Patent Description:
Some types of implantable medical devices, such as cardiac pacemakers or implantable cardioverter defibrillators, provide electrical therapy to a heart of a patient via electrodes of one or more implantable leads. The electrical therapy may be delivered to the heart for pacing, cardioversion or defibrillation. The implantable medical device may include electronic circuitry to deliver the electrical therapy, where the electronic circuitry is encapsulated by a housing, such as a metal titanium housing. <CIT> relates to an electromagnetic interference immune tissue system. <CIT> relates to an implantable medical device with swappable headers. <CIT> relates to methods for delivery of optical signals to tissue for the treatment of a <NUM> disease or condition. <CIT> relates to an implantable medical device header with optical interface. <CIT> relates to a medical device with surface mounted lead connector. <CIT> related to an implantable pulse generator inclunding integrated block feedthru and header assembly.

In general, this disclosure is directed to techniques for providing a polymeric enclosure for an implantable medical device. The polymeric enclosure provides mechanical strength, electrical isolation of the components therein, prevents moisture and fluid ingress into the implantable medical device system, and/or provides other benefits.

In one example, this disclosure describes a method for forming an implantable medical device with a polymeric enclosure, the method comprising: inserting electrical and mechanical couplings for an implantable medical lead receptacle into a first set of openings of a pre-formed polymeric structure, inserting a set of electronics within a second set of openings of the pre-formed polymeric structure, filling the first set of openings around the electrical and mechanical couplings with a first polymeric material, and filling the second set of openings around the set of electronics with a second polymeric material. In some examples, the first polymeric material is different than the second polymeric material.

In one example, this disclosure describes a method for forming an implantable medical device with a polymeric enclosure, the method comprising: inserting a set of electronics and couplings for an implantable lead receptacle into a set of openings of a fixture, electrically coupling the set of electronics and couplings creating a subassembly, disposing the subassembly within a mold; and disposing polymeric material around the set of electronics and couplings forming the polymeric enclosure for the implantable medical device with polymeric material.

In another example, this disclosure describes an implantable medical device system comprising: electronic circuitry configured to deliver cardiac pacing, couplings for an implantable medical lead receptacle, at least some of the couplings electrically connected with the electronic circuitry, and a polymeric enclosure having the electronic circuitry contained therein, the polymeric enclosure formed of polymeric material filled around the electronic circuitry and couplings and forming the implantable medical lead receptacle.

This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the methods and systems described in detail within the accompanying drawings and description below.

The details of one or more examples of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of this disclosure will be apparent from the description and drawings, and from the claims.

In general, this disclosure describes example techniques related to implantable medical devices having a polymeric enclosure and fabricating implantable medical devices with a polymeric enclosure. In some examples, the implantable medical device includes a polymeric enclosure rather than a metallic enclosure as is present in conventional implantable medical devices. The implantable medical device may be hermetically sealed and may include a lead connector and electronics in a single structure of polymeric material that provides mechanical strength and integrity, electrical isolation, and prevents moisture and fluid ingress. In some examples, the implantable medical device is a pacemaker, which may be configured for more temporary use than conventional pacemakers, e.g., for a number of months, rather than years.

<FIG> is a conceptual diagram illustrating a portion of an example implantable medical device system <NUM> in accordance with one or more aspects of this disclosure. Implantable medical device system <NUM> may function as a single chamber, e.g., ventricular, pacemaker, as illustrated by the example of <FIG>, or as dual-chamber pacemaker that delivers pacing to a heart <NUM> of patient <NUM>.

In the example of <FIG>, implantable medical device system <NUM> includes one or more implantable medical leads <NUM> and an implantable medical device (IMD) <NUM>. Implantable medical lead <NUM> includes an elongated lead body <NUM> with a distal portion <NUM>. Distal portion <NUM> of implantable medical lead <NUM> is positioned at a target site <NUM> within a heart <NUM> of a patient <NUM>. Distal portion <NUM> may include one or more electrodes. Target site <NUM> may be located at a wall of a ventricle of heart <NUM>. Lead <NUM> may be a bipolar or multipolar lead.

A clinician may maneuver distal portion <NUM> through the vasculature of patient <NUM> in order to position distal portion <NUM> at or near target site <NUM>. For example, the clinician may guide distal portion <NUM> through the SVC to target site <NUM> on or in a ventricular wall of heart <NUM>, e.g., at the apex of the right ventricle as illustrated in <FIG>. In some examples, other pathways or techniques may be used to guide distal portions <NUM> into other target implant sites within the body of patient <NUM>. Implantable medical device system <NUM> may include a delivery catheter and/or outer member (not shown), and implantable medical lead <NUM> may be guided and/or maneuvered within a lumen of the delivery catheter in order to approach target site <NUM>.

Implantable medical lead <NUM> may include electrodes 124A and 124B (collectively, "electrodes <NUM>") configured to be positioned on, within, or near cardiac tissue at or near target site <NUM>. In some examples, electrodes <NUM> are configured to function as electrodes in order to, for example, provide pacing to heart <NUM>. Electrodes <NUM> may be electrically connected to conductors (not shown) extending through lead body <NUM>. In some examples, the conductors are electrically connected to therapy delivery circuitry of IMD <NUM>, with the therapy delivery circuitry configured to provide electrical signals through the conductor to electrodes <NUM>. Electrodes <NUM> may conduct the electrical signals to the target tissue of heart <NUM>, causing the cardiac muscle, e.g., of the ventricles, to depolarize and, in turn, contract at a regular interval. Electrodes <NUM> may also be connected to sensing circuitry of IMD <NUM> via the conductors, and the sensing circuitry may sense activity of heart <NUM> via electrodes <NUM>. Electrodes <NUM> may have various shapes such as tines, helices, screws, rings, and so on. Again, although a bipolar configuration of lead <NUM> including two electrodes <NUM> is illustrated in <FIG>, in other examples IMD <NUM> may be coupled to leads including different numbers of electrodes, such as <NUM> electrode, three electrodes, or four electrodes.

In one or more examples, IMD <NUM> includes electronic circuitry contained within a polymeric enclosure where the circuitry may be configured to deliver cardiac pacing. In the example of <FIG>, the electronic circuitry within IMD <NUM> may include therapy delivery circuitry electrically coupled to electrodes <NUM>. The electronic circuitry within IMD <NUM> may also include sensing circuitry configured to sense electrical activity of heart <NUM> via electrodes <NUM>. The therapy delivery circuitry may be configured to administer cardiac pacing via electrodes <NUM>, e.g., by delivering pacing pulses in response to expiration of a timer and/or in response to detection of the activity (or absence thereof) of heart.

<FIG> and <FIG> illustrate an example of an implantable medical device (IMD) <NUM> having electronic circuitry <NUM> and a polymeric enclosure <NUM>, where <FIG> show various cross-sections of the IMD <NUM> of <FIG>. In one or more examples, the electronic circuitry, as described above, may include therapy delivery circuitry and/or sensing circuitry. In some examples, at least a portion of the polymeric enclosure <NUM>, such as a single polymeric enclosure, is formed of epoxy. IMD <NUM> includes electronic circuitry contained within the polymeric enclosure <NUM>. As described above, electronic circuitry may include sensing circuitry for receiving signals from electrodes and therapy delivery circuitry configured to deliver cardiac pacing. In some examples, electronic circuitry <NUM> includes processing circuitry for processing signals, and memory IMD <NUM> may also include a battery. In one or more examples, the IMD <NUM> is a small, temporary pacemaker with a single polymeric enclosure.

In one or more examples, implantable medical device <NUM> includes a preformed polymeric structure <NUM> having a first set of openings <NUM>, where the first set of openings <NUM> may include one or more openings, as shown in <FIG>. The first set of openings <NUM> are sized and configured to receive components therein. The preformed polymeric structure <NUM> may be 3D printed, molded, or cast from polymeric material.

In one or more examples, the implantable medical device <NUM> includes electrical and mechanical couplings <NUM> disposed within the first set of openings <NUM>, as shown in <FIG>. The electrical and mechanical couplings <NUM> may be for an electrical contact for an implantable lead receptacle <NUM>, which may include electrical and/or mechanical couplings. The implantable lead receptacle <NUM> allows for a lead to be mechanically inserted into the implantable medical device, and further allows for the lead to be mechanically and electrically coupled with the implantable medical device <NUM>. In one or more examples, the electrical and mechanical couplings <NUM> include a multi beam connector.

In one or more examples, the implantable medical device <NUM> includes couplings <NUM> (<FIG>) disposed within the first set of openings <NUM> (<FIG>). The couplings <NUM> may be for an implantable lead receptacle <NUM>, which may include electrical and/or mechanical couplings. The implantable lead receptacle <NUM> allows for a lead to be mechanically inserted into the implantable medical device, and further allows for the lead to be mechanically and electrically coupled with the implantable medical device <NUM>. In one or more examples, the couplings <NUM> includes a set screw block <NUM>. In one or more examples, the couplings include a setscrew block and setscrew.

In one or more examples, the preformed polymeric structure <NUM> of the implantable medical device <NUM> includes a second set of openings <NUM>, where the second set of openings <NUM> may include one or more openings, as shown in <FIG>. The second set of openings <NUM> are sized and configured to receive components therein. In one or more examples, the implantable medical device <NUM> includes a set of electronics <NUM> disposed within the second set of openings <NUM>. In one example, the set of electronics <NUM> includes a hybrid board, as shown in <FIG>. The hybrid board may include various therapy sensing processing circuitry, as discussed above. In some examples, the set of electronics <NUM> includes a battery pack <NUM>, as shown in <FIG>.

In one or more examples, the first set of openings <NUM> of the preformed polymeric structure <NUM> may be filled with a first material <NUM>, for example backfilled around the components within the first set of openings <NUM>. For example, polymeric material may be back filled with a first material around the first set of electronics <NUM> and couplings <NUM>. The first material may be medical adhesive, such as medical grade silicone material. In one or more examples, the second set of openings <NUM> is filled with a second material <NUM>. In some examples, the second material is epoxy. In one or more examples, the first material is different than the second material, and the first material is medical adhesive and the second material is epoxy. The first material and/or second material is filled around the couplings and electronic components of the implantable medical device <NUM>. The first material and/or the second material, in combination with the preformed polymeric structure <NUM> which may provide a single polymeric enclosure for an implantable medical device <NUM>, such as an implantable medical device <NUM> that is a small temporary pacemaker.

<FIG> illustrate an example of an implantable medical device <NUM> having a polymeric enclosure <NUM>, where <FIG> shows a cross-section of the implantable medical device <NUM> of <FIG>. The implantable medical device <NUM> may include sensing circuitry for receiving signals from electrodes. In one or more examples, the implantable medical device <NUM> includes electronic circuitry configured to deliver cardiac pacing contained within the polymeric enclosure <NUM>. Sensing circuitry can include filtering circuitry and other circuitry for conditioning the sensed signals, as well as amplifiers and/or other circuitry configured to detect depolarizations or other features of the signals. Pacing circuitry may include capacitors switches, and or other circuitry for generating electrical pulses having amplitudes, widths, and timings. Processing circuitry may control pacing circuitry based on features detected by sensing circuity.

In some examples, the implantable medical device <NUM> includes processing circuitry for processing signals, memory, and a battery. In one or more examples, the implantable medical device <NUM> is a small, temporary pacemaker with a single polymeric enclosure.

In one or more examples, the implantable medical device <NUM> includes a set of electronics, such as electrical and mechanical couplings <NUM> where the electrical and mechanical couplings <NUM> may be for electrical contacts for an implantable lead receptacle <NUM>, which may include electrical and/or mechanical couplings. The implantable lead receptacle <NUM> allows for a lead to be mechanically inserted into the implantable medical device, and further allows for the lead to be mechanically and electrically coupled with the implantable medical device <NUM>. In one or more examples, the electrical and mechanical couplings <NUM> include a multi beam connector <NUM>.

In one or more examples, the implantable medical device <NUM> include couplings <NUM> where the couplings <NUM> may be for an implantable lead receptacle <NUM>, which may include electrical and/or mechanical couplings. The implantable lead receptacle <NUM> allows for a lead to be mechanically inserted into the implantable medical device, and further allows for the lead to be mechanically and electrically coupled with the implantable medical device <NUM>. In one or more examples, the couplings <NUM> includes a set screw connector block <NUM>. In one or more examples, the couplings include a setscrew block and setscrew.

In one or more examples, the implantable medical device <NUM> includes a set of electronics <NUM>. In one example, the set of electronics <NUM> e.g., a hybrid board <NUM> that may include sensing circuitry, pacing circuitry, and processing circuitry. In some examples, the set of electronics <NUM> includes a battery pack <NUM>.

In one or more examples, polymeric enclosure <NUM> may be formed of a polymeric material, such as first material <NUM>. In one or more examples, the first material <NUM> may be molded around the components, including the electrical and mechanical couplings <NUM>, and set of electronics <NUM>, as shown in <FIG>. The first material may be medical adhesive. In some examples, the first material is epoxy. The first material may provide a single polymeric enclosure for an implantable medical device <NUM>, such as an implantable medical device <NUM> that is a small temporary pacemaker.

In one or more examples, a method for manufacturing an implantable medical device having a polymeric enclosure is disclosed herein. Referring to <FIG>, the method includes providing a pre-formed polymeric structure <NUM>, as shown in <FIG>. The pre-formed polymeric structure may be a molded structure or 3D printed of polymeric material, for example. The method further includes inserting electrical and mechanical couplings <NUM> into a first set of openings <NUM> within the pre-formed polymeric structure <NUM>, as shown in <FIG>. In one or more examples, the electrical and mechanical couplings include a multi beam connector (MBC). In one or more examples, the couplings include electrical and/or mechanical couplings. In one or more examples, the couplings include a set screw connector block. Referring to <FIG>, a set of electronics <NUM> may be disposed within a second set of openings <NUM>. The set of electronics <NUM> may include a battery pack <NUM> and/or a hybrid board <NUM>. Electrical connections <NUM> are disposed within the polymeric structure <NUM> between the electrical and mechanical couplings <NUM> and the set of electronics <NUM>, and are electrically connected to each of the electrical and mechanical couplings <NUM> and the set of electronics, for example by solder, so that the electrical and mechanical couplings <NUM> are electrically coupled with the set of electronics <NUM>.

The method further may include disposing a setscrew access grommet within the polymeric structure <NUM>, and filling the first set of openings <NUM> around the electrical and mechanical couplings <NUM> with a first polymeric material <NUM>, as shown in <FIG>. In one or more examples, the first polymeric material includes medical adhesive <NUM>. In some examples, the medical adhesive may be medical grade silicone. In one or more examples, the medical adhesive may be room temperature vulcanization silicone (RTV). As shown in <FIG>, the second set of openings <NUM> may be filled with a second polymeric material <NUM>, where the filling of the second set of openings is disposed around the set of electronics <NUM>. In one or more examples, the first polymeric material <NUM> is different than the second polymeric material <NUM>. In one or more examples, the first polymeric material <NUM> is medical adhesive and the second polymeric material <NUM> is epoxy <NUM>.

In one or more examples, a method includes inserting an electrical and mechanical couplings for an implantable lead receptacle into a first set of openings (<NUM>), as shown in <FIG>. In one or more examples, the couplings may include mechanical couplings and/or electrical couplings. In some examples, inserting the electrical and mechanical couplings includes inserting a set screw block, and a set screw, and/or a multi beam connector. In one or more examples, a method includes inserting a set of electronics into a second set of openings (<NUM>). In some examples, inserting the electrical and mechanical couplings includes inserting battery components and/or a hybrid antenna assembly. The method may further include electrically coupling the electrical and mechanical couplings with the set of electronics. In some examples, electrically coupling may include welding and/or soldering processes. The method further may include filling the first set of openings with a first polymeric material and disposing the first polymeric material around the electronics and couplings (<NUM>). The method may further include filling the second set of openings with a second polymeric material (<NUM>) to form a polymeric enclosure for the implantable medical device with polymeric material, where the polymeric material may be epoxy and/or medical adhesive.

In one or more examples, a method for manufacturing an implantable medical device having a polymeric enclosure is disclosed herein. In some examples, the polymeric enclosure is molded around components of the implantable medical device. Referring to <FIG>, a set of electronics and electrical and mechanical couplings may be disposed within a fixture <NUM>. In some examples, the electrical and mechanical couplings may include a set screw block <NUM>, multi beam connector <NUM>, and the set of electronics may include battery pack <NUM> (<FIG>) and hybrid-antenna assembly <NUM> (<FIG>). Hybrid-antenna assembly may further include sensing, therapy, or processing circuitries. In one or more examples, hybrid-antenna assembly may include communication circuitry, for example for wireless communication with external devices. An electrical connection and/or a clamping device may be disposed amongst the set of electronics in preparation for electrically connecting the components. In some examples, a Teflon-coated pin is routed through the set screw block <NUM> and the multi beam connector <NUM>, as shown in <FIG>. In one or more embodiments, niobium pins are added, and a retention device <NUM> for the resistance weld step is added (<FIG>). The electronics may be electrically coupled with each other. For example, <FIG> illustrate placing solder preforms on the hybrid-antenna assembly <NUM>, and the solder is reflowed, for example using a laser, to electrically couple the hybrid antenna assembly <NUM>, battery pack <NUM>, multi beam connector <NUM> and the set screw block <NUM>, and forming a subassembly <NUM>. The subassembly <NUM> may be disposed in a half-mold <NUM>, as shown in <FIG>. In one or more examples, the full mold <NUM> is formed by placing the other portion on the half-mold <NUM> and closing the mold. Polymeric material, such as, but not limited to, epoxy, is disposed within the mold <NUM>, and filled around the components of the subassembly <NUM>. The polymeric material is cured, for example by heat. In some examples, the mold is placed in an oven at <NUM> degrees C for two hours allowing the polymeric to cure. As shown in <FIG>, an implantable medical device <NUM> having a polymeric enclosure <NUM> with a lead receptacle <NUM> is formed.

In one or more examples, a method includes inserting a set of electronics and couplings for an implantable lead receptacle into a set of openings (<NUM>), as shown in <FIG>. In some examples, inserting the set of electronics and couplings includes inserting battery components, an antenna assembly, a set screw block, and a set screw. In one or more examples, the couplings may include mechanical couplings and/or electrical couplings. The method may further include electrically coupling the set of electronics with the couplings and forming a subassembly (<NUM>). The subassembly may further be disposed in a mold (<NUM>), and polymeric material disposed around the electronics and couplings (<NUM>) to form a polymeric enclosure for the implantable medical device with polymeric material, where the polymeric material may be epoxy and/or medical adhesive.

Various aspects of the techniques may be implemented within one or more processing circuitries, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components, embodied in external devices, such as physician or patient external devices, electrical stimulators, or other devices. The term "processing circuitry" may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry or any other equivalent circuitry.

In one or more examples, the functions described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on, as one or more instructions or code, a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media forming a tangible, non-transitory medium. Instructions may be executed by one or more processing circuitries, such as one or more DSPs, ASICs, FPGAs, general purpose microprocessors, or other equivalent integrated or discrete logic circuitry. Accordingly, the term "processing circuitry," as used herein may refer to one or more of any of the foregoing structure or any other structure suitable for implementation of the techniques described herein.

Claim 1:
An implantable medical device (<NUM>) comprising:
electronic circuitry (<NUM>) configured to deliver cardiac pacing;
couplings for an implantable medical lead receptacle (<NUM>), at least some of the couplings electrically connected with the electronic circuitry (<NUM>); and
a polymeric enclosure (<NUM>) having the electronic circuitry (<NUM>) contained therein, the polymeric enclosure (<NUM>) formed of a polymeric material filled around the electronic circuitry (<NUM>) and couplings and forming the implantable medical lead receptacle (<NUM>).