MINIMALLY INVASIVE IMPLANTABLE NEUROSTIMULATION SYSTEM
A medical device system for delivering a neuromodulation therapy includes a delivery tool for deploying an implantable medical device at a neuromodulation therapy site. The implantable medical device includes a housing, an electronic circuit within the housing, and an electrical lead comprising a lead body extending between a proximal end coupled to the housing and a distal end extending away from the housing and at least one electrode carried by the lead body. The delivery tool includes a first cavity for receiving the housing and a second cavity for receiving the lead. The first cavity and the second cavity are in direct communication for receiving and deploying the housing and the lead coupled to the housing concomitantly as a single unit.
The present application claims priority to U.S. Provisional Patent Application No. 61/734,425, filed Dec. 7, 2012 (Atty. Docket C00003998.USP1), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/777,804, filed Mar. 12, 2013 (Atty. Docket C00003998.USP3), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/734,429, filed Dec. 7, 2012 (Atty. Docket C00004420.USP1), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/777,949, filed Mar. 12, 2013 (Atty. Docket C00004420.USP3), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/734,446, filed Dec. 7, 2012 (Atty. Docket C00004588.USP1), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/777,824, filed Mar. 12, 2013 (Atty. Docket C00004588.USP2), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/777,838, filed Mar. 12, 2013 (Atty. Docket C00004588.USP5), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/734,436, filed Dec. 7, 2012 (Atty. Docket P40339.USP1), which application is incorporated herein by reference as if re-written in its entirety.
The present application claims priority to U.S. Provisional Patent Application No. 61/777,787, filed Mar. 12, 2013 (Atty. Docket P0040339.USP3), which application is incorporated herein by reference as if re-written in its entirety.FIELD OF THE DISCLOSURE
The disclosure relates generally to implantable neurostimulation systems and in particular to minimally invasive neurostimulation systems.SUMMARY
Various exemplary embodiments of IMD fixation members and associated methods of deploying and anchoring an IMD are described using minimally invasive implantation procedures in which the incision size and time required to implant and anchor the device can be minimized. The exemplary fixation mechanisms provide stable positioning of the IMD to promote efficient therapy delivery. In illustrative embodiments, an exemplary IMD delivery tool is used to deliver the IMD to a desired implant site and deploy a fixation member.
In one embodiment, a medical device system for delivering a neuromodulation therapy includes an implantable medical device having a housing and an electrical lead coupled to the housing and a delivery tool for deploying the implantable medical device at a neuromodulation therapy site. The tool includes a first cavity for receiving the housing and a second cavity for receiving the lead coupled to the housing. The first cavity and the second cavity are in direct communication with each other for receiving the housing and the lead coupled to the housing as a single unit. The delivery tool may include an electrode along a distal end of the tool for use in testing stimulation sites to identify a neuromodulation therapy site. The lead may be non-removably coupled to the housing or it may be removable.
In various embodiments, the lead may include a lead body having a flattened side. The lead body may include a first fixation member along the distal end of the lead body. The lead body may include a second fixation member spaced apart proximally from the first fixation member along the lead body such that a tissue layer is captured between the first fixation member and the second fixation member when the lead distal end is advanced through a tissue layer.
In one embodiment, the delivery tool includes a distal tool end adapted to be inserted through a tissue layer to implant the lead distal end beneath the tissue layer, the housing remaining superficial to the tissue layer. The delivery tool may further include a handle portion, a first shaft portion extending from the handle portion defining the first cavity for receiving the housing and a second shaft portion having an open-sided lumen extending from the first shaft portion and defining the second cavity for receiving the lead. The first shaft portion includes a distal opening in direct communication with the open-sided lumen of the second shaft portion for receiving the housing coupled to the lead as a single unit. The tool may include a movable cover fitting over at least a portion of the first shaft portion or the second shaft portion to retain the housing and lead within the tool.
In another embodiment, the delivery tool includes a syringe body having a distal needle guiding portion and a proximal device guiding portion. The delivery tool includes a plunger having a proximal shaft, a mid-portion extending from the proximal shaft and through the device guiding portion of the syringe body, and a distal hollow needle having an open sided lumen and extending from the mid-portion and through the needle guiding portion of the syringe body. The plunger is configured to deploy the housing and the lead as a single unit at an implant site when the plunger is advanced through the syringe body. The needle guiding portion of the syringe body may include an open groove so that a fixation member coupled to the lead can extend through the open-sided lumen of the plunger distal hollow needle and through the groove of the needle guiding portion of the syringe body as the plunger is advanced through the syringe body.
The IMD may include a housing fixation member for anchoring the housing at an implant site. In various embodiments, a housing fixation member may include any of a flanged post, a hook, a cross-beam with descending legs, a shroud, a serrated body and ratcheting collet, or a U-shaped clip. The housing fixation member may be formed from a bioabsorbable material or a shape memory alloy in various examples. The housing fixation member may include an electrode. The electrode may be positioned along a major side of the housing with the housing fixation member being adapted to anchor the major side against a tissue layer to position the electrode against the tissue layer for delivering neurostimulation to a nerve beneath the tissue layer.
In one embodiment, a method for delivering an implantable medical device to a neuromodulation therapy site includes positioning an implantable medical device housing coupled to an electrical lead in a delivery tool as a single unit and deploying the housing along with the lead from the delivery tool at the same time, i.e. still coupled as a single unit, to the therapy site.
Applicants have an appreciation that implantable medical device (IMD) technology is continually advancing as new applications are developed for automated therapy delivery in patients. Such advances may be further enhanced by using devices of reduced size and weight, which makes implantation of such devices less invasive and chronic use more comfortable for the patient. Additionally, applicants recognize that such enhancements such as improved power supply systems, wireless telemetry systems for communication with the implanted device, tools for performing implantation procedures, apparatus and methods for targeting a delivered therapy at a desired location, and other system improvements can also enhance therapies in a manner that saves cost, conserves energy and minimizes any burden placed on the patient or clinician. Accordingly, Applicants recognize a need for improved, minimally-invasive implantable medical device systems and associated methods of use for providing patient monitoring and/or therapy delivery. Certain exemplary embodiments disclosed herein may obtain some or all of the aforementioned advantages and enhancements.
When implanting small devices at targeted monitoring or therapy delivery locations, stable fixation of the device can be important, though not necessarily essential, in achieving effective therapy delivery and/or accurate monitoring of physiological signals. Stable fixation at a selected implant site can reduce power requirements of a device delivering an electrical stimulation therapy because therapy delivery electrodes can be positioned at an optimal location to deliver therapeutic pulses. Accordingly, Applicants recognize a need for improved, minimally-invasive implantable medical device systems and associated methods of use for providing stationary and/or ambulatory patient monitoring and/or therapy delivery.
In the following description, references are made to illustrative embodiments. Various embodiments of electrodes, fixation mechanisms and implant delivery tools for an IMD included in an implantable neurostimulation (INS) system for delivering an electrical stimulation therapy to a targeted neural site are described. However, it is recognized that the various embodiments described herein may be implemented in numerous types of IMDs, including, for example, implantable sensors or monitoring devices, implantable communication devices, and other types of implantable therapy delivery systems. The various embodiments of IMD systems described herein and associated methods of manufacture promote and facilitate minimally invasive implantation procedures in which the incision size and time required to implant and anchor the device can be minimized. The fixation mechanisms provide stable positioning of the IMD to promote efficient therapy delivery (and/or accurate monitoring in a sensing device).
IMD 20 includes electronic circuitry comprising one or more electronic circuits for delivering neurostimulation pulses enclosed in a sealed housing and coupled to therapy delivery electrodes. In various embodiments, IMD 20 may include one or more of a primary battery cell, a rechargeable battery cell, and an inductively coupled power source for providing power for generating and delivering stimulation pulses and powering other device functions such as communication functions.
In some embodiments, IMD 20 is less than approximately 30 mm in length, or less than approximately 15 mm in length, and less than approximately 1 cc in volume. In illustrative embodiments, the term “approximately” as used herein may indicate a value of +10% of a stated value or may correspond to a range of manufacturing specification tolerances. In other examples, IMD 20 may be less than approximately 10 mm in length and may be less than approximately 0.6 cc in volume. IMD 20 may be approximately 0.1 cc in volume in some embodiments. The embodiments described herein are not limited to a particular size and volume of IMD 20, but are generally implemented to enable the use of a reduced size device for minimally invasive implantation procedures and minimized discomfort to a patient. It is recognized, however, that the various IMD systems described herein may be implemented in conjunction with a wide variety of IMD sizes and volumes adapted for a particular therapy or monitoring application.
External device 40 may be a wearable device including a strap 42 or other attachment member(s) for securing external device 40 to the patient in operable proximity to IMD 20. When IMD 20 is provided with rechargeable battery cell(s), external device 40 may be embodied as a recharging unit for transmitting power, for example inductive power transmission from external device 40 to IMD 20. In this embodiment, programming device 60 may be a patient handheld device that is used to initiate and terminate therapy delivered by IMD 20 via a bidirectional wireless telemetry link 62. Alternatively, programming device 60 could be operated by a patient for communicating with wearable external device 40 to control therapy on and off times and other therapy control parameters, which are transmitted to IMD 20 via communication link 21. Programming device 60 may communicate with wearable external device 40 via a bidirectional wireless telemetry link 41 that may establish communication over a distance of up to a few feet, enabling distance telemetry such that the patient need not position programming device 60 directly over IMD 20 to control therapy on and off times or perform other interrogation or programming operations (e.g., programming of other therapy control parameters).
When IMD 20 includes primary cell(s), a wearable external device 40 may be optional. Programming of IMD 20 may be performed by the programming device 60, using near- or distance-telemetry technology for establishing bidirectional communication link 62 for transmitting data between programmer 60 and IMD 20. Programming device 60 may be used by a patient or clinician to set a therapy protocol that is performed automatically by IMD 20. Programming device 60 may be used to manually start and stop therapy, adjust therapy delivery parameters, and collect data from IMD 20, e.g. data relating to total accumulated therapy delivery time or other data relating to device operation or measurements taken by IMD 20.
When IMD 20 is configured as an externally powered device, external device 40 may be a power transmission device that is worn by the patient during a therapy session to provide power needed to generate stimulation pulses. For example, external device 40 may be a battery powered device including a primary coil used to inductively transmit power to a secondary coil included in IMD 20. External device 40 may include one or more primary and/or rechargeable cells and therefore may include a power adaptor and plug for re-charging in a standard 110V or 220V wall outlet, for example.
It is contemplated that in some embodiments the functionality required for transmitting power to IMD 20 when IMD 20 is embodied as a rechargeable or externally powered device and for programming the IMD 20 for controlling therapy delivery may be implemented in a single external device. For example, power transmission capability of external device 40 and programming capabilities of patient programmer 60 may be combined in a single external device, which may be a wearable or handheld device.
Physician programming device 80 may include increased programming and diagnostic functionality compared to patient programming device 60. For example, physician programming device 80 may be configured for programming all neurostimulation therapy control parameters, such as but not limited to pulse amplitude, pulse width, pulse shape, pulse frequency, duty cycle, therapy on and off times, electrode selection, and electrode polarity assignments. Patient programming device 60 may be limited to turning therapy on and/or off, adjusting a start time of therapy, and/or adjusting a pulse amplitude without giving access to the patient to full programming functions such that some programming functions and programmable therapy control parameters cannot be accessed or altered by a patient.
Physician programming device 80 may be configured to communicate directly with IMD 20 via wireless, bidirectional telemetry link 81, for example during an office visit. Additionally or alternatively, physician programming device 80 may be operable as remote programming instrument used to transmit programming commands to patient programming device 60 via a wired or wireless communication network link 61, after which patient programming device 60 automatically transmits programming data to IMD 20 via bidirectional telemetry link 62 (or via wearable external device 40 and link 21).
In some embodiments, the patient may be provided with a magnet 90 for adjusting operation of IMD 20. For example, application of magnet 90 may turn therapy on or off or cause other binary or stepwise adjustments to IMD 20 operations.
While IMD 20 is shown implanted along a portion of the lower leg of a patient, IMD 20 could be implanted at numerous sites according to patient need and the particular medical application. In the illustrative embodiment, IMD 20 is provided for stimulating the tibial nerve of the patient to treat overactive bladder syndrome and is merely one example of the type of medical application for which INS system 10 may be used. In another example, IMD 20 may be implanted to deliver a stimulation therapy to muscles of the pelvic floor, such as periurethral muscles or the external urethral sphincter for treating symptoms of urinary incontinence or overactive bladder syndrome. In other examples, IMD 20 may be deployed for delivering neurostimulation therapy to an acupuncture point for treatment of a symptom associated with the acupuncture point. IMD 20 may be implemented in an INS system for providing numerous types of neurostimulation therapies, such as for pain control, autonomic nervous system modulation, functional electrical stimulation, tremor, and more.
Advancement of lead 54 through deep fascia layer 56 promotes anchoring of IMD 50 at the implant site. Lead 54 may include fixation members 49 to further promote anchoring of IMD 50 and fixation of lead 54 at the therapy delivery site. Fixation members 49 are shown as passive fixation members, such as tines or barbs, which extend from lead 54 and passively engage in surrounding tissue without being actively fixed in the surrounding tissue at the time of implant. Fixation members 49 are shown schematically in
As described in detail herein, various embodiments an IMD system deployed in various implant positions, e.g. as shown in
Control unit 22 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some examples, control unit 22 may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to control unit 22 herein may be embodied as software, firmware, hardware or any combination thereof. In one example, a neurostimulation therapy protocol may be stored or encoded as instructions in memory 24 that are executed by controller 22 to cause pulse generator 28 to deliver the therapy via electrodes 30 according to the programmed protocol.
Memory 24 may include computer-readable instructions that, when executed by controller 22, cause IMD 20 to perform various functions attributed throughout this disclosure to IMD 20. The computer-readable instructions may be encoded within memory 24. Memory 24 may comprise non-transitory computer-readable storage media including any volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media with the sole exception being a transitory, propagating signal.
Telemetry module 26 and associated antenna 25 are provided for establishing bidirectional communication with wearable external device 40, patient programmer 60 and/or physician programmer 80. Examples of communication techniques used by IMD 20 and a programming device 60 or 80 include low frequency or radiofrequency (RF) telemetry, which may be an RF link established via Bluetooth, WiFi, or MICS, for example. Antenna 25 may be located within, along or extend externally from housing 34.
Electrodes 30 may be located along an exterior surface of housing 34 and are coupled to pulse generator 28 via insulated feedthroughs or other connections as will be further described below. In other embodiments, electrodes 30 may be carried by a lead or insulated tether electrically coupled to pulse generator 28 via appropriate insulated feedthroughs or other electrical connections crossing sealed housing 34. In still other embodiments, electrodes 30 may be incorporated in housing 34 with externally exposed surfaces adapted to be operably positioned in proximity to a targeted nerve and electrically coupled to pulse generator 28.
Post 112 has a flange 118 at or near distal post end 116. Post 112 and flange 118 may be a single component formed of a biostable polymer or as two components bonded together to form a flanged post. In alternative embodiments, post 112 and flange 118 may be a single component formed of or layered with a conductive electrode material, such as titanium, platinum, iridium, niobium or alloys thereof. The post 112 and flange 118 may then function both as an electrode for delivering a neurostimulation therapy and a fixation member.
In other embodiments, flange 118 may be formed of a different material than post 112. Flange 118 may be formed of an electrically conductive biostable material, such as those listed above, and function as an electrode. Post 112 may be formed from a biostable polymer, ceramic, or other non-conductive material. Post 112 may include an inner lumen through which a conductor extends, or a conductor may be solidly embedded within post 112, to electrically couple flange 118 to one or more electronic circuits, i.e., electronic circuitry, within housing 101. Alternatively, post 112 may be an electrically conductive material and function as an electrode, and flange 118 may be a non-conductive material, such as a polymer or a ceramic.
As shown in
In some applications, puncture tip 120 is used to advance flange 118 through a relatively tough fibrous tissue layer, such as fascia, tendon, ligament, retinaculum, scar or other connective tissue. For example, in an application for treating overactive bladder syndrome, IMD 100 is implanted in the vicinity of the tibial nerve to deliver neurostimulation to the tibial nerve. Fixation members 110 are used to secure IMD 100 over the nerve. Puncture tip 120 is punched through a deep fascia tissue layer extending over the tibial nerve so that flange 118 becomes positioned on one side of the tissue layer and IMD housing 101 is positioned on the other side of the tissue layer. Post 112 extends through the tissue layer. The flange 118 holds the IMD 100 in place over (superficially to) the tissue layer near the nerve. When flange 118 and/or post 112 are formed from conductive material to operate as electrodes, these electrodes are positioned in close proximity to the tibial nerve, under the deep fascia tissue layer, such that stimulation does not need to occur through the tissue layer, which could require relatively higher stimulation pulse energy.
As mentioned previously, post 112 and flange 118 may define an inner lumen 128 for receiving a male connector 130 of puncture tip 120. Connector 130 may be press fit into lumen 128. In other embodiments, flange 118 and post 112 may be solid and puncture tip 120 may be adhesively coupled to flange 118.
In some embodiments, post 112, flange 118 and puncture tip 120 may be manufactured as a single component from a bioabsorbable or dissolvable material such that the entire fixation member 110 is absorbed or dissolved over time, during which fibrotic encapsulation of IMD 100 takes place. In still other embodiments, puncture tip 120 and flange 118 may be absorbable or dissolvable such that over time only post 112 remains to enable easier IMD removal than when flange 118 remains.
As indicated previously, all or any portion of post 112 and flange 118 may function as an electrode. In the embodiment shown in
Posts 112 may be attached to housing 101 on the outer bottom face 104 by fixedly coupling posts 112 at desired spacings along housing 101, using welding, brazing, adhesive bonding or other techniques. Alternatively, posts 112 may extend through housing 101 and be anchored to an inner surface of bottom face 104, e.g. by a flange, by varying outer diameters of post 112 mating with varying diameters of an opening through the wall of housing 101 and/or welded, brazed, or adhesively bonded to an inner surface of bottom face 104. Post 112 may function as insulation and sealing around an electrical feedthrough extending through bottom face 104 to enable electrical connection of flange 118 to electronic circuitry within housing 101.
Body 201 includes a top face 202 and bottom face 204 separated by opposing end side walls 203 and 205. Outer lateral edges 206a, 206b (collectively 206) of top face 202 and outer lateral edges 207a, 207b (collectively 207) of bottom face 204, respectively, define open lateral sides of shroud body 201. The open lateral sides defined by outer lateral edges 206 and 207 extend between opposing end side walls 203 and 205.
Each of top face 202 and bottom face 204 are shown having inner edges 208 and 209 defining an opening extending along the respective top and bottom face 202 and 204. Inner edges 208 and 209 may be configured as needed to expose surfaces of the IMD housing as desired, e.g. to expose electrodes carried on or incorporated in the IMD housing, expose a lead connector or other otherwise providing access to features of the IMD. Inner edges 208 and 209 may define openings to reduce the material required to manufacture shroud 200 and, when manufactured from a bioabsorbable or dissolvable material, reduces the volume of material that is absorbed or dissolved.
Fixation members 210 extend from shroud body 201. In one embodiment, fixation members 210 extend substantially perpendicular to shroud body face 204 to urge the IMD retained within cavity 230 defined by shroud body 201 against a tissue through which fixation members 210 extend. The fixation members 210 include posts 212 extending from a proximal end 214 at bottom face 204 to a distal end 216 extending away from shroud 200. A flange 218 extends radially outward at distal end 216, substantially parallel to bottom face 204. Post 212 terminates in a puncture tip 220 having a sharpened tip 222 for puncturing through a tissue layer to advance flange 218 through the tissue layer. The fixation member 210 will extend through a tissue layer such that shroud body 201 remains on one side of a tissue layer and flange 218 is positioned within or on the opposite side of the tissue layer.
In one embodiment, shroud 200, or at least a portion thereof, is a bioabsorbable or dissolvable component that will be fully absorbed or dissolved over time. Tissue encapsulation of the IMD replaces shroud 200 in limiting movement or migration of the IMD after shroud 200 is absorbed. Examples of bioabsorbable materials for use in fixation members described herein include copolymers of poly-lactic acid and poly-glycolic acid however any bioabsorbable polymer material could be used.
In other embodiments, only puncturing tip 220 is formed of a bioabsorbable or dissolvable device such that flanged posts 212 and shroud body 201 remain after puncturing tip 220 is absorbed. Flanged post 212 and shroud body 201 may be molded as one or more parts from a biostable polymer, such as a high durometer polyurethane, polyether ether ketone, or polysulfone to provide the column strength needed to puncture tips 222 through a tissue layer.
The shroud 200 may be an overmolded component in which the IMD is positioned in a mold and shroud 200 is molded onto and around the IMD. Alternatively, shroud 200 may be pre-molded of a generally rigid material in which an IMD is inserted into and retained in cavity 230.
A bracket 162 extends from a bottom surface 155 of tool 150 for receiving an IMD retaining sleeve 170. Distal portion 160 is characterized by a relatively lower profile than proximal portion 156 in one embodiment such that distal portion 160 can be advanced into an open incision for implantation of IMD 100 while minimizing the size of the incision and the size of the pocket formed for IMD 100. As such, proximal portion 156 is shown having a height 166 from a bottom surface 164 of bracket 162. Distal portion 160 has a smaller height 168 from bracket bottom surface 164 than height 166. Proximal portion 156 has a thickness or height 166 and overall length to provide comfortable gripping of tool 150 by a physician, whereas distal portion 160 may be provided with a relatively smaller height for advancing through an incision and tunneling to an implant site and an overall length needed to reach a desired implant site from the incision site.
The distal portion 160 includes a bottom recessed surface 165 for receiving IMD 100. IMD retaining sleeve 170 extends through bracket 162 to distal tool end 154 to secure IMD 100 between recessed surface 165 and a top surface 174 of sleeve 170. Sleeve 170 includes one or more grooves 172 aligned with fixation member(s) 110 of IMD 100. In this way, sleeve 170 retains IMD 100 within tool 150 while protecting the puncturing tip of fixation member 110. Sleeve 170 extends proximally toward proximal end 152 and may extend fully to proximal end 152. Sleeve 170 may have varying heights such that top surface 174 mates with bottom surface 155 of tool 150.
During an implantation procedure, the distal portion 160 is advanced through an incision to position IMD 100 over a desired implant site. In some embodiments, distal end 154 may include a sharpened edge for incising or a relatively more blunt edge for dissecting and creating a tissue pocket within which IMD 100 is positioned. An incising edge may be provided as an attachable/detachable member or a retracting member for making a skin incision and when removed or retracted a relatively more blunt pocket dissection edge remains along end 154. Alternatively, tool 150 may include a blade cover or guard to be positioned over an incising edge to cover the incising edge when not in use. The blade cover or guard may have a blunt dissecting edge to form a tissue pocket. In other embodiments, edges of tool 150 are blunt or smooth to prevent trauma and provide comfortable gripping by a physician.
After positioning an IMD over a desired implant site, the sleeve 170 is withdrawn proximally by sliding sleeve 170 through bracket 162 in a proximal direction. As will be further described below, in some embodiments tool 150 and other delivery tools described herein may include nerve locating electrodes for identifying a nerve location prior to fixation of IMD 100 at an implant site. For example, an electrode bipole may be formed along a bottom surface of retaining sleeve 170 and coupled to insulated conductors extending within or along sleeve 170 to enable electrical connection to an external pulse generator. Test stimulation pulses may be delivered via the nerve locating electrodes as the position of IMD 100 is adjusted until a desired response is measured or observed. Upon identifying an optimal implant location, IMD 100 may be fixed at the implant site.
When functional as electrodes, fixation members 110 are now positioned in close proximity to nerve 186 for delivering an electrical stimulation therapy. When electrodes are incorporated along the housing of IMD 100, they are held stably against layer 184 for stimulating nerve 186 from above, i.e. superior to, the tissue layer 184, delivering electrical energy through layer 184. For example, housing-based electrodes may be used to stimulate the tibial nerve through a deep fascia tissue layer. Tool 150 is withdrawn proximally (in the direction of proximal end 152 of tool 150, not visible in the view of
While tool 150 is shown and described for use in implanting IMD 100 with fixation members 120, tool 150 may be adapted for use with an IMD mounted within the fixation shroud 200 shown in
One or more fixation members 310 each extend through a pair of lumens 320a and 320b. Fixation member 310 is a substantially “U” shaped, “staple-like” member, having a cross beam 312 and two descending legs 314a and 314b, extending from first and second ends of cross beam 312 through respective housing lumens 320a and 320b. In the embodiment shown, IMD 300 includes two fixation members 310 extending through lumens positioned adjacent opposing end side walls 305 and 306 of housing 301. The arrangement of fixation members 310 and lumens 320 shown in
Legs 314a and 314b terminate at free ends 316a and 316b, collectively 316. Free ends 316 are shown as blunt ends in
In the normally flared position, legs 314 include a descending portion 318 intersecting with a lateral portion 319. When free end 316 is advanced through a tissue layer, lateral portion 319 bends or curves into the flared position. In the flared position, the fixation member legs 314 resist movement up out of the tissue layer, i.e. in a z-direction, thereby urging and anchoring IMD housing bottom face 304 against the tissue layer. The lateral portion 319 may capture a tissue layer between lateral portion 319 and bottom face 304. Descending portions 318 of legs 314a and 314b resist motion of the IMD 300 in the x- and y-directions. In this way, IMD 300 is stably anchored at a desired implant location.
The fixation members 310 are formed such that legs 314a and 314b have a normally flared position, extending laterally outward. For example, legs 314 may bend or curve such that lateral portions 319 approach a plane approximately parallel to cross beam 312. Lateral portions 319 may extend in any direction and are shown to extend in opposite directions, parallel to end side walls 305 and 306, outward from lateral side walls 307 and 308. In other embodiments, lateral portion 319 may extend in other directions, but generally approach a plane that is parallel to bottom face 304 to resist movement in the z-axis. Legs 314 may bend to an approximately 90 degree angle between descending portion 318 and lateral portion 319 such that lateral portion 319 is approximately parallel to bottom face 304. In other embodiments, legs 314 may bend at an angle that is less than or greater than 90 degrees, for example an angle between approximately 45 degrees and 135 degrees.
Fixation member 310 may be formed from nitinol or other superelastic and/or shape memory material. As described above, fixation member 310 is configured to assume a normally flared position, which may occur upon being released from lumens 320 and/or upon reaching body temperature. Fixation member 310 may be formed as a single component. In some embodiments, legs 314 or at least a portion thereof are made from a superelastic or shape memory material and coupled to cross beam 312 which may be formed from another material. Legs 314 or at least a portion thereof may function as electrodes for delivering an electrical stimulation therapy in some embodiments. An extendable conductive interconnect, such as a serpentine interconnect, or other conductive interconnect having excess length or strain relief may electrically couple legs 314 to circuitry enclosed in IMD housing 301. Alternatively a spring contact or other protruding contact formed along lumens 314 may provide electrical connection between legs 314 and IMD internal circuitry to enable legs 314 to function as electrodes.
The normally flared position may correspond to the position shown in
A portion or all of post 412 may be an electrically active surface for functioning as an electrode. Post 412 may be electrically coupled to internal IMD circuitry housed in housing 401 via a feedthrough through bottom face 404 or an electrical interconnect within housing 401.
Tabs 470 include an inner surface 472 defining an aperture 474 through which a housing fixation member 460 can be threaded. Fixation member 460 includes a flexible elongate body 462, which may be a wire or suture, having a fixating structure 464 at elongate body distal end 463. The elongate body 462 is threaded through apertures 474 of tabs 470 such that a portion 466 of body 462 extends along top face 452. A proximal end (not shown in
Fixating structure 464 may be in the form of a “T-bar” that intersects approximately perpendicularly with body 462 as shown in
When the needle is withdrawn, the fixating structure 464 will resist being pulled back through the tissue layer. Elongate body 462 can be pulled proximally in the direction indicated by arrow 480 to remove any slack or excess length of elongate body 462 between tab 470 at end side wall 455 and fixating structure 464. In this way, tissue is captured between fixating structure 464 and tab 470 at end side wall 455. A proximal end of elongate body 462, which can be threaded through an eye of a surgical needle, may be anchored in tissue near tab 470 using a suture stitch that allows elongate body 462 to be pulled in the proximal direction 480, tightened across top surface 452, and subsequently knotted or clipped to hold bottom face 454 securely against the tissue layer by elongate body 462. Fixation member 460 is anchored in place by fixating structure 464 at end side wall 455 and by a knotted or clipped suture stitch at end side wall 456, thereby anchoring IMD 450 in place.
Syringe body 502 includes a distal needle guiding portion 510 extending proximally from the distal end 506 and a proximal IMD guiding portion 508 extending between proximal end 504 and distal needle guiding portion 510. The needle guiding portion 510 may include an open side (not seen in the view of
IMD guiding portion 508 includes an inner surface 512 defining a lumen large enough to retain IMD 450. As plunger 530 is advanced into syringe body 502, the fixation structure 464 of fixation member 460 will be inserted through tissue layer 490. As the plunger 530 is advanced, IMD 450 will be concomitantly ejected from syringe body 508 through opening 516 defined by inner surface 512 and securely anchored against tissue layer 490 as will be discussed in greater detail below.
It is noted that the fixation member 460 is shown to have a diameter that is exaggerated relative to the IMD 450 size for the sake of illustration. The diameter of a wire or suture forming elongate body 462 may be much smaller relative to the IMD 450. Furthermore, while it is shown to generally have a square cross-section in the artists' rendering, the elongate body 462 and T-bar structure may have different cross-sectional shapes, which may include generally round or flattened cross-sections.
Distal hollow needle portion 536 extends along top surface of IMD 450 and along at least a portion of a mid-portion 540 of plunger 530. Mid-portion 530 includes a distal face 542 that interfaces with IMD end side wall 456 within IMD guiding portion 508 of syringe body 502. Distal face 542 may be contoured or include an open groove to receive tab 470 positioned along end side wall 456. Elongate body 462 of fixation member 460 may extend alongside needle portion 546 over the IMD or within a slot or lumen of needle portion 546. When plunger 530 is advanced, distal face 542 of plunger mid-portion 540 advances IMD 450 out a distal opening 516 (
Distal hollow needle 536 has a longitudinal central axis 543 offset from a longitudinal central axis 541 of proximal shaft 532. A second, smaller plunger 550 extends into a lumen of distal hollow needle portion 536. Second plunger 550 is advanced into hollow needle portion 536 when the proximal end 535 of plunger 530 is depressed. Stopping interface 534 of plunger 530 presses against second plunger head 552, thereby advancing second plunger 550 into hollow needle portion 536.
Distal sharpened tip 537 is punctured through a tissue layer 490. Then, in one step of depressing plunger proximal end 535, fixating structure 464 is deployed through the tissue layer 490, and IMD 450 is delivered concomitantly from the syringe body and positioned over the tissue layer 490. A proximal end 465 of elongate body 462 may be pre-threaded on a surgical needle 560. Fixation member 460 may be provided with an elongate body 462 having a greater length than shown, such that excess length is available for suturing using needle 560. After removing implantation tool 500, the needle 560 can be used to anchor end side wall 456 by placing a suture in close proximity to tab 470 through tissue layer 490, then tightening elongate body 462 over top face 452 and securing elongate body 462 with a knot or using a tined elongate body 462 that does not require knotting to be anchored in place.
Elongate body 462 is guided through tissue layer 490 using a surgical needle to secure IMD 450 in the vicinity of end side wall 456 with a suture 482 through tissue layer 490. A knot or clip 484 on elongate body 462, on the outer surface of tissue layer 490, secures elongate body 462 in a taut position to anchor IMD 450 against tissue layer 490 at the implant site.
Hollow needle 602 has a sharpened distal tip 606 for penetrating a tissue layer for deploying flange 614 in or beneath a tissue layer at a target implant site. Hollow needle 602 may include an open side or slot 604 that enables flange 614 to project outward when fixation member 610 is loaded in needle 602. In other embodiments, flange 614 may be collapsed against elongate body 612 when confined within a closed lumen of needle 602.
In one embodiment, fixation member 610 may be confined within a proximal closed lumen portion 608 until distal tip 602 is advanced a desired depth within or through a tissue layer. Fixation member 610 may then be advanced out of a distal opening 605. Open side 604 of the distal portion of needle 602 allows flange 614 to project outward but not until flange 614 is beneath or within the tissue layer. When needle 602 is withdrawn, flange 614 resists withdrawal of the fixation member 610.
Needle 602 is advanced through the opening in tab 470 to deploy flange 614 beneath tissue layer 490 as generally described in conjunction with
Ratcheting collet 620 freely moves distally along elongate body 612 (toward distal end 618) but by interlocking with serrated surface 616, ratcheting collet 620 cannot be moved proximally along elongate body 612. Accordingly, ratcheting collet 622 is advanced along elongate member 612 until tab 470 is firmly held against tissue layer 490 and tissue layer 490 is securely captured between flange 614 and tab 470. Elongate body 612 may then be trimmed off just above ratcheting collet 620. In some embodiments, the serrated surface 616 may be terminated a distance from distal end 618 to prevent over-tightening of the fixation member 610 potentially causing excessive squeezing of tissue layer 490.
Fixation member 660 is advanced through aperture 474 of tab 470 and through tissue layer 490 using an implant tool 650. Tool 650 includes a handle portion 652 and a tool shaft 656 having a distal end 658. Handle portion 652 includes a distal face 654 for interfacing with a top surface 672 of head 670 when tool shaft 656 is advanced into a central lumen 674 of fixation member 660. Central lumen 674 may have a closed end such that distal end 658 meets with a closed end of lumen 674 (not shown in the perspective view of
Fixation member 660 is pushed through tab 470 until head 670 meets tab 470. Accordingly, a length of fixation member shaft 662 can be selected to reach a desired depth of deploying tines 664 beneath or within tissue layer 490.
In other embodiments a fixation member 660 may be fabricated from a rigid material. In these embodiments, a compliant grommet 675 circumscribing shaft 662 may be included to provide the desired compliance of fixation member 660 when tissue layer 490 is sandwiched between tines 664 and head 670.
In an alternative embodiment, the shaft 684 is hollow and an implantation tool includes a wire or shaft that extends through the fixation member shaft, holding it in a straight position until it has been advanced through tab 470 and into a tissue layer. Upon removing the tool from the fixation member shaft, the shaft assumes a deployed, U-shaped position.
In the embodiments described above, the IMDs are generally shown as leadless devices in which electrodes may be incorporated in or along the housing of the IMD. Stimulation of a nerve underlying tissue layer 490 occurs through tissue layer 490 when electrodes are positioned along the IMD housing. In other embodiments, electrodes may be carried by a lead extending away from the IMD. Secure anchoring of the IMD and the lead during a minimally invasive procedure is desired. Techniques and tools are described below for anchoring an IMD and lead system during a minimally invasive procedure.
Lead 740 includes a flattened paddle portion 744 carrying electrodes 748. Paddle portion 744 has a thin, flattened cross-section as compared to the semi-circular cross-section of paddle portion 715 of
The housings 712 and 732 shown in
Implant tool 750 includes a handle portion 752, a first shaft portion 754 and a second shaft portion 758. First shaft portion 754 is at least partially hollow and extends between handle portion 752 and second shaft portion 758. A side wall 756 of first shaft portion 754 defines an opening or cavity 760 in shaft portion 754 for receiving IMD 700. In some examples, first shaft portion 754 may comprise a tubular portion and side wall 754 defining cavity 760.
Second shaft portion 758 extends from first shaft portion to a distal tool end 764 and is an open-sided, hollow needle defining a cavity for receiving lead 706 tethered to IMD 700. The distal opening 762 of first shaft portion 754 communicates directly with the open-sided lumen second shaft portion 758 so that IMD 700 and lead 706 coupled to IMD 700 can be positioned into tool 750 as a single unit.
Tool 750 may include a removable or movable cover 755. Cover 755 may be moved to retain the housing of IMD 700 and lead 706 within the tool after positioning the housing and the lead in the tool, where the cover may fit over at least a portion of one of first shaft portion 754 and second shaft portion 758. Cover 755 may be, for example a slidable, hinged, or clam shell cover, fitting over at least a portion of one or both of first shaft portion 754 and second shaft portion 758 to enclose or retain IMD 700 and lead 706 after being installed in cavity 760 and the lumen of second shaft portion 758 respectfully. In the example shown, cover 755 is a slidable cover that retains IMD 700 within cavity 760. Cover 755 may glide along ridges 753 formed along lateral sides of first shaft portion to enable an open position as shown in
In operation, after IMD 700 and lead 706 are inserted into too 750, cover 755 is moved to a closed position. The tool 750 would be turned over to face the cover 755 down toward a tissue pocket and advanced into an implant site.
Distal tool end 764, which may include a sharpened or tissue penetrating tip, may be inserted through a tissue layer to implant a distal end of lead 706 and one or more electrodes carried by lead 706 along or beneath a tissue layer at a desired implant site. After inserting lead 706 to a desired tissue depth, the cover 755 may be slid open or removed so that IMD 700 and lead 706 can be fully removed from tool 750.
Syringe body 802 includes a distal needle guiding portion 810 extending proximally from the distal end 806 and a proximal IMD guiding portion 808 extending between proximal end 804 and distal needle guiding portion 810. The needle guiding portion 810 may define an open sided lumen 814.
IMD guiding portion 808 defines an inner lumen large enough to retain IMD 700 (indicated by dashed line). Plunger 830 extends between a proximal end 835 and a distal end 837 and includes a proximal shaft 832, a mid-portion 840 (enclosed within IMD guiding portion 808), and a distal hollow needle portion 836 extending through the open sided lumen 814 of distal needle guiding portion 810 of syringe body 802. Proximal end 835 includes a stopping interface 834 that enables a user to advance plunger 830 a controlled distance into syringe body 802. Distal end 837 is a sharpened tip of a distal hollow needle portion 836. Fixation lead 706 is loaded in hollow needle portion 836 and IMD 700 is loaded in IMD guiding portion 808, e.g. through distal opening 809 of IMD guiding portion 808.
As shown in
Plunger 830 is withdrawn from syringe body 802 as shown in
In this way, electrodes 708 can be positioned in close proximity to a nerve such as the tibial nerve without having to deliver stimulation pulses through a tissue layer such as the deep fascia. Placement beneath the tissue layer may reduce the pulse energy required for efficacious therapy. Only a small puncture through the deep fascia or other superficial tissue layer is required to position the electrodes 708 in close proximity to the tibial nerve and by extending lead 706 through the deep fascia, IMD 700 may also be stably anchored over the deep fascia.
IMD 900 may include a second fixation member 920 in some embodiments. A second fixation member 920 may extend from bottom face 904 or an IMD housing sidewall and be advanced through tissue layer 490 as bottom face 904 is rotated down and against tissue layer 490. In the embodiment shown, second fixation member 920 is embodied as a flanged post, e.g. corresponding to the fixation members 110 shown in
IMD 901 further includes one or more electrodes 924 positioned along bottom face 904 of IMD housing 902. Upon rotation of IMD 901 against tissue layer 490 about an intersection between side wall 906 and bottom face 904, hook 910 will penetrate tissue layer 490 and anchor bottom face 904 and electrode(s) 924 against tissue layer 490. Electrode(s) 924 are positioned to deliver neurostimulation through tissue layer 490, to a nerve extending beneath tissue layer 490, e.g. the tibial nerve extending beneath a deep fascia layer. In some embodiments, hook 910 may serve as or include an electrode. Accordingly, hook 910 and electrode 924 may form a bipolar pair for delivering neurostimulation. Fixation of IMD 901 and electrode placement are performed simultaneously.
A feedthrough assembly 970 is shown in
Fixation member 1010 may be coupled to insulator 1004, e.g. by brazing, diffusion bonding, or glass sealing methods. Fixation member 1010 includes a flanged hollow post 1012. Feedthrough pin 1006 extends through post 1012, which may include an aperture 1015 for facilitating welding of post 1012 and feedthrough pin 1006. Aperture 1015 may be sealed, e.g. backfilled with medical adhesive, after welding.
Post proximal end 1014 is fixedly mounted on insulator 1004 and flanged distal end 1016 may be positioned against tissue for delivering stimulation energy. As described previously in conjunction with
Implant tool 1100 includes a body 1102 extending between a first end 1104 and a second end 1106. The first end 1104 is provided with an incising blade 1108 for cutting an incision through the skin. Incising blade 1108 may be configured as a retractable blade or removable blade. Alternatively, a cover or blade guard 1120 may be provided to cover and protect the blade 1108 when not in use. When configured as a retractable blade, a slide, lever, spring or other actuating mechanism for retracting and advancing blade 1108 may be positioned along body 1102, e.g. near second end 1106. The blade 1108 has a width to create an incision that is not wider than required for inserting the IMD. In one embodiment, the blade width is provided to be approximately equal to the incision width needed to insert the IMD.
The second end 1106 includes a blunt edge for performing dissection down to and along a tissue plane, e.g. along the deep fascia, for forming a tissue pocket in which an IMD will be positioned. The tool body 1102 may include graduations, markings, physical protrusions, stops or other features for indicating a depth of a tissue pocket that has been created, enabling a pocket of adequate depth and proper width to be formed for receiving the IMD.
Tool body 1102 includes a straight portion 1103 and an S-shaped bend 1105 as shown such that first end 1104 extends approximately parallel to straight portion 1103. Second end 1106 extends from straight portion 1103. However it is recognized that tool body 1102 may include one or more bends, curves or angles to provide ergonomic, comfortable use of tool 1100 and to position ends 1104 and 1106 at desired angles relative to tool body 1102 to facilitate incising and dissection during an implant procedure.
In some embodiments, implant tool 1100 includes nerve locating electrodes 1110 along a bottom surface of the tool body 1102, near the blunt, dissecting end 1106. As end 1106 is advanced along a tissue plane, electrodes 1110 may be used to deliver test pulses until a location is identified which results in a satisfactory neurostimulation response. A satisfactory response to stimulation may be identified based on a stimulation threshold, an EMG signal, accelerometer or other motion signal, other physiological signal or user observation.
Electrodes 1110 may be electrically coupled to an external pulse generator via contacts 1112 positioned along tool body 1102 near first tool end 1104. Contacts 1112 may be snaps, pads or sockets to facilitate connection of cables, e.g. with alligator clips, extending to an external stimulation pulse generator. Contacts 1112 may each be coupled to respective insulated conductors extending through or along tool body 1102 to respective electrodes 1110. Alternatively conductor wires may be incorporated in tool 1100 and extend away from tool 1100 for connecting to a pulse generator.
Electrodes 1110 may be positioned a distance from end 1106 and sized and spaced from each other to correspond to electrodes along an IMD housing or IMD lead such that stimulation testing can be performed in a manner that simulates stimulation energy being delivered by the IMD electrodes or lead electrodes that will be used in the implanted system. While only two electrodes 1110 are shown, it is recognized that multiple electrodes 1110 may be provided along tool body 1102, with a corresponding number of connectors 1112, to enable testing of multiple electrode combinations and electrode locations without having to reposition tool 1100.
Once an optimal implant location is identified based on measured or observed responses to test stimulation pulses, tool 1100 may be removed and an IMD is inserted into the created tissue pocket at the identified depth using a delivery tool. Alternatively, tool 1100 may be left in place as a guide for inserting and locating the IMD at the desired implant site.
First end 1204 is shown angled approximately ninety degrees from tool body 1202 and second end 1206 is shown angled approximately forty-five degrees from tool body 1202. As described above, numerous configurations of tool body 1202 may be conceived which provide comfortable handling of tool 1200 and facilitate tissue pocket creation at a desired IMD implant site. For example, ease of use and access to a desired implant site may be promoted by implementing particular relative angles between opposing dissecting and incising ends, relative to each other or to a central tool body extending there between. In some embodiments, the shape of tool body 1202 is adjustable, e.g. when formed of a malleable material.
At block 1302, a skin incision is created. A skin incision may be created using a standard scalpel or an incising edge or blade of an implant tool as described above, for example in conjunction with
At block 1304, a tissue pocket is formed for receiving the IMD along a tissue plane at a desired implant site. The tissue pocket may be dissected using a dissecting end of implant tool as described in conjunction with
An optimal stimulation location may be identified at block 1306 prior to deploying the IMD. Electrodes included on an implant tool or on an IMD delivery tool advanced into the created pocket may be used to identify the optimal stimulation location by delivering test stimulation pulses and measuring and/or observing a stimulation response. In some embodiments, electrodes included on the IMD housing or a lead coupled to the IMD may be exposed through an IMD delivery tool and can be used for delivering test pulses from the IMD to test different IMD locations prior to fixing the IMD at an implant site.
Once an optimal implant location is identified, the IMD is delivered to the implant site at block 1308. The IMD may be delivered to the implant site using a delivery tool as described herein to simultaneously deliver the IMD and deploy a fixation member to anchor the IMD at the implant site. Alternatively, a fixation member may be deployed in a separate step after positioning the IMD, which may include verifying efficacious stimulation by the IMD prior to fixation. Fixation of the IMD may include the use of passive and/or active fixation members, such as tines or other passive fixation members extending from the IMD housing and/or from an electrical lead extending from the IMD. In some examples, an IMD incorporating electrodes along the IMD housing is positioned along the superficial tissue surface and passively fixated by tines or other passive fixation members extending from the IMD housing. In other examples, an IMD incorporating electrodes along the IMD housing and/or incorporated in active housing fixation members is positioned along the superficial surface of the tissue layer and the active housing fixation members extend into the tissue layer. An active fixation member may extend into the tissue layer that is superficial to the targeted nerve to capture the tissue layer between a portion of the active fixation member and the IMD housing. In some embodiments described herein, an active fixation member extends through an aperture of the IMD housing. Any of the fixation techniques described herein may be used to anchor the IMD at a desired site.
In still other examples, delivering the IMD to the implant site may include concomitantly delivering a lead coupled to the IMD. The lead may extend along the superficial surface of the tissue layer or be inserted into the tissue layer to both fix the IMD at the therapy delivery site and position electrodes carried by the lead near the targeted nerve.
In various embodiments, electrodes for delivering neurostimulation energy may be carried along the IMD housing, incorporated in or along a fixation member, and/or carried by a lead extending from the IMD. Delivery of the IMD system and fixation of the IMD system can be performed simultaneously in a single step. After implanting and fixating the IMD system, the skin incision is closed.
At block 1310, the IMD is enabled to deliver a neurostimulation therapy according to a prescribed protocol. Depending on the particular IMD configuration being used, the neurostimulation therapy is delivered through a tissue layer, e.g. through a deep fascia layer, using electrodes positioned above (superficially to) the tissue layer to stimulate a relatively deeper nerve extending beneath the tissue layer. In one embodiment, the tibial nerve is stimulated through the deep fascia tissue layer by wholly implanted electrodes positioned superficially to the deep fascia, i.e. on the opposing side of the deep fascia, from the nerve and superior to the flexor retinaculum. In other embodiments, electrodes may be positioned in close proximity to a targeted nerve by advancing the electrodes, which may additionally be configured as fixation members as described herein, through an overlying tissue layer, e.g. a deep fascia layer.
Thus, various embodiments of a minimally invasive IMD system have been presented in the foregoing description with reference to specific embodiments, as well as methods for implanting and securing the same. The various features of IMD fixation members and implant tools and associated methods of use described herein may be implemented in any combination other than the particular combinations shown in the illustrative embodiments, which may include adding or omitting some features. It is appreciated that various modifications to the referenced embodiments may be made without departing from the scope of the disclosure as set forth in the following claims.
1. A medical device system for delivering a neuromodulation therapy, comprising:
- an implantable medical device comprising: a housing; an electronic circuit within the housing; an electrical lead comprising a lead body extending between a proximal end coupled to the housing and a distal end extending away from the housing and at least one electrode carried by the lead body; and
- a delivery tool for deploying the implantable medical device at a neuromodulation therapy site, the tool comprising a first cavity for receiving the housing and a second cavity for receiving the lead, the first cavity and the second cavity in direct communication for receiving the housing and the lead coupled to the housing as a single unit.
18. A method for delivering an implantable medical device to a neuromodulation therapy site, comprising:
- positioning a implantable medical device housing coupled to an electrical lead in a delivery tool as a single unit; and
- deploying the housing and the lead from the delivery tool concomitantly as a single unit to the therapy site,
- the housing enclosing an electronic circuit,
- the electrical lead comprising a lead body extending between a proximal end coupled to the housing and a distal end extending away from the housing and at least one electrode carried by the lead body,
- the delivery tool comprising a first cavity for receiving the housing and a second cavity for receiving the lead, the first cavity and the second cavity in direct communication with each other for receiving the housing and the lead coupled to the housing as a single unit.
19. The method of claim 18, further comprising deploying the housing and the lead to position a flattened side of the lead against a tissue layer.
20. The method of claim 18, further comprising positioning a first fixation member in the tool to extend through an open side of the tool, the first fixation member extending from the distal end of the lead body.
21. The method of claim 20, further comprising:
- positioning a second fixation member in the tool to extend through an open side of the tool, the second fixation member being spaced apart proximally from the first fixation member along the lead body; and
- capturing a tissue layer between the first fixation member and the second fixation member when the lead distal end is advanced through a tissue layer.
22. The method of claim 18, further comprising inserting a distal tool end through a tissue layer to implant the lead distal end beneath the tissue layer, the housing remaining superficially to the tissue layer.
23. The method of claim 18, wherein positioning the single unit comprises:
- positioning the housing in a tool first shaft portion extending from a tool handle portion, the tool first shaft portion comprising a side wall defining the first cavity; and
- positioning the lead in an open-sided, hollow needle of a tool second shaft portion extending from the tool first shaft portion to a distal tool end and defining the second cavity for receiving the lead;
- the single unit extending through a distal opening of the first shaft portion in direct communication with the open-sided lumen of the second shaft portion.
24. The method of claim 23, further comprising moving a cover of the tool to retain the housing and the lead within the tool after positioning the housing and the lead in the tool, the cover fitting over at least a portion of one of the first shaft portion and the second shaft portion.
25. The method of claim 18, wherein positioning the single unit comprises:
- positioning the housing in a proximal device guiding portion of a syringe body of the delivery tool, the device guiding portion defining the first cavity for receiving the housing and extending between a proximal end of the syringe body and a distal needle guiding portion of the syringe body, the distal needle guiding portion comprising an open sided lumen; and
- positioning the lead in a distal hollow needle of a delivery tool plunger, the distal hollow needle comprising an open-sided lumen defining the second cavity for receiving the lead, the distal hollow needle extending through the needle guiding portion of the syringe body between a proximal plunger end and a distal plunger end,
- the plunger further comprising a proximal shaft and a mid-portion extending from the proximal shaft through the device guiding portion to the distal hollow needle,
- wherein deploying the housing and the lead comprises advancing the plunger through the syringe body to advance the distal hollow needle out a distal end of the distal needle guiding portion and the housing out a distal opening of the device guiding portion.
26. The method of claim 25, further comprising positioning a fixation member coupled to the lead to extend through an open groove of the needle guiding portion of the syringe body as the plunger is advanced.
27. The method of claim 18, further comprising deploying a housing fixation member to anchor the housing at the therapy site.
28. The method of claim 27, wherein deploying the housing fixation member comprises one of:
- advancing a flanged post through an aperture of the housing,
- rotating a hook coupled to the housing into a tissue layer;
- advancing descending legs coupled to a cross-beam into a tissue layer to capture the housing between the tissue layer and the cross-beam,
- enclosing the housing in a shroud to which the housing fixation member is coupled,
- advancing a serrated body through an aperture of the housing and fixedly engaging the serrated body with ratcheting collet, and
- advancing a U-shaped clip through an aperture of the housing.
29. The method of claim 27, further comprising deploying a housing fixation member comprising a bioabsorbable material.
30. The method of claim 27, further comprising deploying a housing fixation member comprising a shape memory alloy.
31. The method of claim 27, further comprising deploying a housing fixation member comprising an electrode.
32. The method of claim 27, wherein deploying the housing fixation member comprises anchoring a major side of the housing against a tissue layer, the major side comprising an electrode electrically coupled to the electronic circuitry.
33. The method of claim 18, further comprising delivering test stimulation pulses using an electrode along a distal end of the delivery tool to identify the therapy site.
34. The method of claim 18, further comprising coupling the lead to the housing to be non-removable from the housing.
Filed: Feb 21, 2019
Publication Date: Jun 20, 2019
Inventors: Brad C. Tischendorf (Minneapolis, MN), Eric H. Bonde (Minnetonka, MN), Phillip C. Falkner (Minneapolis, MN), John E. Kast (Hugo, MN), Randy S. Roles (Elk River, MN), Erik R. Scott (Maple Grove, MN), Todd V. Smith (Shoreview, MN), Xuan K. Wei (Minnetonka, MN), Anthony M. Chasensky (St. Paul, MN), Michael J. Ebert (Fridley, MN), Shawn C. Kelley (Shoreview, MN), Gabriela C. Molnar (Fridley, MN), Richard T. Stone (Minneapolis, MN)
Application Number: 16/281,573