Patent Publication Number: US-2020288950-A1

Title: Imaging system

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application Ser. No. 62/591,403 (Attorney Docket No. GTY-003PR), titled “Imaging System”, filed Nov. 28, 2017, and U.S. Provisional Application Ser. No. 62/671,142 (Attorney Docket No. GTY-003PR2), titled “Imaging System”, filed May 14, 2018, the content of each of which is incorporated herein by reference in its entirety. 
     This application is related to U.S. Provisional Application Ser. No. 62/148,355 (Attorney Docket No. GTY-001PR), titled “Micro-Optic Probes for Neurology”, filed Apr. 16, 2015, the content of which is incorporated by reference in its entirety. 
     This application is related to U.S. Provisional Application Ser. No. 62/322,182 (Attorney Docket No. GTY-001PR2), titled “Micro-Optic Probes for Neurology”, filed Apr. 13, 2016, the content of which is incorporated by reference in its entirety. 
     This application is related to International PCT Patent Application Serial Number PCT/US2016/027764 (Attorney Docket No. GTY-001PCT), titled “Micro-Optic Probes for Neurology” filed Apr. 15, 2016, published as WO 2016/168605, published Oct. 20, 2016, the content of which is incorporated by reference in its entirety. 
     This application is related to U.S. patent application Ser. No. 15/566,041 (Attorney Docket No. GTY-001US), titled “Micro-Optic Probes for Neurology”, filed Apr. 15, 2016, published as U.S. Publication No. 2018-0125372, published May 10, 2018, the content of which is incorporated by reference in its entirety. 
     This application is related to U.S. Provisional Application Ser. No. 62/212,173 (Attorney Docket No. GTY-002PR), titled “Imaging System Includes Imaging Probe and Delivery Devices”, filed Aug. 31, 2015, the content of which is incorporated by reference in its entirety. 
     This application is related to U.S. Provisional Application Ser. No. 62/368,387 (Attorney Docket No. GTY-002PR2), titled “Imaging System Includes Imaging Probe and Delivery Devices”, filed Jul. 29, 2016, the content of which is incorporated by reference in its entirety. 
     This application is related to International PCT Patent Applicant Serial Number PCT/US2016/049415 (Attorney Docket No. GTY-002PCT), titled “Imaging System Includes Imaging Probe and Delivery Devices”, filed Aug. 30, 2016, published as WO 2017/040484, published Mar. 9, 2017, the content of which is incorporated by reference in its entirety. 
     This application is related to U.S. patent application Ser. No. 15/751,570 (Attorney Docket No. GTY-002US), titled “Imaging System Includes Imaging Probe and Delivery Devices”, filed Feb. 9, 2018, published as US Publication No. ______, published ______, the content of which is incorporated by reference in its entirety. 
     This application is related to U.S. Provisional Application Ser. No. 62/732,114 (Attorney Docket No. GTY-004PR), titled “Imaging System with Optical Pathway”, filed Sep. 17, 2018, the content of which is incorporated by reference in its entirety. 
    
    
     Field 
     The present disclosure relates generally to imaging systems, and in particular, intravascular imaging systems including imaging probes and delivery devices. 
     BACKGROUND 
     Imaging probes have been commercialized for imaging various internal locations of a patient, such as an intravascular probe for imaging a patient&#39;s heart. Current imaging probes are limited in their ability to reach certain anatomical locations due to their size and rigidity. Current imaging probes are inserted over a guidewire, which can compromise their placement and limit use of one or more delivery catheters through which the imaging probe is inserted. There is a need for imaging systems that include probes with reduced diameter, high flexibility and ability to be advanced to a patient site to be imaged without a guidewire, as well as systems with one or more delivery devices compatible with these improved imaging probes. 
     SUMMARY 
     According to an aspect of the present inventive concepts, an imaging system for a patient comprising: an imaging probe, comprising: an elongate shaft comprising a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion; a rotatable optical core positioned within the lumen of the elongate shaft and comprising a proximal end and a distal end; and an optical assembly positioned in the elongate shaft distal portion and proximate the rotatable optical core distal end, the optical assembly configured to direct light to tissue and collect reflected light from the tissue; and the imaging probe is constructed and arranged to collect image data from a patient site; a rotation assembly constructed and arranged to optically and mechanically connect to the imaging probe, and to rotate the optical assembly; a retraction assembly constructed and arranged to mechanically connect to the imaging probe, and to retract the optical assembly and the elongate shaft in unison. 
     In some embodiments, the imaging probe further comprises a service loop configured to allow retraction of the imaging probe relative to the patient while the rotation assembly remains stationary. 
     In some embodiments, the elongate shaft comprises a first segment and a second segment, and the first segment is more flexible than the second segment. The first segment can comprise a spiral cut. The first segment can comprise a braided construction. The first segment can be positioned proximal to the second segment. 
     In some embodiments, the rotatable optical core comprises a non-zero dispersion shifted fiber. The system can optically match the dispersion of the non-zero dispersion shifted fiber. 
     In some embodiments, the rotatable optical core comprises a radiation-resistant fiber. The rotatable optical core can further comprise an acrylate coating. 
     In some embodiments, the rotatable optical core comprises a first portion and a second portion, and the first portion comprises a first set of properties, and the second portion comprises a second set of properties different than the first set of properties. The first portion can comprise a non-zero dispersion shifted fiber and/or a depressed cladding, and the second portion can comprise a non-shifted optical fiber. 
     In some embodiments, the optical assembly comprises a lens. The lens can comprise a GRIN lens with a distal end, and the distal end can comprise a beam deflector. The lens can comprise a doping profile configured to provide a particular focus requirement and/or to allow polishing of a beam-deflecting surface directly into the lens while preserving intended optical function. The distal end can comprise a plated distal end. The distal end can comprise an aspherical distal end. The distal end can comprise a polished facet. 
     In some embodiments, the imaging probe comprises a proximal connector; and the retraction assembly comprises a pullback module and a linkage assembly; and the pullback module is configured to attach to the elongate shaft of the imaging probe and to retract the imaging probe. The system can further comprise a patient interface module configured to: attach to the proximal connector; attach to the linkage assembly; provide a retraction force to the pullback module via the linkage assembly; and rotate the rotatable optical core. The pullback module can comprise a first discrete component that can be positioned at a first location, and the patient interface module can further comprise a second discrete component that can be positioned at a second location that can be remote from the first location. The imaging probe can enter the patient at a vascular access site, and the first location can comprise a location proximate the vascular access site. The second location can be at least 15 cm remote from the first location. The first location can be within 30 cm of the vascular access site. The retraction assembly can comprise a linkage assembly including a sheath with a distal end, a puller, and a motive element, and the motive element can apply a pullback force to the puller via the linkage assembly to cause the puller to move proximally relative to the distal end of the sheath. 
     In some embodiments, the imaging probe comprises a proximal portion and a proximal connector within the proximal portion; and the system further comprises a connector module including a housing, a first connector, and a linkage, and the housing surrounds the proximal portion of the imaging probe, and the proximal connector is attached to the housing, and the linkage is attached to the elongate shaft of the imaging probe, and the first connector slidingly receives the linkage. The system can further comprise a patient interface module, including a second connector that attaches to the first connector and a third connector that attaches to the proximal connector, and the patient interface module retracts the linkage of the connector module, and the housing of the connector module surrounds the retracted portion of the imaging probe, and the patient interface module rotates the rotatable optical core. 
     In some embodiments, the rotation assembly rotates the optical assembly and the rotatable optical core in unison. 
     In some embodiments, the imaging probe comprises a proximal end including a connector, and the rotation assembly comprises a rotary joint that operably engages the connector, and the rotary joint rotates the rotatable optical core via the connector. The rotary joint can comprise an optical connector and a floating portion, and the floating portion can be configured to compensate for linear motion of the optical connector. The floating portion can be biased toward the optical connector. The floating portion can comprise a spring that provides the bias. The rotary joint can further comprise a rotary coupler and a fiber optic cable, and the rotary coupler can be connected to the floating portion via the fiber optic cable, and the fiber optic cable can be configured to buckle during the linear motion compensation by the floating portion. The rotary joint can further comprise a channel configured to limit buckling of the fiber optic cable, such as to achieve a rotationally balanced configuration. The channel can be configured to confine the buckling of the fiber optic cable to a single plane. The fiber optic cable can comprise a portion configured to accommodate the buckling, and the portion can comprise an S-shape. The channel can comprise an S-shape. The S-shape can comprise a radius configured to minimize light loss through the fiber optic cable. 
     In some embodiments, the retraction assembly comprises a connector assembly configured to attach to a reference point. The reference point can comprise a patient introduction device and/or a surgical table. 
     In some embodiments, the imaging probe further comprises a proximal end and a connector assembly positioned on the proximal end. The connector assembly can be configured to be operably attached to the rotation assembly. The connector assembly can include a fiber optic connector and one or more alignment components, and the one or more alignment components can be configured to maintain a rotational orientation of the fiber optic connector relative to the rotation assembly, and the rotational orientation can be maintained during attachment and detachment of the connector assembly to the rotation assembly. The system may not require additional alignment steps to maintain the rotational orientation. The connector assembly can comprise a rotating assembly operably attached to the rotatable optical core, and the rotation assembly can rotate the rotatable optical core via the rotating assembly of the connector assembly. The rotating assembly can comprise one or more projections and/or one or more reliefs, and the one or more projections and/or the one or more reliefs can be configured to rotationally balance the rotating assembly. The connector assembly can comprise an optical connector, and the optical connector can comprise a rotationally unbalanced optical connector. The rotating assembly can comprise a locking assembly configured to prevent rotation of the rotating assembly when the connector assembly is not attached to the rotation assembly. The locking assembly can include a rotational lock and a spring, and the rotational lock can lock to the rotating assembly via the spring. The rotating assembly can comprise one or more recesses, and the rotational lock can comprise one or more projections that mate with the one or more recesses. 
     In some embodiments, the imaging probe further comprises a viscous dampening material positioned between the elongate shaft and the optical assembly. The viscous dampening material can be further positioned between the elongate shaft and at least a portion of the rotatable optical core. The viscous dampening material can comprise a shear-thinning fluid. The viscous dampening material can comprise a static viscosity of at least 500 centipoise. The viscous dampening material can comprise a shear viscosity and a static viscosity, and the shear viscosity can be less than the static viscosity. The ratio of shear viscosity to static viscosity can be between 1:1.2 and 1:100. The imaging probe can further comprise: a lens; a sheath surrounding and extending beyond the lens; a sealing element positioned within the sheath distal to the lens and in contact with the viscous dampening fluid; and a chamber positioned between the lens and the sealing element. The sealing element can comprise a porous sealing element. The sealing element can be configured to prevent the viscous damping material from contacting the lens. The sealing element can be configured to allow pressure to equalize within the chamber. The sealing element can comprise a porous sealing element. The sealing element can comprise an opening. The chamber can be filled with a gas. 
     In some embodiments, the elongate shaft of the imaging probe comprises a proximal portion, and the imaging probe further comprises a torque shaft including a distal end and surrounding the proximal portion of the elongate shaft. The torque shaft can be configured to rotate in a single direction. The imaging probe can comprise a proximal end, and the torque shaft distal end can be positioned approximately 100 cm from the proximal end of the imaging probe. The torque shaft can be fixedly attached to the rotatable optical core. The rotatable optical core can comprise a proximal portion, and the imaging probe can comprise: a rotating alignment element positioned between the torque shaft and the rotatable optical core; an outer shaft surrounding the torque shaft and the proximal portion of the rotatable optical core; an intermediate shaft surrounding the rotatable optical core distal to the torque shaft; and a tube positioned between the outer shaft and the intermediate shaft; and the rotating alignment element and the tube form a rotary joint such that the torque shaft rotatably attaches to the intermediate shaft. 
     In some embodiments, the imaging probe further comprises a distal tip portion including a sealing element positioned within the elongate shaft at a location distal to the optical assembly. The distal tip portion can comprise a proximal end, and the optical assembly can include a lens, and the sealing element can comprise an angled proximal end that can be configured to reduce coupling of light between the lens of the optical assembly and the proximal end of the distal tip portion. 
     In some embodiments, the system further comprises a compression relief assembly configured to prevent the imaging probe from exceeding a compression threshold, and the compression relief assembly comprises: a first shaft with a proximal end, a distal end, and a first lumen therebetween; a second shaft with a proximal end, a distal end, and a second lumen therebetween; a housing with a proximal end, a distal end, and an opening therebetween; and the distal end of the first shaft connects to the proximal end of the housing; and the proximal end of the second shaft connects to the distal end of the housing; and the imaging probe is configured to pass through the first lumen, through the opening, and into the second lumen; and the opening is sized to accommodate a buckling of a portion of the elongate shaft positioned within the opening when the imaging probe exceeds the compression threshold. 
     In some embodiments, the system further comprises an algorithm. The algorithm can adjust a retraction parameter of the system. The retraction parameter can comprise initiation of retraction, and the algorithm can initiate retraction based on a condition selected from the group consisting of: the lumen in which the optical assembly can be positioned has been flushed; an indicator signal can be received from a fluid injector device; a desired change in image data collected can be detected; and combinations of these. The algorithm can adjust a system parameter that can be related to the imaging probe. The imaging probe can include an ID that can be detectable by the system, and the system parameter can be adjusted based on the ID. The system parameter adjustment can comprise an arm path length parameter. 
     In some embodiments, the system further comprises a fluid injector. The fluid injector can be configured to deliver a first fluid and a second fluid. The fluid injector can be configured to deliver the first fluid and the second fluid simultaneously and/or sequentially. The first fluid can comprise a contrast at a first concentration, and the second fluid can comprise a contrast at a second concentration that can be less than the first concentration. The second fluid can comprise no contrast. 
     In some embodiments, the system further comprises a marker positioned proximate the distal portion of the elongate shaft. 
     In some embodiments, the system further comprises a first delivery catheter constructed and arranged to slidingly receive the imaging probe, and the first delivery catheter is configured to access a body location in the patient selected from the group consisting of: an intracerebral location; an intracardiac location; and combinations of these. The imaging system can further comprise a second delivery catheter constructed and arranged to slidingly receive the first imaging catheter. The first delivery catheter can be further configured to slidingly receive a second device. The first delivery device can be configured to sequentially receive the imaging probe and the second device. The first delivery device can be configured to simultaneously receive the imaging probe and the second device. The second device can comprise a device selected from the group consisting of: a second imaging device; a treatment device; an implant delivery device; and combinations of these. 
     In some embodiments, the system further comprises a light source configured to deliver light to the optical assembly. 
     In some embodiments, the system further comprises a second imaging device. The second imaging device can be selected from the group consisting of: an X-ray; a fluoroscope such as a single plane or biplane fluoroscope; a CT Scanner; an MRI; a PET Scanner; an ultrasound imager; a rotational angiography imaging device; and combinations of these. The system can provide images based on both data provided by the imaging probe, as well as data provided by the second imaging device. The second imaging device can comprise a rotational angiography device. 
     In some embodiments, the system further comprises: two microcatheters; an intermediate catheter; and a treatment device. The intermediate catheter can be constructed and arranged to slidingly receive the two microcatheters in a side-by-side arrangement. The imaging probe can be advanced through the first microcatheter, and the treatment device can be advanced through the second microcatheter. The probe can be configured to perform a pullback imaging procedure prior to, during, and/or after treatment by the treatment device. The treatment device can comprise an implant delivery device. The implant delivery device can comprise a coil delivery device. The system can be configured to automatically deliver a flush medium during the pullback imaging procedure. 
     In some embodiments, the imaging probe comprises a spring tip including a distal end. The imaging probe can comprise a length configured to allow a clinician to position the optical assembly at a first location and subsequently perform a pullback imaging procedure, and the spring tip distal end can be positioned at or distal to the first location at the end of the pullback imaging procedure. The imaging probe can further comprise a marker positioned relative to the distal end of the spring tip distal, and the marker can provide information related to the position of the spring tip at the end of the pullback imaging procedure. The imaging probe can further comprise a marker positioned relative to the optical assembly, and the marker can provide information related to the position of the optical assembly at the end of the pullback imaging procedure. The spring tip can comprise a length of at least 35 mm, at least 50 mm, and/or at least 75 mm. 
     In some embodiments, the system further comprises a microcatheter including a distal transparent window, and the microcatheter can be configured to slidingly receive the imaging probe. The optical assembly can remain within the transparent window during the pullback imaging procedure. The microcatheter can include a reinforced portion proximal to the transparent window. 
     In some embodiments, the system further comprises a bed rail mount for attaching the rotation assembly to a patient bed rail. The bed rail mount can comprise a jaw biased in a closed position. The jaw can be constructed and arranged to capture bed rails of various size. The bed rail mount can comprise a connector that rotatably connects to the rotation assembly. The connector can comprise a persistent frictional rotation resistance. 
     The technology described herein, along with the attributes and attendant advantages thereof, will best be appreciated and understood in view of the following detailed description taken in conjunction with the accompanying drawings in which representative embodiments are described by way of example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a schematic view of an imaging system comprising an imaging probe and independent retraction and rotation assemblies, consistent with the present inventive concepts. 
         FIG. 1A  illustrates a schematic view of an imaging system comprising an imaging probe operably attachable to a patient interface module, and an independent pullback module operably attachable to the patient interface module and the imaging probe, consistent with the present inventive concepts. 
         FIG. 1B  illustrates a schematic view of an imaging system comprising an imaging probe operably attachable to a module comprising a first connector for attaching to a rotation motive element and a second connector for attaching to a retraction motive element, consistent with the present inventive concepts. 
         FIG. 2  illustrates a schematic view of an optical probe, consistent with the present inventive concepts. 
         FIG. 2A  illustrates a magnified view of transition T 1 , consistent with the present inventive concepts. 
         FIG. 2B  illustrates a magnified view of transitions T 2  and T 3 , consistent with the present inventive concepts. 
         FIG. 2C  illustrates a magnified view of the distal portion of imaging probe  100 , consistent with the present inventive concepts. 
         FIG. 3  illustrates an exploded view of a connector assembly, consistent with the present inventive concepts. 
         FIGS. 3A-D  illustrate four assembly views of a connector assembly, consistent with the present inventive concepts. 
         FIGS. 3E-G  illustrate a partial sectional view, a partially exploded view, and a perspective view of a connector assembly, consistent with the present inventive concepts. 
         FIGS. 4A-C  illustrate two perspective views of connectors being attached to a patient interface module and a perspective view of a portion of the patient interface module with the outer casing removed, consistent with the present inventive concepts. 
         FIG. 5  illustrates a perspective, partial cut away view of components of a patient interface module, consistent with the present inventive concepts. 
         FIGS. 5A-D  illustrate perspective, partial cut away views of components of a patient interface module, consistent with the present inventive concepts. 
         FIGS. 6A-D  illustrate schematic views of a locking mechanism, consistent with the present inventive concepts. 
         FIGS. 7A-C  illustrate an exploded view, a perspective view, and a sectional view of a connector assembly, consistent with the present inventive concepts. 
         FIGS. 8A-C  illustrate an exploded view, a perspective view, and an end view of a pullback housing, consistent with the present inventive concepts. 
         FIG. 9  illustrates a perspective view of components of a patient interface module, consistent with the present inventive concepts. 
         FIGS. 10A and 10B  illustrate perspective and partial sectional views of a connector assembly, respectively, consistent with the present inventive concepts. 
         FIGS. 11A and 11B  illustrate perspective views of connectors being attached to a patient interface module, consistent with the present inventive concepts. 
         FIG. 12  illustrates a side sectional anatomical view of a system including an imaging probe in a side-by-side arrangement with an implant delivery device, consistent with the present inventive concepts. 
         FIGS. 13A and 13B  illustrate side sectional anatomic views of a system including an imaging probe including a position marker, consistent with the present inventive concepts. 
         FIG. 14  illustrates a flow chart of a method of creating an image, consistent with the present inventive concepts. 
         FIGS. 15A and 15B  illustrate schematic views of a system including an imaging probe, consistent with the present inventive concepts. 
         FIGS. 16A-C  illustrate perspective, side, and front views, respectively, of a patient interface module attached to a bed rail mount, consistent with the present inventive concepts. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Reference will now be made in detail to the present embodiments of the technology, examples of which are illustrated in the accompanying drawings. Similar reference numbers may be used to refer to similar components. However, the description is not intended to limit the present disclosure to particular embodiments, and it should be construed as including various modifications, equivalents, and/or alternatives of the embodiments described herein. 
     It will be understood that the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     It will be further understood that, although the terms first, second, third etc. may be used herein to describe various limitations, elements, components, regions, layers and/or sections, these limitations, elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one limitation, element, component, region, layer or section from another limitation, element, component, region, layer or section. Thus, a first limitation, element, component, region, layer or section discussed below could be termed a second limitation, element, component, region, layer or section without departing from the teachings of the present application. 
     It will be further understood that when an element is referred to as being “on”, “attached”, “connected” or “coupled” to another element, it can be directly on or above, or connected or coupled to, the other element, or one or more intervening elements can be present. In contrast, when an element is referred to as being “directly on”, “directly attached”, “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g. “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). 
     It will be further understood that when a first element is referred to as being “in”, “on” and/or “within” a second element, the first element can be positioned: within an internal space of the second element, within a portion of the second element (e.g. within a wall of the second element); positioned on an external and/or internal surface of the second element; and combinations of one or more of these. 
     As used herein, the term “proximate” shall include locations relatively close to, on, in and/or within a referenced component or other location. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like may be used to describe an element and/or feature&#39;s relationship to another element(s) and/or feature(s) as, for example, illustrated in the figures. It will be further understood that the spatially relative terms are intended to encompass different orientations of the device in use and/or operation in addition to the orientation depicted in the figures. For example, if the device in a figure is turned over, elements described as “below” and/or “beneath” other elements or features would then be oriented “above” the other elements or features. The device can be otherwise oriented (e.g. rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terms “reduce”, “reducing”, “reduction” and the like, where used herein, are to include a reduction in a quantity, including a reduction to zero. Reducing the likelihood of an occurrence shall include prevention of the occurrence. 
     The term “and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example, “A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein. 
     In this specification, unless explicitly stated otherwise, “and” can mean “or,” and “or” can mean “and.” For example, if a feature is described as having A, B, or C, the feature can have A, B, and C, or any combination of A, B, and C. Similarly, if a feature is described as having A, B, and C, the feature can have only one or two of A, B, or C. 
     The expression “configured (or set) to” used in the present disclosure may be used interchangeably with, for example, the expressions “suitable for”, “having the capacity to”, “designed to”, “adapted to”, “made to” and “capable of” according to a situation. The expression “configured (or set) to” does not mean only “specifically designed to” in hardware. Alternatively, in some situations, the expression “a device configured to” may mean that the device “can” operate together with another device or component. 
     As described herein, “room pressure” shall mean pressure of the environment surrounding the systems and devices of the present inventive concepts. Positive pressure includes pressure above room pressure or simply a pressure that is greater than another pressure, such as a positive differential pressure across a fluid pathway component such as a valve. Negative pressure includes pressure below room pressure or a pressure that is less than another pressure, such as a negative differential pressure across a fluid component pathway such as a valve. Negative pressure can include a vacuum but does not imply a pressure below a vacuum. As used herein, the term “vacuum” can be used to refer to a full or partial vacuum, or any negative pressure, as described hereabove. 
     The term “diameter” where used herein to describe a non-circular geometry is to be taken as the diameter of a hypothetical circle approximating the geometry being described. For example, when describing a cross section, such as the cross section of a component, the term “diameter” shall be taken to represent the diameter of a hypothetical circle with the same cross-sectional area as the cross section of the component being described. 
     The terms “major axis” and “minor axis” of a component where used herein are the length and diameter, respectively, of the smallest volume hypothetical cylinder which can completely surround the component. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. For example, it will be appreciated that all features set out in any of the claims (whether independent or dependent) can be combined in any given way. 
     It is to be understood that at least some of the figures and descriptions of the invention have been simplified to focus on elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the invention. However, because such elements are well known in the art, and because they do not necessarily facilitate a better understanding of the invention, a description of such elements is not provided herein. 
     Terms defined in the present disclosure are only used for describing specific embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. Terms provided in singular forms are intended to include plural forms as well, unless the context clearly indicates otherwise. All of the terms used herein, including technical or scientific terms, have the same meanings as those generally understood by an ordinary person skilled in the related art, unless otherwise defined herein. Terms defined in a generally used dictionary should be interpreted as having meanings that are the same as or similar to the contextual meanings of the relevant technology and should not be interpreted as having ideal or exaggerated meanings, unless expressly so defined herein. In some cases, terms defined in the present disclosure should not be interpreted to exclude the embodiments of the present disclosure. 
     Provided herein are systems for use in a patient to create an image of the patient&#39;s anatomy. The image can comprise a two-dimensional and/or three-dimensional image of the patient&#39;s anatomy, and it can further include an image of one or more devices positioned proximate the patient&#39;s anatomy being imaged. The systems include an imaging probe, a rotation assembly, and a retraction assembly. The imaging probe collects image data from a patient site and includes an elongate shaft with a proximal end and a distal portion, with a lumen extending therebetween. A rotatable optical core is positioned within the elongate shaft lumen and an optical assembly is positioned in the elongate shaft distal portion. The optical assembly directs light to tissue at the patient site and collects reflected light from the tissue. The rotation assembly connects to the imaging probe and rotates the optical assembly. The retraction assembly connects to the imaging probe and retracts the optical assembly and the elongate shaft in unison. 
     Referring now to  FIG. 1 , a schematic view of an imaging system comprising an imaging probe and independent retraction and rotation assemblies is illustrated, consistent with the present inventive concepts. Imaging system  10  is constructed and arranged to collect image data and produce one or more images based on the recorded data, such as when imaging system  10  comprises an Optical Coherence Tomography (OCT) imaging system constructed and arranged to collect image data of an imaging location (e.g. a segment of a blood vessel, such as during a pullback procedure). Imaging system  10  comprises catheter-based probe, imaging probe  100 , as well as a rotation assembly  500  and a retraction assembly  800 , each of which can operably attach to imaging probe  100 . Imaging system  10  can further comprise console  50  which is configured to operably connect to imaging probe  100 , such as via rotation assembly  500  and/or retraction assembly  800 . Imaging probe  100  can be introduced into a conduit of the patient, such as a blood vessel or other conduit of the patient, using one or more delivery catheters, for example delivery catheter  80  shown. Alternatively or additionally, imaging probe  100  can be introduced though an introducer device, such as an endoscope, arthroscope, balloon dilator, or the like. In some embodiments, imaging probe  100  is configured to be introduced into a conduit selected from the group consisting of: an artery; a vein; an artery within or proximate the heart; a vein within or proximate the heart; an artery within or proximate the brain; a vein within or proximate the brain; a peripheral artery; a peripheral vein; through a natural body orifice into a conduit, such as the esophagus; through a surgically created orifice into a body cavity, such as the abdomen; and combinations of these. Imaging system  10  can further comprise one or more (additional) imaging devices, such as second imaging device  15  shown. Imaging system  10  can further comprise a device configured to treat the patient, treatment device  16 . Imaging system  10  can further comprise a fluid injector, such as injector  20 , which can be configured to inject one or more fluids, such as a flushing fluid, an imaging contrast agent (e.g. a radiopaque contrast agent, hereinafter “contrast”) and/or other fluid, such as injectate  21  shown. Imaging system  10  can further comprise an implant, such as implant  31 , which can be implanted in the patient via a delivery device, such as an implant delivery device  30  and/or delivery catheter  80 . 
     In some embodiments, imaging probe  100  and/or another component of imaging system  10  can be of similar construction and arrangement to the similar components described in applicants co-pending U.S. patent application Ser. No. 15/566,041, titled “Micro-Optic Probes for Neurology”, filed Oct. 12, 2017; the content of which is incorporated herein by reference in its entirety for all purposes. Imaging probe  100  can be constructed and arranged to collect image data from a patient site, such as an intravascular cardiac site, an intracranial site, or other site accessible via the vasculature of the patient. In some embodiments, imaging system  10  can be of similar construction and arrangement to the similar systems and their methods of use described in applicants co-pending U.S. patent application Ser. No. 15/751,570, titled “Imaging System includes Imaging Probe and Delivery Devices”, filed Feb. 9, 2018; the content of which is incorporated herein by reference in its entirety for all purposes. 
     Delivery catheter  80  comprises an elongate shaft, shaft  81 , with a lumen therethrough, and a connector  82  positioned on its proximal end. Connector  82  can comprise a Touhy or valved connector, such as a valved connector configured to prevent fluid egress from the associated delivery catheter  80  (with and/or without a separate shaft positioned within the connector  82 ). Connector  82  can comprise a port  83 , such as a port constructed and arranged to allow introduction of fluid into delivery catheter  80  and/or for removing fluids from delivery catheter  80 . In some embodiments, a flushing fluid, as described herebelow, is introduced via one or more ports  83 , such as to remove blood and/or other undesired material from locations proximate optical assembly  115  (e.g. from a location proximal to optical assembly  115  to a location distal to optical assembly  115 ). Port  83  can be positioned on a side of connector  82  and can include a luer fitting and a cap and/or valve. Shafts  81 , connectors  82 , and ports  83  can each comprise standard materials and be of similar construction to commercially available introducers, guide catheters, diagnostic catheters, intermediate catheters and microcatheters used in interventional procedures. Delivery catheter  80  can comprise a catheter configured to deliver imaging probe  100  to an intracerebral location, an intracardiac location, and/or another location within a patient. 
     Imaging system  10  can comprise two or more delivery catheters  80 , such as three or more delivery catheters  80 . Multiple delivery catheters  80  can comprise at least a vascular introducer, and other delivery catheters  80  that can be inserted into the patient therethrough, after the vascular introducer is positioned through the skin of the patient. Two or more delivery catheters  80  can collectively comprise sets of inner diameters (IDs) and outer diameters (ODs) such that a first delivery catheter  80  slidingly receives a second delivery catheter  80  (e.g. the second delivery catheter OD is less than or equal to the first delivery catheter ID), and the second delivery catheter  80  slidingly receives a third delivery catheter  80  (e.g. the third delivery catheter OD is less than or equal to the second delivery catheter ID), and so on. In these configurations, the first delivery catheter  80  can be advanced to a first anatomical location, the second delivery catheter  80  can be advanced through the first delivery catheter to a second anatomical location distal or otherwise remote (hereinafter “distal”) to the first anatomical location, and so on as appropriate, using sequentially smaller diameter delivery catheters  80 . In some embodiments, one or more delivery catheters are configured to deliver (e.g. sequentially and/or simultaneously deliver) both imaging probe  100  and a second device (e.g. a second catheter-based device), such as another delivery catheter  80 , a second imaging device (e.g. second imaging device  15 ), a treatment device (e.g. treatment device  16 ), and/or a coil, stent, and/or other implant delivery device (e.g. implant delivery device  30 ). In some embodiments, delivery catheters  80  can be of similar construction and arrangement to the similar components described in applicants co-pending U.S. patent application Ser. No. 15/751,570, titled “Imaging System includes Imaging Probe and Delivery Devices”, filed Feb. 9, 2018; the content of which is incorporated herein by reference in its entirety for all purposes. 
     Imaging probe  100  comprises an elongate body, comprising one or more elongate shafts and/or tubes, elongate shaft  120  herein. Shaft  120  comprises a proximal end  1201 , distal end  1209 , and a lumen  1205  extending therebetween. In some embodiments, lumen  1205  includes multiple coaxial lumens within the one or more elongate shafts  120 , such as one or more lumens abutting each other to define a single lumen  1205 . Shaft  120  further comprises a distal portion  1208 . Shaft  120  construction is described herebelow in reference to  FIGS. 2 and 2A -C. Shaft  120  operably surrounds a rotatable optical fiber, optical core  110  (e.g. optical core  110  is positioned within lumen  1205 ), comprising a proximal end  1101  and a distal end  1109 . An optical assembly, optical assembly  115 , is positioned on the distal end  1109  of optical core  110 . A connector assembly, connector assembly  150 , is positioned on the proximal end of shaft  120 . Connector assembly  150  operably attaches imaging probe  100  to rotation assembly  500 , as described herein. Connector assembly  150  surrounds and operably attaches to an optical connector  161 , fixedly attached to the proximal end of optical core  110 . In some embodiments, connector assembly  150 , including optical connector  161 , can be of similar construction and arrangement to those described herebelow in reference to  FIGS. 3 and 3A -G. A second connector, pullback connector  180 , is positioned on shaft  120 . Connector  180  can be removably attached and/or adjustably positioned along the length of shaft  120 . Connector  180  can be positioned along shaft  120 , such as by an operator, proximate the proximal end of delivery catheter  80  after imaging probe  100  has been inserted into a patient via delivery catheter  80 . Shaft  120  can comprise a portion between connector assembly  150  and the placement location of connector  180  that accommodates slack in shaft  120 , a proximal portion of shaft  120  (e.g. a proximal portion of imaging probe  100 ), service loop  185 . 
     Imaging probe  100  can comprise one or more visualizable markers along its length (e.g. along shaft  120 ), markers  131   a - b  shown (marker  131  herein). Marker  131  can comprise markers selected from the group consisting of: radiopaque markers; ultrasonically reflective markers; magnetic markers; ferrous material; and combinations of these. In some embodiments, marker  131  comprises a marker positioned at a location (e.g. a location within and/or at least proximate distal portion  1208 ) to assist an operator of imaging system  10  in performing a pullback procedure, such as to cause tip  119  to be positioned at a location distal to the proximal end of an implant after the pullback is completed (e.g. so that imaging probe  100  can be safely advanced through the implant after the pullback). 
     Rotation assembly  500  comprises a connector assembly  510 , operably attached to a rotary joint  550 . Rotation assembly  500  further comprises a motor or other rotational energy source, motive element  530 . Motive element  530  is operably attached to rotary joint  550  via a linkage assembly  540 . In some embodiments, linkage assembly  540  comprises one or more gears, belts, pulleys, or other force transfer mechanisms, such as described herebelow in reference to  FIGS. 5A-D . Motive element  530  can drive (e.g. rotate via linkage assembly  540 ) rotary joint  550  (and in turn core  110 ) at speeds of at least 100 rotations per second, such as at least 200 rotations per second or 250 rotations per second, or between 20 rotations per second and 1000 rotations per second. Motive element  530  can comprise a mechanism selected from the group consisting of: a motor; a servo; a stepper motor (e.g. a stepper motor including a gear box); a linear actuator; a hollow core motor; and combinations of these. 
     Connector assembly  510  operably attaches to connector assembly  150  of imaging probe  100 , allowing optical connector  161  to operably engage rotary joint  550 . In some embodiments, connector assembly  510  operably engages connector assembly  150 , as described herebelow in reference to  FIGS. 5A-D . In some embodiments, connector assembly  510  operably engages connector assembly  150  such that rotary joint  550  and optical connector  161  are free to rotate within the engaged assemblies. 
     Retraction assembly  800  comprises a connector assembly  820 , that operably attaches to a reference point, for example connector  82  of delivery catheter  80 , such as to establish a reference for retraction assembly  800  relative to the patient. Connector assembly  820  can attach to a reference point such as a patient introduction device, surgical table, and/or another fixed or semi-fixed point of reference. A retraction element, puller  850 , releasably attaches to connector  180  of imaging probe  100 , such as via a carrier  855 . Retraction assembly  800  retracts at least a portion of imaging probe  100  (e.g. the portion of imaging probe  100  distal to the attached connector  180 ), relative to the established reference. Service loop  185  of imaging probe  100  can be positioned between retraction assembly  800  and/or at least connector assembly  820 , and rotation assembly  500 , such that imaging probe  100  can be retracted relative to the patient while rotation assembly  500  remains stationary (e.g. attached to the surgical table and/or to a portion of console  50 ). 
     Retraction assembly  800  further comprises a linear drive, motive element  830 . In some embodiments, motive element  830  comprises a linear actuator, a worm drive operably attached to a motor, a pulley system, and/or other linear force transfer mechanisms. In some embodiments, motive element  830  can be of similar construction and arrangement to motive element  830  described herebelow in reference to  FIG. 9 . Puller  850  can be operably attached to motive element  830  via a linkage assembly  890 . In some embodiments, linkage assembly  890  comprises one or more components of a “pullback assembly”, as described herebelow in reference to  FIGS. 1A, 7A -C and  8 A-C. Alternatively or additionally, linkage assembly  890  can comprise one or more components of an enclosed pullback connector, as described herebelow in reference to  FIGS. 1B and 10A -B. One or more components of linkage assembly  890  can establish a frame of reference (e.g. an internal pullback reference) between puller  850  and the motive element  830 , such that motive element  830  applies a pullback force to puller  850  via linkage assembly  890 , and puller  850  retracts relative to the distal portion of linkage assembly  890  (e.g. relative to the distal end of sheath  895 ), as described herebelow. In some embodiments, the distal end of linkage assembly  890  and connector assembly  820  are fixed relative to each other, and puller  850  translates linearly between the two in reaction to a force applied from motive element  830 . 
     Console  50  comprises an imaging assembly  300 , a user interface  55 , and one or more algorithms  51 . Imaging assembly  300  can be configured to provide light to optical assembly  115  (e.g. via optical core  110 ) and collect light from optical assembly  115  (e.g. via optical core  110 ). Imaging assembly  300  can include a light source  310  configured to provide the light to optical assembly  115 . Light source  310  can comprise one or more light sources, such as one or more light sources configured to provide one or more wavelengths of light to optical assembly  115  via optical core  110 . Light source  310  is configured to provide light to optical assembly  115  (e.g. via optical core  110 ) such that image data can be collected (e.g. reflected light is collected by an opto-electronic module of optical assembly  115  that is configured to collect and analyze light returned from optical assembly  115 ). The collected image data can comprise cross-sectional, longitudinal and/or volumetric information related to a patient site and/or implanted device being imaged. Light source  310  can be configured to provide light such that the image data collected includes characteristics of tissue within the patient site being imaged, such as to quantify, qualify or otherwise provide information related to a patient disease or disorder present within the patient site being imaged. Light source  310  can be configured to deliver broadband light and have a center wavelength in the range from 800 nm to 1700 nm, such as from 1280 nm and 1310 nm, or such as approximately 1300 nm (e.g. light delivered with a sweep range from 1250 nm to 1350 nm). The light source  310  bandwidth can be selected to achieve a desired resolution, which can vary according to the needs of the intended use of imaging system  10 . In some embodiments, bandwidths are about 5% to 15% of the center wavelength, which allows resolutions of between 20 microns and 5 microns. Light source  310  can be configured to deliver light at a power level meeting ANSI Class 1 (“eye safe”) limits; higher power levels can be employed. In some embodiments, light source  310  delivers light in the 1.3 μm band at a power level of approximately 20 mW. Tissue light scattering is reduced as the center wavelength of delivered light increases, and water absorption increases. Light source  310  can deliver light at a wavelength approximating 1300 nm to balance these two effects. Light source  310  can be configured to deliver shorter wavelength light (e.g. approximately 800 nm light) to traverse patient sites to be imaged including large amounts of fluid. Alternatively or additionally, light source  310  can be configured to deliver longer wavelengths of light (e.g. approximately 1700 nm light), such as to reduce a high level of scattering within a patient site to be imaged. In some embodiments, light source  310  comprises a tunable light source (e.g. light source  310  emits a single wavelength that changes repetitively over time), and/or a broad-band light source. Light source  310  can comprise a single spatial mode light source or a multimode light source (e.g. a multimode light source with spatial filtering). 
     Console  50  can comprise an algorithm, such as algorithm  51  shown, which can be configured to adjust (e.g. automatically and/or semi-automatically adjust) one or more operational parameters of imaging system  10 , such as an operational parameter of console  50 , imaging probe  100  and/or a delivery catheter  80 . Alternatively or additionally, algorithm  51  can be configured to adjust an operational parameter of a separate device, such as injector  20  or implant delivery device  30  described herebelow. In some embodiments, algorithm  51  is configured to adjust an operational parameter based on one or more sensor signals, such as a sensor signal provided by a sensor-based functional element of the present inventive concepts, as described herein. Algorithm  51  can be configured to adjust an operational parameter selected from the group consisting of: a rotational parameter such as rotational velocity of optical core  110  and/or optical assembly  115 ; a retraction parameter of shaft  120  and/or optical assembly  115 , such as retraction velocity, distance, start position, end position and/or retraction initiation timing (e.g. when retraction is initiated); a position parameter, such as position of optical assembly  115 ; a line spacing parameter, such as lines per frame; an image display parameter, such as a scaling of display size to vessel diameter; an imaging probe  100  configuration parameter; an injectate  21  parameter, such as a saline to contrast ratio configured to determine an appropriate index of refraction; a light source  310  parameter, such as power delivered and/or frequency of light delivered; and combinations of these. In some embodiments, algorithm  51  is configured to adjust a retraction parameter, such as a parameter triggering the initiation of the pullback, such as a pullback that is initiated based on a parameter selected from the group consisting of: lumen flushing (the lumen proximate optical assembly  115  has been sufficiently cleared of blood or other matter that would interfere with image creation); an indicator signal is received from injector  20  (e.g. a signal indicating sufficient flushing fluid has been delivered); a change in image data collected (e.g. a change in an image is detected, based on the image data collected, that correlates to proper evacuation of blood from around optical assembly  115 ); and combinations of these. In some embodiments, algorithm  51  is configured to adjust an imaging system  10  configuration parameter related to imaging probe  100 , such as when algorithm  51  identifies (e.g. automatically identifies via an RF or other embedded ID) the attached imaging probe  100  and adjusts an imaging system  10  parameter, such as an arm path length parameter, a dispersion parameter, and/or other parameter as listed above. 
     Imaging system  10  can comprise one or more interconnect cables, bus  58  shown. Bus  58  can operably connect rotation assembly  500  to console  50 , retraction assembly  800  to console  50 , and or rotation assembly  500  to retraction assembly  800 . Bus  58  can comprise one or more optical transmission fibers, electrical transmission cables, fluid conduits, and combinations of these. In some embodiments, bus  58  comprises at least an optical transmission fiber that optically couples rotary joint  550  to imaging assembly  300  of console  50 . Alternatively or additionally, bus  58  comprises at least power and/or data transmission cables that transfer power and/or motive information to one or more of motive elements  530  and  830 . 
     Second imaging device  15  can comprise an imaging device such as one or more imaging devices selected from the group consisting of: an X-ray; a fluoroscope, such as a single plane or biplane fluoroscope; a CT Scanner; an MRI; a PET Scanner; an ultrasound imager; and combinations of these. In some embodiments, a clinician uses images provided by imaging device  15  in combination with images provided by probe  100 . In some embodiments, system  10  provides image processing to combine images provided by probe  100  and images provided by second imaging device  15  (e.g. co-register and/or digitally combined images based on data provided by probe  100  and device  15 ). In some embodiments, second imaging device  15  comprises a device configured to perform rotational angiography. In these embodiments, system  10  can provide combined images including rotational angiography images and probe  100  derived images. 
     Treatment device  16  can comprise an occlusion treatment device or other treatment device selected from the group consisting of: a balloon catheter constructed and arranged to dilate a stenosis or other narrowing of a blood vessel; a drug eluting balloon; an aspiration catheter; a sonolysis device; an atherectomy device; a thrombus removal device such as a stent retriever device; a Trevo™ stentriever; a Solitaire™ stentriever; a Revive™ stentriever; an Eric™ stentriever; a Lazarus™ stentriever; a stent delivery catheter; a microbraid implant; an embolization system; a WEB™ embolization system; a Luna™ embolization system; a Medina™ embolization system; and combinations of these. In some embodiments, imaging probe  100  is configured to collect data related to treatment device  16  (e.g. treatment device  16  location, orientation, and/or other configuration data), after treatment device  16  has been inserted into the patient. 
     Injector  20  can comprise a power injector, syringe pump, peristaltic pump or other fluid delivery device configured to inject a contrast agent, such as radiopaque contrast, and/or other fluids. In some embodiments, injector  20  is configured to deliver contrast and/or other fluid (e.g. contrast, saline and/or Dextran). In some embodiments, injector  20  delivers fluid in a flushing procedure as described herebelow. In some embodiments, injector  20  delivers contrast or other fluid through a delivery catheter  80  with an ID of between 5 Fr and 9 Fr, a delivery catheter  80  with an ID of between 0.53″ to 0.70″, or a delivery catheter  80  with an ID between 0.0165″ and 0.027″. In some embodiments, contrast or other fluid is delivered through a delivery catheter as small as 4 Fr (e.g. for distal injections). In some embodiments, injector  20  delivers contrast and/or other fluid through the lumen of one or more delivery catheters  80 , while one or more smaller delivery catheters  80  also reside within the lumen. In some embodiments, injector  20  is configured to deliver two dissimilar fluids simultaneously and/or sequentially, such as a first fluid delivered from a first reservoir and comprising a first concentration of contrast, and a second fluid from a second reservoir and comprising less or no contrast. 
     Injectate  21  can comprise fluid selected from the group consisting of: optically transparent material; saline; visualizable material; contrast; Dextran; an ultrasonically reflective material; a magnetic material; and combinations of these. Injectate  21  can comprise contrast and saline. Injectate  21  can comprise at least 20% contrast. During collection of image data, a flushing procedure can be performed, such as by delivering one or more fluids, injectate  21  (e.g. as propelled by injector  20  or other fluid delivery device), to remove blood or other somewhat opaque material (hereinafter non-transparent material) proximate optical assembly  115  (e.g. to remove non-transparent material between optical assembly  115  and a delivery catheter and/or non-transparent material between optical assembly  115  and a vessel wall), such as to allow light distributed from optical assembly  115  to reach and reflectively return from all tissue and other objects to be imaged. In these flushing embodiments, injectate  21  can comprise an optically transparent material, such as saline. Injectate  21  can comprise one or more visualizable materials, as described herebelow. 
     As an alternative or in addition to its use in a flushing procedure, injectate  21  can comprise material configured to be viewed by second imaging device  15 , such as when injectate  21  comprises a contrast material configured to be viewed by a second imaging device  15  comprising a fluoroscope or other X-ray device; an ultrasonically reflective material configured to be viewed by a second imaging device  15  comprising an ultrasound imager; and/or a magnetic material configured to be viewed by a second imaging device  15  comprising an MRI. 
     Implant  31  can comprise an implant (e.g. a temporary or chronic implant) for treating one or more of a vascular occlusion or an aneurysm. In some embodiments, implant  31  comprises one or more implants selected from the group consisting of: a flow diverter; a Pipeline™ flow diverter; a Surpass™ flow diverter; an embolization coil; a stent; a Wingspan™ stent; a covered stent; an aneurysm treatment implant; and combinations of these. 
     Implant delivery device  30  can comprise a catheter or other tool used to deliver implant  31 , such as when implant  31  comprises a self-expanding or balloon expandable portion. In some embodiments, imaging system  10  comprises imaging probe  100 , one or more implants  31  and/or one or more implant delivery devices  30 . In some embodiments, imaging probe  100  is configured to collect data related to implant  31  and/or implant delivery device  30  (e.g. implant  31  and/or implant delivery device  30  anatomical location, orientation and/or other configuration data), after implant  31  and/or implant delivery device  30  has been inserted into the patient, such as is described in reference to  FIG. 12  herebelow. 
     In some embodiments, one or more system components, such as console  50 , delivery catheter  80 , imaging probe  100 , rotation assembly  500 , retraction assembly  800 , treatment device  16 , injector  20 , and/or implant delivery device  30 , further comprise one or more functional elements (“functional element” herein), such as functional elements  59 ,  89 ,  199 ,  599 ,  899 ,  99   a,    99   b,  and/or  99   c,  respectively, shown. Each functional element can comprise at least two functional elements. Each functional element can comprise one or more elements selected from the group consisting of: sensor; transducer; and combinations of these. The functional element can comprise a sensor configured to produce a signal. The functional element can comprise a sensor selected from the group consisting of: a physiologic sensor; a pressure sensor; a strain gauge; a position sensor; a GPS sensor; an accelerometer; a temperature sensor; a magnetic sensor; a chemical sensor; a biochemical sensor; a protein sensor; a flow sensor, such as an ultrasonic flow sensor; a gas detecting sensor, such as an ultrasonic bubble detector; a sound sensor, such as an ultrasound sensor; and combinations of these. The sensor can comprise a physiologic sensor selected from the group consisting of: a pressure sensor, such as a blood pressure sensor; a blood gas sensor; a flow sensor, such as a blood flow sensor; a temperature sensor, such as a blood or other tissue temperature sensor; and combinations of these. The sensor can comprise a position sensor configured to produce a signal related to a vessel path geometry (e.g. a 2D or 3D vessel path geometry). The sensor can comprise a magnetic sensor. The sensor can comprise a flow sensor. The system can further comprise an algorithm configured to process the signal produced by the sensor-based functional element. Each functional element can comprise one or more transducers. Each functional element can comprise one or more transducers selected from the group consisting of: a heating element, such as a heating element configured to deliver sufficient heat to ablate tissue; a cooling element, such as a cooling element configured to deliver cryogenic energy to ablate tissue; a sound transducer, such as an ultrasound transducer; a vibrational transducer; and combinations of these. 
     As described herein, retraction assembly  800  and rotation assembly  500  can be constructed and arranged to independently perform a retraction operation and a rotation operation, respectively. For example, retraction assembly  800  can be configured to independently retract at least a portion of imaging probe  100 , with or without simultaneous rotation of optical core  110 . Rotation assembly  500  can be configured to independently rotate optical core  110 , with or without simultaneous retraction of probe  100 . Additionally or alternatively, retraction assembly  800  and rotation assembly  500  can comprise separate (discrete) components that can be positioned independently. For example, retraction assembly  800  can be constructed and arranged such that it imparts no tensile forces and/or other forces, on rotation assembly  500  (e.g. retraction assembly  800  does not cause nor require rotation assembly  500  to retract or otherwise move during retraction of probe  100 ). Alternatively or additionally, rotation assembly  500  can be constructed and arranged such that it imparts no rotational forces and/or other forces, on retraction assembly  800  (e.g. rotation assembly  500  does not cause nor require retraction assembly  800  to rotate or otherwise move during rotation of optical core  110 ). 
     Referring now to  FIG. 1A , a schematic view of an imaging system is illustrated, the system comprising an imaging probe operably attachable to a patient interface module, and an independent pullback module operably attachable to the patient interface module and the imaging probe, consistent with the present inventive concepts. Imaging system  10  can comprise a patient interface module  200 . Patient interface module  200  comprises a housing, housing  201 , surrounding at least a portion of rotation assembly  500 , and at least a portion of retraction assembly  800 . Imaging system  10  can further comprise a second, discrete component, pullback module  880 . Pullback module  880  comprises a housing, housing  881 , surrounding at least a portion of retraction assembly  800 . Pullback module  880  and patient interface module  200  can be operably attached to each other via a connector assembly, linkage assembly  890  described herein. Pullback module  880  and patient interface module  200  can be constructed and arranged (e.g. via each having a separate housing) to enable positioning at different locations (e.g. linkage assembly  890  connecting modules  880  and  200  can comprise a length of at least 15 cm such that the two remote locations can be at least 15 cm apart). For example, patient interface module  200  can be positioned on or near a surgical bed rail, and pullback module  880  can be positioned near a vascular access site of the patient (e.g. within 30 cm of the vascular access site thru which imaging probe  100  enters the patient). Linkage assembly  890  can comprise a linkage  891  slidingly received within sheath  895 . Linkage  891  is operably attached to puller  850 , and the proximal end  893  of linkage  891  can comprise a connection point,  842 . Components shown in  FIG. 1A  can be of similar construction and arrangement to like components described in  FIG. 1  hereabove, and elsewhere herein. 
     Pullback module  880  and its associated components can be of similar construction and arrangement to pullback module  880  described herebelow in reference to  FIGS. 7A-8C . Housing  881  and its associated components can be of similar construction and arrangement to housing  881  described herebelow in reference to  FIGS. 8A-C . Connector assembly  845  and its associated components can be of similar construction and arrangement to connector assembly  845  described herebelow in reference to  FIG. 7A-B . Pullback module  880  can comprise a connector assembly  820   b  that operably attaches to connector  82  of delivery catheter  80 , such as described herebelow in reference to  FIGS. 8A-C . Connector assembly  845  can comprise a connector  840  that operably attaches to a connector assembly  820   a  of patient interface module  200 , as described herebelow in reference to  FIGS. 4A-C . Imaging probe  100  can comprise a connector assembly  150  that operably attaches to a connector assembly  510  of patient interface module  200 , as described herebelow in reference to  FIGS. 4A-C . 
     Referring now to  FIG. 1B , a schematic view of an imaging system is illustrated, the system comprising an imaging probe operably attachable to a module comprising a first connector for attaching to a rotation motive element and a second connector for attaching to a retraction motive element, consistent with the present inventive concepts. Imaging system  10  can comprise a patient interface module  200 , as described herein. Imaging system  10  can further comprise a connector module, module  410 . Module  410  comprises a housing, housing  411 , surrounding at least a portion of retraction assembly  800 , service loop  185  of imaging probe  100 , connector assembly  150 ′, and connector  840 ′. Module  410  can be configured to operably attach both imaging probe  100  and a linkage, puller  850 ′, to patient interface module  200 , and can be of similar construction and arrangement to module  410  and its associated components (e.g. delivery catheter  480  which includes window  485 ) described herebelow in reference to  FIGS. 10A-B . Components shown in  FIG. 1B  can be of similar construction and arrangement to like components described in  FIG. 1  hereabove, and elsewhere herein. 
     Referring now to  FIG. 2 , a schematic view of an optical probe is illustrated, consistent with the present inventive concepts. Imaging probe  100  can comprise an elongate body, including one or more elongate shafts along its length, surrounding optical core  110 , for example a rotatable core comprising an optical fiber, which is configured to transmit light. Collectively, the one or more elongate shafts may be referred to herein as shaft  120 . Optical core  110  can comprise a non-zero dispersion shifted (NZDS) fiber, for example a fiber in which the dispersion of the fiber is shifted away from a natural dispersion zero of approximately 1300 nm. In these embodiments, imaging system  10  can operate such that the system uses optically matched dispersion where the total dispersion of optical components within console  50  matches the optical core  110  (e.g. a NZDS fiber) dispersion in the desired wavelength operation range. Alternatively or additionally, algorithm  51  can detect and numerically correct any dispersion mismatches between console  50  and optical core  110 . Optical core  110  can comprise a fiber with a pure silica core, and a low index, or “depressed”, cladding. Optical core  110  can comprise a low bend loss fiber, such as less than 5% transmission loss at a minimum radius of less than or equal to 6 mm, and/or less than 30% transmission loss at a minimum radius of less than or equal to 3 mm. Optical core  110  can also comprise a radiation resistant fiber, capable of maintaining its optical transmission properties after radiation exposure, such as exposure from a radiation-based sterilization process. In some embodiments, imaging probe  100  is sterilized using E-beam sterilization. In these embodiments, materials used in optical core  110  can be selected that are compatible with (e.g. not damaged by) E-beam sterilization. For example, optical core  110  can comprise an acrylate coating which is compatible with E-beam sterilization. Optical core  110  can comprise a single mode fiber similar to those used in telecommunication applications. Optical core  110  can comprise a diameter (e.g. a diameter including cladding) of less than 130 microns, such as a diameter less than 85 microns, such as diameter of approximately 80 microns. In some embodiments, optical core  110  comprises at least a first portion comprising an NZDS fiber and/or a depressed cladding optical fiber, and at least a second portion comprising an optical fiber comprising differing optical properties (e.g. a non-shifted optical fiber). Optical core  110  can comprise an optical fiber with an outer diameter (e.g. including cladding) of less than or equal to 120 microns, such as less than or equal to 80 microns. In some embodiments, optical core  110  comprises a silica core with a diameter of approximately 6 μm, with a circumferential cladding with a thickness of approximately 37 μm, and a circumferential polyimide and/or acrylate coating, such as a coating with a thickness of approximately 10 μm. 
     Connector assembly  150  is positioned at a proximal portion of imaging probe  100  (e.g. a proximal portion of imaging probe  100  terminates at connector assembly  150 ), and optical core  110  is operably attached to fiber optic connector  161  of connector assembly  150 . A rotatable first shaft, torque shaft  105 , surrounds a proximal portion of optical core  110 , and extends from connector assembly  150  distally to a first shaft transition point T 1 . An outer second shaft, outer shaft  101 , surrounds torque shaft  105  and a proximal portion of optical core  110 , and extends from connector assembly  150 , distally to the first shaft transition point T 1 . Torque shaft  105  can comprise a length of approximately 100 cm, such as when imaging probe  100  comprises a length of approximately 300 cm. As described herebelow in reference to  FIG. 2A , one or more components (e.g. intermediate shafts) can be used to operably connect, join, align, or otherwise transition from outer shaft  101  to an intermediate third shaft, shaft  125 . Shaft  125  extends distally from the first transition point T 1 , past a second transition point T 2 , to a third transition point T 3 . In some embodiments, shaft  125  comprises a segment configured to have a greater flexibility than the remainder of shaft  125 , such as a segment including a spiral cut or other flexibility-enhancing feature, segment  127  shown. Segment  127  extends from the second transition point T 2  distally to the third transition point T 3 . In some embodiments, segment  127  comprises a braided or other flexible construction. 
     As described herebelow in reference to  FIG. 2B , one or more components (e.g. an outer shaft or covering) can surround segment  127 , such as to prevent fluid ingress into shaft  125  via segment  127 . Also described in reference to  FIG. 2B , one or more components (e.g. intermediate shafts) can be used to operably connect, join, align, or otherwise transition from shaft  125  to a distal fourth shaft, window  130 . Window  130  extends distally, from the third transition point T 3  to the distal end of imaging probe  100 . Window  130  can comprise a length D 3 . D 3  can comprise a length greater than 225 mm and/or less than 450 mm, such as a length of 250 mm. 
     In some embodiments, imaging probe  100  includes a viscous dampening material, gel  118 , injected (or otherwise installed in a manufacturing process) into the distal portion of window  130 . Gel  118  can comprise a non-Newtonian fluid, for example a sheer thinning fluid. In some embodiments, gel  118  comprises a static viscosity of greater than 500 centipoise, and a sheer viscosity of less than the static viscosity. In these embodiments, the ratio of static viscosity to sheer viscosity of gel  118  can be between 1.2:1 and 100:1. Gel  118  surrounds the distal portion of optical core  110 , including optical assembly  115 . In some embodiments, gel  118  is installed a distance D 2  into window  130  (e.g. D 2  represents the distance between the proximal end of gel  118  and the distal end of gel  118  within window  130 ). In some embodiments, D 2  comprises a length greater than 175 mm and/or less than 400 mm, such as a length of 200 mm. Gel  118  can comprise a gel as described in reference to applicants co-pending U.S. patent application Ser. No. 15/566,041, titled “Micro-Optic Probes for Neurology”, filed Oct. 12, 2017, the content of which is incorporated herein by reference in its entirety for all purposes. 
     Imaging probe  100  can include a distal tip portion, distal tip  119 . In some embodiments, distal tip  119  comprises a spring tip, configured to improve the “navigability” of imaging probe  100  (e.g. to improve “trackability” and/or “steerability” of imaging probe  100 ), for example within a tortuous pathway. In some embodiments, tip  119  comprises a length of between 5 mm and 100 mm. Alternatively or additionally, tip  119  can comprise a cap or plug, configured to seal the distal opening of window  130 . In some embodiments, tip  119  comprises a radiopaque marker, configured to increase the visibility of imaging probe  100  under an X-ray or fluoroscope. In some embodiments, tip  119  comprises a “rapid exchange” type tip. 
     In some embodiments, at least the distal portion of imaging probe  100  (e.g. the distal portion of shaft  120 ) comprises an outer diameter of no more than 0.020″, or no more than 0.016″. 
     In some embodiments, imaging probe  100  can be constructed and arranged for use in an intravascular neural procedure (e.g. a procedure in which the blood, vasculature and other tissue proximate the brain are visualized, and/or devices positioned temporarily or permanently proximate the brain are visualized). The dimensions of imaging probe  100  for use in a neural procedure can be as follows. Imaging probe  100  can comprise an overall length L 1  of approximately 300 cm. Outer shaft  101  can extend a length D 5  of approximately 100 cm from connector assembly  150  to transition T 1 . In some embodiments, D 5  comprises a length greater than 10 cm and/or less than 150 cm. From transition T 1  to T 2 , length D 6  can comprise a length of approximately 175 cm. D 6  can comprise a length of greater than 1250 mm and/or less than 2000 mm, such as a length of 1525 mm. Between transition T 2  and T 3 , length D 4  (the length of segment  127 ) can comprise a length of greater than 10 mm and/or less than 50 mm, such as a length of 25 mm. 
     Alternatively or additionally, imaging probe  100  can be constructed and arranged for use in an intravascular cardiac procedure (e.g. a procedure in which the blood, vasculature, and other tissue proximate the heart are visualized, and/or devices positioned temporarily or permanently proximate the heart are visualized). The dimensions of imaging probe  100  for use in a cardiovascular procedure can be as follows. Imaging probe  100  can comprise an overall length L 1  of at least 220 cm, such as an overall length L 1  of approximately 280 cm. In some embodiments, L 1  comprises a length greater than 2600 mm and/or less than 3200 mm. Outer shaft  101  can extend a length D 5  of approximately 100 cm from connector assembly  150  to transition T 1 . From transition T 1  to T 2 , length D 6  can comprise a length of approximately 155 cm. Between transition T 2  and T 3 , length D 4  (the length of segment  127 ) can comprise a length of approximately 10 mm. In some embodiments, D 4  comprises a length of greater than 10 mm and/or less than 50 mm. 
     Referring now to  FIG. 2A , a magnified view of Section  1  of  FIG. 2  is illustrated, consistent with the present inventive concepts. Section  1  details transition T 1  of imaging probe  100 . The following describes a set of components constructed and arranged to transition shaft  120  from a first diameter shaft, outer shaft  101 , that surrounds torque shaft  105 , to a smaller diameter shaft, intermediate shaft  125 , that surrounds optical core  110  after torque shaft  105  terminates. Outer shaft  101  can comprise a greater stiffness than shaft  125 , a different material, and/or other varied physical properties. The components described also operably attach the distal end of torque shaft  105  to optical core  110 , as described herebelow. Alternatively, various other components can be implemented to achieve the transition T 1 . Optical core  110  can comprise a coating  111 . Coating  111  can comprise a cladding, such as an optical cladding known to those skilled in the art of optical design, a protective coating such as a polyimide coating, and/or combinations of these. 
     Torque shaft  105 , which surrounds optical core  110 , terminates at T 1 , approximately 100 cm from the proximal end of imaging probe  100 . Torque shaft  105  is configured to rotate within outer shaft  101 , and is fixedly attached to optical core  110 , such as to transfer rotational force between the two. In some embodiments, torque shaft  105  is constructed and arranged to rotate in a single direction (unidirectionally). Alternatively, torque shaft  105  can be constructed and arranged to rotate in either direction (bidirectionally). A rotating alignment element, tube  106 , is positioned between the distal portion of torque shaft  105  and optical core  110 , (e.g. slidingly receives optical core  110  and is slidingly received by torque shaft  105 ). Tube  106  extends beyond the distal end of torque shaft  105 . A bond  107 , for example a bond comprising an epoxy or UV glue, fixedly attaches tube  106  to optical core  110  and/or torque shaft  105 . Alternatively or additionally, a press or other frictional bond fixedly attaches tube  106  to optical core  110  and/or torque shaft  105 . An intermediate “transition” tube, tube  122 , is positioned between outer shaft  101  and shaft  125 , as shown. Tube  122  is slidingly received within a distal portion of outer shaft  101 , and the proximal portion of shaft  125  is slidingly received within the distal portion of tube  122  (as well as outer shaft  101 ). In some embodiments, shafts  101 ,  125 , and tube  122  are fixedly attached to each other, such as via a glue and/or frictional fit. In some embodiments, the distal end of outer shaft  101  extends beyond the distal end of tube  122 . A second alignment element, tube  121 , can be positioned within tube  122 , abutting the proximal end of shaft  125 . In some embodiments, tube  106  does not rotate relative to tube  122 . The distal end of tube  106  is slidingly and rotatably received within the proximal portion of tube  122 , and frictionally abuts tube  121 . Tube  121  can comprise a material selected to minimize the friction between tube  121  and tube  122 . Tubes  121 ,  106 , and  122  form a rotary type joint, allowing torque shaft  105  to rotatably attach to shaft  125 . Tubes  121  and  106  abut to prevent torque shaft  105  and/or optical core  110  from moving distally within shaft  125 . 
     Several dimensions of and/or between various components of imaging probe  100  are illustrated in  FIG. 2A . Tube  106  can comprise a length D 7 . Imaging probe  100  can comprise a gap with length D 8 , D 8  representing the length between the distal end of torque shaft  105  and the proximal end of tube  122 . Tube  122  can overlap tube  106  with an overlapping length D 9 . Tube  121  can comprise a length D 10 . Tube  122  can comprise a length D 11 . 
     In some embodiments, D 7  comprises a length of greater than 5 mm and/or a length of less than 50 mm, such as a length of 20 mm. D 8  can comprise a length of greater than 1 mm and/or less than 10 mm, such as a length of 5 mm. Overlap D 9  can comprise a length of greater than 3 mm and/or less than 30 mm, such as a length of 5 mm. D 10  can comprise a length of greater than 3 mm and/or less than 30 mm, such as a length of 5 mm. Overlap D 11  can comprise a length of greater than 10 mm and/or less than 100 mm, such as a length of 25 mm. 
     Referring now to  FIG. 2B , a magnified view of Section  2  of  FIG. 2  is illustrated, consistent with the present inventive concepts. Section  2  details transitions T 2  and T 3  of imaging probe  100 . The following describes a set of components constructed and arranged to transition shaft  120  from a first portion with a first flexibility, to a second portion with a second flexibility (at transition T 2 ), and from a first shaft comprised of a first material (shaft  125 ), to a second shaft comprised of a second material (window  130 , comprising an optically transparent material). Alternatively, various other components can be implemented to achieve the transitions T 2  and T 3 . 
     At transition T 2 , segment  127  of shaft  125  begins, transitioning shaft  125  from a first flexibility, to a second, greater flexibility. Segment  127  can comprise a flexibility enhancing “feature”, such as a modification applied to segment  127  of shaft  125  selected from the group consisting of: a spiral cut (as shown); a corrugation; one or more relief cuts; one or more openings; a thinning of the outer wall; and combinations of these. In some embodiments, the modification of segment  127  creates one or more passageways (e.g. holes) into and/or out of shaft  125 , such as passageways through which bodily fluids and/or other contaminates can enter and/or exit shaft  125 . Alternatively or additionally, the modification of segment  127  can weaken the column and/or other structural strength of shaft  125 . A covering, tube  129 , can be slidingly received over segment  127 , configured to prevent contamination ingress and/or provide additional structural support to segment  127 . Tube  129  can comprise a flexible material, such as a material more flexible than segment  127  of shaft  125 . 
     Shaft  125  terminates at T 3 . A covering, for example tube  129  shown, or alternatively a separate covering, can surround the transition point T 3 . Tube  129  can provide a seal around segment  127 , for example when segment  127  comprises a spiral cut that could otherwise allow ingress and/or egress to or from shaft  120 . Alternatively or additionally, segment  127  of shaft  125  can comprise a flexible material (e.g. a material with a greater flexibility than the remainder of shaft  125 ), such as a polymer, and can comprise a braided construction, such as a braided construction including a metallic and/or non-metallic braid. Window  130  begins at transition T 3 . Optical core  110  is slidingly received by both shaft  125  and window  130 , exiting the distal end of shaft  125  and entering the proximal end of window  130  at transition T 3 . Tube  129  maintains the relative position of the distal portion of shaft  125  with the proximal portion of window  130 , including the relative axial positions of each (e.g. a coaxial arrangement), and the longitudinal positioning of the proximal end of window  130  relative to the distal end of shaft  125  (e.g. the ends abut each other, or nearly abut each other). Additionally or alternately, other methods of maintaining the relative position of window  130  and shaft  125  can be used, such as in a manufacturing process, for example a reflowing process, a welding process, and/or a splicing process that can be used to join, and position, window  130  and shaft  125 . 
     As shown, the gel  118  can be positioned from the proximal end of tip  119  to a location proximate location T 3 , where T 3  is a location distal to the proximal end of window  130 . Gel  118  can be injected (e.g. in a manufacturing process) into shaft  120  (e.g. from the distal end of window  130 ) such that the proximal end of gel  118  (after injection is complete) is positioned at a location between 50 mm and 500 mm from the proximal end of tip  119 , such as at a location between 200 mm and 250 mm from the proximal end of tip  119  (e.g. distance D 1 +D 2  of  FIG. 2 ). 
     Several dimensions of and/or between various components of imaging probe  100  are illustrated in  FIG. 2B . Tube  129  can extend a length D 12  proximally beyond the proximal end of segment  127 . Imaging probe  100  can comprise a gap with length D 14 , with D 14  representing the length between the distal end of shaft  125  and the proximal end of window  130 . Tube  129  can extend a length D 13  over window  130 , as shown. 
     In some embodiments, D 12  comprises a length of greater than 5 mm and/or less than 20 mm, such as a length of 10 mm. D 14  can comprise a length of less than 1 mm, such as less than 0.2 mm, such as a length of approximately 0, such as when shaft  125  abuts window  130 . D 13  can comprise a length of greater than 5 mm and/or less than 20 mm, such as a length of 15 mm. 
     Referring now to  FIG. 2C , a magnified view of Section  3  of  FIG. 2  is illustrated, consistent with the present inventive concepts. Section  3  details the distal portion of imaging probe  100 . Optical assembly  115  is operably (e.g. optically) attached to the distal end of optical core  110 . Optical assembly  115  is located within window  130 , and it is configured to rotate about its longitudinal axis (e.g. rotate with optical core  110  within imaging probe  100 ). Gel  118  surrounds at least optical assembly  115  within window  130 . Gel  118  can comprise a sheer thinning material, as described herein. Distal tip  119  can comprise sealing element  1192 , configured to “plug” (e.g. prevent egress from) the distal end of window  130 , such as to prevent gel  118  from exiting the distal end of window  130 . Distal tip  119  can comprise a spring tip (not shown, but known to those skilled in the art of catheter design). Distal tip  119  can comprise a radiopaque, or other marker configured to increase the visibility of at least the distal tip  119  of imaging probe  100  using an imaging device, for example X-ray and/or fluoroscopy. In some embodiments, sealing element  1192  of distal tip  119  comprises an angled proximal end  1191 , as shown, such as to prevent or at least reduce the reflection of light escaping from the distal end of lens  116  back towards lens  116  (e.g. to prevent or at least reduce coupling of light between lens  116  and the proximal end of distal tip  119 ). Proximal end  1191  can comprise an angled proximal end between 15° and 80°, such as 45°. 
     Optical assembly  115  can comprise a focusing element, lens  116 , such as a GRIN lens. Optical assembly  115  can further comprise a covering, sheath  117 , and an enclosed volume, chamber  114 , positioned distal to lens  116  (e.g. the distal end of lens  116  defines the proximal end of chamber  114 ). A sealing element, plug  113 , defines the distal end of chamber  114 . Lens  116  can be optically connected to optical core  110 , such as via a weld, as is typical in the art of fiber optic design. Coating  111  (or another coating) of optical core  110  can be removed proximate the distal end of optical core  110 , such that coating  111  does not interfere with the fiber optic joining process. Lens  116  can comprise an outer diameter of less than 300 microns, such as less than 250 microns, or less than 200 microns. Lens  116  can comprise a length of greater than or equal to 0.5 mm, such as a length greater than or equal to 1 mm. Lens  116  can comprise numerous configurations, such as when lens  116  comprises a beam deflector (e.g. a reflective surface configured to direct light into and out of lens  116 ) polished or otherwise formed onto the distal end of lens  116  (e.g. a GRIN lens with a polished facet). Additionally or alternatively, lens  116  can comprise a planar distal end, an aspherical distal end, a spherical distal end, and/or a cylindrical distal end. The distal end of lens  116  can comprise a directly reflecting beam deflector (e.g. a beam deflector reflectively coated with metallic and/or dielectric coatings) and/or a total internally reflective beam deflector (e.g. internal reflection within lens  116 ). In some embodiments, lens  116  comprises a doping profile configured to provide particular focus requirements and/or to allow polishing of a beam-deflecting surface directly into lens  116  (e.g. in manufacturing), without causing excessive beam distortion (e.g. while preserving the intended optical function of lens  116 ). In some embodiments, lens  116  comprises a numerical aperture of less than 0.2, such as less than 0.18. Additionally or alternatively, lens  116  can comprise a parabolic and/or quadratic doping profile constant of less than 2 mm −1 , such as less than 1.7 mm −1 . Sheath  117  can slidingly receive lens  116 , and at least a distal portion of optical core  110  including coating  111 , such that any portion of optical core  110  in which coating  111  has been removed is covered by sheath  117 . In some embodiments, a protective material, filler  112 , surrounds the uncladded portion of optical core  110  within sheath  117 . Filler  112  can comprise a glue, such as an epoxy or a UV glue, configured to protect optical core  110  and/or increase the internal reflection within optical core  110  to help prevent light from escaping the fiber. In some embodiments, the distal end of lens  116  provides an internal reflective surface, configured to reflect light approximately 90° into and/or out of lens  116 . Chamber  114  can be filled with atmospheric air, and/or a gas, such as an inert gas. Chamber  114  can provide a protective barrier, preventing gel  118  from contacting the distal end of lens  116 , such that the index of refraction between lens  116  and the gas within chamber  114  facilitates the internal reflection of lens  116 . Plug  113  can comprise a porous sealing element, such as when plug  113  comprises a filter material, such as a porous filter material, configured to prevent ingress of gel  118  into chamber  114  (e.g. during a manufacturing process in which gel  118  is injected into window  130 ) and/or to allow pressure to equalize within chamber  114  (e.g. during a manufacturing process, a sterilization process, or otherwise). In some embodiments, plug  113  comprises a plug with an opening (e.g. a non-porous plug with an opening), channel  113   a,  such as to allow pressure equalization. 
     Several dimensions of and/or between various components of imaging probe  100  are illustrated in  FIG. 2C . Sheath  117  can overlap coating  111  with an overlap length D 15 . Optical core  110  can comprise a portion with length D 16 , with coating  111  removed. Lens  116  can comprise a length D 17 . Chamber  114  can comprise an opening with a length D 18 . Sheath  117  can extend beyond the distal end of lens  116  a length D 20 . Plug  113  can comprise a length D 19 . Imaging probe  100  can comprise a gap with length D 21 , D 21  representing the length between the distal end of plug  113  and sealing element  1192 . Sealing element  1192  can comprise a length D 1 . 
     In some embodiments, D 15  comprises a length of greater than 0.5 mm and/or less than 10 mm, such as a length of 0.7 mm. D 16  can comprise a length of greater than 0.5 mm and/or less than 10 mm, such as a length of 0.7 mm. D 17  can comprise a length of greater than 0.5 mm and/or less than 5 mm, such as a length of 1.1 mm. D 18  can comprise a length greater than 0.2 mm and/or less than 5 mm, such as a length of 0.4 mm. D 19  can comprise a length greater than 0.2 mm and/or less than 5 mm, such as a length of 0.5 mm. D 20  can comprise a length greater than 0.4 mm and/or less than 10 mm, such as a length of 0.9 mm. D 21  can comprise a length greater than 0.5 mm and/or less than 10 mm, such as a length of 0.7 mm. D 1  can comprise a length greater than 1 mm and/or less than 5 mm, such as a length of 2 mm. 
     Referring now to  FIGS. 3, 3A -D, and  3 E-G, an exploded view, four assembly views, a partial sectional view, a partially exploded view, and a perspective view of a connector assembly are illustrated, respectively, consistent with the present inventive concepts. Connector assembly  150  can be operably attached to the proximal end of an optical probe, such as imaging probe  100 , as described herein. Connector assembly  150  can be constructed and arranged to operably attach (e.g. optically and mechanically attach) imaging probe  100  to a rotating fiber optic connector (e.g. a standard Fiber Optic Rotary Joint, FORJ). Connector assembly  150  comprises a fiber optic connector  161 , configured to operably engage a mating connector and maintain a fiber optic connection. In some embodiments, fiber optic connector  161  comprises a commercially available fiber optic connector, such as a SC/APC fiber optic connector, such as those that are commonly used in telecommunication networks. In these embodiments, as described herein, connector assembly  150  can comprise one or more components constructed and arranged to operably engage, manipulate, and/or maintain the relative position and orientation of fiber optic connector  161  within connector assembly  150 . Connector assembly  150  can include one or more alignment components, as described herebelow, to operably attach to a rotation assembly, such as rotation assembly  500  described herein, while maintaining the rotational orientation of fiber optic connector  161  relative to rotation assembly  500  during attachment and/or detachment. Connector assembly  150  can comprise numerous forms of connectors, such as a bayonet or other locking connector. The following describes a bayonet type connector constructed and arranged to provide the necessary forces and constraints to make and maintain a connection between imaging probe  100  and rotation assembly  500 . 
     Connector assembly  150  comprises a rotating assembly  160 , a locking assembly  170 , and a housing, connector body  151 , surrounding at least a portion of rotating assembly  160  and locking assembly  170 . Connector assembly  150  can include a protective covering, skirt  154 . Skirt  154  can provide a seal between connector assembly  150  and connector assembly  510  of patient interface module  200 , as described herein, such as to prevent ingress of contaminates into housing  201  of patient interface module  200 . Rotating assembly  160  comprises optical connector  161 . In some embodiments, optical connector  161  comprises a connector requiring proper rotational alignment with a mating optical connector, such as optical rotary joint  550  of rotation assembly  500  described herein. Connector assembly  150  can be constructed and arranged to provide the proper alignment between the two connectors when connecting and/or disconnecting without the need for an additional alignment step, such as to obviate the need for any user (e.g. manual) and/or systematic alignment step. Optical connector  161  further comprises a coupling shaft, shaft  169 . Optical connector  161  (including coupling shaft  169 ) slidingly receives the proximal end of optical core  110  and torque shaft  105  (not shown). Torque shaft  105  and/or optical core  110  can operably attach to optical connector  161  (e.g. via coupling shaft  169 ), such that rotational force is applied to torque shaft  105  and/or optical core  110  by optical connector  161  (e.g. rotation of optical connector  161  causes the rotation of torque shaft  105  and/or optical core  110 ). In some embodiments, rotating assembly  160  is configured to rotate optical core  110  in a single direction (unidirectionally). Alternatively, rotating assembly  160  is configured to rotate optical core  110  in either direction (bidirectionally). The proximal end of optical core  110  is positioned within optical connector  161  such that the proximal end of optical core  110  is aligned with the proximal end of connector  161 , forming a first optical transmission surface  161   a,  configured to abut a second optical transmission surface  555  (e.g. of a mating optical connector), to form an optical connection. In some embodiments, the first and second optical transmission surfaces  161   a,    555 , can each comprise a bevel, such as to increase the amount of light transmitted thru the connection. Optical connector  161  can comprise a non-circular shape (e.g. a rectangular shape as shown), with an asymmetric profile, such that optical connector  161  can only mate with a second connector in a particular, aligned orientation (e.g. such that the beveled optical transmission surfaces are properly aligned). Rotating assembly  160  includes a circular housing, carrier  163 , and a locking connector, clip  162 , configured to fixedly maintain optical connector  161  within carrier  163 , such as is shown in  FIGS. 3A and 3B , two assembly views of rotating assembly  160 . Carrier  163  comprises a first radial recess, slot  164 , and one or more alignment recesses, holes  165 . Carrier  163  and/or clip  162  can comprise one or more reliefs (e.g. openings, slots and/or recesses) and/or projections sized and positioned to rotationally balance rotating assembly  160 . These reliefs and/or projections can be configured to offset any rotational imbalances of optical connector  161  or other component of rotating assembly  160  (e.g. optical connector  161  can be an unbalanced connector). When fully assembled, rotating assembly  160  is rotationally balanced such as to limit vibration or other adverse effects of an imbalanced load at high rotational speeds. 
     Locking assembly  170  comprises a housing, rotational lock  171 , a retention mechanism, connector retainer  175 , comprising one or more retention elements, projections  176 , and a biasing element, locking spring  179 . 
     Referring to  FIGS. 3C and 3D , opposing, partial sectional views of a portion of connector assembly  150  are illustrated. Rotational lock  171  comprises one or more projections, locking teeth  172  (three teeth  172   a - c  shown). Rotating assembly  160  is slidingly received within rotational lock  171 , such that locking teeth  172   a - c  slidingly engage holes  165  of carrier  163  ( 165   a  and  165   c  shown, with  165   b  positioned opposite projection  172   b ), when rotating assembly  160  is fully inserted within rotational lock  171 . This engagement locks the rotational orientation between rotational lock  171  and rotating assembly  160 . In some embodiments, locking teeth  172  comprises an asymmetric pattern, and holes  165  comprise a matching asymmetric pattern, such that there is a single rotational orientation in which carrier  163  can be fully engaged within rotational lock  171  (e.g. hole  165   a  and projection  172   a  are sized to mate exclusively). Alternatively or additionally, rotational lock  171  can comprise a friction plate for frictionally engaging carrier  163 . Connector retainer  175  is positioned about rotational lock  171  and carrier  163  (e.g. slidingly positioned about rotational lock  171  and carrier  163  in an assembly process), such that projections  176  are captured within slot  164 , preventing rotating assembly  160  from exiting rotational lock  171 . Slot  164  can comprise a width greater than the width of projection  176 , such that rotating assembly  160  can travel longitudinally (e.g. axially) within rotational lock  171 . For example, rotating assembly  160  can travel proximally such that locking teeth  172  disengage from holes  165  (e.g. rotational lock  171  can travel distally relative to rotating assembly  160  when a force is applied to rotational lock  171  as described herebelow). Projections  176  can operably engage the distal edge of slot  164 , preventing rotating assembly  160  from exiting rotational lock  171 . Additionally, carrier  163  can travel distally from the proximal most position, such that locking teeth  172  engage holes  165 , and the distal end of carrier  163  abuts the back wall of rotational lock  171 . 
     Referring to  FIGS. 3E-G , rotating and locking assemblies  160 ,  170  shown are slidingly received within connector body  151 . Locking assembly  170  is rotationally fixed within connector body  151 . Rotating assembly  160  is rotationally fixed to locking assembly  170  when locking teeth  172  are engaged with holes  165 , and therefore also fixed to connector body  151 ; otherwise rotating assembly  160  is free to rotate within connector body  151 . In some embodiments, connector retainer  175  is fixedly positioned within connector body  151 , and rotational lock  171 , as well as rotating assembly  160  “float” within connector body  151 , relative to connector retainer  175 . Rotating assembly  160  is “captured” by connector retainer  175 , such that it is allowed to rotate and travel longitudinally, as described hereabove, between a proximal-most location (where projections  176  engage slot  164 ) and a distal-most location (where the distal end of rotating assembly  160  abuts rotational lock  171 ). Connector assembly  150  can further comprise a biasing element, spring  179 , configured to bias one or more components of connector assembly  150 , such as when connector assembly  150  is not connected to a mating connector. For example, spring  179  can be positioned between a portion of connector body  151  and rotational lock  171 , biasing rotational lock  171  distally against rotating assembly  160 . Rotating assembly  160  is in turn biased against connector retainer  175  in its proximal-most position. This biased arrangement can prevent disengagement of locking teeth  172  from holes  165 , maintaining the relative rotational orientation between rotating assembly  160  and connector body  151 , while connector assembly  150  is not connected to a mating connector. Alternatively or additionally, when connector assembly  150  is connected to a mating connector, spring  179  can bias connector body  151  “out of” the mating connector, helping to facilitate one or more interlocking mechanisms, as described herebelow in reference to  FIGS. 6A-D . 
     Connector body  151  includes one or more projections for alignment and engagement with a mating connector. As shown, connector body  151  comprises a first projection, alignment marker  152 , configured to visually and operably align connector assembly  150  to a mating connector, as described herebelow in reference to  FIGS. 4A through 6D . Alignment marker  152  can indicate the “top” of connector body  151 , and be rotationally aligned with the “top” of optical connector  161 , for example when optical connector  161  is rotationally locked relative to connector body  151  via rotational lock  171 . Connector body  151  can further include one, two or more locking projections, projections  153   a  and  153   c  shown (projection  153   b  not shown but positioned behind connector body  151 ). Connector assembly  150  can further comprise a second body portion, cover  155 . Cover  155  can comprise one or more mating elements, recess  159   a  shown, configured to properly align cover  155  to connector body  151  by aligning with one or more mating elements of connector body  151 , projection  159   b  shown. Cover  155  can include instructional markings, markings  156 , and one or more depressed, contoured, or otherwise ergonomic portions, grips  157 . Grips  157  can be constructed and arranged such that a user can naturally grasp connector assembly  150 , align connector assembly  150  with a mating connector (e.g. while using markers  152  and  156  for alignment and instruction), and insert and twist connector assembly  150  to secure the connection. Markings  156 , along with marking  152  can indicate to the user the steps for engaging connector assembly  150  to a mating connector, for example, insert, push, and turn. 
     Connector assembly  150  can further include an element configured to reduce strain between connector  150  and one or more components of imaging probe  100 , strain relief  158 . As shown, imaging probe  100  comprises an outer proximal shaft, outer shaft  101 , surrounding at least optical core  110  and torque shaft  105 . Strain relief  158  slidingly receives outer shaft  101 , which is fixedly attached to connector assembly  150 . Optical core  110  and torque shaft  105  are free to rotate within outer shaft  101 . 
     Referring now to  FIGS. 4A-C , two perspective views of connectors being attached to a patient interface module and a perspective view of a portion of the patient interface module with the outer casing removed are illustrated, respectively, consistent with the present inventive concepts. Patient interface module  200  is configured to provide rotation to a rotatable optical core of an imaging probe, and to provide a motive force to translate at least a portion of the imaging probe, such as is described herebelow. Patient interface module  200  comprises rotation assembly  500 , and at least a portion of retraction assembly  800 . A housing  201  surrounds patient interface module  200 . Patient interface module  200  can comprise one or more user interface elements, such as one or more inputs, buttons  205   a,b,  and one or more outputs, indicator  206  shown. Patient interface module  200  comprises a first physical connector assembly, connector assembly  510 , for operably connecting to connector assembly  150 , as described herein. Patient interface module  200  can further comprise a second physical connector assembly, connector assembly  820   a,  for operably connecting to connector  840 , also as described herein. As shown in  FIG. 4A , connector assembly  150  and connector  840  can each comprise bayonet type connectors, constructed and arranged to be at least partially inserted into connector assemblies  510  and  820   a,  respectively. Connector assembly  150  and connector  840  can be subsequently rotated (e.g. an approximately 45° rotation) to lock their connections with connector assemblies  510  and  820   a,  respectively, as described herein. Connector assembly  150  and/or  840  can comprise numerous forms of connectors, such as a bayonet or other locking connectors. The following describes bayonet type connectors constructed and arranged to provide the necessary forces and constraints to make and maintain a connection between imaging probe  100  and rotation assembly  500 . 
     As shown in  FIG. 4C , connector assembly  510  comprises a floating locking portion, sleeve  515 . Sleeve  515  comprises one or more “cut away” portions or reliefs, openings  517   a - c  ( 517   b,c  not shown, but positioned about sleeve  515 , such as positioned equally about sleeve  515 ). The distal edge of openings  517   a - c  comprise an engineered shape, locking profiles  518   a - c  (profile  518   a  shown). Locking profiles  518   a - c  can be constructed and arranged to operably engage projections  153   a - c  of connector body  151 , as described herebelow (projection  153   a  shown in  FIG. 4C ). Sleeve  515  can comprise one or more passageways, recesses  516   a - c  (recess  516   a  shown in  FIG. 4C ). Recesses  516   a - c  ensure proper alignment of connector assembly  150  when inserted into connector assembly  510 . Projections  153   a - c  pass thru recesses  516   a - c,  and into openings  517   a - c,  respectively. As projections  153   a - c  enter openings  517   a - c,  connector assembly  150  is free to rotate relative to connector assembly  510 . 
     After connector body  151  is inserted into connector assembly  510 , connector assembly  150  is rotated, as shown in  FIG. 4B , and projections  153   a - c  slidingly engage locking profiles  518   a - c.  Locking profiles  518   a - c  are constructed and arranged such that projections  153   a - c  (as well as connector assembly  150 ) are initially forced inward, towards connector assembly  510  when rotated. Connector assembly  510  can comprise one or more biasing elements, retention elements  519 . Retention elements  519  can comprise one or more retention elements, such as three elements spaced equally around the perimeter of sleeve  515 . Retention elements  519  can comprise spring assemblies, constructed and arranged to bias sleeve  515  “inward”, towards the proximal end of connector assembly  510 . Retention elements  519  allow sleeve  515  to travel outward, as forced by projections  153   a - c  against locking profiles  158   a - c.  Retention elements  519  can be constructed and arranged such that sleeve  515  applies a predetermined force to connector assembly  150  when rotated to engage locking profiles  518   a - c.    
     Patient interface module  200  comprises a structural support, frame  202 , onto which the elements of rotation assembly  500  and retraction assembly  800  can be mounted (e.g. directly and/or indirectly mounted, to secure the relative position of the elements within patient interface module  200 ). Connector  840 , described herebelow in detail in reference to  FIGS. 7A-C , can similarly be attached to connector assembly  820   a.  An embodiment of connector assembly  820   a  is described in detail herebelow in reference to  FIG. 9 . 
     Referring now to  FIGS. 5, and 5A -D, perspective, partial cut away views of components of a patient interface module are illustrated, consistent with the present inventive concepts.  FIG. 5  illustrates the connector assemblies  510  and  820   a,  and components of rotation assembly  500  within patient interface module  200 , with housing  201  removed.  FIGS. 5A and 5B  illustrate connector assembly  150  operably connected to connector assembly  510 . In  FIG. 5A , one or more components are sectioned, revealing sleeve  512 , rotational lock  171 , and connector retainer  175 . In  FIG. 5B , sleeve  512 , rotational lock  171 , and connector retainer  175  are also sectioned, revealing rotating assembly  160  and mating components within sleeve  512 .  FIGS. 5C and 5D  illustrate an assembly comprising a fiber optic rotary joint  560 . In  FIG. 5C , multiple components are shown sectioned, and multiple components are shown transparently. In  FIG. 5D , multiple components are shown sectioned. 
     Rotation assembly  500  comprises an optical connector, rotary joint  550 , and a fiber optic rotary joint, rotary joint  560 . As shown in  FIGS. 5C and 5D , rotary joint  560  comprises a fixed portion, housing  561 . A rotating portion, spindle  562 , rotates relative to housing  561 . At least a portion of spindle  562  is positioned within housing  561 . Rotary joint  560  can comprise one or more rotary bearings, bearings  563   a - b  shown, configured to limit friction and provide a smooth interface for rotation between spindle  562  and housing  561 . 
     Sleeve  515  surrounds a fixed connection element, sleeve  512 . Connector body  151  is slidingly received between sleeves  515  and  512  (i.e. during and while connector assembly  150  is connected to connector assembly  510 ). As connector assembly  150  is inserted into connector assembly  510 , sleeve  512  opposes rotational lock  171 , preventing rotational lock  171  from traveling proximally (further “into” connector assembly  510 ) beyond a predetermined distance. As connector body  151  is pushed further into connector assembly  510 , locking spring  179  is depressed by rotational lock  171 . Connector body  151  can be configured to abut carrier  163  when spring  179  is sufficiently depressed, such as to apply a force to carrier  163  as connector body  151  is pushed further into connector assembly  510  (e.g. pushed further via rotation of connector body  151  within sleeve  515 , as locking profiles  518   a - c  force connector body  151  forward). This force between connector body  151  and carrier  163  can be sufficient to ensure optical connector  161  fully engages receptacle  551 . 
     Referring back to  FIG. 5 , Rotation assembly  500  comprises motive element  530  which can be configured to provide a motive force that causes translation (e.g. retraction) of at least a portion of an imaging probe of the present inventive concepts. Motive element  530  can comprise a motor, configured to provide a rotary force to spindle  562 . Motive element  530  can comprise a force transfer element, pulley  535 , operably attached to a force transfer element of spindle  562 , gear  511 . Pulley  535  and gear  511  can be operably connected via a drive mechanism, linkage  536 . In some embodiments, linkage  536  comprises a chain or other drive mechanism. In some embodiments, pulley  535  and gear  511  comprise a force and/or speed multiplying relationship, such as a 1:2 ratio. 
     Referring to  FIGS. 5C and 5D , rotary joint  550  can comprise a receptacle  551 , configured to slidingly receive optical connector  161  of rotating assembly  160 . Receptacle  551  can comprise a recess  552 , configured to slidingly receive a projection from optical connector  161  when connector  161  is properly aligned with receptacle  551 . Rotary joint  550  can comprise a “floating” portion  553 , configured to compensate for motion (e.g. linear motion) during and/or after the connection of optical connector  161  to rotary joint  550 . Compensation is achieved by floating portion  553  moving axially within rotary joint  550 . Floating portion  553  can be biased towards the distal end of receptacle  551  (e.g. biased toward optical connector  161 ), such as when floating portion  553  includes a biasing spring. In some embodiments, after the connection of rotary joint  550  and connector  161 , the resulting axial forces are balanced, such that there is minimal axial movement of floating portion  553  after the connection is made. In some embodiments, the balanced axial forces are adjusted (e.g. by adjusting the spring force of one or more force balancing springs) such that the force between optical transmission surfaces  555  and  161   a  is both sufficient for optical transmission, and below a level that may damage either optical transmission surface  555  and/or  161   a.  Floating portion  553  surrounds and is operably attached to an intermediate fiber optic conduit, fiber optic cable  556 . Fiber optic cable  556  terminates distally at an optical transmission surface  555 . Optical transmission surface  555  is configured to abut optical transmission surface  161   a  when connected to optical connector  161 , as described hereabove. The medial portion of fiber optic cable  556  is positioned within a recess or other space within spindle  562 , channel  554 . Fiber optic cable  556  terminates proximally at a fiber optic rotary coupling, rotary coupler  565 . To compensate for linear displacement of floating portion  553 , channel  554  can be constructed and arranged to allow fiber optic cable  556  to “buckle” within channel  554  (e.g. transition into in the “S” shape shown), and it can be sized and arranged to accommodate the maximum linear displacement of floating portion  553 . Channel  554  can be further constructed and arranged such that the buckling of fiber optic cable  556  is rotationally balanced (e.g. limited to a single plane, such that the axis of symmetry of the “S” is coincident with the axis of rotation of spindle  562 ), such as to not induce a wobble and/or other vibration in spindle  562  when rotated at high speed. In some embodiments, channel  554  comprises an “S” shape. The “S” shape can comprise a radius configured to minimize light loss through fiber optic cable  556 . 
     Rotary coupler  565  operably attaches to fiber optic cable  556  and to an output fiber optic cable, output fiber  569 . Rotary coupler  565  optically and rotatably couples fiber optic cable  556 , which rotates with spindle  562 , to output fiber  569 , which is fixedly attached (e.g. does not rotate) to housing  561 . 
     Sleeve  515  surrounds a fixed connection element, sleeve  512 . Connector body  151  is slidingly received between sleeves  515  and  512  (i.e. during and while connector assembly  150  is connected to connector assembly  510 ). As connector assembly  150  is inserted into connector assembly  510 , sleeve  512  opposes rotational lock  171 , preventing rotational lock  171  from traveling proximally (further “into” connector assembly  510 ) beyond a predetermined distance. As connector body  151  is pushed further into connector assembly  510 , locking spring  179  is depressed by rotational lock  171 . Connector body  151  can be configured to abut carrier  163  when spring  179  is sufficiently depressed, such as to apply a force to carrier  163  as connector body  151  is pushed further into connector assembly  510  (e.g. push further via rotation of connector body  151  within sleeve  515 , as locking profiles  518   a - c  force connector body  151  forward). This force between connector body  151  and carrier  163  can be sufficient to ensure optical connector  161  fully engages receptacle  551 . 
     Referring now to  FIGS. 6A-D , schematic views of a locking mechanism are illustrated, consistent with the present inventive concepts. A projection  153  and alignment marker  152  of connector body  151  are shown, with all other components of connector assembly  150  removed for illustrative clarity. A line connecting projection  153  and marker  152  is shown,  151 ′, representing the relative position of a portion of connector body  151  between  FIGS. 6A-D . An opening  517  and a locking profile  518  of sleeve  515  are also shown, with other components of connector assembly  510  removed for illustrative clarity. The following describes the interaction of projection  153  and alignment marker  152  (also a projection from connector body  151 ) with locking profile  518 , as connector body  151  is slidingly received and rotated within sleeve  515 , such as to lock connector assembly  150  with connector assembly  510 . 
     As connector body  151  is inserted (in a proximal direction) into sleeve  515 , alignment marker  152  is slidingly received by recess  516 , followed by projection  153 . As projection  153  exits recess  516  and enters opening  517 , connector body  151  is free to rotate (e.g. clockwise as indicated). Also, as projection  153  exits recess  516 , optical connector  161  has been at least partially slidingly received by receptacle  551 , such that the proper alignment between the two is maintained. Sleeve  512  opposes rotational lock  171 , such as to release locking teeth  172   a - c  from holes  165   a - c  as rotating assembly  160  is forced forward, such that connector body  151  is free to rotate about rotating assembly  160  (as described hereabove). As connector body  151  is rotated clockwise, a first portion of locking profile  518 , ramp  518   i,  forces projection  153  proximally, as shown in  FIG. 6B . This in turn forces connector body  151 , and rotating assembly  160  forward. Locking assembly  170  is maintained in its axial position by sleeve  512 . Rotating assembly  160  does not rotate, as it is operably engaged to receptacle  551 , and freed from locking assembly  170 . In  FIG. 6C , projection  153  is shown in its most proximal position (e.g. as forced by point  518   ii  of locking profile  518 ). Connector assemblies  150  and  510  can be constructed and arranged such that in the position indicated in  FIG. 6C , connector body  151  forces optical connector  161  proximally such that it fully engages receptacle  551 . In some embodiments, sleeve  515  is biased proximally (such as with one or more retention elements  519 , as described herein), such that connector assembly  510  is constructed and arranged to provide a maximum force to projection  153  when forced proximally by point  518   ii.  In some embodiments, retention elements  519  allow accommodation of tolerances in and/or between connector assembly  150  and connector assembly  510  when the two are mated. 
     As connector body  151  is rotated further (i.e. further clockwise as indicated), ramp  518   iv  of locking profile  518  forces marker  152  distally, as ramp  518   iii  allows projection  153  to also retract distally, as shown in  FIG. 6D . As projection  153  passes point  518   ii,  the bias of spring  179  between connector body  151  and locking assembly  170  also drives projection  153  along ramp  518   iii.  Connector assemblies  150  and  510  can be constructed and arranged such that in the final locked position of connector body  151  within sleeve  515 , one or more of the following conditions are met: optical connector  161  is fully engaged within receptacle  551 ; connector body  151  is displaced laterally (e.g. distally) from the distal end of rotating assembly  160  such that there is no and/or limited frictional force between connector body  151  and rotating assembly  160 ; projections  176  of connector retainer  175  are positioned within slot  164  of rotating assembly  160 , such that there is no and/or limited frictional force between rotating assembly  160  and locking assembly  170 . During operation, such as during a clinical procedure, motive element  530  is constructed and arranged to rotate spindle  562 , and in turn rotate rotating assembly  160  which is operably attached to receptacle  551 . In order to maintain rotational alignment with components of connector assembly  150 , motive element  530  can be constructed and arranged to only stop spindle  562  in the position aligned with the connection orientation (e.g. spindle  562  only stops at “top dead center” when motive element  130  is stopped). Motive element  530  can comprise a servo type motor to achieve this, and/or one or more sensors or biasing elements can be used to ensure this rotational orientation upon stopping. In some embodiments, motive element  530  and/or spindle  562  comprise a bias, such that top dead center is always achieved, even in the event of a power loss to rotation assembly  500 . 
     When connector assembly  150  is disconnected from connector assembly  510 , connector body  151  is rotated clockwise as indicated. Projection  153  is forced forward by ramp  518   iii,  beyond point  518   ii,  and can be retracted (e.g. by the user) along ramp  518   i  towards recess  516 . As connector body  151  is retracted from sleeve  515 , projection  153  and marker  152  align with recess  516 , ensuring the alignment of rotating assembly  160  with locking assembly  170 . Projections  176  can operably engage the distal edge of slot  164 , pulling rotating assembly  160  from receptacle  551 , as rotational lock  171  is biased against carrier  163 . Connector assemblies  150  and  510  can be constructed and arranged such that locking teeth  172  operably engage holes  165 , prior to optical connector  161  disengaging from receptacle  551 , such that the orientation of rotating assembly  160  is continuously maintained. 
     Referring now to  FIGS. 7A-C , an exploded view, a perspective view, and a sectional view of a connector assembly are illustrated, respectively, consistent with the present inventive concepts. Connector assembly  840  can be operably attached to the proximal end of a mechanical linkage, linkage assembly  890 . Linkage assembly  890  operably attaches to pullback module  880 , as described herebelow in reference to  FIGS. 8A-B . Connector assembly  840  can operably attach linkage  891  of linkage assembly  890  to motive element  830 . Motive element  830  can comprise a linear actuator or other component that provides a force to linkage  891  such that linkage  891  advances and/or retracts relative to sheaths  895 ,  896 , as described hereabove in reference to  FIG. 1A . In some embodiments, patient interface module  200  is configured to only retract linkage  891 , for example when linkage  891  can be manually or otherwise advanced, as described herein. 
     Linkage assembly  890  comprises outer sheath  895 , inner sheath  896 , and linkage  891 . In some embodiments, sheath  895  provides a protective barrier for inner sheath  896 . Inner sheath  896  can comprise a conduit configured to provide column strength to linkage assembly  890 , such as a conduit comprising a torque wire. Sheaths  895 ,  896  slidingly receive linkage  891 . Linkage  891  can comprise a wire, cable, or other filament. Linkage  891  comprises a proximal end  893 . Proximal end  893  can extend beyond the proximal end of sheath  896 , through connector  840 , and into capture port  846  as described herebelow. Proximal end  893  can comprise a termination point such as a knot, crimp, and/or other feature to allow for the engagement of linkage  891  to capture port  846 . 
     Connector  840  can comprise housing  848 , such as a two-part housing with distal and proximal portions, housing  848   a  and housing  848   b  respectively. Housing  848   a,b  can comprise keyed geometries such that the two portions do not rotate relative to each other when assembled, as shown in  FIG. 7B . Connector  840  can include a protective covering, skirt  849   b.  Skirt  849   b  can provide a seal between housings  848   a,b,  as well as around connector assembly  820   a  of patient interface module  200 , as described herein, such as to prevent ingress of contaminates into housing  848 . Connector  840  can further include a tension relieving element, strain relief  849   a.  In some embodiments, strain relief  849   a  surrounds a portion of linkage assembly  890  near the distal end of connector assembly  840 , providing strain relief near the entry point of linkage assembly  890  into housing  848   a.  Connector  840  can comprise one, two or more locking projections, projection  844   a  and projection  844   b  shown. In some embodiments, projection  844   a  and projection  844   b  are positioned and spaced equally about housing  848   b  (e.g. two projections  844   a,b,  as shown, are positioned 180 degrees relative to each other). Connector  840  can further comprise locking elements, pins  843   a  and  843   b  shown. Pins  843   a,b  can be slidingly received through and engaged with a receiving portion (e.g. a hole, cutout, recess, or the like) of both housing  848   a  and housing  848   b,  locking the housings together. Alternatively or additionally, housing  848   a  and housing  848   b  can be glued or otherwise permanently or semi-permanently attached to each other. 
     Connector  840  can comprise connector assembly  845 . Connector assembly  845  is slidingly received within the proximal end of connector  840 , and it receives and fixedly attaches to proximal end  893  of linkage  891 . Connector assembly  845  can comprise capture port  846  and connection point  842 . Proximal end  893  of linkage  891  can comprise a geometry such that proximal end  893  is captured within capture port  846  (e.g. proximal end  893  is passed thru an opening in the distal end of capture port  846 , and a knot is tied, preventing egress of the distal end from the port). A bulbous connecting point, connecting point  842 , is operably attached to the proximal end of capture port  846 . Connecting point  842  can be configured to operably engage motive element  830 , of retraction assembly  800 , as described herein. 
     Connector  840  can comprise a tensioning element, tensioning assembly  841 . Tensioning assembly  841  can comprise a tensioning screw  841   a  and a tensioning nut  841   b.  Tensioning screw  841   a  can operably attach to the proximal end of sheath  895  and/or to the proximal end of sheath liner  896 . As shown in  FIG. 7C , sheath  895  terminates near the distal end of tensioning screw  841   a,  and sheath liner  896  is received within tensioning screw  841   a,  and is fixedly attached thereto. Sheath liner  896  can be glued or otherwise fixedly attached to tensioning screw  841   a.  Linkage  891  extends to connector assembly  845  through an opening at the proximal end of screw  841   a.  Housing  848   a  comprises a cavity configured to receive and secure tensioning screw  841   a,  preventing the rotation of screw  841   a  within housing  848   a.  Housing  848   b  can comprise a cavity configured to receive and secure tensioning nut  841   b,  preventing the rotation of nut  841   b  within housing  848   b,  and positioning nut  841   b  a set distance from the proximal end of connector  840 . Tensioning assembly  841  can adjust the relative position of proximal end  893  of linkage  891  to the proximal end of sheath  895 , such as an adjustment performed in an assembly process as described immediately herebelow. 
     Linkage assembly  890  can be singly received by strain relief  849   a  and housing  848   a.  Housing  848   a  can be temporarily positioned about linkage assembly  890  away from the proximal end of linkage assembly  890 , to allow for tensioning adjustments or other assembly steps (e.g. during the manufacturing process). Linkage  891  can subsequently be slidingly received by tensioning assembly  841 , skirt  849   b,  housing  848   b,  and capture port  846 , with the proximal end  893  of linkage  891  extending beyond the proximal end of capture port  846 . Proximal end  893  can then be knotted, or otherwise modified for securement, such that capture port  846  can be slid proximally, capturing proximal end  893 , as shown in  FIG. 7C . Connection point  842  can then be secured to the proximal end of capture port  846 , and housing  848   b  can be slid proximally along linkage  891 , such that connection assembly  845  is partially received within the proximal end of housing  848   b,  as shown. Tensioning nut  841   b  can be positioned within the distal end of housing  848   b.  Housing  848   b  comprises a geometry such that a minimum distance between connection assembly  845  and tensioning nut  841   b  is maintained. Sheath  895  and/or sheath  896  are fixedly attached to tensioning screw  841   a,  as described hereabove, and tensioning screw  841   a  is operably attached to tensioning nut  841   b,  (i.e. tensioning screw  841   a  is at least partially screwed into tensioning nut  841   b ). Tensioning assembly  841  can be adjusted, such as to adjust the minimum relative distance between proximal end  893  of linkage  891 , and the proximal end of sheath  895  and/or sheath  896 . This distance can be adjusted to modify the relative positions of one or more connected components of pullback housing  881 , as described herebelow in reference to  FIG. 8A . After the optimal relative position of components is achieved, housing  848   a  can be slid proximally, along linkage assembly  890 , such that tensioning screw  841   a  is captured within housing  848   a,  preventing rotation of tensioning screw  841   a  relative to nut  841   b,  locking the relative component positions. Housing  848   a  is then fixedly or removably attached to housing  848   b.  After assembly, translation of connection assembly  845  proximally away from housing  848   b  pulls linkage  891 , slidingly through sheath  895 , such that the distal end of linkage  891  translates relative to the distal end of sheath  895 , as described herebelow in reference to  FIG. 8A . As linkage  891  is pulled distally, again as described herebelow, connector  840  prevents translation beyond the established minimum relative distance between proximal end  893  and the proximal end of sheath  895 . 
     Referring now to  FIGS. 8A-C , an exploded view, a perspective view, and an end view of a pullback assembly are illustrated, respectively, consistent with the present inventive concepts. Pullback module  880  can be operably attached to a portion of an imaging probe of the present inventive concepts, and provide a retraction force to the probe, pulling at least a portion of the probe proximally relative to a patient (e.g. relative to a patient introduction device), as described herebelow. Pullback module  880  can be operably attached to the distal end of a linkage  891 . The proximal portion of linkage  891  operably attaches to connector assembly  840 , as described hereabove in reference to  FIGS. 7A-C . 
     Pullback module  880  can comprise a two-part housing  881 , including a top housing  881   a  and bottom housing  881   b,  as shown in  FIG. 8A . Module  880  can comprise one or more guide elements, rails  883   a,b.  Module  880  can contain a translating cart, puller  850 . Puller  850  can be designed to translate within module  880  along rails  883   a,b.  Puller  850  slidingly receives rails  883   a,b  via recesses  851   a,b.  Recesses  851   a,b  are designed to partially or completely encompass rails  883   a,b,  such as to limit movement of puller  850  to translation along the axis of the rails  833   a,b.  Alternatively or additionally, housing  881  can comprise a geometry such that the motion of puller  850  is limited to axial translation within housing  881 . Module  880  can comprise a biasing element, spring  852 . Spring  852  can provide a biasing force to puller  850 , such as to bias puller  850  distally. 
     Linkage assembly  890  can be slidingly received through strain relief  887 . Strain relief  887  can be fixedly attached to the proximal end of module  880 . Sheath  895  and/or sheath  896  can be fixedly attached to the proximal end of module  880 . In some embodiments, strain relief  887  comprises a “hub” positioned between a flexible strain relieving portion and a portion of sheath  895  and/or sheath  896  and attached thereto. Strain relief  887  can aid in the attachment of sheath  895  and/or sheath  896  to module  880 . Linkage  891  is slidingly received along the length of module  880  and is operably attached at its distal end to puller  850 . Linkage  891  can comprise distal end  892  and can comprise a geometry that aids in the attachment of linkage  891  to puller  850 . For example, distal end  892  can comprise a termination element, such as a knot or other feature arranged to allow for the secure engagement of linkage  891  to puller  850 . 
     Top housing  880   a  can comprise a first cavity, retention port  884  and a second cavity, trench  889 . Retention port  884  and trench  889  can be separated by a projection, retention wall  888 . Physical connector assembly  820   b  can comprise a retention port of housing  881   a,  including wall  888 , and a retention mechanism, clip  885 . Clip  885  can be configured to releasably engage the proximal end of a delivery catheter such as sheath connector  82  of delivery catheter  80 , such as when connector  82  comprises a Tuohy Borst connector. Physical connector assembly  820   b  can further comprise a biasing element, spring  886 . Spring  886  can provide a biasing force to maintain clip  885  in an engaged position about connector  82 , as shown in  FIG. 8B . 
     Clip  885  can comprise a first projection, projection  885   a,  configured to partially surround connector  82  when connector  82  is inserted into retention port  884 , as shown in  FIG. 8C . Clip  885  can rotate about an axis, axis A 1 , to allow sheath connector  82  to enter retention port  884  and rotate projection  885   a  “back” to engage connector  82 . Second projection  885   b  extends through module  880  (e.g. through an opening in the wall of housing  881   a ). Clip  885  rotates about axis A 1  to release connector  82  when second projection  885   b  is engaged (e.g. engaged by a user). 
     Pullback module  880  can further comprise a carrier  855 . Carrier  855  can operably attach to puller  850 , such as through a slot  889   a  in housing  881   a.  Carrier  855  can translate within trench  889  in response to puller  850 , which translates in response to linkage  891 . Carrier  855  can operably attach to a portion of imaging probe  100 , such as to a pullback connector  180 . Pullback connector  180  can comprise a “torquer”, or other device affixed to shaft  120  of imaging probe  100 . Sheath  895  and/or sheath liner  896  of linkage assembly  890  provide a frame of reference between connector  840  and pullback module  880 , such that when the proximal end of linkage  891  is retracted relative to connector  840  (as described hereabove in reference to  FIGS. 7A-C ), the distal end of linkage  891  is retracted towards sheath  895  (i.e. towards the proximal end of pullback module  880 ). This relative motion transfers motive force applied at connector  840  (e.g. via motive element  830 , as described herein), to puller  850 . Puller  850 , subsequently transfers the motive force to imaging probe  100 , and imaging probe  100  is retracted relative to the patient. 
     In operation, imaging probe  100  can be manually (e.g. by a user) advanced through the vasculature of the patient. Pullback module  880  can be attached to the patient (e.g. to delivery catheter  80  via connector  82 ), and connector  180  can be operably connected to imaging probe  100 , and positioned proximate delivery catheter  80  (e.g. a torquer connector  180  can be tightened to imaging probe  100  proximate delivery catheter  80 ). Connector  180  (not shown) can be operably positioned within carrier  855 , and a motive force can be applied to the distal end of linkage  891 . Carrier  855  retracts within trench  889 , retracting imaging probe  100  relative to the patient. After retraction, connector  180  can be removed from carrier  855  (e.g. lifted out of), and carrier  855  and imaging probe  100  can be re-advanced independently. For example, carrier  855  can re-advance via the bias of spring  852 , as the proximal end of linkage  891  is allowed to advance, and imaging probe  100  can be re-advanced manually by a user. Subsequent retractions can be performed by repositioning connector  180  in carrier  855  after both have been re-advanced. Carrier  855  can comprise a capturing portion, such as the “cup-like” geometry shown, a hook, or other capture-enabling portion, such that carrier  855  can only impart a retraction force on connector  180 . In this configuration, if carrier  855  were to translate distally, connector  180  would automatically disengage from carrier  855  (e.g. connector  180  would fall out of the cup portion of carrier  855 ). 
     Referring back to  FIG. 7C , tensioning assembly  841  can be adjusted to assure proper operation. If tensioning assembly  841  is too “tight”, distal end  892  of linkage  891  will not reach puller  850  (e.g. when puller  850  is in its distal most position). In these instances, adjustment of tensioning assembly  841  can be made to cause the distal end of linkage  891  to “reach” puller  850 . If tensioning assembly  841  is too “loose”, there will be slack in linkage  891  when connection assembly  845  is fully seated within housing  848   b.  In these instances, adjustment of tensioning assembly  841  can be made to remove the slack in linkage  891 . 
     Referring now to  FIG. 9 , a perspective view of components of a patient interface module is illustrated, consistent with the present inventive concepts. Patient interface module  200  is configured to provide rotation to a rotatable optical core of an imaging probe, and to provide a motive force to translate at least a portion of the imaging probe, such as is described herebelow. In  FIG. 9 , housing  201 , and other components of patient interface module  200  are removed for illustrative clarity, revealing connector assembly  820   a  and retraction assembly  800 . In the illustrated embodiment, connector assembly  820   a  comprises a floating locking portion, sleeve  825 . Sleeve  825  comprises one or more cut away portions, slots  827   a,b  (slot  827   a  not shown but positioned opposite slot  827   b ), and one or more passageways, recesses  826   a,b  (recess  826   b  not shown but positioned opposite recess  826   a ), providing sliding access into slots  827   a,b  as described herebelow. Sleeve  825  can further comprise one or more locking elements, projections  828   a,b  (projection  828   a  not shown but positioned opposite projection  828   b ), extending into slots  827   a,b,  respectively. 
     Sleeve  825  surrounds a fixed connection element, sleeve  822 . Sleeve  822  is fixedly attached to frame  202  of patient interface module  200  (portions of frame  202  removed for illustrative clarity). Sleeve  822  can comprise one or more elongate cut away portions, slots  821   a,b  (slot  821   b  not shown but positioned opposite slot  821   a ), and one or more cut away portions, slots  827   a,b,  that slidingly receive projections  844   a,b  of connector  840  (connector  840  and projections  844  not shown). Sleeve  825  is slidingly received over sleeve  822 . Slots  827   a,b  are aligned with slots  823   a,b,  (slot  823   a  not shown but positioned opposite slot  823   b ) and recesses  826   a,b  are aligned with the distal opening of slots  823   a,b,  such that when housing  848   b  (not shown) of connector  840  is slidingly received within sleeve  822 , projections  844   a,b  are slidingly received by both slots  823   a,b  and slots  827   a,b,  respectively. Slots  823   a,b  and  827   a,b  can each comprise a geometry (e.g. an elongated, curvilinear opening) such that after projections  844   a,b  are received therein, connector  840  can be rotated (e.g. rotated clockwise), as projections  844   a,b  translate within slots  823   a,b  and  827   a,b,  locking connector  840  to connector assembly  820   a.    
     Sleeve  825  can be slidingly attached to sleeve  822  via one or more securing elements, pins  824   a,b  (pin  824   b  not shown but positioned opposite pin  824   a ) through sleeve  822 , extending into slots  821   a,b  of sleeve  822 . In some embodiments, connector assembly  820   a  comprises a biasing element, spring  829 . Spring  829  can provide a biasing force to sleeve  825 , such that pins  824   a,b  engage the distal end of slots  821   a,b,  respectively. In this embodiment, as connector  840  is rotated within connector assembly  820   a,  projections  828   a,b  impede the rotation by frictionally engaging projections  844   a,b  within slots  827   a,b,  respectively. As projections  844   a,b  engage projections  828   a,b,  sleeve  825  is forced inwards against spring  829 , and returns as projections  844   a,b  continue past projections  828   a,b.  Spring  829  provides a retention force, preventing (or at least limiting the likelihood of) connector  840  from rotating past projections  828   a,b  and unintentionally disconnecting from connector assembly  820   a.    
     Patient interface module  200  includes motive element  830  of retraction assembly  800 . Motive element  830  can be configured to provide a motive force that causes translation (e.g. retraction) of at least a portion of an imaging probe of the present inventive concepts. In the embodiment shown, motive element  830  comprises a linear actuator including a worm gear driven cart. Motive element  830  includes motor  831 , operably attached to a worm gear, drive  832 . A translating fixture, cart  833 , is slidingly affixed to a linear bearing, slide  834 . Slide  834  and motor  831  are fixedly attached to frame  202  of patient interface module  200 . Drive  832  operably engages cart  833 , such that as drive  832  is rotated by motor  831 , cart  833  translates along slide  834 . A connector that is fixedly attached to cart  833 , connector  835 , releasably attaches to connection point  842  (not shown) of connector  840 , for example when connector  840  is operably attached to connector assembly  820   a.  Connector  835  can comprise a clamshell or other locking construction, configured to “grasp” or otherwise engage a connector, such as connection point  842 . Connector  835  can be biased in an “open” position, as shown, when cart  833  is in its distal most position, ready to receive a connection point. As cart  833  is moved proximally, connector  835  can close around an inserted connection point, operably attaching thereto. One or more cams, springs, hinges, leavers, ramps, or other mechanisms can be included in connector  835  and/or motive element  830  to bias and/or operably open and close connector  835 . In some embodiments, connector  835  comprises an electromagnetic connector, such as an electromagnet, configured to operably attach to a connection point via magnetic attraction. In these and other embodiments, connector  835  can automatically disconnect from an attached connection point in the case of an emergency (e.g. a power loss), to allow a user to disconnect a pullback device from retraction assembly  800 . 
     Referring now to  FIGS. 10A and 10B , perspective and partial sectional views of a connector assembly are illustrated, respectively, consistent with the present inventive concepts. As described hereabove in reference to  FIG. 1B , in some embodiments, a patient interface module  410  operably connects an imaging probe of the present inventive concepts to a patient interface module (e.g. module  200  described herein), to provide rotation of its optical core and to provide translation to at least a portion of the probe.  FIG. 10A  is a perspective view of patient interface module  410 , and  FIG. 10B  is a partial sectional view of module  410  with a portion of the housing of module  410  removed. 
     Module  410  can comprise a two-part housing  411 , comprising top portion  411   a  and bottom portion  411   b,  surrounding an opening therein, chamber  413 . Module  410  can include an extending portion surrounding a lumen, conduit  415 , extending distally from housing  411 . Conduit  415  can comprise a flexible conduit. Conduit  415  can comprise an additional strain relief  412  at its distal end, fixedly attached to a proximal shaft  481  of attached delivery catheter  480 . Delivery catheter  480  can be of similar construction to delivery catheter  80  described herein. Delivery catheter  480  can comprise at least a portion that is optically transparent, window  485 . Window  485  can be positioned at or near a distal portion of delivery catheter  480 . Window  485  can comprise a material transparent to imaging modalities utilized by imaging probe  100 , such that imaging probe  100  can image through window  485 , for example when optical assembly  115  is retracted within window  485 . Delivery catheter  480  can comprise a distal tip  483 , comprising a rapid exchange type tip and or a spring tip construction. Imaging probe  100  is slidingly received through delivery catheter  480 , proximally through conduit  415 , into chamber  413 . Within chamber  413 , service loop  185  accommodates at least a partial retraction of imaging probe  100  into chamber  413 . Imaging probe  100  operably attaches to an optical connector assembly, connector assembly  150 ′. Connector assembly  150 ′ can be of similar construction and arrangement to connector assembly  150  described hereabove in reference to  FIGS. 3 through 6D . For example, connector assembly  150 ′ can connect to patient interface module  200  in a similar manner to connector assembly  150 , as described herein. Connector body  151  of connector assembly  150 ′ is slidingly received within connector assembly  510 , and projections  153  rotatably engage openings  517 , as described hereabove in reference to  FIGS. 6A-D , providing a locked, floating (rotatable) optical connection of imaging probe  100  to optical rotary joint  550 , also as described herein. Connector assembly  150 ′ can comprise a projection, lever  157 ′, which allows a user to rotate connector body  151 , engaging connector assembly  510 . Module  410  can comprise a biasing element, spring  414 . Spring  414  can provide a biasing force to a portion of connector assembly  150 ′, such as a portion of connector assembly  150 ′ configured to translate to accommodate motion required to perform a locking action to operably connect connector assembly  150 ′ to connector  510 . 
     Module  410  can comprise a linkage, puller  850 ′. Puller  850 ′ can comprise a rod, a cable, and/or other linkage configured to apply a retraction force to one or more portions of imaging probe  100 . In some embodiments, puller  850  is further configured to advance imaging probe  100 . Puller  850 ′ extends from a connector, connector  840 ′, through housing  411  and conduit  415 , terminating proximate the distal end of conduit  415 . Puller  850 ′ can operably attach to imaging probe  100 , for example puller  850 ′ can be fixedly attached (e.g. glued or clamped) to imaging probe  100  proximate the distal end of puller  850 ′. Puller  850 ′ can comprise a connection point  842 ′. Connection point  842 ′ can be of similar construction and arrangement to connection point  842  of connector  840 , as described hereabove in reference to  FIGS. 7A-B . Connector  840 ′ can also be of similar construction and arrangement to connector  840  of  FIGS. 7A-B . For example, connector  840 ′ can connect to patient interface module  200  in a similar manner to connector  840 , as described herein. In some embodiments, connection point  842 ′ connects to connector  835  of motive element  830  in a similar manner to connection point  842 . In some embodiments, connector  840 ′ provides a “snap” or other linear type connection to connector  820   a,  aligning connection point  842 ′ with connector  835 , without providing a rotationally locking engagement. 
     Delivery catheter  480  can comprise a proximal portion and a distal portion, proximal shaft  481  and distal shaft  482  shown. Delivery catheter  480  can comprise a purge assembly  490  (e.g. positioned between shafts  481  and  482  as shown), that allows a user to inject a fluid (e.g. a purge fluid) through distal shaft  482 . Purge assembly  490  includes housing  493  which on its proximal end can attach to the distal end of shaft  481 , and on its distal end attach to the proximal end of shaft  482 . Fluid can be delivered through catheter  480 , along imaging probe  100 , exiting through and/or near the distal end of catheter  480 . Purge fluid can be delivered through catheter  480  to perform one or more of: improve optical transmission by minimizing any refractive index mismatch between sheathes of imaging probe  100  and catheter  480 ; provide lubricity for the imaging probe  100  sliding within catheter  480 ; and/or remove air from the interstitial region between catheter  480  and imaging probe  100 . Purge assembly  490  can comprise an injection inlet, port  491  (e.g. positioned on housing  493  as shown). Port  491  can comprise a lumen and a luer connector, or other components configured to allow a syringe or other fluid source to fluidly attach to purge assembly  490  and/or distal shaft  482  of delivery catheter  480 . Purge assembly  490  can prevent or limit fluid injected into port  491  from exiting purge assembly  490  proximally, for example into proximal shaft  481 , of delivery catheter  480 . Housing  493  can comprise a projection, grip  492 , to make purge assembly  490  easier to manipulate (e.g. by a user). 
     In some embodiments, purge assembly  490  is configured as an imaging probe  100  compression relief assembly that allows imaging probe  100  to safely buckle (e.g. to avoid imaging probe  100  experiencing compression above an undesired compression level threshold), such as to avoid undesired buckling within the patient (with or without additionally being configured as an assembly that allows a user to inject fluid, as described hereabove). In these embodiments, housing  493  can comprise an opening, safety port  495 . When imaging probe  100  is inserted into delivery catheter  480  (e.g. inserted through proximal shaft  481 , through safety port  495  and into distal shaft  482 ), imaging probe  100  is unsupported within safety port  495 , such that safety port  495  provides a “buckle point” for imaging probe  100  in that location (e.g. safety port  495  is sized to accommodate the buckling). Should imaging probe  100  encounter resistance as it is advanced through distal shaft  482  of delivery catheter  480  (e.g. compression of imaging probe  100  increases as imaging probe  100  is advanced manually by a user or automatically by motive element  830  of patient interface module  200 , as described herein), safety port  495  can allow imaging probe  100  to buckle, preventing or at least limiting the likelihood that imaging probe  100  punctures and/or otherwise undesirably exits delivery catheter  480 . 
     Additionally or alternatively, safety port  495  can provide access for an emergency removal of imaging probe  100  from delivery catheter  480 . For example, a user can manipulate the unsupported section of imaging probe  100  within safety port  495  (e.g. purposely buckle imaging probe  100  through safety port  495 ), grasp a portion of imaging probe  100 , and remove (e.g. pull proximally) imaging probe  100  from delivery catheter  480 . In some embodiments, a guide wire or other flexible elongate device is subsequently inserted into delivery catheter  480  via safety port  495 . 
     Referring now to  FIGS. 11A and 11B , two perspective views of connectors being attached to a patient interface module are illustrated, consistent with the present inventive concepts. Patient interface module  200  can be of similar construction and arrangement to patient interface module  200 , as described hereabove in reference to  FIGS. 4A-C ,  5 ,  5 A-B, and  9 . Patient interface module  200  comprises a first physical connector assembly, connector assembly  510 , for operably connecting to connector assembly  150 ′, as described hereabove in reference to  FIGS. 10A-B . Patient interface module  200  can further comprise a second physical connector assembly, connector assembly  820   a,  for operably connecting to connector  840 ′, also as described hereabove in reference to  FIGS. 10A-B . As shown in  FIG. 11A , connector assembly  150 ′ and connector  840 ′ can each comprise bayonet type connectors, constructed and arranged to be at least partially inserted into connector assemblies  510  and  820   a,  respectively. As shown in  FIG. 11B , connector assembly  150 ′ can be subsequently rotated (e.g. an approximately 45° rotation) to lock its connection with connector assembly  510 , as described hereabove in reference to  FIG. 4A-C . 
     Referring now to  FIG. 12 , a side sectional anatomical view of a system including an imaging probe in a side-by-side arrangement with an implant delivery device is illustrated, consistent with the present inventive concepts. System  10  includes imaging probe  100  (the distal portion of probe  100  is shown in  FIG. 12 ), a treatment device, such as implant delivery device  30  shown, and one or more delivery catheters  80 . System  10  includes at least an intermediate delivery catheter  80   INT , and at least two micro delivery catheters  80   a  and  80   b.  Micro delivery catheters  80   a,b  are shown slidingly positioned within intermediate delivery catheter  80   INT  in a side-by-side configuration. Micro delivery catheter  80   a  has slidingly received implant delivery device  30 , and micro delivery catheter  80   b  has slidingly received imaging probe  100 , also as shown. In some embodiments, imaging probe  100 , delivery catheters  80 , and implant delivery device  30  can be of similar construction and arrangement to similar components of system  10 , as described herein. 
     Each micro delivery catheter  80   a,b  can comprise an inner diameter sufficient to slidingly receive implant delivery device  30  and imaging probe  100 , respectively. Micro delivery catheters  80   a,b  can each further comprise an outer diameter such that micro delivery catheters  80   a,b,  collectively, can be slidingly received, in a side-by-side arrangement, within intermediate delivery catheter  80   INT . Imaging probe  100  can comprise an outer diameter of not more than 0.020″, for example an outer diameter of approximately 0.014″. Imaging probe  100  and the various components of system  10  shown in  FIG. 12  can be introduced into the patient, as described hereabove in reference to  FIG. 1 . 
     Intermediate delivery catheter  80   INT  can be advanced to a first anatomic location. Subsequently, micro delivery catheters  80   a,b  can each be advanced to a second anatomic location distal to the first anatomic location. Imaging probe  100  can be advanced beyond the distal end of micro delivery catheter  80   b,  and beyond an anatomic feature, for example aneurysm A 1  as shown. Implant delivery device  30  can be advanced beyond the distal end of micro delivery catheter  80   a,  towards the anatomic feature, such as to subsequently deliver one or more implants  31  (e.g. to deliver one or more embolization coils or other aneurysm treatment components). In some embodiments, system  10  is constructed and arranged to collect image data related to implant  31 , the image data collected prior to, during and/or after implantation of implants  31  (e.g. collected during a pullback procedure of probe  100 ). In some embodiments, implant  31  comprises multiple implants  31 , for example multiple embolization coils. In these embodiments, system  10  can be constructed and arranged to collect image data during implantation (e.g. during deployment from delivery device  30 ) of one or more of the implants  31 , and/or after implantation of one or more of each of the implants  31 . In some embodiments, system  10  is configured to perform real time or near-real time (“real time” herein) imaging of implant  31  implantation (e.g. real time imaging of deployment of one or more coils or other implants). For example, system  10  can be used to perform one or more (e.g. repeating) relatively short pullbacks, each pullback including a small injection of a clearing flush. These pullbacks could be automated, and could include, approximately: a repeated set of 25 mm pullbacks, each over a time period of 1 second. For example, system  10  could be configured to (in an automated manner) deliver a 5-10 ml flush media, such as flushes delivered during every 30 seconds of deployment of one or more portions (e.g. coils) of implant  31 . 
     In some embodiments, imaging probe  100  comprises a spring tip, tip  119   SPRING . Tip  119   SPRING  can comprise a length (e.g. a sufficient length) such that the distal end of tip  119   SPRING  remains distal to the aneurysm during a pullback procedure of imaging probe  100  (e.g. a pullback procedure in which imaging data is collected at an imaging location while optical assembly  115  is retracted through a segment of the vessel to be imaged). After a pullback procedure is completed, and at least the distal end of tip  119   SPRING  extends beyond the aneurysm, imaging probe  100  can be re-advanced beyond the aneurysm, such that optical assembly  115  is positioned distal to aneurysm A 1  (as shown). The distance between the distal end of tip  119   SPRING  and optical assembly  115 , distance D 1  shown, can be chosen such that after a pullback procedure is performed to image any anatomical location (e.g. an aneurysm) and/or to image any implanted device (e.g. an implanted coil and/or stent), the distal end of tip  119   SPRING  is positioned to allow safe advancement of imaging probe  100  (e.g. the distal end of tip  199   SPRING  is positioned within or beyond the anatomical location and/or within or beyond the implanted device). For example, distance D 1  can comprise a length of at least 40 mm, such as when tip  199   SPRING  comprises a length of at least 35 mm, at least 50 mm, or at least 75 mm (e.g. to support a pullback of up to 25 mm, 40 mm, or 65 mm). 
     Referring now to  FIGS. 13A and 13B , side sectional anatomic views of a system including an imaging probe including a position marker are illustrated, consistent with the present inventive concepts.  FIG. 13A  illustrates system  10  that includes imaging probe  100 , such as is described herein, shown advanced into a patient and extending beyond an anatomic feature (e.g. aneurysm A 1  shown). System  10  further includes one or more delivery catheters used to deliver imaging probe  100 , such as intermediate delivery catheter  80   INT  and micro delivery catheter  80   MICRO  shown.  FIG. 13B  illustrates imaging probe  100  after a pullback procedure has been performed (e.g. to create image data in a segment of the vessel including aneurysm A 1 ). 
     Aneurysm A 1  of  FIGS. 13A-B  has been treated with one or more embolization coils, implant  31   a,  and with a flow diverter, second implant  31   b,  implanted across the neck of the aneurysm, each as shown. Imaging probe  100  can include a first marker, marker  131   D , positioned relative to optical assembly  115  along shaft  120  (e.g. proximal to optical assembly  115 ). Imaging probe  100  can further include a second marker, marker  131   P , positioned proximal to marker  131   D  along shaft  120 . Markers  131   D  and/or  131   P  (singly or collectively marker  131 ) can comprise a marker selected from the group consisting of: radiopaque marker; ultrasonically visible marker; magnetic marker; visible marker; and combinations of these. Imaging probe  100  can include a spring tip  119   SPRING , such that the distance between the distal end of tip  119   SPRING  and optical assembly  115  comprises distance D 1  shown. Tip  119   SPRING  and distance D 1  can comprise lengths (e.g. minimum lengths), as described hereabove in reference to  FIGS. 13A-B  (e.g. minimum lengths configured to allow safe advancement of imaging probe  100  after a pullback procedure has been performed, also as described hereabove). Imaging probe  100  can comprise marker  131   D  or marker  131   P , or it can comprise both marker  131   D  and marker  131   P . 
     Marker  131   D  can be positioned along shaft  120  at a particular location relative to the distal end of tip  119   SPRING . The position of marker  131   D  can provide a reference (e.g. under fluoroscopy or other imaging modality) to the user of the estimated position that the distal end of tip  119   SPRING  will reach after a pullback procedure (e.g. a pullback procedure of a predetermined distance, such as a maximum distance that system  10  can retract imaging probe  100 ). For example, as shown in  FIG. 13B , after a pullback procedure, the distal end of tip  119   SPRING  is a distance D REF  from the initial position of marker  131   D . Distance D 1  (e.g. as determined by the length of tip  119   SPRING ) and the position of marker  131   D  can be chosen such that the estimated position of the distal end of tip  119   SPRING  after a pullback procedure is performed is the same as or distal to the initial position of marker  131   D  prior to the pullback procedure (e.g. for the maximum pullback distance enabled by system  10 ). For example, system  10  can be configured to retract imaging probe  100  a distance relatively equal to distance D 1 . Alternatively or additionally, system  10  can be configured to retract imaging probe  100  a distance of no more than distance D 1  (e.g. after the retraction, the distal end of tip  119   SPRING  is at or distal to the previous position of marker  131   D ). 
     In some embodiments, marker  131   P  is positioned along shaft  120  relative to optical assembly  115 . The position of marker  131   P  can provide a reference to the user of the estimated position of optical assembly  115  after a pullback procedure of a predetermined distance. 
     Referring now to  FIG. 14 , a flow chart of a method of creating an image is illustrated, consistent with the present inventive concepts. Method  1400  of  FIG. 14  will be described using the devices and components of system  10  described hereabove in reference to  FIGS. 13A and 13B . In Step  1410 , an imaging probe (e.g. imaging probe  100  described herein) is inserted into the vasculature of the patient. In Step  1420 , a marker of the imaging probe (e.g. marker  131 ) is positioned relative to an imaging location, for example a location to be imaged by system  10  such as a location proximate an aneurysm, such as an aneurysm about to be treated and/or already treated (e.g. treated via implantation of a flow diverter). 
     System  10  can be constructed and arranged such that after a pullback procedure is performed, the distal end of imaging probe  100  (e.g. the distal end of tip  119  or tip  119   SPRING ) is positioned (e.g. “lands”) relative to the initial position of the marker  131 . For example, the relative distance between the distal end of imaging probe  100  and the marker  131  can be configured such that the distal end of tip  119  lands approximately at the initial position of the marker  131 . In these embodiments, a user can position the marker  131  at or distal to a point where distal access is desired to be maintained by imaging probe  100  after the pullback procedure is performed, ensuring the distal tip of imaging probe  100  will not retract to a location proximal to that point. In Step  1430 , the catheter is retracted in a pullback procedure, as described herein. In Step  1440 , imaging probe  100  can be safely advanced (e.g. an advancement in which optical assembly  115  is positioned distal to the imaging location) to perform another imaging procedure (e.g. another pullback in which imaging data is collected). Alternatively, in Step  1440  a microcatheter is safely advanced over imaging probe  100 , then imaging probe  100  is removed from the microcatheter, and a separate device (e.g. a treatment device) is advanced through the distally-positioned microcatheter. The separate device can then be used in a treatment or other procedure (e.g. a coil deployment procedure). 
     Referring now to  FIGS. 15A and 15B , schematic views of a system including an imaging probe are illustrated, consistent with the present inventive concepts. System  10  can include imaging probe  100 , positioned within a delivery catheter  80  (e.g. pre-loaded into a delivery catheter  80  in a manufacturing or packaging process). Imaging probe  100  and delivery catheter  80  can be of similar construction and arrangement to similar components, as described herein. Delivery catheter  80  can comprise a transparent portion, window  85 . Window  85  can be constructed and arranged such that imaging probe  100  can collect image data by transmitting and receiving light that passes through window  85 . In these embodiments, the optical assembly  115  can be retracted (e.g. probe  100  is retracted) and image data collected while optical assembly  115  is positioned within window  85  of delivery catheter  80 . In these embodiments, access distal to the imaging location is maintained by delivery catheter  80 , as imaging probe  100  can subsequently be re-advanced through delivery catheter  80  for additional pullback procedures. In some embodiments, catheter  80  is filled with saline or another optically transparent fluid, such as to limit optical distortion that can be caused by imaging through multiple layers of catheter walls (e.g. through the walls of optical probe  100  and delivery catheter  80 ). In some embodiments, delivery catheter  80  comprises a reinforced portion, portion  87 , proximal to window  85 . Portion  87  can comprise a braided construction, and/or the wall of portion  87  can comprise a greater thickness than the non-reinforced wall of delivery catheter  80 . Portion  87  can be constructed and arranged to prevent or at least limit collapsing of portion  87  of delivery catheter  80  under a compressive load, for example when a connector of system  10  is attached to catheter  80  at a location within portion  87 . Shaft  81  of delivery catheter  80  can comprise an outer diameter near its distal end of approximately 2.8 F. Shaft  81  can comprise an outer diameter proximate its proximal end (e.g. the outer diameter of portion  87 ) of approximately 3.2 F. Delivery catheter  80  can comprise a length of approximately 150 cm. The distal portion of shaft  81  can comprise a greater flexibility than the more proximal portion of shaft  81 . This distal portion can comprise a length of approximately 300 mm. Delivery catheter  80  can comprise a hydrophilic coating. Delivery catheter  80  can comprise one or more markers, such as one or more radiopaque markers. Shaft  81  can comprise a braided construction. In some embodiments, one or more braids of shaft  81  terminates proximal to window  85 . Shaft  81  can comprise one or more segments along its length that comprise varying durometers. The durometers of shaft  81  can vary between 45 D (e.g. segments near the distal end of shaft  81 ) and 74 D (e.g. segments near the proximal end of shaft  81 ). 
     In some embodiments, imaging probe  100  comprises a spring tip, tip  119   SPRING , as described herein. Imaging probe  100  and delivery catheter  80  can be constructed and arranged to be inserted into a patient&#39;s vasculature, coaxially, using an “inch worm” type method. In these embodiments, imaging probe  100  can be advanced beyond the distal end of delivery catheter  80 , tip  119   SPRING  acting as a guidewire to navigate the vasculature. Subsequently, delivery catheter  80  can be advanced along imaging probe  100 . This process can be repeated (e.g. in an “inch worm” method) until a target location has been reached (e.g. optical assembly  115  is positioned distal to the imaging location). 
     In some cases, a user (e.g. a clinician) may decide to use imaging probe  100  without a microcatheter, or with a different microcatheter than the one in which imaging probe  100  is provided. In these cases, the user can remove imaging probe  100  from delivery catheter  80  prior to performing a procedure (e.g. remove by retracting proximally from delivery catheter  80 , via connector  82 ), and use imaging probe  100  with any number of delivery devices similar to those as described herein. 
     Referring now to  FIGS. 16A-C , perspective, side, and front views, respectively, of a patient interface module attached to a bed rail mount are illustrated, consistent with the present inventive concepts. Bed rail mount  60  comprises an upper portion, hook  61 , and a lower portion, jaw  62 . Jaw  62  is configured to rotate relative to hook  61  about a pivot, axle  64 . Jaw  62  can be biased in a closed position, such as via a spring or other biasing element. Jaw  62  can be locked (e.g. temporarily locked) in an open position, as shown in  FIGS. 16A-B . In some embodiments, mount  60  comprises a release mechanism, button  66 , positioned within hook  61 . Button  66  can be configured to release jaw  62  from the (locked) open position when depressed (e.g. depressed by a bed rail as hook  61  engages the bed rail as shown in  FIG. 16B ), such that jaw  62  subsequently closes around the bed rail, securing mount  60  to the rail. Jaw  62  can comprise a projection, lever  63 , such that a user can manipulate jaw  62  relative to hook  61 . In some embodiments, jaw  62  and hook  61  are sized and oriented to capture bed rails of varying size, collectively securing to the rail (e.g. via a biasing force applied to jaw  62 ). Patient interface module  200  can attach to mount  60  via a connector  68 . In some embodiments, connector  68  comprises a rotatable connector, such that patient interface module  200  can rotatably attach to mount  60  (e.g. module  200  can “swivel” in either direction). In these embodiments, a user can rotatably orient module  200  relative to the bed rail, as shown in  FIG. 16C . In some embodiments, connector  68  is lockable in a rotated position, and/or connector  68  comprises persistent frictional rotation resistance, such that a user can reposition module  200  by overcoming the frictional force. Mount  60  can be attached to and/or rotated relative to module  200  before and/or after mount  60  is attached to a bedrail. 
     The above-described embodiments should be understood to serve only as illustrative examples; further embodiments are envisaged. Any feature described herein in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.