straight, extending generally along a local axis thereof. The anchors  3090 ,  3094  may have a curved or other non-straight proximal portion where they attach to the tubular body  3080 . In some embodiments, the anchors  3090 ,  3094  or portions thereof may be non-straight, curved, rounded, segmented, other trajectories, or combinations thereof. In some embodiments, the tissue engaging tips may be curved. In some embodiments, the anchors  3090 ,  3094  may have engagement features extending radially away from the anchor  3090 ,  3094 , such as barbs, hooks, or other features. 
     The cross-section of the anchors  3090 ,  3094  may be rectangular. In some embodiments, the cross-section may be circular, rounded, non-rounded, square, rectangular, polygonal, other shapes, or combinations thereof. The cross-sections may or may not be uniform along the length of the anchor  3090 ,  3094 . The anchors  3090 ,  3094  may be about 0.006″ thick and about 0.008″ wide. The anchors  3090 ,  3094  may range from about 0.003″ to about 0.009″ in thickness and from about 0.003″ to about 0.015″ in width. The cross-section of the anchors  3090 ,  3094  may reduce in size, for example taper, toward the distal tip. 
     In some embodiments, the anchors  3090 ,  3094  in the deployed configuration are inclined at an incline angle of about 30° relative to a portion of the central axis that extends proximally from the device  3000 . This incline angle may be from about 10 degrees to about 50°, from about 15° to about 45°, from about 20° to about 40°, from about 25° to about 35°, or about 30°. This incline angle of the anchors  3090 ,  3094  in the delivery configuration may be smaller than in the deployed configuration. The deployed anchors  3090 ,  3094  may have the angle B, as shown in and described with respect to  FIGS. 12A-12C . 
     The anchors  3090 ,  3094  may have various lengths. The length of the anchor  3090 ,  3094  is measured from a proximal end that connects to the tubular body  3080  to a distal tissue engaging tip of the anchor. In some embodiments, the length of the anchors  3090 ,  3094  may be from about 0.5 mm to about 10 mm, from about 1 mm to about 9 mm, from about 2 mm to about 8 mm, from about 3 mm to about 7 mm, from about 4 mm to about 6 mm, about 5 mm, or other greater or lesser lengths. In some embodiments, the anchors  3090 ,  3094  are 5 mm long. In some embodiments, the anchors  3090 ,  3094  are about 5 mm long. In some embodiments, the anchors  3090 ,  3094  have a length of at least 2.5 mm, at least 3 mm, at least 3.5 mm, at least 4 mm, at least 4.5 mm, at least 5 mm or more. The anchors  3090 ,  3094  may each be the same or similar length. In some embodiments, the anchors  3090 ,  3094  may not be the same length. In some embodiments, some or all of the proximal anchors  3090  may have lengths that are less than or greater than some or all of the lengths of the distal anchors  3094 . The anchors  3090 ,  3094  may have the length L, as shown in and described with respect to  FIGS. 12A-12C . Further, the outer tips of the deployed anchors  3090 ,  3094  may extend to an outer radial location that is less than, the same as, or more than a radially outermost surface of the foam body  3002 , as shown in and described with respect to  FIGS. 12A-12C . 
     In the expanded configuration, the anchors  3090 ,  3094  extend for a length outside of the uncompressed sidewall  3014 . This length of the anchor  3090 ,  3094  is measured along a local longitudinal axis of the anchor from the outer surface  3016  of the body  3002  to the distal tip of the anchor. The anchors  3090 ,  3094  may extend through the sidewall  3014  and/or the cover  3100 , and then be trimmed so that the anchors  3090 ,  3094  extend beyond the sidewall  3014  and/or cover  3100  by the desired length. In a free, unconstrained state, the anchors  3090 ,  3094  extend about 0.5 mm beyond the outer surface  3016  of the sidewall  3014 . In some embodiments, in the free, unconstrained state, the anchors  3090 ,  3094  extend beyond the outer surface  3016  of the sidewall  3014  for a length of from about 0.1 mm to about 1.5 mm, from about 0.2 mm to about 1.25 mm, from about 0.3 mm to about 1.0 mm, from about 0.4 mm to about 0.8 mm, from about 5 mm to about 0.6 mm, or other greater or lesser lengths. In a compressed state, such as in the delivery configuration or after implantation, the anchors  3090 ,  3094  extend about 1.0 mm beyond the outer surface  3016  of the sidewall  3014 . In some embodiments, in the compressed state, the anchors  3090 ,  3094  extend beyond the outer surface  3016  of the sidewall  3014  for a length of from about 0.25 mm to about 2.5 mm, from about 0.5 mm to about 2 mm, from about 0.75 mm to about 1.5 mm, from about 0.875 mm to 1.125 mm, or other greater or lesser lengths. 
     The geometry of the anchors  3090 ,  3094  provides several advantages. For example, the relatively long length allows for flexibility of the anchors  3090 ,  3094 . This provides for potentially less trauma to the LAA tissue should the device  3000  need to be unanchored and/or retrieved. The anchors  3090 ,  3094  are less susceptible to loss of strength with off-axis orientation within the LAA. Further, the anchors  3090 ,  3094  provide high resistance to pull out. For instance, the device  3000  may provide at least about 0.5 lb-force of dislodgment resistance from the LAA. Such pullout tests may be simulated with in vitro or benchtop models, as further described below. 
     The anchors  3090 ,  3094  in the illustrated embodiment are located in two circumferential rows. One row is located proximal to the other distal row. Each row has ten anchors each. This configuration may be incorporated, for example, in the device  3000  having a foam body  3002  with a free, unconstrained outer diameter of 27 mm. Each row may have fourteen anchors each. This configuration may be incorporated, for example, in the device  3000  having a foam body  3002  with a free, unconstrained outer diameter of 35 mm. In some embodiments, a single row of anchors  3090 ,  3094  may have twelve anchors. In some embodiments, a single row of anchors  3090 ,  3094  may have from two to twenty-four, from four to twenty-two, from five to twenty, from six to eighteen, from seven to sixteen, from eight to fifteen, from nine to fourteen, from ten to thirteen anchors, or greater or fewer amounts of anchors  3090  or  3094 . In some embodiments, there may only be one row or greater than two rows of anchors. The anchors  3090 ,  3094  may be spaced circumferentially in a single row. In some embodiments, the device has twenty-four total anchors  3090 ,  3094 , with each row having twelve anchors, and twelve of the proximal recapture struts  3061 , for example for the 35 mm diameter device  3000 . In some embodiments, the device has twenty total anchors  3090 ,  3094 , with each row having ten anchors, and ten of the proximal recapture struts  3061 , for example for the 27 mm diameter device  3000 . 
     In embodiments with multiple rows of anchors  3090 ,  3094 , the rows may be circumferentially offset, as shown. That is, as viewed from the proximal or distal end of the device  3000 , the anchors  3090 ,  3094  are angularly spaced apart from each other about the axis. The anchors  3090 ,  3094  may not be circumferentially offset, e.g. they may be evenly angularly spaced when viewed as described. The anchors  3090 ,  3094  are located axially at or near a middle portion of the sidewall  3014 . The anchors  3090 ,  3094  may be located such that the tips of the anchors  3090 ,  3094  extend to adjacent tissue at a middle portion of the sidewall  3014 . The offset and middle locations of the anchors  3090 ,  3094  may ensure engagement with the LAA tissue distal to the ostium. Having the anchors  3090 ,  3094  located at the largest width, increases the stability of the device  3000 . With a cylindrical or generally cylindrical shaped device  3000 , the anchors  3090 ,  3094  effectively sit on the largest diameter of the device  3000 . The cylindrical shape provides advantages over typical LAA occluders which taper distally thus decreasing implant stability and locating the anchors on a smaller diameter than the ostial diameter of the occluding surface. In addition to adding stability, the cylindrical shape of the device  3000  along the axial length helps with dislodgement resistance by allowing the anchors  3090 ,  3094  to be placed on the largest diameter section of the device  3000 . In some embodiments, the anchors  3090 ,  3094  may be located proximal, distal, or centrally along the length of the frame body  3080 . In some embodiments, the anchors  3090 ,  3094  may not be offset and/or may not be angularly evenly spaced. 
     The anchors  3090 ,  3094  may provide advantageous flexibility, as demonstrated by pullout tests and in comparison to existing devices. For example, the device  3000  was tested to determine the force required to dislodge the device  3000  from a simulated tissue model by pulling the device  3000  proximally outward from the model. A low durometer silicone tube with a circular inner diameter (ID) was used as the model. For the device  3000  having a foam body  3002  with a 27 mm outer diameter in a free unconstrained state, tubes with ID&#39;s of 16.5 mm, 21 mm and 25 mm were tested. The pullout forces for existing devices drop off significantly going up to a 21 mm model, whereas the forces for the device  3000  drop only slightly. 
     In the largest diameter (25 mm) model, where there is not a lot of interference in the fit, the forces for the existing devices approach zero as the device does not engage the model wall because the anchors are sitting at a smaller diameter on a trailing edge of the device. The device  3000  consistently resists dislodgment with about 0.7 lbs of force. Since there is very little friction resisting pullout, that force is almost entirely resisted by the anchors  3090 ,  3094 . When examining failure modes, all devices eventually begin to slide out of the model. Upon failure, the anchors  3090 ,  3094  fold backward or sideways before slipping starts. Assuming 0.7 lbs force is required to cause all twenty anchors  3090 ,  3094  to fold backward, then the force per anchors is estimated to be about 0.035 lbs. 
     The frame  3040  may be laser cut. The tubular body  3080  may be laser cut from a single tube. The body  3080  may be cut from a tube having a thickness from about 0.002″ to about 0.014″, or about 0.008″. The tube may have an outer diameter (OD) from about 0.05″ to about 0.30″. The tube may have an outer diameter (OD) of 0.124″ for the 27 mm device  3000  (i.e. the embodiment of the device  3000  having a foam body  3002  with an OD of 27 mm in the unconstrained, free state). The tube may have an OD of 0.163″ for the 35 mm device  3000  (i.e. the embodiment of the device  3000  having a foam body  3002  with an OD of 35 mm in the unconstrained, free state). 
     In some embodiments, the body  3080  is laser cut from a superelastic nitinol tube, however, numerous other biocompatible metallic materials can be utilized such as shape memory Nitinol, stainless steel, MP35N, or Elgiloy. The frame  3040  is self-expandable. In some embodiments, a balloon-expandable frame  3040  could be utilized. Additionally, the body  3080  could be fabricated from drawn wire as opposed to being laser cut from a tube. 
     As shown, an embodiment of the device  3000  includes the frame  3040  having ten proximal recapture struts  3061  and twenty total anchors  3090 ,  3094 , with the foam body  3002  having an outer diameter of 27 mm. In some embodiments, the device  3000  may include the frame  3040  having fourteen proximal recapture struts  3061  and twenty-eight total anchors  3090 ,  3094 , with the foam body  3002  having an outer diameter of 35 mm. 
     In one embodiment, the frame  3040  includes a proximal hub  3050 , tether pin  3051 , front face with ten or fourteen recapture struts  3061 , a diamond pattern cylindrical body  3080 , and twenty or twenty-eight anchors  3090 ,  3094 . The frame proximal face  3060  supports recapture, the frame body  3080  supports the foam cylinder body  3002 , and the anchors  3090 ,  3094  located on the cylinder provide resistance to embolization. 
     The design of the device  3000  provides numerous advantages, some of which have been described. As further example, the frame  3040  provides many advantages, including but not limited to: 1) implant radial stiffness/compliance—the frame  3040  provides enhanced radial stiffness while still being sufficiently compliant to allow for off-axis implantation, recapture, etc.; 2) dislodgement resistance—the frame  3040  provides for high pullout strength, as described; 3) transcatheter delivery—the frame  3040  can be compressed into a delivery catheter and then fully expand when delivered; 4) recapture—the frame  3040  allows for recapture/retrieval into the delivery catheter after deployment or even after implantation in the LAA; and 5) mechanical integrity—the frame  3040  has acute and long term structural integrity, for example the ability to withstand loading into the delivery catheter, deployment from the catheter, and cyclic loading/fatigue. The frame  3040  also provides a conformable structure to enable the foam body  3002  to compress against the LAA tissue to facilitate sealing and anchoring with minimal compression (oversizing). The resulting compliance of the frame  3040  provides better anchoring than existing solutions, as described. 
     As further example, the device  3000  seals against irregularly shaped LAA ostia and necks. For instance, a combination of a Nitinol frame  3040  with a foam body  3002  having a coating of PTFE and cover  3100  of ePTFE contribute to ability of the device  3000  to conform to the anatomy and seal against irregular projections and shapes, while providing a smooth thromboresistent LA surface. 
     As further example, the device  3000  provides for controlled &amp; safe delivery. The design of the combined frame  3040  and foam body  3002  facilitates delivery in a controlled fashion by slowing the speed of expansion. The bumper  3026  acts as an atraumatic leading edge portion when delivering the implant into the LAA mitigating the risk of injury. The user has the ability to recapture and redeploy the device  3000 , if necessary. A flexible tether  3240  attachment, as further described, from the delivery catheter to the device  3000  permits the device  3000  to sit tension free immediately following implantation so the user can ensure final appropriate positioning prior to release of the device  3000 . 
     As further example, the device  3000  provides for simplified placement. The foam-covered cylindrical design makes alignment of the device  3000  with the central axis of the LAA during delivery non-critical (by allowing deployment up to, for example, 45 degrees off-axis), which is designed to simplify the implantation procedure, as further described. 
     As further example, the device  3000  provides for simple sizing. The foam and frame design contributes to the ability to need only two diameters (e.g., 27 mm and 35 mm) to seal the range of expected LAA configurations and diameters (e.g. targeting LAA diameters of 16 to 33 mm). The conformability of the foam and frame allow the 20 mm long implant to fit into LAA&#39;s as short as 10 mm deep. The short landing zone requirement (LAA depth) of the device  3000 , combined with the need for only two implant diameters, enables treatment of a wide range of LAA anatomies with minimal need for burdensome echo and CT sizing. The conforming nature of the implant is key to facilitating a simple to use product platform that is adaptable to a variety of anatomic structures. 
     As further example, the device  3000  provides thromboresistant materials and design. The removable tether leaves a smooth, metal-free surface in the LA. Thromboresistant materials (PTFE-coated foam and an ePTFE cover) create a smooth LA face (no metal attachment connection) to reduce anticoagulation needs, enhance thromboresistance, and encourage endothelialization. 
     As further example, the device  3000  provides thin, low profile anchors  3090 ,  3094  around the midpoint of the device  3000  to provide secure yet atraumatic anchoring. 
     4. Distal Bumper 
     The foam body  3002  has a distal bumper  3026 , for example as shown in  FIG. 4C . The bumper  3026  may be a foam distal region of the body  3002 , such as a distal portion of the sidewall  3014 . The bumper  3026  may be a portion of the foam body  3002  that extends beyond the distal end  3044  of the frame  3040 . The bumper  3026  may extend beyond the distal end  3044  of the frame  3040  in the delivery configuration and in the deployed configuration. The body  3002  may be attached to the frame  3040  in various locations such that the body  3002  may stretch in some embodiments, for example in the delivery configuration, to ensure the bumper  3026  extends beyond the frame  3040  upon initially retracting the sheath during delivery. 
     The device  3000  can conform both in length and diameter due to conformability of both the foam body  3002  and the frame  3040 . This allows for the device  3000  to accommodate most patient LAA anatomies with only a couple or few different sizes of the device  3000 , such as 27 mm and 35 mm outer diameter body  3002  as described herein, and one length, such as 20 mm. The frame  3040  may thus be shorter than the foam body  3002 , resulting in some embodiments in about 5 mm of foam bumper  3026  distal to the distal-most end of the frame  3040 . The distal bumper  3026  acts as an atraumatic tip during delivery of the device  3000  and can be compressed following implantation to allow the device  3000  to conform to appendages with a depth (landing zone) as short as 10 mm. This ability to conform both in length and diameter is due to the conformability of both the foam body  3002  and the frame  3040 . 
     The length of the bumper  3026  may be measured axially from the distal-most end of the frame  3040  to the distal surface  3022  of the body  3002 . For example, the bumper  3026  may extend from the distal apexes  3088  to the distal surface  3022 . The bumper  3026  may have a length of 5 mm or about 5 mm. The bumper  3026  may have a length of about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or more. The bumper  3026  may have a length from about 2.5 mm to about 7.5 mm, from about 3 mm to about 7 mm, from about 3.5 mm to about 6.5 mm, from about 4 mm to about 6 mm, from about 4.5 mm to about 5.5 mm. 
     In some embodiments, the bumper  3026  may fold in response to axial and/or radial compression of the device  3000 . The bumper  3026  may fold inward, for example radially inward. The folds may be in the axial or approximately in the axial direction. The folds may be circumferential or approximately in the circumferential direction. The folds may be combinations of the radial and circumferential directions, or angled with respect thereto. The folding of the bumper  3026  is further discussed herein, for example in the section “Device Compliance.” 
     5. Cap &amp; Pin 
       FIGS. 8A-8C  are proximal perspective views of the frame  3040  having a cap  3180 .  FIG. 8D  is a distal perspective view of the cap  3180 . In some embodiments, the pin  3051  is placed across the proximal hub  3050  diameter and serves to engage the delivery catheter tether  3240  (e.g. a suture), which is wrapped around the pin  3051  for temporary attachment to the delivery catheter  3220 , as described further herein for example with respect to  FIGS. 7A-7B and 31A-32B . As shown, the hub  3050  has a pair of opposite side openings  3053  extending through a sidewall of the hub  3050 . The cap  3180  has a corresponding pair of opposite side openings  3190  extending through a sidewall  3184  of the cap  3180 . When the cap  3180  is assembled with the hub  3050 , the pin  3051  may be inserted through the aligned pairs of openings  3053 ,  3182 . The assembly can be further secured by welding the ends of the pin  3051  to the hub  3050 . 
     As shown in  FIG. 8D , the cap  3180  includes a proximal end  3182  and a distal end  3184 . The cap  3180  includes a rounded sidewall  3186  extending from the proximal end  3182  to the distal end  3184 . The sidewall  3186  defines a longitudinal opening  3188  through the cap  3180 . The sidewall  3186  includes a pair of lateral openings  3190  located opposite each other. The cap  3180  includes a flange  3192  at the proximal end  3182  extending radially outward. 
     The cap  3180  is formed from titanium and the pin  3051  is formed from Nitinol or superelastic Nitinol. In some embodiments, the cap  3180  and/or pin  3051  may be formed from other materials, for example numerous biocompatible metallic or polymeric materials such as shape memory Nitinol, stainless steel, MP35N, Elgiloy, polycarbonate, polysulfone, polyether ether keytone (PEEK), or polymethyl methylacrylate (PMMA) or other materials. 
     The cap  3180  and pin  3051  facilitate attachment to the tether  3240 . The cap  3180  and pin  3051  also mitigate damage to the foam body  3002  during recapture of the device  3000 . The cap  3180  also creates an atraumatic surface for the hub  3050  of the frame  3040 . For example, the cap  3180  may prevent the hub  3050  from cutting through the foam body  3002  as the device  3000  is collapsed into an access sheath. Without the cap  3180 , the sharp edges of the hub  3050  may shear through the foam body  3002  during recapture of the device  3000  into the access sheath. 
     6. Loading System 
       FIG. 9  is a side view of an embodiment of a loading system  3200  for loading the device  3000  into a delivery catheter  3220 . The system  3200  includes a loading tool  3210 . The loading tool  3210  has a conical portion  3212 , having a distal opening  3213 , and a cylindrical portion  3214 . The delivery catheter  3220  extends through the cylindrical portion  3214  with a distal end  3222  of the delivery catheter  3220  located within the cylindrical portion  3214 . A pusher  3230 , such as a pusher catheter, extends through the delivery catheter  3220 . A tether  3240  (see, e.g.,  FIGS. 10A-10C ) is attached to the device  3000  and extends through the loading tool  3210 , the delivery catheter  3220  and the pusher  3230 . The tether  3240  and pusher  3230  are pulled in the proximal direction while the delivery catheter  3220  and the loading tool  3210  are held stationary. The device  3000  is compressed laterally by the conical portion  3212  as the device  3000  is pulled proximally by the tether  3240  through the loading tool  3210 . A distal end  3232  of the pusher  3230  remains adjacent to the proximal end  3004  of the device  3000  as the device  3000  is loaded into the delivery catheter  3220 . The removable tether  3240 , which may be fabricated from ultra-high molecular weight polyethylene (UHMWPE), is used to attach the implant to the delivery catheter. The material UHMWPE for the tether  3240  may provide high strength and low friction to facilitate delivery of the device  3000 . 
     In some embodiments, the conical portion  3212  of the loading tool  3210  has a chamfered distal edge of approximately 45°-75° (degrees), preferably 60°. In some embodiments, the conical portion  3212  has a distal inner diameter (ID) greater than the outer diameter (OD) of the device  3000  and an angle A of ideally between 15° and 25°, and in one implementation about 20°, to appropriately collapse the anchors  3090 ,  3094  which may protrude off the foam body  3002  surface at an angle of 30° or about 30°. The distal opening of the conical portion  3210 , for example the diameter or greatest width, may be greater than the proximal opening of the conical portion  3210 , for example the diameter or greatest width, that couples with the cylindrical portion  3214 . The cylindrical portion  3214  may have an opening, for example diameter or greatest width, that is smaller than the distal opening of the conical portion  3210  and/or the same or similar size as the opening at the proximal end of the conical portion  3210 . 
     The decreasing width, for example gradual taper, of the loading tool  3210  ensures, for example, that the frame  3040  folds evenly without crossovers or extra strain. The angled conical portion  3212  may ensure that the anchors  3090 ,  3094  fold or rotate proximally and not distally. The sidewall of the conical portion  3212  may extend at a “total” angle A as measured between two opposite portions of the sidewall, as shown in  FIG. 30 . The angle A may be from about 12° to about 35°, from about 15° to about 30°, from about 17° to about 25°, from about 18° to about 22°, about 20°, or 20°. The angle A may be at least 10°, at least 15°, at least 20°, at least 25°, or at least 30°. The angle A may be constant along the axial length of the conical portion  3212 . The angle of the conical portion  3212  may also be described with respect to a longitudinal geometric center axis, defined by the conical portion  3212  and/or the cylindrical portion  3214 . The sidewall may extend in a direction that is at an angle with respect to such longitudinal axis and which is half of the value of the total angle A. This “half angle” may thus be at least 5°, at least 7.5°, at least 10°, at least 12.5°, or at least 15°, etc. The conical portion  3212  may have a frustoconical shape. The cross-sectional shape of the conical portion  3212  perpendicular to its longitudinal axis may be circular or approximately circular. In some embodiments, this cross section may be rounded, non-circular, segmented, other shapes, or combinations thereof. The cross-sectional shape of the conical portions  3212  may be constant along its axis, or there may be different shapes along the axis. In some embodiments, the angle A may change along the axial length of the conical portion  3212 , for example where the inner surface is curved in the axial direction. 
     The loading tool  3210  may be smooth or generally smooth on its inner surface or surfaces. Inner surfaces  3211 ,  3215  of the conical portion  3212  and/or cylindrical portion  3214  may be smooth or generally smooth. In some embodiments, these inner surfaces  3211 ,  3215  or portions thereof may not be smooth. In some embodiments, these inner surfaces  3211 ,  3215  or portions thereof may be smooth, non-smooth, rough, etched, scored, grooved, have varying degrees of roughness or smoothness, other features, or combinations thereof. 
     In one example, the tool  3210  may be used by positioning a proximal end of a loading body, such as the tool  3210 , adjacent the distal end  3222  of the delivery catheter  3220 . The loading body may have a sidewall defining a channel therethrough with the distal opening  3213  at a distal end that is larger than a proximal opening at a proximal end. The left atrial appendage occlusion device  3000  may be advanced proximally through the loading body to thereby radially compress the device  3000 . The retracting step may comprise pulling the tether  3240  proximally through the delivery catheter  3220 . The device may then be received into the distal end  3222  of the delivery catheter  3220 . The device  3000  may be radially compressed within the delivery catheter  3220  having an outer diameter of no more than fifteen French. In some embodiments, the device  3000  may be radially compressed within the delivery catheter  3220  having an outer diameter of no more than ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, or twenty French. The proximal end of the loading tool  3210  may have an inner diameter configured to provide an interference fit with the distal end  3222  of the delivery catheter  3220 . The proximal end of the loading tool,  3210 , such as the cylindrical portion  3214 , may have an inner diameter slightly larger than the outer diameter of the delivery catheter  3220 , for instance slightly larger than 5 mm for a delivery catheter  3220  having an outer diameter of fifteen French. The device  3000  may compress radially to a compressed width in a constrained state that is less than fifty, forty, thirty, twenty, ten, and/or five percent of a radial uncompressed width of the device in an unconstrained state. The radial widths here may be measured perpendicularly to a longitudinal axis of the device  3000 , such as defined by the tubular foam body  3002 . 
     The loading tool  3210  may be formed of a material that is biocompatible, strong, transparent and can be molded smooth to minimize friction, such as polycarbonate. In some embodiments, the loading tool  3210  could be formed from hard plastics like Delrin, UHMWPE, Ultem®, polyetherimide, acrylic, metals like stainless steel, aluminum, other materials, or combinations thereof. In some embodiments, the loading tool  3210  may have one or more coatings. Such coating may be applied to reduce friction and therefore loading forces. The coating may be silicone, hydrophilics, various oils, other suitable coatings, or combinations thereof. Additional embodiments of a loading tool and system are described herein, for example with respect to  FIGS. 22A-22B . 
     7. Delivery System 
       FIG. 10A  is a side view of a schematic of a delivery system  3201  for delivering the device  3000 .  FIGS. 10B-10C  are additional views of the system  3201 . Various embodiments and features for delivery systems are also shown and described herein in  FIGS. 22A-27C . Any of these delivery systems may have the same or similar features and/or functions as the others. As shown in  FIG. 10A , the delivery system  3201  includes the delivery catheter  3220  having a distal end  3222  and a proximal end  3224 . The delivery system  3201  includes the pusher  3230 , such as a pusher catheter, having a distal end  3232  and a proximal end  3234 . The tether  3240  includes a first end  3242  and a second end  3244 . A restraint  3246  secures the first and second ends  3242 ,  3244 . 
     To deliver the device  3000  to the LAA, an access sheath is placed across the interatrial septum into the LAA through which the delivery catheter  3220 , containing the device  3000 , is placed. The device  3000  is loaded into the distal end  3222  of the delivery catheter  3220  using the loading tool  3210 , either at the point of manufacture or at the treatment site. To load the implant device  3000 , the pusher  3230  and tether  3240  are pulled proximally, collapsing the implant device  3000  as it enters the distal tip of the delivery catheter  3220 . Once the loaded delivery catheter  3220  is placed through the sheath into the LAA, the pusher  3230 , such as a catheter or rod, is held axially steady as the delivery catheter  3220  and access sheath are simultaneously retracted proximally, deploying the implant device  3000 . 
     The tether  3220  passes from the proximal end of the delivery catheter  3220 , through an opening  3221  of the catheter pusher  3230 , around the implant tether pin  3051 , and back through the delivery catheter  3220 . When both ends of the tether  3240  (held together by the restraint  3246  at the proximal end of the catheter) are pulled, the device  3000  is pulled into the delivery catheter  3220 . Once the device  3000  is properly placed in the anatomy, one end of the ends  3242 ,  3244  of the tether  3240  is cut and the entire tether  3240  can be removed from the system by pulling proximally on the uncut end and sliding the cut end distally into the system and around the pin  3051 , disengaging from the pin  3051 . The distal end  3232  of the pusher  3230  and/or the distal end  3222  of the delivery catheter  3220  may contact, for example push against, the proximal end of the device  3000 , such as in the relative locations shown in  FIG. 10A . For example, the distal end  3232  of the pusher  3230  may contact and prevent proximal movement of the device  3000  during tether  3240  retrieval, as further described herein. Further details of the release of the tether are provided herein, for example with respect to  FIGS. 10B-11B . 
     In some embodiments, the delivery system  3201  may include other features. For example, the delivery catheter  3220  may include an injection lumen. The injection lumen may allow for injecting a radiopaque dye distal to the device  3000  following implantation to check for leaks using fluoroscopy. 
     8. Tether Release System 
       FIGS. 10B and 10C  are proximal and distal perspective views of the delivery system  3201 . An approach to releasing the tether, and other features of the system, are described in this section. For clarity, some features are not shown, such as the cover  3100 , foam body  3002 , and frame  3040 . 
     The system  3201  as shown in  FIGS. 10B and 10C  shows the delivery catheter  3220 , the pusher  3230  and the hub  3050  in different axial positions relative to each other. In some embodiments, during release, the distal end  3222  of the delivery catheter  3220  may be co-extensive with, or otherwise near or adjacent, the distal end  3232  of the pusher  3230 . Further, the distal ends  3222  and/or  3232  may contact or be adjacent the proximal end  3004  of the device  3000 , such as contacting or adjacent the cover  3100  and/or foam body  3002 . In some embodiments, the distal end  3232  of the pusher may be located distally of the distal end  3222  of the delivery catheter  3220 , as shown, during tether  3240  release. 
     The tether  3240  may extend from a proximal end of the pusher  3230 , through the opening  3221  of the pusher  3230 , wrap around the pin  3051 , and extend proximally back through the opening  3221  of the pusher  3230  and out the proximal end of the pusher  3230 , as described with respect to  FIG. 10A . The tether  3240  may extend through the cover  3100  and foam body  3002 . The tether  3240  may extend distally through first aligned paths in the cover  3100  and foam body  3002 , around the pin  3051 , and extend proximally back through second aligned paths in the cover  3100  and foam body  3002 . The tether  3240  may extend through openings within the inner cover  3101 , as described for example with respect to  FIGS. 3D and 5D . The tether  3240  may only extend around a distal surface or surfaces of the pin  3051 , as shown. The tether  3240  may extend distally and wrap around the pin  3051  and extend distally at 180° or approximately 180° relative to the proximally extending portion. In some embodiments, the tether  3240  may be wrapped one or more times, for example two, three or more times, around the pin  3051 . In some embodiments, the tether  3240  may be on a spool about the pin  3051 . In some embodiments, the tether  3240  may be wrapped, partially, fully or multiple times, about a bushing that is rotatable coupled about the pin  3051 . 
     The system  3201  may facilitate removal of the tether  3240  while the pusher catheter  3230  is in contact with the device  3000 . Such contact may assist, for example, with avoiding or reducing inadvertent dislodgement of the device  3000  from the LAA after implantation and anchoring. For instance, during release of the tether  3240 , the pusher  3230  may have the positioning relative to the device  3000  as shown in  FIG. 10A . The pusher  3230  may contact the device  3000  on the proximal end  3002  of the device to prevent or reduce any proximal movement of the device  3000  upon tether  3240  removal. For example, there may be friction between the tether  3240  and the pin  3051  as the tether  3240  unwraps about the pin  3051 . The distal end of the pusher  3230  may prevent this friction or other forces from dislodging or otherwise moving the device  3000  proximally. In some embodiments, the delivery catheter  3220  may also be contacting, adjacent to, etc. the device  3000 . In some embodiments, during tether release and removal, the distal ends of the delivery catheter  3220  and pusher  3230  may be axially co-extensive, adjacent or near each other, etc., as described. Further, the tether  3240  may be proximally pulled completely out of the delivery catheter  3220  and/or pusher  3230  before the delivery catheter  3220  and/or pusher  3230  are removed from the patient. In some embodiments, the tether  3240  may be removed from the patient along with the delivery catheter  3220  and/or pusher  3230 , for example while the tether  3240  is still entirely or partially within the pusher  3230 . 
       FIGS. 11A and 11B  are proximal and distal perspective views respectively of another embodiment of a tether release system  3400 . The release system  3400  includes a tube  3420  and a lock  3402 . The tube  3420  has a proximal end  3422  and a distal end  3424 . An opening  3426  extends through the tube  3420 . The system  3400  may be used similarly as described with respect to the system  3201 , except as otherwise noted. For example, the pusher  3230  and/or tube  3420  may contact the device  3000  during tether removal, as described. 
     The lock  3402  includes a proximal end  3404  and a distal end  3406 . An opening  3408  defined by a sidewall  3409  extends through the lock  3402  from the proximal end  3404  to the distal end  3406 . The tube  3420  extends through the opening  3408  at the proximal end  3404  of the lock  3402  and to the distal end  3406  of the opening  3408 . The sidewall  3409  of the lock  3402  has a first groove  3410  extending longitudinally from the proximal end  3404  to the distal end  3406  and extending radially partially through the thickness of the sidewall  3409 . The sidewall  3409  of the lock  3402  has a second groove  3412  extending longitudinally from the proximal end  3404  partially along the sidewall  3409  toward the distal end  3406  and radially partially through the thickness of the sidewall  3409 . 
     The tether  3240  includes a first end  3243  and the second end  3245 . The tether  3240  extends distally from the first end  3243  within the opening  3426  of the tube  3240  and out through the distal end  3424  of the tube  3420  to the cap  3180 . The tether  3240  extends distally into the opening  3188  of the cap  3180  and around the pin  3051  and back in the proximal direction. The tether  3240  then extends proximally into the first groove  3410  of the lock  3402 , around the proximal end  3404  of the lock  3402 , and then distally into and through the second groove  3412 . The tether  3240  terminates at the second end  3245  in a knot  3247 . 
     In use, the knot  3247  may be secured due to the relative location of the lock  3402  and the pusher catheter  3230  inside the delivery catheter  3220 . The knot  3247  may be prevented from advancing distally due to the inner diameter of the distal end of the pusher  3230  fitting tightly about the outer diameter of the lock  3402 . The grooves  3410  and/or  3412  in the lock  3402  may hold the tether  3240  in an orientation that prevents the tether  3240  from slipping (e.g., if pulled hard enough) when the lock  3402  is engaged in the pusher  3230 . The pusher  3230  may be advanced distally to expose the lock  3402 , for example the full length of the lock  3402 , or portions thereof. When the proximal end of the tether  3240  is pulled proximally, the knot  3247  falls away from the second groove  3412 , advances around the proximal end  3404  of the lock  3402 , advances distally by falling away from the first groove  3410 , into the cap  3180  and around the pin  3051 , and then distally through the opening  3408  of the lock  3402  and can be retrieved with the pusher  3230 . In some embodiments, the distal end of the lock  3402  may be located axially proximal to the distal end of the tube  3420 , for example to contact the device  3000  with the tube  3420  to prevent proximal movement of the device  3000  after implantation, as described above. Additional embodiments of a delivery system and associate features, such as a proximal delivery control handle and dual lumen delivery catheter pusher, are described herein, for example with respect to  FIGS. 23A-27C . 
     9. Off-Axis Delivery and Deployment 
     The device  3000  may be deployed off-axis within an LAA while still providing a complete, stable, and atraumatic seal. In some embodiments, the device  3000  may be deployed at an angle of at least about 15° or 25° and in some embodiments as much as 35° or 45°, for example, relative to a central longitudinal LAA axis and still provide an effective seal. The LAA axis here is defined as the geometric center of the ostium to the LAA, and tracks the best fit geometric center of the LAA cavity. 
     This ability of the device  3000  to be deployed off-axis is due in part to the relatively thick, compressible foam body  3002  material, the compliant frame  3040  and the cylindrical shape of the device  3000  with the foam bumper  3026 . The device  3000  is stable within the LAA despite having a length that is less than the diameter, or having L/D&lt;1. As described, the length may be 20 mm for the device  3000  having an OD of both 27 mm and 35 mm. Thus not only is flexibility and simplicity allowed with manufacturing processes by having one length, but also stability and effectiveness of the device in use. Further, the axial compressibility of the bumper  3026 , combined with the axially compliant frame  3040 , allows a 20 mm long device  3000  to be placed within a 10 mm deep LAA, whereas existing LAA closure devices require longer landing zones, or at least landing zones equal to the size of the length of the metallic frame. 
     In some embodiments, the device  3000  may be configured to allow for sufficient flow of blood in case of accidental embolization, as described herein. Further, the device  3000  may be configured to allow for sufficient flow of blood even if the device  3000  embolizes and is misaligned with the direction of flow of blood. For example, the device  3000  may define a longitudinal axis, and the direction of flow of blood may define a flow axis. The device longitudinal axis may be at an angle with respect to the flow axis and still provide for a sufficient blood flow through the device  3000  should it embolize and lodge within the circulatory system of a patient. Thus, the capabilities of the device  3000  with regard to flow of blood through the device in case of embolization, or tests thereof with water under controlled conditions, as described herein for example with respect to the section “Proximal Cover,” may also apply to the device  3000  in such off-axis configurations or orientations with the circulatory system of the body. The device axis may be at an angle of five, ten, twenty, thirty or more degrees with respect to the flow axis and still provide sufficient flow of blood through the device  3000 . 
     10. Anchor/Foam Interface 
     As described, the frame  3040  with anchors  3090 ,  3094  and foam body  3002  may have a variety of geometries, such as lengths, thicknesses, etc. This section discusses some particular embodiments of the frame  3040 , in particular the anchors  3090 ,  3094 , and the foam body  3002 .  FIGS. 12A-12C  depict various embodiments of an anchor/foam interface  3500 , using the anchor  3090  as an illustrative example.  FIGS. 12A-12C  are side cross-section views of a portion of the device  3000  showing an embodiment of the interface  3500 . In some embodiments, the outer tips of the anchors  3090 ,  3094  may, or may not, extend radially beyond portions of the outer surface  3016  of the foam body  3002 , even in an unconstrained configuration, as further described herein. 
     The interface  3500  includes a portion of the tubular body  3080  of the frame  3040 , having the proximal strut  3082  and the distal strut  3086 , as described in further detail herein, for example with respect to  FIG. 7A . The anchor  3090  extends radially outwardly in a proximal direction from the frame  3040 , such as from the tubular body  3080 . The same or similar features and/or functionalities as described in this section with respect to the interface  3500  having the anchor  3090  may apply to other anchor/foam interfaces with other anchors, such as anchor/foam interfaces with the distal anchor  3094 . For example, the frame  3080  could have a distal end at the base of the anchor  3094 , where the distal apes  3088  is located (see, e.g.,  FIG. 7A ). 
     As shown in  FIGS. 12A-12C , the anchor  3090  extends outwardly and proximally from the frame  3040 , which may be from the proximal apex  3084  as described herein. The anchor  3090  has an axial length L. The length L extends from the distal base of the anchor  3090  at the frame  3040  to a proximal tip  3091  of the anchor  3090 . The length L may include only the straight portion of the anchor  3090 , for example if the base of the anchor  3090  is bent. In some embodiments, the length L can include the complete anchor  3090 , such that L extends axially along the anchor  3090  from a tip  3091  of the anchor  3090  to the frame  3040 . The anchor  3090  is shown with a flat end, but it may be sharpened, angled, etc. The length L may extend proximally to the farthest endpoint axially along the length of the anchor  3090 , such as to the tip  3091 . In some embodiments, L is 2.5 mm, about 2.5 mm, or from about 2.25 mm to about 2.75 mm. The length L may be a variety of other lengths or within other ranges of lengths, for example as described in further detail herein with respect to the anchors  3090 ,  3094  in the section “Compliant Frame.” 
     The anchor  3090  extends at an angle B relative to the proximal strut  3082 . In some embodiments, the proximal strut  3082  as shown may be considered a projection of the proximal strut  3082  onto a vertical plane that intersects the longitudinal axis of the device  3000  and the anchor  3090 . Thus the angle B may be relative to such plane and/or to the strut  3082 . For simplicity, the angle B will be described relative to the strut  3082 . The angle B may be 30° or about 30°. The angle B may be a variety of other angles or within ranges of angles, for example as described in further detail herein with respect to the anchors  3090 ,  3094  in the section “Compliant Frame.” The anchor further has a radial height H. The radial height H may be the radially outermost extent of the anchor  3090 , such as the proximal tip  3091  of the anchor  3090 . The length L and angle B may define the radial height H of the anchor  3090 . The height H may be in a direction perpendicular to the longitudinal axis of the device  3000  (see, e.g.,  FIG. 5B ). 
     Further shown is the sidewall  3014  of the foam body  3002 . The sidewall  3014  has a thickness T. The thickness T extends radially outward from the inner surface  3018  to the outer surface  3016  of the sidewall  3014 . The thickness T may extend radially outward perpendicularly to the longitudinal axis of the device  3000 . The thickness T may be equal to a distance from a radially outer portion of the frame  3040  to the outer surface  3016  of the sidewall  3014 , for example where the inner surface  3018  of the sidewall  3014  contacts the outside of the frame struts  3082 ,  3086 . The thickness T could be the thickness of the sidewall  3014  in an unconstrained configuration, a compressed configuration while inside the delivery catheter, or a compressed configuration after implantation within the LAA, as further described. The measurement of the thickness T of the sidewall  3014  may be in the same direction as the measurement of the height H of the anchor  3090 . The thickness T of the sidewall  3014  may be 2.5 mm or about 2.5 mm. The thickness T of the sidewall  3014  may be other values or ranges of values, for example as described in further detail herein in the section “Compressible Foam Body.” 
     As shown in  FIG. 12A , in some embodiments, the height H of the anchor  3090  may be greater than the thickness T of the foam sidewall  3014 . The difference may be equal to a delta D. The device  3000  may have this configuration in an unconstrained configuration, for example as resting on a tabletop as described herein. The delta D may be from about 0.05 mm to about 5 mm, from about 0.075 mm to about 4 mm, from about 0.1 mm to about 3 mm, from about 0.2 mm to about 2 mm, from about 0.3 mm to about 1.5 mm, from about 0.4 mm to about 1 mm, about 0.5 mm, or 0.5 mm. In some embodiments, these example values for delta D may be negative, where T is greater than H. In some embodiments, the delta D may be zero, as described with respect to  FIG. 12B . 
     As shown in  FIG. 12B , in some embodiments, the height H of the anchor  3090  may be the same as or about the same as the thickness T of the foam sidewall  3014 . Thus the delta D may be zero or about zero. The device  3000  may have this configuration in an unconstrained configuration, for example as resting on a tabletop as described herein. The anchors  3090 ,  3094  may extend through the foam body  3002  to the outer surface  3016  in the unconstrained configuration, and then extend radially outward beyond the outer surface  3016  when loaded for delivery and/or after implantation in the LAA. In other embodiments, the foam body  3002  is locally compressed so the anchor extends beyond the outer surface  3016 , as further described. 
     As shown in  FIG. 12C , the device  3000  may include one or more attachments, such as sutures, for example the attachment  3001  described in further detail herein with respect to  FIG. 5D . The attachment  3001  may connect the foam body  3002  to the frame  3040 . As shown, the attachment  3001  may extend out through the sidewall  3014  and around the outer surface  3016 , back in through the sidewall  3014  and around the frame  3040 , such as around the proximal strut  3082 . The attachment  3001  may locally compress the sidewall  3014  as shown. The sidewall  3014  may have a local radial thickness R. The thickness R may be less than the thickness T. The thickness R may be a local minimum of the thickness of the foam body  3002 . The thickness T may be located adjacent or otherwise around the location of the thickness R. The sidewall  3014  may increase in thickness from the location of the thickness R to the surrounding thicknesses T. The increase may be gradual or abrupt. 
     The local compression of the sidewall  3014  may allow for the anchor  3090  to extend proximally and outwardly beyond the outer surface  3016  of the foam body  3002 . As shown, the attachment  3001  may locally compress the thickness of the sidewall  3014  such that the proximal tip  3091  of the anchor  3090  extends at the angle B for the length L beyond the outer surface  3016  of the foam body  3002 . The attachment  3001  may be located proximally to the anchor  3090  as shown, or in other location, such as distally to the anchor  3090 , adjacent the base of the anchor  3090 , farther proximally/distally from the base of the anchor  3090 , etc. The attachment  3090  may be located and configured to allow for local compression of the sidewall  3014  to allow the tip  3091  of the anchor  3090  to extend beyond the outer surface  3016  of the foam that is located directly radially inwardly of the tip  3091  of the anchor  3090 . In some embodiments the attachment  3001  may be located directly radially inwardly of the tip  3091  of the anchor  3090  (e.g., directly “below” the tip  3091  of the anchor  3090  as oriented in the figure). In some embodiments, there may be multiple attachments  3001  distributed axially along the frame  3040  and all contributing to a single local compression of the foam body  3002  about a particular one of the anchors  3090 . 
     The foam sidewall  3014  may be compressed into the configuration shown in  FIG. 12C  in an unconstrained configuration. The foam sidewall  3014  may be compressed into the configuration shown in  FIG. 12C  in a constrained configuration, for example within the delivery catheter or after deployment from the delivery catheter. The foam sidewall  3014  may be compressed into the configuration shown in  FIG. 12C  from the configurations shown or described with respect to  FIG. 12A or 12B . Thus in  FIG. 12C , the height H may equal to or approximately equal to the thickness T, or the height H may be greater or less than the thickness T. In some embodiments, in an unconstrained configuration, the length L is 2.5 mm or about 2.5 mm, the angle B is 30° or about 30°, and the thickness T is 2.5 mm or about 2.5 mm. 
     Design of the anchor length may be based on a balance between longer length to provide flexibility to assist with removal, and shorter length for not penetrating through the LAA wall. The anchors  3090 ,  3094  may be flexible and capable of bending in the distal direction due to their length. The anchors  3090 ,  3094  are thus less likely to tear tissue during repositioning and therefore less traumatic. The anchors  3090 ,  3094  may be longer than other tissue engaging features of existing solutions for LAA occlusion. In some embodiments of the device  3000 , the anchors  3090 ,  3094  are designed to be long enough to effectively anchor into the LAA wall. The foam body  3002  and corresponding thickness of the sidewall  3014  allows the anchors  3090 ,  3094  to have longer length. An advantage of making the anchors  3090 ,  3094  longer is to increase their flexibility, making them less damaging to tissue during removal and repositioning. However, anchors  3090 ,  3094  beyond a certain length may penetrate through the LAA wall, which is not desirable. The foam body  3002  and thickness thereof assists with preserving the advantageous longer length of the anchors  3090 ,  3094  while mitigating the risk of the anchors  3090 ,  3094  penetrating through the LAA wall. For example, the foam sidewall  3014  between the struts of the frame  3040  and the tips  3091  of the anchors  3090 ,  3094  limits how far the anchors  3090 ,  3094  will penetrate allowing for longer and therefore more flexible anchors  3090 ,  3094 . 
     For example, with a 2.5 mm foam sidewall  3014  thickness, the anchors  3090 ,  3094  may be 2.5 mm in axial length and formed at an angle between 30-40 degrees, or 25-45 degrees, off the struts. In some embodiments, as discussed, when the frame  3040  is first placed into the foam body  3002  and anchors  3090 ,  3094  pierce into the foam sidewall  3014 , the tips  3091  of the anchors  3090 ,  3094  may not extend all the way through the foam as the anchors  3090 ,  3094  may be radially too short. In some embodiments, the frame  3040  OD is about 24 mm and the foam body  3002 , such as foam cup shape, has a sidewall  3014  with an ID of about 22 mm. So there may be an interference fit where the frame  3040  bulges into the foam sidewall  3014 . With the anchor  3090 ,  3094  length and angle, the tips  3091  of the anchors  3090 ,  3094  are at about 27 mm diameter, which corresponds to just getting to the outer surface  3016  of the sidewall  3014 . As discussed, the assembly may be attached by suturing the foam body  3002 , and the frame  3040  (and in some locations the cover  3100 ) together at every anchor-frame interface location. This may cause a dimpling of the foam body  3002  local to the corresponding anchor  3090 ,  3094 , thus exposing a length of the anchor  3090 ,  3094  at the outer surface  3016 . The exposed length of the anchor  3090 ,  3094  may be a fraction of the total anchor  3090 ,  3094  length. Further, the anchor  3090 ,  3094  length and radial height of the foam sidewall  3014  surrounding the anchor  3090 ,  3094  can be adjusted to expose the desired amount of the anchor  3090 ,  3094 . 
     In some embodiments, the tip  3091  may be exposed beyond the foam body  3002  when the foam is compressed, but the tip  3091  may be positioned within the foam, below the outer surface  3016 , when the foam is uncompressed. Thus, with the foam uncompressed the tip  3091  may not be positioned radially outwardly relative to the outer surface  3016 , but with the foam compressed the tip  3091  may be positioned radially outwardly relative to the adjacent portion of the outer surface  3016 . Therefore, the tip  3091  may not be exposed with “H” less than “T” in the uncompressed configuration, and the tip  3091  may be exposed with “H” greater than “T” in the compressed configuration. 
     11. Device Compliance 
     The device  3000  is capable of conforming to the geometry of the LAA. The device  3000  is designed for compliance such that it can conform to the LAA and reduce or minimize remodeling of the LAA. For example, the device  3000  may be implanted into the LAA and after a period of time the ostium or opening of the LAA may have the same or similar profile as before implantation of the device  3000 . Further, the device  3000  may exhibit such properties while conforming to extreme non-circular shapes, both at the opening of the LAA and within the LAA. A single size of the device  3000  may be used for all or a wide range of patients with varying geometries, due to the compliance and other advantages. 
       FIG. 13A  is a schematic showing an embodiment of a profile of the ostium  110 . The view shown may be looking into the LAA, for example in a plane that is perpendicular to a geometrically centered axis at the ostium. The geometry of the ostium  110  may vary greatly, as described herein, for example with respect to  FIG. 1 . As shown in  FIG. 13A , the ostium may be approximated as an oval or ellipse having a relatively shorter minor axis A 1  and relatively longer major axis A 2 . The ostium  110  is shown as generally symmetric about the axes A 1 , A 2 , but the ostium  110  may have asymmetries, other local grooves, discontinuities, etc. Thus the ostium  110  schematic shown is merely for illustrative purposes to describe the enhanced compliance capabilities of the device  3000 . In some embodiments, the minor axis A 1  may refer to a maximum width of the ostium  110  in a first direction, and the major axis A 2  may refer to a maximum width in a second direction. The first direction may be perpendicular to the second direction. 
     The lengths of the axes A 1 , A 2  may have a variety of values or ranges of values. The minor axis A 1  may be from about 5 mm to about 30 mm, from about 7.5 mm to about 20 mm, from about 10 mm to about 17.5 mm, from about 12 mm to about 15 mm, about 14 mm, or 14 mm. The major axis A 2  may be from about 10 mm to about 40 mm, from about 15 mm to about 37 mm, from about 20 mm to about 35 mm, from about 22 mm to about 32 mm, from about 25 mm to about 30 mm, about 27 mm, or 27 mm. 
       FIG. 13B  shows the ostium  110  from the same perspective but with the device  3000  implanted into the LAA. The cover  3100  is visible, showing the proximal surface  3102  with proximal openings  3122 . Other covers as described herein may be included, such as the cover  3150 , etc. The ostium in  110  with the device  3000  may have the same or similar shape and size as the ostium shown in  FIG. 13A  without the device  3000 . The other portions of the LAA may also have the same shape and sizes before and after implantation of the device  3000 . The device  3000  may therefore conform to the shape of the LAA, such as the ostium  110 . The device  3000  may conform to the anatomical shape due to the configuration of the foam body  3002  and frame  3040  as described herein. The device  3000  may exhibit sufficient compliance to assume the anatomical shape to provide a sufficient occluding function and without remodeling or otherwise deforming the shape of the LAA, such as the ostium  110 . 
     The LAA may retain the same or similar original size and shape of the LAA immediately after implantation of the device  3000  and for a period of time thereafter. In some embodiments, the anatomical geometry, for example size and shape, of the LAA will still be the same or approximately the same after implantation of the device  3000  after a period of twenty four hours or more, seven days or more, thirty days or more, six months or more, one year or more, five years or more, or longer periods. A test construct having approximately the same geometry, stiffness, etc. may be constructed to confirm the minimal long-term changes in the construct due to the device  3000 . A construct having an opening with a minor axis of about 14 mm and a major axis of about 27 mm and with a stiffness generally present in normal LAA ostiums of patients may have the same or similar size and shape after implanting the device  3000  for the aforementioned periods. The device  3000  may allow for the same or similar geometry along the length of the LAA, e.g. distal to the ostium  110 , for these periods of time as well, as further described. 
     In one example use, the device  3000  may be configured to insert into a non-cylindrical opening, having a non-cylindrical profile, of a test body. The test body may be rigid such that the test body does not deform in response to the device  3000  being implanted therein. The test body may be formed of rigid plastics, metals, etc. The opening and profile may have a size and shape substantially similar to that of a native left atrial appendage. The device  3000  may expand radially within the non-cylindrical opening, and conform to the non-cylindrical profile, which may be at least at the opening of the test body. The device  3000  may conform to the opening and have no visible gaps between the device  3000  and the opening. There may be one or more radial gaps that are each no more than five, four, three, two and/or one millimeter across at their widest portion. Such gaps may be measured radially, or perpendicularly to a longitudinal axis extending through the geometric center of the test body opening. The gap may be measured between the outer surface of the device  3000  and the inner surface of the opening of the test body. The gap may be measured at the location of maximum space between the device  3000  and the test body. The device may conform to this shape after a period of at least thirty days, at least sixty days, and/or at least one hundred twenty days after implantation. In another example use, the device  3000  may be configured to insert into a non-cylindrical opening of a test body having a size and radial stiffness substantially similar to that of a native left atrial appendage, expand radially within the non-cylindrical opening, and assume a non-cylindrical profile at least at the opening of the test body after a period of at least thirty days, at least sixty days, and/or at least one hundred twenty days. 
       FIG. 14A  depicts a side view of the device  3000  in a radially constrained configuration. The device  3000  may have the configuration shown after implantation in the LAA, for example after the aforementioned time periods above. The device  3000  is shown with a proximal end  3004  having a width D 1  and a distal end having a width D 2 . The widths D 1 , D 2  may be diameters, or they may be maximum widths of the respective ends of the device  3000 . The width D 1  is greater than the width D 2 . In some embodiments, the width D 1  may be less than the width D 2 . In some embodiments, the width D 1  may be equal to or approximately equal to the width D 2 . In some embodiments, the width D 2  may be about 15% of the width D 1 . The width D 2  may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 35% or less, 30% or less, 25% or less, 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, or 10% or less of the width D 1 . In some embodiments, the width D 2  may be at other locations along the device  3000  alternatively or in addition to the distal end of the device  3000 , for example a portion proximal to and adjacent or near the distal end, a middle portion of the device  3000 , etc. In some embodiments, the entire device  3000  or a substantial portion of the device  3000  may have the width D 2 . For example, the entire device may have the width D 2  when constrained within the delivery catheter, as described herein for example in the section “Loading System.” 
       FIG. 14B  depicts a side view of the device  3000  in an axially constrained configuration relative to an axially unconstrained configuration. The device  3000  has an axial length L 1  in an unconstrained state, and an axial length L 2  in the constrained state. The lengths L 1 , L 2  between the proximal end  3004  and the distal end  3006  of the device  3000  in the respective configurations. The device  3000  may have the configuration shown with the length L 2  after implantation in the LAA, for example after the aforementioned time periods above. The length L 2  is less than the length L 1 . The length L 2  may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, 45% or less, or 40% or less of the length L 1 . In some embodiments, L 2  may be equal to or approximately equal to L 1 . 
     In some embodiments, the bumper  3026  may allow for extreme shortening of the distal end  3006  of the device. In some embodiments, the bumper  3026  may fold inward to accommodate radial and/or axial constraining of the device  3000 . The bumper  3026  may fold radially inward and/or proximally inward. Further, the compliant frame  3040  within the foam body  3002  may allow for further axial shortening beyond the length of the bumper  3026 . The frame  3040  may fold radially and/or axially inward. 
     Further, the cylindrical shape of the device  3000  facilitates with sealing the LAA, even with atypical geometries of the LAA anatomy. The cylindrical shape ensures that the anchors are located at the locations of maximum width of the device  3000 . The tubular body  3080  may provide a cylindrical foundation for the anchors  3090 ,  3094 , as described herein, such that the anchors are located at the radially outer most portion of the device  3000 . Such cylindrical shape of the device along its longitudinal axis assists with the device  3000  performing the necessary sealing, even in the constrained configurations shown in  FIGS. 14A  and  14 B. In some embodiments, the device  3000  may be constrained both axially and radially, for example with both of the deformations shown in  FIGS. 14A and 14B . The compliance of the device  3000  along with the cylindrical shape can ensure superior sealing performance compared to currently available typical LAA occlusion devices. 
       FIG. 15  is a side view of an embodiment a laser cut tube frame  3040  shown in a flat configuration. The frame  3040  may have the various dimensions as shown in inches. The dimensions are just one embodiment and some or all dimensions may be different in other embodiments. The hub  3050  is located at a proximal end having holes  3053 . The struts  3061  extend distally from the hub  3050 , having curved (when assembled) proximal portions  3062 , straight portions  3064 , and outer curved (when assembled) portions  3066 . The struts  3061  connect at proximal apexes  3084  to the proximal struts  3082 . Proximal anchors  3090  extend proximally from intermediate vertices  3087 . Distal struts  3086  extend from the vertex  3087  to form the distal apexes  3088 , from which the distal anchors  3094  extend proximally. The frame  3040  may have approximately the dimensions shown, or they may vary therefrom. The frame  3040  shown may be used with the device  3000  having a width of 27 mm or about 27 mm. 
     The device  3000  provides many advantages over existing solutions to LAA occlusion, as described herein. A key advantage is that the device is highly compliant while still providing superior resistance to embolization. This unique feature of being more compliant yet better anchoring is counterintuitive. As compared to existing solutions, the device  3000  is much more conformable and thus able to take the oval shape of the LAA ostium, as described, while also providing superior dislodgement resistance, in some embodiments with a pull out force in bench testing of greater than 0.8 pounds (lbs). 
     12. Conformability 
     The device  3000  provides superior conformability to a range of different shapes and sizes of LAA&#39;s compared with existing solutions to LAA occlusion. This section further details some of the features of the device  3000  that contribute to its conformability, among other advantages. For example, some of the features described herein relate to the shape or contour of the proximal face  3060 , the angular transition between the proximal face  3060  and the tubular body  3080 , the lengths of the struts  3082 ,  3086  forming the diamond or square shapes along the tubular body  3080 , and the angles of the proximal and distal apexes  3084 ,  3088  of the diamond or square shapes. For instance, and as further detailed herein, the frame  3040  may have a flat or substantially flat shape or contour of the proximal face  3060 , a 90° or approximately 90° angular transition between the proximal face  3060  and the tubular body  3080 , relatively short lengths of the struts  3082 ,  3086  forming the diamond or square shapes along the tubular body  3080 , and relatively larger angles of the proximal and distal apexes  3084 ,  3088  of the diamond or square shapes. 
       FIGS. 16A-16C  are various views of the frame  3040  indicating some of the structural aspects contributing to the LAA occlusion device&#39;s  3000  conformable capabilities.  FIG. 16A  is a side view of the frame  3040 .  FIG. 16B  is a detail view of a portion of the frame  3040  showing the detail region  98 B as labelled in  FIG. 16A .  FIG. 16C  is a detail view of a portion of the frame  3040  showing the detail region  98 C as labelled in  FIG. 16A . The frame  3040  in  FIGS. 16A-16C  is shown in an unconstrained configuration, for example after deployment from a delivery catheter and without any outside forces acting radially inwardly on the device frame  3040 . 
     As shown in  FIG. 16A , the frame  3040  includes the proximal face  3060  having a plurality of the proximal struts  3061 , and a tubular body  3080  or “landing zone” extending distally from the proximal face  3060 , between a proximal transition and a distal end. The frame  3040  includes the proximal anchors  3090  and distal anchors  3094  extending from the tubular body  3080 , as described. The anchors  3090 ,  3094  incline radially outward in a proximal direction from the tubular body  3080 . 
     As indicated in  FIG. 16A , the anchors  3090  in an unconstrained configuration may extend at an angle C with respect to the central longitudinal axis defined by the frame  3040 . The angle C may be from 25° (degrees) to 45°, about 35°, or 35°. In some embodiments, the angle C may be from 5° to 65°, from 10° to 60°, from 15° to 55°, from 20° to 50°, from 25° to 45°, or from 30° to 40°. In some embodiments, the angle C is 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, or 45°. The distal anchor  3094  may also be inclined at any of the angles C as described with respect to the proximal anchor  3090 . The distal anchor  3094  may be inclined at the same or different angle as the proximal anchor  3090 . Each of the proximal anchors  3090  may be inclined at the same angle  25  as the other proximal anchors  3090 , or some may be inclined at different angles as compared to others of the proximal anchors  3090 . Similarly, each of the distal anchors  3094  may be inclined at the same angle as the other distal anchors  3094 , or some may be inclined at different angles as compared to others of the distal anchors  3094 . 
     The frame  3040  further includes the proximal face  3060  defined at least partially by a plurality of the proximal struts  3061 , as described. The struts  3061  each include a straight portion  3064  extending radially outward and defining a line. The plurality of straight portions  3064  may extend radially outward and together define a geometric surface. 
     As indicated in  FIG. 16A , the straight portions  3064 , or the lines or surface defined thereby, in an unconstrained configuration may extend at an angle D with respect to the central longitudinal axis. The angle D may be from 85° (degrees) to 110°, about 100°, or 100°. Thus the straight portions  3064  in an unconstrained configuration may extend radially outward in a distal direction or directly radially outward. In some embodiments, the straight portions  3064  in an unconstrained configuration may extend radially outward in a proximal direction. In some embodiments, the angle D may be from 80° to 120°, from 85° to 115°, or from 95° to 105°. In some embodiments, the angle D may be greater than 90°. In some embodiments, the angle D may be greater than 80°, greater than 85°, greater than 95°, greater than 100°, greater than 105°, or greater than 110°. 
     The angle D is measured relative to a straight colinear extension of the part of the strut  3061 , which may be or include the straight portion  3064 , as mentioned. In some embodiments, the straight portion  3064  may not be perfectly straight. It may be slightly curved, have one or more curved portions therein, or not be perfectly flat, for example as further described with respect to  FIG. 16B . In such cases, the angle D may be measured from a straight part of the strut  3061 , if any, or the angle D may be measured from a line of best fit as determined by the straight portion  3064 . 
       FIG. 16B  shows a detail of the region  98 B as indicated in  FIG. 16A . As shown in  FIG. 16B , the strut  3061  extends radially outward from the hub  3050  to the proximal strut  3082 . The strut  3082  may be part of the tubular body  3080  or “landing zone” as described herein. In particular, the strut  3061  includes the inner curved portion  3062  extending arcuately from the hub  3050  in the distal and radially outward directions, to the straight portion  3064  extending radially outwardly, and to the outer curved portion  3066  extending arcuately in the distal direction, as described herein. The outer curved portion  3066  is connected with the proximal strut  3082  of the tubular body  3080 , as described. 
     As indicated in  FIG. 16B , the straight portion  3064  of the proximal face strut  3061  and the proximal strut  3082  of the tubular body  3080  may be angled relative to each other at an angle E. The angle E may be measured relative to the straight portion  3064 , for example relative to a line, plane and/or surface defined by the straight portion  3064 , as described with respect to  FIG. 16A . The angle E may be measured relative to the outer surface of tubular body  3080  or portions thereof. For example, the proximal strut  3082  may extend distally along a linear or curved path, as viewed from the side. The strut  3082  is shown as curved, but it may be straight or define a line of best fit. Similarly, the distal struts  3086  of the tubular body  3080  may be curved, straight, and/or define a line of best fit, as viewed form the side. Further, the proximal and distal struts  3082 ,  3086  may together define a line, plane, and/or surface, as viewed from the side. For example, the tubular body  3080  may be cylindrical or generally cylindrical, as described, and thus the proximal and distal struts  3082 ,  3086  may together define a line, plane, and/or surface, that as viewed from the side is parallel or substantially parallel to the longitudinal axis. In some embodiments, the proximal and distal struts  3082 ,  3086  may together define a curved path and/or surface, that as viewed from the side initially extends distally and radially outward and then distally and radially inward, and from which a line of best fit may be determined. The angle E may thus be measured relative to any of these geometric references of the tubular body  3080 . 
     In some embodiments, the angle E is measured relative to portions of the frame located on either side of the curved portion  3066 . The proximal end of the curved portion  3066  may be attached to a radial outer end of the straight portion  3064 . The angle E may be measured relative to this radial outer end of the straight portion  3064 . The distal end of the curved portion  3066  reaches a transition to a proximal end of the proximal strut  3082 , for example at the proximal apex  3084  as described herein and as shown in  FIG. 16C . The angle E may be measured relative to this proximal end of the proximal strut  3082 . 
     The angle E may be 90° or about 90°. In some embodiments, the angle E is from 70° to 110°, from 75° to 105°, from 80° to 100°, or from 85° to 95°. In some embodiments, the angle E is greater than 90°. In some embodiments, the angle E is greater than 70°, greater than 75°, greater than 80°, greater than 85°, greater than 95°, or greater than 100°. 
     Further, the inner curved portion  3062  may have a radius R 1  as indicated in  FIG. 16B . The radius R 1  may have a proximally-facing concavity as shown, i.e. a positive or upward concavity as oriented in the figure. 
     The substantially straight portion  3064  may have a radius R 2  to produce a distally facing concavity and proximally facing convex surface. In some embodiments, the radius R 2  is infinite, where the straight portion  3064  is linear. The straight portion  3064  as shown may therefore not have a concavity, whether proximally-facing or distally-facing. In some embodiments, the straight portion  3064  may have a slight concavity proximally and/or distally. The portion  3064  may have a single concavity from inner transition to curve  3062  to outer transition  3066  without any points of inflection. The concavity may have a radius R 2  of at least about 2 cm, 5 cm or 10 cm or more. 
     As shown, the straight portion  3064  extends radially inwardly to an inner transition to the inner curved portion  3062 . The entire straight portion  3064  may therefore be located distally of the inner curved portion  3062  in the unconstrained configuration as shown. In some embodiments, the entire straight portion  3064  is located distally of a distal end of the inner curved portion  3062 . In some embodiments, all portions of the strut  3061  besides the inner curved portion  3062  are located distally of the inner curved portion  3062 , and there are no points of inflection along the strut portion  3064 . 
     The straight portion  3064  may have a flatness defined by a width S as indicated in  FIG. 16B . The straight portion  3064  may extend radially outward between the two parallel closest fit geometric reference lines that are separated by the width S. The width S may be the strut width, for example where the straight portion  3064  is perfectly straight. In some embodiments, the width S may be no greater than 0.2 mm, no greater than 0.3 mm, no greater than 0.4 mm, no greater than 0.5 mm, no greater than 0.6 mm, no greater than 0.7 mm, no greater than 0.8 mm, no greater than 0.9 mm, no greater than 1 mm, no greater than 1.1 mm, no greater than 1.2 mm, no greater than 1.3 mm, no greater than 1.4 mm, or no greater than 1.5 mm more than the strut width. 
     The outer curved portion  3066  may have a radius R 3  as indicated in  FIG. 16B . The radius R 3  may have a distally-facing concavity as shown, i.e. a downward concavity as oriented in the figure. The radius R 3  may be 1 mm or about 1 mm. In some embodiments, the radius R 3  may be from about 0.2 mm to 2 mm, from about 0.3 mm to 1.8 mm, from about 0.4 mm to 1.6 mm, or from about 0.5 mm to 1.4 mm. 
     The radius R 3  may extend along an arc having an arc length. The arc length may be measured from a first transition between a radially outward end of the straight portion  3064  to a second transition to the proximal end of the strut  3082 , for example at the proximal vertex  3084  (shown in  FIG. 16C , for example). This arc length may be no greater than 0.2 mm, no greater than 0.3 mm, no greater than 0.4 mm, no greater than 0.5 mm, no greater than 0.6 mm, no greater than 0.7 mm, no greater than 0.8 mm, no greater than 0.9 mm, no greater than 1.0 mm, no greater than 1.1 mm, no greater than 1.2 mm, no greater than 1.3 mm, no greater than 1.4 mm, no greater than 1.5 mm, no greater than 1.6 mm, no greater than 1.7 mm, no greater than 1.8 mm, no greater than 1.9 mm, or no greater than 2.0 mm. 
       FIG. 16C  shows a detail of the region  98 C as indicated in  FIG. 16A . As shown in  FIG. 16C , the quadrilateral shape defined by the struts  3082  and  3086  may define angles G and F as indicated. The angles G may be defined by the proximal and distal apexes  3084 ,  3088 . The angles G may therefore be measured between adjacent proximal struts  3082  and between adjacent struts  3086 . The two angles G may be the same or within about 2° or 4° of each other. In some embodiments, the angles G may be different for the proximal apex  3084  as compared to the distal apex  3088 , for example where one or more of the struts  3082 ,  3086  forming the quadrilateral shape are a different length than the other struts. The angles F are defined between adjacent proximal and distal struts  3082 ,  3086  as indicated. 
     The angles G and F may each be 90° in the unconstrained configuration. In some embodiments, the angles G and F may each be approximately 90° such as within about ±1°, ±2°, ±4° or ±6° of 90°. Thus the quadrilateral formed by the struts  3082 ,  3086  may be a square or approximately a square. The angles G may be no less than 85°. In some embodiments, the angles G may be no less than 45°, no less than 50°, no less than 55°, no less than 60°, no less than 65°, no less than 70°, no less than 75°, no less than 80°, or no less than 90°. The sum of the four angles G and F may be 360°. Thus, the angles F may each be equal to (360°−(2×G))/2. 
     The quadrilateral shapes defined by the struts  3082 ,  3086  may define a longitudinal length between opposing apexes  3084  and  3088 , for example between opposing apexes forming angles G. A longitudinal distance between a proximal apex  3084  and an opposing distal apex  3088  may be no more than 5 mm, no more than 4.5 mm, no more than 4 mm, no more than 3.5 mm, no more than 3 mm, no more than 3 mm, or no more than 2.5 mm. 
     The various structural aspects detailed in this section and elsewhere contributes to the enhanced conformability of the device  3000 . For example, the struts  3082 ,  3086  of the tubular body  3080  may be mechanically independent such that applying a radially inward force on one strut of the struts  3082 ,  3086 , or on one of the quadrilateral shapes defined by four adjacent struts  3082 ,  3086 , does not cause the adjacent struts or quadrilateral shapes to collapse in a similar manner. Such radial force may cause the perimeter of the frame  3040  to instead bulge out. The struts  3082 ,  3086  may therefore behave independently which contributes to allowing the device  3000  to conform to various and extremely non-circular, for example oval, cross sectional shapes of LAA&#39;s, as further described herein, for example with respect to  FIGS. 13A-13B and 17A-17B , while still providing a fully sealed and occluded LAA. In some embodiments, the device  3000  may conform to non-uniform (not circular and not oval) shapes to form a seal with non-uniform anatomy. 
     Further, the relatively shorter longitudinal lengths between opposing apexes  3084 ,  3088 , the flat shape of the proximal face  3060 , and the approximately 90° transition between the proximal face  3060  and the tubular body  3080  each provides enhanced conformability capabilities, as further described herein for example with respect to  FIGS. 13A-13B and 17A-17B . 
     This conformability of the device  3000  allows the device  3000  to be sized based on the average diameter of a patient&#39;s LAA, and not the maximum diameter which is used for other existing LAA occluders. This allows a given size of the device  3000  to effectively seal a much larger range of LAA sizes, simplifying the implantation procedure and reducing costs associated with design and manufacturing. 
     An advantage of the device  3000  that contributes to its conformability is that when the device  3000  is compressed radially along a first, transverse axis, the average diameter remains relatively constant. As the frame  3040  is compressed to create a short, minor axis, the opposing major axis lengthens, maintaining the overall circumference or average diameter. This is in contrast to existing solutions for LAA occlusion devices, where compression of the outer diameter causes an inward collapse of the struts on the proximal side, resulting in an overall lengthening of the device in the distal and proximal directions. 
       FIGS. 17A-17B  are top views of the device of  FIGS. 3A-6E  shown, respectively, in an uncompressed configuration and a compressed configuration. The device  3000  shown may have the same or similar features and/or functions as the devices described herein, for example with respect to  FIGS. 3A-6E . 
       FIG. 17A  shows the device  3000  unconstrained prior to application of a compressive radial force P on opposing sides of the device  3000 . The force P may be applied by two planar plates located on opposite sides of the device  3000 . The plates may be brought together a desired distance to compress the device  3000 , where the device  3000  takes an oval-like shape, such as that shown in  FIG. 17B . 
       FIG. 17B  shows the device  3000  compressed after being inserted into a collapsible tube  4000  and compressed to form a minor axis and mimic deployment within a non-cylindrical LAA. The tube  4000  has a wall  4002  with an inner surface  4004  and an outer surface  4006 . The wall  4002  may extend along the longitudinal length of the device  3000 . The tube  4000  may be compressed by the compressive radial forces P as shown such that the device  3000  takes the oval-like shape shown. The tube  4000  may be an elastic tube capable of compression, either by hand or by two plates as mentioned. The device  3000  may be placed into the circular tube  4000  and then the tube  4000  may be compressed. Or the tube  4000  may be pre-compressed to have the oval-like shape, and then the device  3000  may be deployed within the tube  4000  to take the pre-existing shape of the tube  4000 . 
     The compressed device  3000  may have a minor axis A 1  and a major axis A 2 , where the minor axis A 1  is shorter than the major axis A 2 . As the device  3000  is compressed, A 1  may decrease relative to a starting uncompressed width W (see  FIG. 17A ) as A 2  increases relative to the starting uncompressed width W. A mean diameter “MD” may be calculated based on the resulting minor axis A 1  and major axis A 2 . MD may be equal to (A 1 +A 2 )/2. The mean diameter MD may remain constant or relatively constant before, during and after compression. Thus the MD as calculated for the configuration in  FIG. 17A  (for example, where A 1 =A 2 =W) may be equal to or approximately equal to the MD as calculated for the configuration in  FIG. 17B . In some embodiments, the compressed MD for the device  3000  may be within 98% or more, within 96% or more, within 94% or more, within 92% or more, within 90% or more, within 88% or more, within 86% or more, within 84% or more, within 82% or more, or within 80% or more of the uncompressed MD for the device  3000 . 
     In some embodiments, the device  3000  may seal LAA&#39;s having widths that are larger than the uncompressed MD of the device  3000 , as long as the MD of the LAA is less than or equal to the uncompressed MD of the device minus 2 mm. In other words, for this embodiment, MD LAA ≤(MD DEVICE −2 mm). Thus the device  3000  may be used for extreme oval shapes where the major diameter of the oval shape is larger than the uncompressed diameter of the device  3000 , due to the conformable features of the device  3000 . Other sizes of the device  3000  for other ranges of sizes of ostia may be similarly determined based on the MD. 
     As an example, the device  3000  having an uncompressed MD of 27 mm may be used to seal and anchor in a 25 mm diameter or smaller circular hole. Thus, for oval-shaped holes, the device  3000  having an uncompressed MD of 27 mm may be used to seal any oval having an MD that is less than or equal to 25 mm. For example, an oval having a major diameter of 27 mm and a minor diameter 20 mm results in an MD of 23.5 mm, which is less than or equal to 25 mm, and thus the device  3000  having an uncompressed MD of 27 mm may be used for that oval shaped ostium. As further example, an oval having a major diameter of 30 mm and a minor diameter 16 mm results in an MD of 23 mm, which is less than or equal to 25 mm, and thus the device  3000  may be used for that oval shaped ostium. As further example, an oval having a major diameter of 38 mm and a minor diameter 10 mm results in an MD of 24 mm, which is less than or equal to 25 mm, and thus the device  3000  may be used for that oval shaped ostium. 
     Any of the above relationships for the compressed and uncompressed MD may apply for various compressions of the device  3000  from a starting uncompressed width W, as shown in  FIG. 17A . The above relationships between the compressed and uncompressed MD may apply where the device  3000  is compressed such that the compressed minor diameter A 1  (shown in  FIG. 17B ) is no more than 90%, no more than 80%, no more than 70%, no more than 60%, no more than 50%, no more than 40%, no more than 30%, or no more than 20% of W. Thus, for example, in some embodiments, the compressed MD for the device  3000  may be within 90% or more of the uncompressed MD for the device  3000  when the device  3000  is compressed such that the compressed minor diameter A 1  is less than 30% of W. 
     Further, the major axis A 2  of the compressed device  3000  may be larger than, and in some cases much larger than, the starting width W of the uncompressed device  3000 . In some embodiments, the major axis A 2  may be more than 100%, more than 105%, more than 110%, more than 115%, more than 120%, more than 125%, more than 130%, more than 135%, more than 140%, more than 145% or more than 150% of W. 
     Further contributing to the enhanced sealing capability of the device  3000  is the behavior of the circumference of the device  3000 . As shown in  FIGS. 17A and 17B , the device  30  may have a circumference C as measured along a perimeter of the device  3000 , which may be at or near a proximal end of the device  3000 . In cylindrical embodiments, the circumference C may also be measured in other locations, for example at or near the distal end of the device  3000 , or between proximal and distal ends. 
     The circumference C, as measured at a given longitudinal point along the length of the device  3000 , may be the same or approximately the same in the uncompressed and compressed configurations, for example in the configurations of  FIG. 17A  and  FIG. 17B  respectively. In some embodiments, the circumference C of the compressed device  3000  may be within 1%, within 2%, within 3%, within 4%, within 5%, within 6%, within 7%, within 8%, within 9%, within 10%, or within 15% of the circumference C of the uncompressed device  3000  measured at the same longitudinal transverse plane. Such relationships for the compressed and uncompressed circumferences may apply along with any of the other described relationships herein, such as the relationships between A 2  and W, between A 1  and W, and/or between the compressed MD and uncompressed MD. 
     The above relationships of the device  3000  may be tested using the plates (for example a vice) or tube as shown and described with respect to  FIGS. 17A and 17B , respectively. For example, the device  3000  having a 27 mm diameter (width W) may be placed in a metal vice submerged within a body temperature saline bath. The vice may be initially set with an opening of 25 mm. The vice may then be closed to discrete distances between the plates. At each measurement point, the minor axis A 1  (equal to the opening of the vice) and major axis A 2  of the compressed device  3000  may be determined. The mean diameter MD may be calculated based on the determined lengths A 1  and A 2 . The circumference may be measured, or otherwise determined based on known geometric equations for calculating a circumference based on A 1  and A 2 . 
     Another feature of the device  3000  that contributes to the enhanced sealing capability is the foam body  3002 . The foam material of the body  3002  has a stiffness that may naturally bow radially outward, as opposed to collapsing inwards like the existing prior art devices that have polyester or ePTFE fabric which can “scallop” to form outward concavities between struts which may cause residual leaks. In contrast, the device  3000  has foam in the body  3002  which provides more stiffness and shape memory than knitted or woven polyester fabric or the like, contributing to the device&#39;s  3000  ability to conform to the irregular geometry of the interior surface of the LAA and thereby provide a better seal. 
     The device  3000  may also apply less of a radial outward force on the LAA while providing a superior seal, as compared to existing LAA occlusion devices. Thus the device  3000  may provide a “softer” solution for LAA occlusion devices. The radial stiffness of the device, which is an indication of the radial outward force the device  3000  would apply to an LAA, may be tested. For example, the device  3000  may be compressed, for example using the vice discussed in connection with  FIG. 17A  and/or a compressive force gauge, to measure the applied force. The applied force may then be compared to the resulting change in the width W of the device  3000  due to the applied force. In some embodiments, the required force in pounds (lbs) to compress the device  3000  a distance of D in inches (in) may be within 20%, within 15%, within 10%, or within 5% of F, where F=0.23 D+0.04. 
       FIGS. 18A-18C  are data plots  5000 ,  5100 ,  5200  respectively of test results showing various structural characteristics for certain embodiments of the device of  FIGS. 3A-6E .  FIG. 18A  shows the data plot  5000  for the relationship between the mean diameter MD of the device  3000  (on the Y axis) and the minor diameter A 1  or “short axis” of the device  3000  (on the X axis).  FIG. 18B  shows the data plot  5100  for the relationship between the major diameter A 2  or “long axis” of the device  3000  (on the Y axis) and the minor diameter A 1  or “short axis” of the device  3000  (on the X axis).  FIG. 18C  shows the data plot  5200  for the relationship between an applied compressive force to the device  3000  (on the Y axis) and the decrease in the width W of the device or “compression” (on the X axis). 
     As the minor axis is compressed by 10 mm from an unconstrained diameter such as from 25 mm (in an unconstrained 25 mm device, or at a starting diameter of 25 mm in a larger device) to 15 mm, the mean diameter has a reduction of no more than about 5 mm, and preferably no more than about 3 mm or 2 mm or 1 mm or less. As the minor axis is compressed by 15 mm such as from 25 mm to 10 mm, the mean diameter has a reduction of no more than about 8 mm, and preferably no more than about 6 mm or 4 mm or 3 mm or less. As the implant is compressed from an unconstrained configuration starting diameter to a minor axis diameter that is 15 mm less than the starting diameter, the mean diameter has a reduction of no more than about 10 mm and in some implementations no more than about 8 mm or 6 mm or 4 mm or 3 mm or 2 mm or less, depending in part upon the starting diameter. 
     Referring to  FIG. 18B , reduction of the short axis by 10 mm such as from 25 mm (unconstrained) to 15 mm produces an elongation of the major axis of at least about 2 mm and in some implementations at least about 4 mm or 6 mm or 8 mm or 10 mm or more. Reduction of the short axis by 20 mm such as from 25 mm (unconstrained) to 5 mm produces an elongation of the major axis of at least about 2 mm and in some implementations at least about 4 mm or 8 mm or 10 mm or more, enabling the implant to conform to a wide variety of non cylindrical LAA configurations. 
     Referring to  FIG. 18C , Application of 0.10 lbs compressive force produces a compression along the minor axis of at least about 0.05 inches or 0.10 inches or 0.20 or more. Application of 0.20 lbs compressive force produces a compression along the minor axis of at least about 0.15 inches or 0.20 inches or 0.25 inches or 0.30 inches or 0.40 inches or more. Application of no more than about 0.37 lbs or 0.33 lbs. or 0.30 lbs or 0.27 lbs or less compressive force produces a compression along the minor axis of at least about 0.35 inches or 0.40 inches or 0.45 inches or 0.50 inches or more to produce a soft and conformable implant. 
     The foregoing relationships can be scaled and converted to a percent basis to apply to implants having an unconstrained expanded diameter that differs from 25 mm. 
       FIGS. 19A-19C  are data plots  6000 ,  6100 ,  6200  respectively of test results showing various structural characteristics for embodiments of the device of  FIGS. 3A-5E  having an unconstrained outer diameter of 35 mm.  FIG. 19A  shows the data plot  6000  for the relationship between the mean diameter MD of the device  3000  (on the Y axis) and the minor diameter A 1  or “short axis” (under compression) of the device  3000  (on the X axis).  FIG. 19B  shows the data plot  6100  for the relationship between the major diameter A 2  or “long axis” (under compression) of the device  3000  (on the Y axis) and the minor diameter A 1  or “short axis” of the device  3000  (on the X axis).  FIG. 19C  shows the data plot  6200  for the relationship between an applied compressive force to the device  3000  (on the Y axis) and the decrease in the width W of the device or “compression” (on the X axis). 
     Table 2 below lists the compression data points from  FIG. 19A  along with the corresponding maximum or major diameter (Dmax), corresponding to certain embodiments of the device  3000  having a 35 mm unconstrained outer diameter. 
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Dmin (mm) 
                 Dmax (mm) 
                 Dmean (mm) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 35 
                 35 
                 35 
               
               
                 30 
                 40 
                 35 
               
               
                 25 
                 45 
                 35 
               
               
                 20 
                 50 
                 35 
               
               
                 15 
                 53 
                 34 
               
               
                 10 
                 54 
                 32 
               
               
                 5 
                 54 
                 29.5 
               
               
                   
               
            
           
         
       
     
     As shown in  FIG. 19A  and in Table 2, as the minor axis is compressed by 10 mm from an unconstrained diameter such as from 35 mm (in an unconstrained 35 mm device, or at a starting diameter of 35 mm in a larger device) to 25 mm, the mean diameter has a reduction of no more than about 5 mm, and preferably no more than about 3 mm or 2 mm or 1 mm or less. As the minor axis is compressed by 15 mm such as from 35 mm to 20 mm, the mean diameter has a reduction of no more than about 5 mm, and preferably no more than about 3 mm or 2 mm or 1 mm or less. As the minor axis is compressed by 20 mm such as from 35 mm to 15 mm, the mean diameter has a reduction of no more than about 5 mm, and preferably no more than about 3 mm or 2 mm or 1 mm or less. As the minor axis is compressed by 25 mm such as from 35 mm to 10 mm, the mean diameter has a reduction of no more than about 8 mm, and preferably no more than about 6 mm or 4 mm or 3 mm or less. As the minor axis is compressed by 30 mm such as from 35 mm to 5 mm, the mean diameter has a reduction of no more than about 15 mm and in some implementations no more than about 12 mm or 10 mm or 8 mm or 6 mm or 5.5 mm or less. 
     Referring to  FIG. 19B , reduction of the short (minor) axis by 10 mm such as from 35 mm (unconstrained) to 25 mm produces an elongation of the long (major) axis of at least about 2 mm and in some implementations at least about 4 mm or 6 mm or 8 mm or 10 mm or more. Reduction of the short axis by 15 mm such as from 35 mm (unconstrained) to 20 mm produces an elongation of the major axis of at least about 4 mm and in some implementations at least about 6 mm or 8 mm or 10 mm or 12 mm or 14 mm or 15 mm or more. Reduction of the short axis by 20 mm such as from 35 mm (unconstrained) to 15 mm produced an elongation of the major axis of at least about 6 mm and in some implementations at least about 8 mm or 10 mm or 12 mm or 14 mm or 16 mm or 18 or more. Reduction of the short axis by 25 mm such as from 35 mm (unconstrained) to 10 mm produced an elongation of the major axis of at least about 6 mm and in some implementations at least about 8 mm or 10 mm or 12 mm or 14 mm or 16 mm or 18 or 19 or more. Reduction of the short axis by 30 mm such as from 35 mm (unconstrained) to 5 mm produced an elongation of the major axis of at least about 6 mm and in some implementations at least about 8 mm or 10 mm or 12 mm or 14 mm or 16 mm or 18 or 19 or more, enabling the implant to conform to a wide variety of non cylindrical LAA configurations. 
     Referring to  FIG. 19C , for some embodiments of the 35 mm unconstrained outer diameter device, application of 0.10 lbs compressive force produces a compression along the minor axis of at least about 0.05 inches or 0.10 inches or 0.20 inches or 0.25 inches or more. Application of 0.20 lbs compressive force produces a compression along the minor axis of at least about 0.45 inches or 0.40 inches or 0.45 inches or 0.50 inches or 0.55 inches or more. Application of no more than about 0.37 lbs or 0.33 lbs. or 0.30 lbs or 0.26 lbs or less compressive force produces a compression along the minor axis of at least about 0.5 inches or 0.55 inches or 0.6 inches or 0.65 inches or more to produce a soft and conformable implant. 
     The foregoing relationships can be scaled and converted to a percent basis to apply to implants having an unconstrained expanded diameter that differs from 35 mm. 
     Table 3 includes test results showing various structural characteristics for certain embodiments of the devices of  FIGS. 3A-6E . Table 3 illustrates the results of a visual evaluation of a seal between certain embodiments of the device of  FIGS. 3A-6E  and a Silicon (Si) test tube in which the tube includes a visible amount of fluid, the device is placed inside the tube, and the tube and device are then placed under compression. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Dmin (mm) 
                 Dmax (mm) 
                 Dmean (mm) 
                 Seal 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 33 
                 33 
                 33 
                 Sealed 
               
               
                   
                 30 
                 35 
                 32.5 
                 Sealed 
               
               
                   
                 25 
                 38 
                 31.5 
                 Sealed 
               
               
                   
                 20 
                 40 
                 30 
                 Sealed 
               
               
                   
                 15 
                 44 
                 29.5 
                 Not Sealed 
               
               
                   
                   
               
            
           
         
       
     
     With respect to Table 3, an unconstrained 35 mm device was placed within a Si tube having an internal diameter of 33 mm and compressed. As the minor axis is compressed by 3 mm so that the mean diameter is between 33 and 30 mm, a seal is present between the device and the Si tube. As the minor axis is compressed so that the major axis is between 33 mm and 40 mm, a seal is present between the device and the Si tube. In some embodiments, the 35 mm device can seal in oval openings with a mean diameter of 33 mm or 32 mm or less and a maximum diameter of 40 mm or less. In some embodiments, the device can seal in non-uniform (not round or oval) openings. “Seal” as used in this context includes visual verification of no drops of fluid located behind the device inside the tube. The seal may also include devices tested as described above with escape of fluid having a volume of 5 ml or 4 ml or 3 ml or less when the tube with the device inside is held upside down, with the fluid above the device, for a time period of 15 seconds or 30 seconds or 1 minute or 2 minutes or more. The fluid may be saline, water, or combinations thereof. 
       FIG. 20  is a schematic of an embodiment of a test setup  5300  that may be used to perform a flat plate test method, such as described herein, to characterize the stiffness and other structural attributes of the device  3000 . The data plots  5000 ,  5100 ,  5200 ,  6000 ,  6100 , and  6200  in  FIGS. 18A-19C  and the data of Tables 2 and 3 may be generated using the test setup  5300 . The data of Table 3 may be generated using the test setup  5300  with the device  3000  positioned within an Si tube. The test setup  5300  may thus be used for determining whether a given occlusion device exhibits the same or similar structural characteristics as the device  3000 . 
     As shown in  FIG. 20 , the test setup  5300  includes a volume  5310 , which may be a bath. The volume  5310  contains water  5320 . The water  5320  may partially or completely fill the volume  5310 . A thermal conditioner  5350 , such as heating or cooling device, may be used to heat or cool the water to the desired temperature. A recirculator  5360 , such as a pump, may be used to recirculate the water to provide a uniform distribution of temperature in the water. 
     The test setup  5300  further includes a mechanical press  5330 . The press  5330  may be a compression test stand. A variety of suitable compression test apparatuses known in the art may be used for the press  5330 . The press  5330  may be submerged, partially or completely, in the water  5320 . The press  5330  may be a vertical press as shown. A horizontal arrangement may be used. The press  5330  may have a graduated scale or scales. The press  5330  includes a lower plate  5332  having a force gage  5334  thereon. The force gage  5334  may instead be located on an upper plate. The force gage  5334  detects a compressive force and provides output indicative of the compressive force applied to the gage  5334 . The gage  5334  may be fitted with or include a flat surface for applying compression to the device  3000 . The occlusion device  3000  is shown located on top of the force gage  5334 , with an upper moveable plate  5336  located above the device  3000 . In some embodiments, the force gage  5334  may be located on top of the device  3000 , for example on an underside (as oriented in the figure) of the upper plate  5336 . 
     The upper plate  5336  is lowered from the position shown by dashed outline to contact the upper side of the device  3000  (as oriented in the figure) to the current location of the upper plate  5336  shown in solid line in the figure. The upper plate  5336  may be lowered farther to compress the device  3000 . The resulting compressive load as registered by the force gage  5334  as the upper plate  5336  is lowered may be recorded and plotted. The resulting plot of force versus amount of compression of the device  3000  may be the same or similar as the data plot  5200  shown in  FIG. 18C  or the plot  6200  shown in  FIG. 19C . In some embodiments, the resulting data plot using the test setup  5300  may be within +/−5%, +/−10%, +/−15%, +/−20% or +/−25% of the data points or line of best fit shown in  FIG. 18C . 
     The test setup  5300  may also be used to measure or approximate dimensions of the device  3000  as the device  3000  is compressed. As described herein, for example with respect to  FIGS. 17A-17B , the minor and major axes of the device  3000  may be measured. The test setup  5300  may have dimensions located on the setup  5300  showing vertical and horizontal scales for determining the lengths of the major and minor axes of the device  3000  as the device  3000  is compressed. In some embodiments, a separate measurement device, such as a ruler, may be used to measure the lengths. The resulting plot of minor (short) axis versus major (long) axis of the device  3000 , or parameters related thereto such as the mean diameter, may be the same or similar as the data plots  5000  and  5100  show respectively in  FIGS. 18A-18B  and the plots  6000  and  6100  shown respectively in  FIGS. 19A-19B . In some embodiments, the resulting data plots using the test setup  5300  may be within +/−5%, +/−10%, +/−15%, +/−20% or +/−25% of the data points or lines of best fit shown in  FIGS. 18A-18B or 19A-19B . 
       FIG. 21  is a flow chart depicting an embodiment of a flat plate test method  5400 . The method  5400  may be performed using the test setup  5300 . The method  5400  may be performed to characterize the stiffness and other structural attributes of the device  3000 . The data plots  5000 ,  5100 ,  5200 ,  6000 ,  6100 , and  6200  in  FIGS. 18A-19C  and the data of Tables 2 and 3 may be generated using the method  5400 . The method  5400  may thus be used for determining whether a given embodiment of an occlusion device exhibits the same or similar structural characteristics as the device  3000 . 
     The method  5400  begins with step  5410  wherein the device  3000  is submerged in a bath or other volume of water, such as the volume  5310  having the water  5320 . The device  3000  may be submerged and placed onto a lower test plate, such as the lower plate  5332  having the force gage  5334 . The device  3000  may be submerged within the volume for a sufficient amount of time to equilibrate to the temperature within the volume of water. In some embodiments, the device  3000  may be submerged for one minute. In some embodiments, the device  3000  may be submerged for two, three, four, five or more minutes. The volume of water may be at a temperature of 37° C. (98.6° F.). The method  5400  may be performed at or near sea-level, or otherwise under sea-level conditions (e.g. sea-level atmospheric pressure). A thermometer may be used to determine the temperature at or near the device  3000 . A water heater and/or water recirculator, such as the thermal conditioner  5350  or recirculator  5360 , and/or other tools, may be used to achieve the desired temperature. 
     The method  5400  next moves to step  5420  wherein the device is secured on the compressive test apparatus, such as the test setup  5300 . The device  3000  may be placed and secured between the compressive test plates of the test setup. The distance between the two plates may be reduced. The upper plate  5336  may be lowered to contact and secure the device  3000  between the two plates. The upper plate  5336  may be lowered as shown in  FIG. 20  to contact a side of the device  3000 . The initial compressive load on the device  3000  may be measured and recorded with just enough contact from the upper plate  5336  on the device  3000  to hold the device  3000  in position. This may be about 0.05 lbs. 
     The method  5400  next moves to step  5430  wherein the device  3000  is compressed an incremental amount by reducing the distance between the plates an incremental amount. The upper plate  5336  may be lowered a first increment to compress the device  3000  radially inwardly. The upper plate  5336  may be moved 0.10″. In some embodiments, a larger or smaller compressive increment may be used. 
     The method  5400  next moves to step  5440  wherein the resulting compressive force for the given incremental compression is measured and recorded. Thus the compressive load may be measured with the upper plate having been lowered 0.10″ in step  5400 . 
     The method  5400  may next return to step  5430  and compress the device  3000  another incremental amount, after which step  5440  may be performed again to record the corresponding compressive load. Steps  5430  and  5440  may be repeated until a desired amount of compression is obtained. In some embodiments, steps  5430  and  5440  may be repeated at compressive increments of 0.10″, 0.20″, 0.30″, 0.40″, and 0.50″. In some embodiments, the order of steps  5430  and  5440  as shown in  FIG. 21  may be reversed. For example step  5440  may include applying a specified load (e.g. 0.05 lbs., 0.1 lbs., 0.15 lbs., 0.2 lbs., 0.25 lbs.) and step  5430  may include measuring the resulting compressive change in width, if any, of the device  3000  under each incremental given load. The method  5400  in this manner may be repeated for each incremental applied load. 
     The method  5400  may be repeated with the device  3000 . The device  3000  may be rotated an angular amount and the method  5400  may be performed again. This may be repeated several times after completing the method  5400  as described. For example, the method  5400  may be performed a first time, then the device  3000  may be rotated in first direction about its longitudinal axis sixty degrees, then the method  5400  may be repeated, then the device  3000  may be rotated in the first direction about the longitudinal axis another sixty degrees, and the method  5400  may be repeated. The load measurements during repeated tests at different angular amounts may be averaged for a given compression amount at a particular angle. In some embodiments, the averages of three measurements may be calculated, after initially testing the device  3000  and then rotating the device  3000  by sixty degrees twice as described, and the resulting plot may be the same or similar as the data plot  5200  shown in  FIG. 18C  or the data plot  6200  shown in  FIG. 19C . In some embodiments, the resulting data plot using the averages may be within +/−5%, +/−10%, +/−15%, +/−20% or +/−25% of the data points or line of best fit shown in  FIG. 18C  or  FIG. 19C . 
     B. Loading Tool with Ribs, Submersion, and Catheter Locking 
       FIGS. 22A and 22B  are perspective and cross-section views, respectively, of an embodiment of a loading tool  3600 . The cross-section view of  FIG. 22B  is taken along the line  103 B- 103 B as indicated in  FIG. 22A . The loading tool  3600  may have the same or similar features and/or functions as other loading tools described herein, such as the loading tool  3210 , and vice versa. The loading tool  3600  may be used with any of the embodiments of the LAA implant and related devices and systems described herein, such as the device  3000 , and vice versa. 
     As further described herein, the tool  3600  includes radially inwardly projecting ribs forming grooves therebetween, which among other things improves implant folding and helps align the barbs. Further, the tool  3600  includes a locking connection between the loader and catheter, to provide among other things a seal and eliminate gaps while assuring alignment (e.g., to prevent implant damage). Further, the tool  3600  is configured to hold fluid, so that among other things the implant can be fully submerged during loading, thus eliminating air bubbles from within the foam. 
     The loading tool  3600  includes a distal reservoir  3610  attached to a conical portion  3612 . A proximal projection  3614  attaches at a proximal end of the conical portion  3612 . The device  3000  is placed into the reservoir  3610  and pulled through the conical portion  3612  and then the projection  3614 . A delivery catheter is attached at the projection  3614  so that the device  3000  is constrained and delivered to the delivery catheter for implantation into the patient. For clarity, the reservoir  3610 , the conical portion  3612 , and the projection  3614  are shown as transparent in  FIG. 22A . 
     The conical portion  3612  includes ribs  3611 . The loading tool  3600  may include a plurality of internal guides such as at least four or ten or twenty or more axially oriented ribs  3611 . The ribs  3630  are formed between adjacent internal grooves  3631  formed on the inner surface of a conical portion  3612 . In one implementation, the grooves  3631  have a substantially constant width along their axial lengths, resulting in ribs  3611  having a width that increases in the distal direction as the inside diameter of the conical portion  3612  increases. The ribs  3630  may be longitudinally elongated, radially inwardly projecting structures located along the radially inwardly facing surface of the conical portion  3612 . Between adjacent ribs  3630  the may be one of the internal grooves  3631  defined partially by the adjacent ribs  3611  and the inner surface of the conical portion  3612 . The ribs  3630  improve implant folding and help align the anchors  3090 , among other advantages. Such alignment may be through the foam sidewall of the implant, for example where the anchors  3090  press against the foam sidewall and occupy the grooves  3631  between the ribs  3611 . In some embodiments, some or all of the anchors  3090  may protrude through the foam sidewall of the implant to contact and be directly guided by the grooves  3631  and ribs  3630 . For clarity only some of the ribs  3611  and grooves  3631  are labelled in the figures. 
     The conical portion  3612  terminates at the distal end at a conical portion opening  3613 . The opening  3613  may open into the fluid reservoir  3610 . The fluid reservoir  3610  has a distal opening  3620  and an outwardly extending support flange  3650 . In some embodiments the location of the support flange  3650  may be different. The flange  3650  may extend outward in two opposite directions. The flange  3650  may secure the tool  3600  in an upright position on a table top for loading. The fluid reservoir  3610  may be defined within a housing having the distal opening  3620  and one or two or more stabilizing feet such as the transverse support flange  3650  for helping the loading tool  3600  to sit upright on a counter surface. 
     The reservoir  3610  is designed to hold fluid (e.g., saline) with the device  3000  also located therein so the implant can be fully submerged during loading, thus eliminating air bubbles from within the foam. In some embodiments the fluid reservoir  3610  may have a tubular, e.g., cylindrical side wall, with a closed base which incorporates a ramp such as a quarter-spherical portion to facilitate entry of the implant from the reservoir  3610  into the opening  3613 . 
     The distal opening  3620  of the fluid reservoir  3610  allows the device  3000  to be inserted into the loading tool  3600 . The reservoir  3610  is configured to receive the device  3000  therein, and the device  3000  may be oriented therein such that the proximal end of the device  3000  faces the conical portion  3612  and a sidewall of the device  3000  faces the proximal opening  3620  of the tool  3600 . For clarity, the tool  3600  in  FIGS. 22A and 103B  is shown without the device  3000  loaded therein. 
     The projection  3614  includes a sidewall  3618  that extends longitudinally away from the proximal end of the conical portion  3612  and defines a channel therethrough configured to receive a distal end of the delivery catheter therein. “Distal end” of the catheter here refers to the end of the catheter in the delivery context, where the distal end is advanced to the heart. The projection  3614  at a proximal end thereof includes a radially outwardly protruding lip  3617 . The lip  3617  projects outward and has a greater outer radius than the sidewall  3618 . The sidewall  3618  includes a series of longitudinal notches  3615 . There are four notches  3615  as shown, but there may be two, three, five, six, or more notches  3615 . The notches  3615  extend distally from the proximal end of the projection  3614 . 
     The loading tool  3600  may also include a lock  3640 . In  FIGS. 22A-22B  the delivery catheter  3220  is shown as a dotted line for clarity. A proximally extending projection  3614  of the loading tool is configured to abut against or fit inside of the distal opening into the lumen of the delivery catheter to facilitate transfer of the implant. At least one or two or three or more axially extending slits  3615  through the sidewall  3618  of the projection  3614  allow the inside diameter of the projection  3614  to adjust slightly in response to radial force from the compressed implant. The lock  3640  may include a sliding collar for sealing and aligning with the distal end of the delivery catheter  3220 . The collar is axially movable between a distal position as seen in  FIG. 22A  to expose the proximal projection  3614  for mounting within the delivery catheter, and a proximal position in which it overlaps over the outside surface of the delivery catheter sidewall to reversibly support the connection. The lock may include grooves  3644  and ridges  3642  to provide a friction surface and improve user handling. The collar is configured to slide concentrically over the cylindrical portion  3614  and lock the delivery catheter  3220  between the projection  3614  and the collar. In some embodiments the projection  3614  may be cylindrical or a shape other than cylindrical. 
     In some embodiments, the lock  3640  may be a sliding cylindrical structure surrounding the projection  3614 , for sealing and aligning the catheter  3220 . The lock may include outer grooves  3644  defined between adjacent radially outwardly protruding ridges  3642 . For clarity only some of the ridges  3642  and grooves  3644  are labelled in the figures. The lock  3640  includes an inner channel  3645  extending longitudinally therethrough and defined by the sidewall of the lock  3640 . At a proximal end of the channel  3645  is a relatively wider opening  3646 . The opening  3646  is configured to surround the lip  3617  of the projection  3614  when the lock  3640  is slid to the proximal end of the projection  3614 . 
     In some embodiments, in a free state, where the lock is in the distal location as shown in  FIGS. 22A and 22B , the projection  3614  has a wider inner diameter relative to the diameter when inward compressive forces are applied, so that the catheter can be easily inserted. The lock  3640  may then be slid proximally with the catheter inside the projection  3614 . The lock  3640  in a proximal location will cause the portions of the sidewall  3618  located adjacent the notches  3615  to move circumferentially closer to each other and to compress radially inwardly, to thereby reduce the inner diameter defined by the sidewall  3618 . The catheter tip will then be “sandwiched” by the inner surfaces of the sidewall  3618  to create radially inward securement forces acting on the catheter tip to secure the catheter. The opening  3646  may contact and secure therein the lip  3617  of the projection  3614  when the lock  3640  is slid to the proximal end of the projection  3614 . The inner diameter of the opening  3646  may be the same or less than the outer diameter of the lip  3617 , for example to create a compressive force thereon. 
     In some embodiments, in a free state, the outer surface of the sidewall  3618  may be tapered such that the outer surface has a greater outer width, e.g. radius or diameter, at a proximal end thereof (left end as oriented in the figures) as compared to a distal end thereof (right end as oriented in the figures). The lock  3640  may then be moved proximally and contact the outer surfaces of the sidewall  3618  to thereby decrease the inner diameter of the sidewall  3618 , as described. The lock  3640  is advantageous to provide a seal and eliminate gaps while assuring alignment of the catheter  3220  to the loading tool  3600 , among other advantages. For example, the seal, alignment and gap reduction serve to reduce the chance of the implant being damaged during loading. The tool  3600  and components thereof may be made of plastic, polymer, metal, other suitable materials, or combinations thereof. 
     C. Delivery Catheter Handle 
       FIGS. 23A-23D  depict an embodiment of a delivery catheter handle  3700 .  FIG. 23A  is a perspective view,  FIG. 23B  is a cross-section view as taken along the line  104 B- 104 B indicated in  FIG. 23A ,  FIG. 23C  is a detailed partial cross-section view, and  FIG. 23D  is a partial cross-section view of the handle  3700 . The handle  3700  may be used with the various LAA implants and associated devices and methods described herein. For example, the handle  3700  may be used to deliver the device  3000 . The loading tool  3600  may be used to load the device  3000  into a delivery catheter, which then may be used with the handle  3700  to deliver and secure the device  3000  within the human body.  FIG. 26  depicts an embodiment of a delivery system comprising the delivery catheter handle  3700 , the loading tool  3600 , the delivery catheter  3220 , and the pusher  3230 . 
     The handle  3700  extends from a proximal end  3701  to a distal end  3702 . A main body  3703  attaches at a proximal end to a cap  3720  and at a distal end to a ribbed body  3760 . The ribbed body  3760  may be a tether control switch  3780 , as described with respect to  FIGS. 24A-24C . The cap  3720  attaches to a tether  3772  (see  FIGS. 23C-23D ) and can be secured, for example screwed, to the proximal end of the body  3703 . Unsouring, for example unscrewing, the cap  3720  allows for the tether  3772  to be pulled proximally after implantation of the device  3000 , to remove the tether from the delivery catheter. The tether  3772  may have the same or similar features and/or functions as other tethers or sutures described herein, for example the tether  3240 , and vice versa. For clarity, the tether  3772  is not shown in  FIG. 23B . 
     A locking mechanism  3740  includes a button  3741  that when depressed allows for axial movement of an internal shaft  3750 . When released, the button  3741  is spring-loaded via a pivot arm  3744 . Each arm  3744  pivots about a pin  3743 . There may be a torsion spring at each pin  3743  that bias the two arms  3744  toward the shaft  3750 . The shaft  3750  may be in the distal location as shown during implantation of the device  3000  and then moved proximally after implanting the device  3000  in the LAA, so that the pusher and/or delivery catheter can likewise be moved proximally prior to releasing the device  3000  from the tether  3000 . This removes the “snap back” effect of removing a pusher and/or delivery catheter from contacting LAA occlusion devices right after implantation in the LAA, in which the occlusion device may move slightly due to the backing off of the pusher. 
     The shaft  3750  locks in with the arms  3744  via protrusions  3745  on the arm  3744 , such as teeth, extending inwardly away from each arm  3744  and forming lateral grooves between adjacent protrusions  3745 . Corresponding lateral protrusions  3742  on the shaft  3750  extend outwardly away from the shaft  3750 . The protrusions  3742  of the shaft  3750  are received into grooves between corresponding protrusions  3745  of the arms  3744  when the shaft  3750  is in the proximal position as shown. When the shaft  3750  is advanced axially distally, the protrusions  3745  are received into grooves  3752  defined by protrusions  3751  at a proximal end of the shaft  3750 . 
     A tether  3772 , or suture, travels through the handle  3700  and wraps around a pin  3722  in a manner that incorporates a pulley-like effect so the tether  3772  only has to be pulled half the distance of the length of the catheter during removal. The need to pull a suture the entire length of the catheter during removal is one of the disadvantages of using a suture as an attachment tether. This modification makes it less burdensome and more appealing to the user. 
     The handle  3700  may be configured to enable an operator to easily remove the tether  3772  from a patient. Specifically, during removal, the operator pulls the end cap portion  3720  proximally while holding the body  3703  fixed relative to the patient. As the cap  3720  moves proximally away from the body  3703 , the tether  3772  feeds over the pin  3722 . Since the tether  3772  is fixed to the body  3703  at a tether end  3710 , all of the four tether segments  3772  elongate. The tether end  3710  may be secured to the body  3703  or other components therein in a variety of suitable manners, for example screwed, bonded, wrapped, other suitable approaches, or combinations thereof. The outcome of this elongation is that the tether  3772  portions inside the patient body translate twice as far as the cap  3720  translates. This phenomena is similar to a movable pulley arrangement used in reverse. The net effect of the system is to halve the applied force and double the length of the tether  3772  pulled. This reversed movable pulley arrangement is advantageous to reduce the pulled distance and applied force required to remove the tether  3772  from the patient, so the retraction of the tether from the patient may be at least about two times or four times or more the length of retraction of the proximal control. This makes the removal less arduous and time consuming for the operator. 
     The system arrangement includes, in some embodiments, a pulley in the form of the pin  3722 , on which the tether  3772  is wrapped. The pin moves relative to the tether end  3710 . Various embodiments are possible wherein the pin  3722  moves relative to the tether end  3710 . Various such embodiments result in a pulley-like effect to reduce the total motion required to remove the tether  3772  from the patient. An arrangement with the pin  3722  and tether end  3710  is effective to reduce the total tether pull distance requirement by half. 
     In the example embodiment depicted in  FIGS. 23A-23D , the cap  3720  is threaded onto the proximal end  3734  of the body  3703 . The locking mechanism  3740  is coupled to the side of the body  3703 , as described. The locking mechanism  3740  may include protrusions  3745  and can actuate to lock into the notches  3752  disposed on the inner shaft  3750 . The inner shaft  3750  is fastened at the distal end  3754  to the ribbed body  3760 , or in some embodiments to the tether control switch  3780  (shown in  FIGS. 24A-24C ). The ribbed body  3760  has a ribbed region  3762  and a cylindrical portion  3764 . The tether  3772  extends through a central hole disposed through both the ribbed body  3760  and the inner shaft  3750 . The body  3760  may be replaced with a tether control switch, such as a switch  3780  as described herein, for example with respect to  FIGS. 24A-24C . 
     In the depicted embodiment, the notches  3752  interface with the protrusions  3742  when the locking mechanism  3740  is in the locked position. In the locked position, the relative positions of the inner shaft  3750  and the outer body  3730  are fixed. The locking mechanism  3740  can be actuated to allow relative motion between the inner shaft  3750  and the outer body  3750 , as described. 
       FIGS. 24A-24D  are various views of an embodiment of a tether control switch  3780  that may be used with the various LAA implant delivery handles, such as the handle  3700  of  FIGS. 23A-23D , and associated devices and systems, described herein.  FIG. 24A  is a side view,  FIG. 24B  is a partial side cross-section view,  FIG. 24C  is a partial view of some components of the switch  3780 , and  FIG. 24D  is a bottom view of a slider  3786  used with the switch  3780 . 
     The switch  3780  includes a body  3781  extending longitudinally from a proximal end  3784 , that attaches to the delivery handle, to a distal end  3782  that receives the tether and the delivery catheter therein. A series of outwardly protruding grips  3788  extend outwardly away from the body  3781  for gripping the device. There may be seven grips  3788  as shown, or fewer or greater than seven grips  3788 . The grips  3788  may be held by a user while a slider  3786  is moved axially along the body  3781 . 
     The slider  3786  moves axially to selectively engage and disengage the tether  3772 . As shown, in the proximal position (right as oriented), the slider  3786  is not engaged with the tether  3772 , such that the tether can freely move through the switch  3780 . When the slider  3786  is moved to the distal position (left as oriented), the slider  3786  is engaged with the tether  3772 , such that the tether cannot freely move through the switch  3780 . The switch  3780  includes a compression tube  3790  and pill  3792  to effectuate the engagement/disengagement of the tether  3772  via the slider  3786 . 
     As shown in  FIGS. 24B-24D , the slider  3786  has an inner ramped surface  3787  that is located farther from the longitudinal central axis of the switch  3780  at a proximal end and closer to the axis at a distal end. As the slider  3786  is moved proximally, the ramped surface  3787  applies an increasing force to the pill  3792 , which then compresses the tube  3790  onto the tether  3772 . The slider  3786  may be locked at the proximal and/or distal positions, for example to maintain the freedom or restriction of the movement of the tether  3772  therethrough. In some embodiments, the orientation of the ramped surface  3787  may be flipped to be in an opposite direction, such that the inner ramped surface  3787  is located farther from the longitudinal central axis of the switch  3780  at a distal end and closer to the axis at a proximal end. The tube  3790  may be formed of a foam or other compressible material. The pill  3792  may be relatively more rigid so as to transfer the force from the slider  3786  to the tube  3790 . Further, with the tube  3790  compressed, fluid may be prevented from flowing through the switch  3780 . 
     D. Dual Lumen Pusher 
       FIGS. 25A-25C  depict various views of various embodiments of a dual lumen delivery catheter pusher  3770  and  3800 . Any of the features of the pusher  3700  may be implemented with the pusher  3800 , and vice versa.  FIG. 25A  is an end view of an embodiment of the delivery catheter pusher  3770  with a two lumen shaft. A first lumen  3774  is separated from a second lumen  3772  by a wall  3776  extending therebetween. The first lumen  3774  is rounded, for example cylindrical. The second lumen  3772  is crescent or moon shaped. The cross-sectional opening of the second lumen  3772  may extend angularly about a central longitudinal axis of the pusher  3770  for about 30 degrees, about 45 degrees, about 60 degrees, about 90 degrees, from about 30 degrees to about 90 degrees, from about 30 degrees to about 60 degrees, or other amounts or ranges. During implant delivery, an obturator (e.g. a solid plastic tube) is placed within the first lumen  3774  to stiffen the lumen  3774 . The tether  3772  that attaches to the implant is in the second lumen  3772 . 
     Following deployment of the implant, the clinician may remove the obturator and insert an intracardiac echo (ICE) catheter through the lumen  3772 . This provides the clinician with direct access to the left atrium to visualize the implant  3000 . This design is advantageous to allow the clinician to visualize the implant  3000  without the use of transesophageal echocardiography (TEE). TEE requires the use of general anesthesia. Administering general anesthesia increases risks to the patient and complicates the scheduling of the procedure. 
     Without the two shaft lumen, inserting an ICE catheter to visualize the implant would require a second transseptal puncture to access the left atrium. This is technically challenging and may increase the risk of leaving a residual iatrogenic atrial septal defect due to the extra catheter manipulation required with two sheaths crossing the atrial septum simultaneously. The second puncture also carries the inherent risk of cardiac perforation arising due to the use of sharp needles in the heart. 
     In various embodiments the shapes of the lumens and wall may vary. For example,  FIG. 25B  shows an embodiment of a pusher  3800  having semi-circular openings of approximately equal size. Other sizes and shapes of the lumens may be used in the pusher. The first lumen  3810  is divided from the second lumen  3812  by a wall  3820 . In some embodiments the two sides could be the same size, or different sizes, the shapes could be a ‘D’ shape or other shapes. During implant delivery, an obturator (solid plastic tube) is placed within the first lumen  3810  to stiffen it. The tether  3772  that attaches to the implant is in the second lumen  3812 . 
       FIG. 25C  depicts the proximal end of an embodiment of a delivery catheter pusher  3800 . Similar features may be implemented with the pusher  3700 . The pusher  3800  has a bifurcation at the proximal end. At the bifurcation, the obturator containing lumen, or first lumen  3810 , goes straight and the tether containing lumen, or second lumen is set at 45 degrees. After the bifurcation point  3822 , the first lumen  3810  extends into a bifurcated first lumen  3814 , and the second lumen  3812  extends into a bifurcated second lumen  3816 . Delivery catheter pusher  3770  may be similarly bifurcated. 
     E. Hydraulic Loader 
       FIG. 26  is a side view of a catheter delivery system that may be used with the various occlusion devices described herein.  FIGS. 27A-27C  depict various views of various embodiments of a hydraulic loader  3900 .  FIGS. 27A-27C  are side views of the hydraulic loader  3900  coupled to components of the delivery system of  FIG. 26 . The hydraulic loader  3900  may be used with various LAA implants and associated devices and methods described herein. For example, the hydraulic loader  3900  may be used to load the device  3000  into a delivery catheter. After loading of the device  3000  into the delivery catheter, the delivery catheter may be used with the handle  3700  to deliver and secure the device within the human body. 
     The hydraulic loader  3900  may couple to components of the delivery system to move portions of the delivery system. The loader  3900  may be mounted about a pusher (such as pusher  3230 , pusher  3700 , or pusher  3800 ) between a proximal end of the delivery catheter and a distal end of the handle to retract the occlusion device into the delivery catheter. As shown in  FIGS. 27A-27C , a piston actuator  3902  includes a barrel  3904  having a connector  3906  coupled to the delivery catheter  3220 . A plunger  3908  of the piston actuator  3902  includes a connector  3910  coupled to the pusher  3230  and abutting the distal end of the handle or components thereof. A hydraulic fluid, such as saline can be introduced into the barrel  3904  of the piston actuator  3902  to apply a force to the plunger  3908  in a proximal direction to cause the plunger  3908  to move proximally relative to the barrel  3904 . Proximal movement of the plunger  3908  may cause proximal movement of the pusher  3230 , the handle  3700 , and/or tether  3240  relative to the delivery catheter  3220  to proximally retract the device into the delivery catheter  3220  when the connector  3906  and the connector  3910  are coupled to the delivery catheter  3220  and the pusher  3230 , respectively. 
       FIG. 27B  depicts the plunger  3908  in a first position relative to the barrel  3904 , and  FIG. 27C  depicts the plunger  3908  in a second position relative to the barrel  3904  in which the plunger  3908  is positioned proximally relative to the first position, for example, due to the introduction of a hydraulic fluid into the barrel  3904 . Fluid may be introduced into the barrel  3904  via a fluid path tube  3912  of the hydraulic loader  3900 . 
     A syringe  3914  of the hydraulic loader  3900  may be coupled to the tube  3912  to introduce fluid thereto. A plunger  3916  of the syringe  3914  can be advanced into a barrel  3918  of the syringe  3914 , for example by a user manipulating the plunger  3916 , to advance fluid from the barrel  3918  through a tip  3920  of the syringe  3914  and into the tube  3912 . Thus, the syringe  3914  can be operated to advance a hydraulic fluid through the tube  3912  and into the piston actuator  3902  to cause the plunger  3908  of the piston actuator  3902  to move proximally relative to the barrel  3904  of the piston actuator  3902 . As described above, when coupled to the delivery system, proximal movement of the plunger  3908  relative to the barrel  3904  can cause retraction of the device into the delivery catheter  3220 , for example by causing proximal movement of the pusher  3230  and/or tether  3240 . 
     Use of the hydraulic loader  3900  can also improve control over the positioning of the device within the catheter to allow the device to be loaded at a position close to the distal end of the delivery catheter. For example, an amount of hydraulic fluid may be selected to cause the piston actuator to move a predetermined distance so as to position the device at a position close to the distal end of the delivery catheter. Additionally, or alternatively, a range of motion of the plunger  3908  of the piston actuator  3902  can be selected so that movement of the plunger  3908  to its proximal most position relative to the barrel  3904  causes the device to be retracted to a position close to the distal end of the delivery catheter. 
     The hydraulic loader  3900  can reduce the force needed to be applied by a user to load the delivery device into the delivery catheter, for example in comparison to application of a pulling force by the user on the pusher and/or tether. In some embodiments, this reduction of force can facilitate loading in delivery catheters of a smaller diameter, such as the smaller diameters described herein. In some embodiments, the cross-sectional areas of the plunger  3908  and the plunger  3916  can be sized so that the force imparted by the piston actuator  3902  is amplified relative to the force applied by a user to the syringe  3914 . The force (F 2 ) applied by the piston actuator  3902  is related to the cross-sectional area (A 2 ) of the plunger  3908 , the force (F 1 ) applied to the syringe, and the cross-sectional area (A 1 ) of the plunger  3916  as shown in Equation 1: 
         F   2   =F   1 *( A   2   /A   1 )  Equation 1:
 
     As shown in Equation 1, the force applied by the piston actuator (F 2 ) is larger than the force applied by the user to the syringe (F 1 ) when the cross-sectional area A 2  of the plunger  3908  is greater than the cross-sectional area A 1  of the plunger  3916 . A ratio of the force (F 2 ) applied by the piston actuator to the force (F 1 ) applied by the user to the syringe  3914  is equivalent to a ratio of the cross-sectional area (A 2 ) of the plunger  3908  to the cross-sectional area (A 1 ) of the plunger  3916 . 
     In some embodiments, the piston actuator  3902  is a 12 cubic centimeter (cc) syringe (or has a plunger  3908  equivalent to that of a 12 cc syringe) and the syringe  3914  is a 30 cc syringe. In some embodiments, the syringe  3914  may be a 5 cc or 10 cc or larger syringe. In some embodiments, multiple syringes  3914  can be coupled to the fluid path  3912  to supply hydraulic fluid to the piston actuator  3902  or a single syringe  3914  can be refilled and reconnected to the fluid path  3912  to supply additional hydraulic fluid to the piston actuator  3902 . 
     Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the claims, the principles and the novel features disclosed herein. The word “example” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “example” is not necessarily to be construed as preferred or advantageous over other implementations, unless otherwise stated. 
     Certain features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features can be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination can be directed to a sub-combination or variation of a sub-combination. 
     Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. 
     It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”