Patent Publication Number: US-2019184077-A1

Title: Skin interface device having a skin attachment device and method to implant same

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit under 35 USC § 119. (e) to U.S. Application Ser. No. 61/953,880 filed Mar. 16, 2014, the disclosure of which is considered part of and is incorporated by reference in the disclosure of this application. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention is directed to a skin interface device (SID), where the skin interface device includes a skin attachment device. 
     Background Information 
     Implantation of certain prior art skin interface devices required surgically forming a circular aperture in a patient&#39;s skin to allow a tubular portion of the skin interface device to extend outwardly from an implanted skin interface base portion. 
     The use of cardiac assist devices (CADs) is a well known method for treating heart failure and often utilize a SID. A pump is positioned inside the aorta, typically in the proximal descending aorta. The pump typically comprises a displacement volume of 40-50 cc, and works in series with the heart to augment blood flow. During diastole, the pump is inflated, thereby driving blood in the ascending aorta and aortic arch into the coronary arteries to supply oxygen to the heart muscle. During systole, as the left ventricle contracts, the pump is deflated so as to decrease the afterload. 
     The use of SIDs is well known. However, implantation of existing SIDs often lead to infection and other complications. There exists a need for a SID that may be used in multiple types of procedures without risk of infection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which like reference designators are used to designate like elements, and in which: 
         FIG. 1  illustrates Applicants&#39; skin interface device (“SID”) and various pneumatic conduits and sensor attachments thereto; 
         FIGS. 2A and 2B  illustrate Applicants&#39; SID base  200 ; 
         FIG. 3  illustrates Applicants&#39; SID cap; 
         FIGS. 4A ; 4 B, and  4 C, illustrate Applicants&#39; skin attachment device; 
         FIGS. 5A, 5B, 5C, and 5D , illustrate Applicants&#39; fixturing assembly, and various sub-assemblies used to form same; 
         FIG. 6A  illustrates a portion of Applicants&#39; SID base and SID cap in combination with Applicants&#39; skin attachment device and Applicants&#39; fixturing assembly; 
         FIG. 6B  is a top view showing Applicants&#39; skin attachment device sutured to a patients&#39; skin tissues during implantation of Applicants&#39; SID; 
         FIG. 6C  is a perspective view showing Applicants&#39; fixturing device attached to a distal end of Applicants&#39; implanted SID base, where that fixturing device is mechanically attached to Applicants&#39; skin attachment device which has been sutured to a patient&#39;s skin tissues 
         FIG. 7  is a perspective view of a handle and base portion  700  of Applicants&#39; surgical guide instrument  800  used to subcutaneously position Applicants&#39; SID  400  within a patient; 
         FIG. 8A  is a perspective view of Applicants&#39; surgical guide instrument  800  used to subcutaneously implant Applicants&#39; SID  400  within a patient; 
         FIG. 8B  is a section view of the surgical guide instrument  800 , wherein bottom platen  710  has been used to form a subcutaneous pocket to receive Applicants&#39; SID base  500 , and wherein upper assembly  810  is being used to form a linear incision in the skin through which a tubular portion of SID base  500  can extend outwardly; 
         FIG. 9  is a cross section view illustrating Applicants&#39; skin interface device (“SID”); and 
         FIG. 10  is a cross section view illustrating Applicants&#39; skin interface device (“SID”). 
     
    
    
     DETAILED DESCRIPTION 
     U.S. patent applications having Ser. Nos. 14/017,109 and 14/476,656, and having a common inventive entity herewith, and assigned to the common assignee hereof, are incorporated herein in their entireties. The components, devices, modules, source code, and the like, disposed in the skin interface device (“SID”) base and the SID cap described and claimed in the &#39;109 and &#39;656 Applications are also disposed in the SID base and the SID cap described herein. In addition, as the functions and methods described and claimed in the &#39;109 and &#39;656 Applications that utilize those components, devices, modules, source code, and the like, are also operative using the SID base and the SID cap described herein. 
     This invention is described in preferred embodiments in the following description with reference to the Figures, in which like numbers represent the same or similar elements. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
     The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
     While the skin attachment device of the present invention is generally discloses with use of a SID of the disclosure may be utilized with a variety of devices and in a variety of procedures which involve access though the skin in which infection may arise. For example, the present device may be utilized with devices and procedures utilizing Pic Lines, central IV access lines, LVAD drivelines, gastrostomy tubes, indwelling bladder catheters, orthopedic pins, and the like in which infection is a well documented problem. 
     The fundamental problem arises from the fact that no cellular in-growth occurs at the skin foreign body (metal, silicone) interface. The reason is the smooth surface does not allow it and just as importantly the constant movement breaks the adherence. 
     The present invention addresses both these issues. A linear incision is made to a minimal length such that the skin snaps into the elliptical rim of the SID. The concept of elliptical versus round is absolutely key. Round would require cutting out skin, while elliptical allows for a straight line incision with no skin excision. This makes closure of the defect much easier when the device is removed not to mention much more cosmetically acceptable. The rim itself creates a stable platform which is additionally secured by circumferential tie in sutures holes disposed in the lip of the skin attachment device. Further, vapor blasting of the titanium creates a surface where there is micro adherence akin to a cuticle on a nail bed. These features promote the long term interface necessary as a barrier against bacterial and fungal infection. 
       FIG. 1  shows Applicants&#39; skin interface device (“SID”)  100 . A first end of a pneumatic drive line  150  is attached to SID  100 , and a second end of drive line  150  is attached to a fluid driver which remains external to a patient&#39;s body. Pneumatic drive line  140  interconnects Applicants&#39; SID  100  and an implanted cardiac assist device. 
     In certain embodiments, sensors are implanted into the patient, and these sensors connect to one or more communication interfaces  130 . 
     Applicants&#39; SID  100  comprises a SID base  200  (also interchangeably referred to herein as a skin attachment device) and a SID cap  300 . SID base  200  and SID cap  300  can be coupled so as to create an air-tight conduit between the pneumatic drive line  140  and external air line  150 , and such that the SID cap is rotatable around the SID base while maintaining an air-tight seal. In this way, pneumatic drive line  140 , SID  100 , and external air line  150 , can be part of a closed fluid system. In certain embodiments, an air-tight seal is formed using gaskets and other sealing systems. 
     When implanted Applicants&#39; skin interface device  100  includes a SID base  200 , comprising a subcutaneous portion internal to the patient, in combination with a supracutaneous portion which is not disposed within the patient&#39;s body. SID cap  300  is attached to the supracutaneous portion of SID base  200 . Those skilled in the art will appreciate that it is possible to implant SID  100  in a variety of different locations on the patient, for example abdominally or thoracically. 
     In certain embodiments, Applicants&#39; SID base  200  further comprises a fabric cover disposed over a portion of the exterior surface thereof. In certain embodiments that fabric cover is formed to include a plurality of pores extending therethrough. In certain embodiments, the fabric cover comprises a polymeric material such as ePTFE of pore size 10-100 microns. In certain embodiments, the fabric cover is formed to include pores having a diameter of between about 30 to about 60 microns. The plurality of pores formed in the fabric cover comprise a diameter sufficient to allow cells to form attachments thereto. 
     Referring to  FIGS. 2A and 2B , SID base  200  comprises a disk-shaped portion  240  and a cylindrical assembly  210 , wherein cylindrical assembly  210  extends outwardly from disk-shaped portion  240 . The distal end  230  of cylindrical assembly  210  comprises an annular lip  235  which defines the opening of aperture  220 . 
     Referring to  FIG. 3 , SID cap  300  comprises a housing  310  having an electrical winding  320  extending outwardly therefrom. When SID  100  is assembled, electrical winding  320  is inserted into aperture  220  formed in cylindrical assembly  210 . 
       FIG. 6A  illustrates a portion of disk-shaped SID base portion  240  and a portion of cylindrical assembly  210  wherein an elliptical-shaped skin attachment device  400  is disposed around a portion of cylindrical assembly  210 , and wherein an elliptical-shaped fixturing assembly  500  is mechanically attached to the skin attachment device  400 , and wherein that fixturing assembly  500  is also disposed around a portion of cylindrical assembly  210 . The two “halves” of fixturing assembly  500  form a compression clamp on the neck of the SID Base. When assembled the clamps  501  and  503  are affixed to the neck  210  of the SID Base, and the skin attachment device  400  is affixed to the fixturing clamps thereby creating a rigid assembly. 
     As shown in  FIG. 6A , the distal portion of cylindrical assembly  210 , including annular lip  235 , extend outwardly from both skin attachment device  400  and fixturing assembly  500 . SID cap  300  can be inserted into aperture  220  when both skin attachment device  400  and fixturing assembly  500  are disposed around cylindrical assembly  210  as shown in  FIG. 6A . 
     Referring now to  FIGS. 4A, 4B, and 4C , skin attachment device  400  comprises an elliptical shape having a major axis  402  and a minor axis  404 . Skin attachment device  400  comprises an upper lip  412  and a lower lip  414  which define an U-shaped pocket  416  formed along the periphery. In certain embodiments, U-shaped pocket  416  comprises a depth  418  of about 3 mm to about 4 mm. 
     U-shaped pocket  416  is defined by surfaces  413 ,  415 , and  417 . In certain embodiments, surfaces  413 ,  415 , and  417 , are textured with a surface roughness to facilitate adhesion of tissues thereto. The surgical procedure utilized to implant SID  100  into a patient, which is described in more detail hereinbelow, includes forming a linear incision at the implantation site, and then inserting skin attachment device into that incision such that tissues defining the periphery of the surgical incision are disposed within U-shaped pocket  416 . 
     Skin attachment device  400  is formed to include a circular aperture  430  extending therethrough. Aperture  430  is defined by cylindrical wall  435 . As described hereinabove, during implantation a distal portion of cylindrical assembly  210  will be passed through aperture  430  such that cylindrical wall  435  is in contact with cylindrical assembly  210 . 
     Skin attachment device  400  is further formed to include six sets of aperture  440 ,  450 ,  460 ,  470 ,  480 , and  490 , extending through lip  412 . During implantation, the tissues defining the periphery of a surgical incision described immediately hereinabove will be sutured to skin attachment device  400  using these  12  apertures. 
     Skin attachment device  400  is further formed to include a set of threaded apertures  420  and  425  extending into lip  412 . During implantation, fixturing assembly  500  will be placed in contact with lip  412 , such that a set of apertures  530  ( FIG. 5A ) and  540  ( FIG. 5A ) extending through fixturing device  500  overlie threaded apertures  420  and  425 , respectively. Fastening devices can then to used to attach fixturing assembly  500  to skin attachment device  400 . 
     Referring now to  FIG. 5A , fixturing assembly  500  comprises an elliptical shape and is formed to include a circular aperture  510  extending therethrough. Aperture  510  is defined by cylindrical wall  520 . In embodiments, surface  520  includes an annular groove disposed of the surface  520  to house a gasket ring. For example, an annular circular depression is provided on surface  520  to accept the gasket ring. 
     As described hereinabove, during implantation a distal portion of cylindrical assembly  210  will extend through aperture  430  in the sutured-in-place skin attachment device  400 . Subsequently, fixturing assembly will be disposed about cylindrical assembly  210  such that cylindrical wall  520  is in contact with that cylindrical assembly  210 . 
     Fixturing assembly  500  is formed to include vertical apertures  530  and  540  extending therethrough. As described hereinabove, during implantation fixturing assembly  500  will be placed in contact with tissue attachment device  400 , such that vertical apertures  530  and  540  overlie threaded aperture  420  ( FIGS. 4A, 4B ) and  425  ( FIGS. 4A, 4B ), respectively. Fastening devices can then be passed through vertical apertures  530  and  540  and into threaded apertures  420  and  425 , respectively, to attach fixturing assembly  500  to skin attachment device  400 . 
     Referring to  FIG. 5B , in certain embodiments fixturing assembly  500  comprises two sub-assemblies, namely sub-assemblies  501  and  503 . Sub-assembly  501  comprises arcuate member  502  comprising curved surface  522 . Sub-assembly  501  is formed to include aperture  530  extending therethrough. Sub-assembly  503  comprises arcuate member  504  comprising curved surface  524 . Sub-assembly  503  is formed to include aperture  540  extending therethrough. 
     Referring now to  FIGS. 5C and 5D , in certain embodiments the two sub-assemblies used to form fixturing assembly  500  are identical. In the illustrated embodiment of  FIGS. 5C  and  5 D, fixturing assembly  500  is formed using a first sub-assembly  501 A and a second sub-assembly  501 B. 
     Subassemblies  501 A and  501 B are both formed to include a threaded aperture  550 A and  550 B, respectively, extending inwardly into ends  560 A and  560 B, respectively, and lateral apertures  540 A and  540 B, respectively, extending through ends  570 A and  570 B, respectively. A first fastening device can be inserted through lateral aperture  560 A and into threaded aperture  550 B, and a second fastening device can be inserted through lateral aperture  560 B and into threaded aperture  550 A, to form fixturing assembly  500 . Curved surface  522 A in combination with curved surface  522 B forms aperture  510 . 
     In embodiments, the Applicants&#39; skin interface device (“SID”)  100  allows the design of the system to be composed of parts both implanted and external to the patient&#39;s body. 
     In certain embodiments, one or more sensors transmit data, by wire or wirelessly, to Applicants&#39; SID  100 . Examples of sensors include, without limitation, electrical leads to measure an electrocardiogram, sensors to detect body temperature, sensors to detect blood analytes (such as blood gases), sensors to detect intra-arterial pressure directly or indirectly, and/or sensors to measure humidity within an external pump. Indirect sensors include, for example and without limitation, a microphone to monitor heart sounds. 
     In certain embodiments, a controller is disposed in SID  100 . In certain embodiments, a controller integral with an external driver. 
     In certain embodiments, signals from one or more sensors are used by the controller to monitor the cardiac cycle and, thereby, the counterpulsation cycle. In certain embodiments, combinations of signals from one or more sensors are used by the controller to monitor the cardiac cycle. 
     In certain embodiments, sensors are used to determine the state of the air inside the system. In certain embodiments, air pressure is measured to determine whether the pump is properly inflating, or if there is a leak in the system. In certain embodiments, data from the air pressure sensor is communicated to the controller. 
     In certain embodiments, sensors for arterial blood pressure are in communication with controller. In certain embodiments, these sensors communicate a detected arterial blood pressure to the controller, either by wire or wirelessly. 
     Applicants&#39; SID  100  comprises a SID base  200  and a SID cap  300 . SID base  200  and SID cap  300  are coupled so as to create an air-tight conduit between the pneumatic drive line  140  and external air line  150 . In this way, pneumatic drive line  140 , SID  100 , and external air line  150 , can be part of a closed fluid system. In certain embodiments, an air-tight seal is formed using gaskets and other sealing systems. 
     When implanted Applicants&#39; skin interface device  100  includes a SID base  200 , comprising a subcutaneous portion internal to the patient, in combination a supracutaneous portion. SID cap  300  is attached to the supracutaneous portion of SID base  200 . Those skilled in the art will appreciate that it is possible to implant SID  100  in a variety of different locations on the patient, for example abdominally or thoracically. 
     Referring now to  FIGS. 4A and 4C , Applicants&#39; SID  100  wirelessly provides electrical energy from SID cap  300  to SID base  200 , and also wirelessly and bi-directionally passes electrical signals, i.e. data, between SID cap  300  and SID base  200 . In order to optimize the transmission of power from SID cap  300  to SID base  200 , and at the same time optimize the transmission of data between SID cap  300  and SID base  200 , Applicants have “decoupled” the transmission of power from the transmission of data. The transmission of power from SID cap  300  to SID base  200  is done by induction. 
     Applicants&#39; SID  100  includes a transformer comprising a primary winding disposed in SID cap  300  and a secondary winding disposed in SID base  200 . The SID transformer is configured to power Applicants&#39; SID  400  via an external power source, such as a battery, or conventional 120V or 220V alternating current. During operation of the device the SID transformer transfers power from the external power source to the patient. Importantly, however, the patient is not directly wired to the external power source and is therefore not directly connected to the external power source. SID cap  300  comprises an annular sleeve attached to and extending outwardly from a housing. The annular sleeve defines an interior bore having a diameter. The primary winding is disposed around the exterior surface of the annular sleeve. 
     A cylindrical member may be disposed within a bore formed in a tubular portion. The secondary winding is disposed around the cylindrical member. In certain embodiments, connectors may be used to attach EKG sensors to Applicants&#39; SID  100 . In certain embodiments, connectors may be used to attach sensor leads from an implants pressure sensor to Applicants&#39; SID  100 . 
     SID cap  300  is configured to be disposed over, and rotationally attached to the tubular portion of SID base  300 , to form a wireless power transfer assembly. After such attachment, the relative positions of the primary winding and the secondary winding are fixed both laterally and vertically. A rotation of SID cap  300  about SID base  200  cannot alter the electrical/magnetic coupling of the primary winding and the secondary winding. 
     In embodiments, SID cap  300  and the tubular portion of SID base  200  are fixed to one another so that they remain attached to each other but are rotatable with respect to one another once initially connected to one another. In this way, SID base  200  can remain stationary with respect to the patient while SID cap  300  can be rotated to accommodate any convenient orientation of the external drive line  140  and any external electrical line. Such rotational decoupling can help reduce orprevent tugging or other stress on the patient&#39;s skin or other organs. 
     In certain embodiments, the primary winding comprises Np turns and the secondary winding comprises Ns turns. In certain embodiments, Np is substantially equal to Ns. In these embodiments, when first electrical power having a voltage Vp is passed through the primary winding, a second electrical power having a voltage Vs is induced in the secondary winding, wherein Vp substantially equals Vs. By “substantially equals,” Applicants mean within about plus or minus ten percent (10%). 
     In certain embodiments, Np is less than Ns. In these embodiments, the wireless power transfer assembly comprises a “step up” transformer wherein Vs is greater than Vp. In certain embodiments, Np is greater than Ns. In these embodiments, the wireless power transfer assembly comprises a “step down” transformer wherein Vs is less than Vp. 
     In certain embodiments, annular sleeve  602  is formed from a material comprising a relative magnetic permeability greater than 1. In certain embodiments, the annular sleeve is formed from a ferrite. As those skilled in the art will appreciate, ferrites are ceramic materials with iron(III) oxide (Fe 2 O 3 ) as a principal component. In certain embodiments, annular sleeve is formed from one or more “soft ferrites.” In certain embodiments, annular sleeve comprises nickel, zinc, and/or manganese moieties. In these embodiments, the annular sleeve comprises a low coercivity and the annular sleeve&#39;s magnetization can easily reverse direction without dissipating much energy (hysteresis losses), while the material&#39;s high resistivity prevents eddy currents in the core. 
     Those skilled in the art will appreciate, that the size of a transformer decreases as the frequency of power passed through the primary winding increases. Use of a soft ferrite facilitates the use of higher frequencies. 
     In certain embodiments Applicants&#39; SID  100  utilizes a wireless power transfer assembly comprising a polyetheretherketone (“PEEK”) core. In certain embodiments Applicants&#39; SID  100  utilizes a wireless power transfer assembly comprising a polyetherimide core. 
     In certain embodiments, the use of a soft ferrite moieties and frequencies between about 100 kHz and about 1 MHz, in combination with the invariant vertical and lateral alignment of the the primary winding and the secondary winding, maximizes the efficiency of wireless power transmission within SID  100 . 
     Power that is not effectively transmitted from the SID cap  300  to the SID base  200  is lost as heat. SID  100  is an implantable device and is intended for long-term use in a patient. It is known that at temperatures in the range of about 41° C. to about 43° C., damage to adjacent tissues can begin. It is further known that at temperatures greater than about 43° C., surrounding tissues will be damaged. 
     Needless to say, tissue damage in near vicinity to an implanted medical device can be a source of infection. The optimized efficiency of power transmission within Applicants&#39; implantable SID  100  allows the use of more power within that device without increasing a likelihood of infection. 
     Applicants&#39; SID  100  further comprises a pair of infrared transceiver assemblies to bi-directionally wirelessly transmit data between SID cap  300  and SID base  200 . SID cap  300  comprises a first infrared data transceiver assembly. SID base  200  comprises a second infrared transceiver assembly. 
     In certain embodiments, the infrared transceiver assemblies each comprise at least one infrared diode and signal processing circuitry. In certain embodiments, the infrared transceiver assemblies each utilize one or more infrared diodes emitting infrared energy at wavelengths between about 780 nm to about 1550 nm. 
     In certain embodiments, the infrared diode and processing circuitry are efficient enough to fit into a small module whose transceiver has the dimensions of a child&#39;s fingernail. In certain embodiments, the infrared transceiver assemblies, are capable of exchanging data at a rate of about 1 Gbps. 
     The infrared transceiver assembly disposed in SID base  200  comprises one or more infrared diodes. The infrared transceiver assembly disposed in SID cap  300  comprises one or more infrared diodes. 
     In certain embodiments Applicants&#39; SID  100  comprises a controller. The controller comprises a processor and non-transitory computer readable medium. In certain embodiments, the computer readable medium comprises a non-volatile memory device, such as and without limitation battery-backed up RAM; an electronic storage medium; a hard disk drive assembly comprising a magnetic disk storage medium and ancillary hardware, software, and firmware needed to write data to, and read data from, the magnetic disk; an optical disk drive assembly comprising a rewriteable optical disk and ancillary hardware, software, and firmware needed to write data to, and read data from, the optical disk. 
     In certain embodiments, the computer readable medium comprises a rewritable memory device, such as and without limitation an EEPROM or NAND flash memory. 
     In certain embodiments, patient data is encoded in the computer readable medium. In certain embodiments, patient data comprises timing data related to the inflation and deflation of an external pump. When a patient changes drive units, the new drive unit reads the timing data from Applicants&#39; SID  100  and adjusts its timing parameters accordingly. 
     In certain embodiments, the computer readable medium is configured to store data; e.g., in primary or secondary memory storage module, accumulated during operation of Applicants&#39; SID  100 , or information obtained during a doctor&#39;s visit. The information may be accessed either by a doctor, for example to investigate the past performance of Applicants&#39; SID  100 , or to obtain data on the patient&#39;s health as detected by sensors used to collect data during operation. Or the information may be accessed by a processor, for example to set parameters for operation of Applicants&#39; SID  100 . 
     In certain embodiments, the computer readable medium is configured to store various types of data accumulated during operation of Applicants&#39; SID  100 . For example, data obtained from sensors by be stored in a memory storage module to assess a patients well being, such as EKG signals, pulse, body temperature, blood pressure, blood analytes and the like, all which may be measured and stored as a function of time. Additionally, data may be stored to assess performance of Applicants&#39; SID  100  during operation. For example data pertaining to operational parameters of components of Applicants&#39; SID  100  may be stored, such as drive unit usage, including timing and volume of pumping, as well as errors in component operation or function. In this manner component usage logs may be compiled and stored on the computer readable medium. Similarly, event logs may be compiled and stored on the computer readable medium. As discussed above, the information may be accessed either by a doctor, for example to investigate the past performance of Applicants&#39; SID  100  or to obtain data on the patient&#39;s health. Or the information may be accessed by the processor, for example to set parameters for operation of Applicants&#39; SID  100 . 
     Computer readable program code is encoded in the computer readable medium. The processor is in bi-directional communication with the computer readable medium. The processor utilizes computer readable program code to operate Applicants&#39; SID  100 . 
     In certain embodiments, the processor, the computer readable medium, and the computer readable program code, are integrated in an Application Specific Integrated Circuit. 
     In certain embodiments the housing for base  200  is machined from a block of titanium. The housing is formed to include a central tubular portion. 
     In embodiments, Applicants&#39; SID is provided with circuitry that allows the device to withstanding an externally applied electrical shock from a conventional defibrillation device (about 5000V) while still being able to detect, process and store low power signals, such as those from an EKG sensor. The SID includes passive circuitry which functions to “clamp” down a high voltage shock which is administered to a patient who is wearing the device but required defibrillation. This feature ensures that the device is not rendered nonoperational which could pose great harm to the patient. Advantageously, however, patients undergoing cardiac support through use of the device according to the invention can be expected to continue functioning at no lower than baseline (cardiac function prior to device operation) and potentially at a higher level of function, without risk of advsere cardiac effects (see, e.g., Kantrowitz, et al.,  ASAIO Journal,  41(3): M340-M345 (1995) (no histological damage following in vivo operation and deactivation of a ventricle assist device in cows); Li, et al.,  ASAIO Journal,  46(2): 205 (2000) (no ill effects from deactivation then reactivation after two months); and, Jeevanandam, et al.,  Circulation,  106:1-183-1-188 (2002) (cardiac evaluation in humans implanted with a permanent ventricle assist device)). 
     SID cap  300  may additionally include one or more access ports for both electrical signals and fluid lines (not shown). For example, SID cap  300  may have additional access ports for fluid communication with more than one external drive line, such as multiple drive lines. Similarly, SID cap  300  may include one or more access ports for external electrical lines. For example, one or more access ports may be provided such that the SID may be connected to external electrical line for connection to an external processor or memory. In this manner data may be transferred from the computer readable medium to an external processor. The access port may also be configured to receive data from an external processor. 
     Power supplied to the SID cap is provided to the primary winding, which wirelessly provides power to SID base  200  via the secondary winding. In certain embodiments, the controller receives power from the secondary winding. In certain embodiments, SID base  200  comprises one or more rechargeable batteries, wherein those one or more rechargeable batteries receive power from the secondary winding. 
     In certain embodiments, SID cap  300  further comprises one or more communication ports. In certain embodiments, the communication ports may include a USB port. 
     In certain embodiments, the communication port comprises an IEEE 1394 interface, i.e. a “firewire” port. In certain embodiments, the communication port is in communication with the controller via infrared transceivers. 
     In certain embodiments, SID cap  300  further comprises a wireless communication module configured to communicate wirelessly with one or more computing devices external to SID  400 . In certain embodiments, the wireless communication module is in communication with the controller via infrared transceivers. 
     In certain embodiments, wireless communication module  630  utilizes “WI FI” technology in accord with the IEEE  802 . 11  Standard. As those skilled in the art will appreciate, the 802.11 family consist of a series of half-duplex over-the-air modulation techniques that use the same basic protocol. Standard 802.11n is a new multi-streaming modulation technique. Other standards in the family (c-f, h, j) are service amendments and extensions or corrections to the previous specifications. 
     In certain embodiments, the wireless communication module utilizes “Bluetooth” technology. As those skilled in the art will appreciate, Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions in the ISM band from 2400-2480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. 
     In certain embodiments, the controller can provide data to one or more computing devices external to Applicants&#39; SID. In certain embodiments, controller utilizes a wireless communication module. In certain embodiments, the controller utilizes a wired interconnection with the one or more external computing devices utilizing the communication port. 
     Referring now to  FIGS. 7 and 8A , Applicants&#39; SID  100  can be implanted into a patient using Applicants&#39; surgical guide instrument  800 . Surgical guide instrument  800  comprises base portion  700  in combination with removeably attachable assembly  810 . 
     Referring now to  FIGS. 7 and 8A , Applicants&#39; SID  100  can be implanted into a patient using Applicants&#39; surgical guide instrument  800 . Surgical guide instrument  800  comprises base portion  700  in combination with removeably attachable assembly  810 . 
     Implantation of SID  100  and addition of skin attachment device  400  and fixturing assembly  500  to that implanted SID  100  requires use of a surgical guide instrument  800 . Referring to  FIG. 7 , surgical guide instrument base portion  700  comprises platen  710  having a diameter  712 . Platen  710  is formed to include plastic disk  714  having a diameter  716  disposed in the center of platen  710 . 
     Implantation of SID  100  and addition of skin attachment device  400  and fixturing assembly  500  to that implanted SID  100  requires use of a surgical guide instrument  800  ( FIG. 8A ). Referring to  FIG. 7 , surgical guide instrument base portion  700  comprises platen  710  having a diameter  712 . Platen  710  is formed to include plastic disk  714  having a diameter  716  disposed in the center of platen  710 . 
     A first end of member  730  is attached to the periphery of platen  710  and extends upwardly therefrom. Handle  740  is attached to a second end of member  730 . Handle  740  is formed to include a threaded aperture  745  extending inwardly therein from a top surface. 
     When preparing to subcutaneously implant Applicants&#39; SID  100 , a surgeon can subcutaneously insert platen  710  through a first lateral incision in the skin. The surgeon then utilizes platen  710  as a guide to dissect a subcutaneous pocket correctly dimensioned to accept Applicants&#39; SID  100 . 
     The subcutaneous pocket must be dissected upon fascia rather than subcutaneous fat in the subdermis. As a result, the portion of the cylindrical assembly  210  skin surface extending outwardly from the skin surface may vary by patient. The notched and gasketed subassembly  210  when “married” to subassembly  500 , which is fixed to subassembly  400  allows for waterproof fixation of the SID base to the skin interface device  400  at various heights depending on the thickness of the patient&#39;s subcutaneous tissue. 
     Referring now to  FIGS. 8A and 8B , after forming a subcutaneous pocket dimensioned to accept SID base  200 , the surgeon can attach upper assembly  810  using a securing means  815  inserted through horizontal member  820  and into threaded aperture  745 . Upper assembly  810  comprises horizontal member  820  having annular ring  830  disposed on a distal end thereof. 
     Cylindrical member  840  is slidingly disposed through annular ring  830 . A circular handle  850  is disposed on an upper end of cylindrical member  840 . A guide assembly  860  is disposed on the lower end of cylindrical member  840 . 
       FIG. 8B  shows a section view of surgical guide instrument  800  with platen  710  disposed within a subcutaneous pocket, as described hereinabove. Downward pressure can be applied to handle  850  to urge cylindrical member  840  downwardly through annular ring  830  such that blade assembly  860  passes through the skin and onto plastic disk  714  thereby forming a linear second incision through the skin. 
     The surgical guide instrument  800  is then removed from the patient. Implantation begins with skin attachment device  400  being inserted into the second incision made by the  860  guide such that tissues defining the periphery of that surgical incision are disposed within U-Shaped pocket  416  ( FIGS. 4A, 4C ). Skin attachment device  400  is then sutured to those tissues using the sets of apertures  440 ,  450 , 460 , 470 , 480 , and  490 . 
       FIG. 6B  illustrates a top view of skin attachment device  400  sutured to the periphery of an incision using sutures  620  through apertures  440 , sutures  630  through apertures  450 , sutures  640  through apertures  460 , sutures  650  through apertures  470 , sutures  660  through apertures  480 , and sutures  670  through apertures  490 .  FIG. 6B  further illustrates distal portion  230  and aperture  220  of cylindrical assembly  210  extending outwardly through aperture  430  in skin attachment device  400 . 
     SID base  200  is then moved through the first incision into the subcutaneous pocket formed using the platen base  710 , and the distal end  230  of cylindrical assembly  210  is inserted in and through aperture  430  of the skin attachment device  400  which has already been sutured to the patient. 
     Fixturing assembly  500  is then disposed around a distal portion of cylindrical assembly  210  that extends outwardly from skin attachment device  400 . Fixturing assembly  500  is then attached to skin attachment device  400 . 
       FIG. 6C  illustrates fixturing device  500  disposed on lip  412  of skin attachment device.  FIG. 6C  further illustrates fastening devices  680  and  685  extending through apertures  420  and  425 , respectively, to attach fixturing assembly  500  to skin attachment device  400 . In addition,  FIG. 6C  further illustrates fastening device  690  extending though lateral aperture  540 A and into threaded aperture  550 B to attach sub-assembly  501 A to sub-assembly  501 B to form fixturing assembly  500 . 
     Finally, SID cap  300  is attached to distal end  230  of cylindrical assembly  210 . 
     Referring to  FIGS. 9 and 10 , skin attachment device  900  is formed to include a circular aperture  910  extending therethrough. Aperture  910  is defined by cylindrical wall  920 . As described hereinabove, during implantation a distal portion of cylindrical assembly  940  will be passed through aperture  910  such that cylindrical wall  920  is in contact with cylindrical assembly  940 . 
     Skin attachment device  900  is further formed to include one or more sets of apertures  440 ,  450 ,  460 ,  470 ,  480 , and  490  (as shown in  FIG. 4 ) extending through lip  930 . During implantation, the tissues defining the periphery of a surgical incision described immediately hereinabove will be sutured to skin attachment device  900  using these apertures. 
     Skin attachment device  900  is further formed to optionally include a set of threaded apertures  950  and  955  extending into lip  930 . During implantation, fixturing assembly  960  will be placed in contact with lip  930 , such that a set of apertures  530  ( FIG. 5A ) and  540  ( FIG. 5A ) extending through fixturing device  960  overlie threaded apertures  950  and  955 , respectively. Fastening devices can then to used to attach fixturing assembly  960  to skin attachment device  900 . 
     Fixturing assembly  960  comprises an elliptical shape and is formed to include a circular aperture  970  extending therethrough. Aperture  970  is defined by cylindrical wall  920 . In embodiments, surface  920  includes an annular recesses  980  to house a gasket ring  990 , such as a silicone gasket ring. 
     As in  FIG. 5 , fixturing assembly  960  of SID  900  may be formed to include vertical apertures  956  and  957  extending therethrough. As described hereinabove, during implantation fixturing assembly  960  will be placed in contact with tissue attachment device  905 , such that vertical apertures  956  and  957  overlie threaded aperture  955  and  950 , respectively. Fastening devices can then be passed through vertical apertures  956  and  957  and into threaded apertures  955  and  950 , respectively, to attach fixturing assembly  960  to skin attachment device  900 . 
     Finally, one or more surfaces of the SID of the present invention, for example any surface the contacts skin, is texturized to promote adherence to the skin, for example by vapor blasting. 
     While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth herein.