Implantable medical device with biocompatible circuit board and embedded electrodes

Abstract

Embodiments of the present disclosure relate to implantable medical devices (IMDs). In an example embodiment, an IMD includes a housing including a plurality of feedthroughs extending through the housing, a first electrode, a second electrode, and a biocompatible circuit board disposed about an outer surface of the housing. The biocompatible circuit board includes a plurality of traces, wherein a first trace of the plurality of traces is coupled to the first electrode and a first feedthrough of the plurality of feedthroughs, and a second trace of the plurality of traces is coupled to the first electrode and a second feedthrough of the plurality of feedthroughs.

Description

[0001] Related Applications

[0002] This application claims priority to provisional application number 62 / 976,075, filed February 13, 2020, the entirety of which is incorporated by reference herein. TECHNICAL FIELD

[0003] Embodiments of the present disclosure relate to medical devices and systems for sensing physiological parameters and / or delivering therapy. More particularly, embodiments of the present disclosure relate to devices and methods for biocompatible circuit boards for implantable medical devices. BACKGROUND

[0004] Implantable medical devices (IMDs) can be configured to sense physiological parameters and / or provide therapy, and can include one or more electrodes for performing various aspects of these functions. IMDs can also include an antenna for communicating with other devices. Conventionally, devices such as programmers have been used to cause IMDs to take various actions, such as, for example, marking recordings of physiological parameters, initiating communications with other devices, and the like. SUMMARY

[0005] Exemplary embodiments of the present disclosure include, but are not limited to, the following examples.

[0006] In Example 1, an implantable medical device, comprising: a housing including a plurality of feedthroughs extending through the housing; a first electrode; a second electrode; and a biocompatible circuit board disposed about an outer surface of the housing, the biocompatible circuit board including a plurality of traces, wherein a first trace of the plurality of traces is coupled to the first electrode and a first feedthrough of the plurality of feedthroughs, and a second trace of the plurality of traces is coupled to the first electrode and a second feedthrough of the plurality of feedthroughs.

[0007] In Example 2, the implantable medical device of Example 1, wherein the first electrode and the second electrode are integrated into the biocompatible circuit.

[0008] In Example 3, the implantable medical device of Example 1 or 2, wherein the biocompatible circuit board includes a plurality of layers, and the plurality of traces are disposed between two layers of the plurality of layers.

[0009] In Example 4, the implantable medical device of any of Examples 1-3, wherein the biocompatible circuit board is a flexible circuit board.

[0010] In Example 5, the implantable medical device of any of Examples 1-4, wherein the housing is formed of an electrically conductive material.

[0011] In Example 6, the implantable medical device of any of Examples 1-5, wherein the biocompatible circuit board further comprises an antenna, and wherein a third trace of the plurality of traces is coupled to the antenna and a third feedthrough of the plurality of feedthroughs.

[0012] In Example 7, the implantable medical device of Example 6, the housing further comprising a non-conductive window, wherein the antenna is positioned proximate to the non-conductive window.

[0013] In Example 8, the implantable medical device of Example 7, wherein the non-conductive window is formed of sapphire.

[0014] In Example 9, the implantable medical device of any of Examples 6-8, further comprising an isolation layer disposed between the antenna and the housing.

[0015] In Example 10, the implantable medical device of any of Examples 1-9, further comprising a third electrode and a fourth electrode.

[0016] In Example 11, the implantable medical device of any of Examples 1-10, further comprising a power source disposed substantially along an entire length of the housing.

[0017] In Example 12, a method for constructing an implantable medical device, the method comprising: disposing an antenna, a first electrode, and a second electrode on a circuit board substrate; disposing a plurality of traces on the circuit board substrate, wherein a first trace of the plurality of traces is coupled to the first electrode, wherein a second trace of the plurality of traces is coupled to the second electrode, and a third trace of the plurality of traces is coupled to the antenna; coupling the first trace to a first feedthrough of an implantable medical device housing; coupling the second trace to a second feedthrough of the implantable medical device housing; coupling the third trace to a third feedthrough of the implantable medical device housing; and disposing the circuit board substrate around the implantable medical device housing.

[0018] In Example 13, the method of Example 12, wherein disposing the circuit board substrate around the implantable medical device housing comprises: aligning the antenna with a non-conductive window of the implantable medical device housing.

[0019] In Example 14, the method of Example 12 or 13, further comprising disposing an isolation layer between the antenna and the implantable medical device housing.

[0020] In Example 15, the method of any of Examples 12-14, further comprising adhering the circuit board substrate to the implantable medical device housing with an epoxy.

[0021] In Example 16, an implantable medical device comprising: a housing comprising a plurality of feedthroughs extending through the housing; a first electrode; a second electrode; and a biocompatible circuit board disposed about an outer surface of the housing, the biocompatible circuit board comprising a plurality of traces, wherein a first trace of the plurality of traces is coupled to the first electrode and a first feedthrough of the plurality of feedthroughs, and a second trace of the plurality of traces is coupled to the first electrode and a second feedthrough of the plurality of feedthroughs.

[0022] In Example 17, the implantable medical device of Example 16, wherein the first electrode and the second electrode are integrated into the biocompatible circuit.

[0023] In Example 18, the implantable medical device of Example 16 or 17, wherein the biocompatible circuit board comprises a plurality of layers, and the plurality of traces is disposed between two layers of the plurality of layers.

[0024] In Example 19, the implantable medical device of any one of Examples 16-18, wherein the biocompatible circuit board is a flexible circuit board.

[0025] In Example 20, the implantable medical device of any one of Examples 16-19, wherein the housing is formed of an electrically conductive material.

[0026] In Example 21, the implantable medical device of any one of Examples 16-20, wherein the biocompatible circuit board further comprises an antenna, and wherein a third trace of the plurality of traces is coupled to the antenna and a third feedthrough of the plurality of feedthroughs.

[0027] In Example 22, the implantable medical device of Example 21, the housing further comprising a non-conductive window, wherein the antenna is positioned proximate to the non-conductive window.

[0028] In Example 23, the implantable medical device of Example 22, wherein the non-conductive window is formed of sapphire.

[0029] In Example 24, the implantable medical device of any one of Examples 21-23, further comprising an isolation layer disposed between the antenna and the housing.

[0030] In Example 25, the implantable medical device of any one of Examples 16-24, further comprising a third electrode and a fourth electrode.

[0031] In Example 26, the implantable medical device of any one of Examples 16-25, further comprising a power source disposed substantially along an entire length of the housing.

[0032] In Example 27, an apparatus for supporting components configured to be coupled to an implantable medical device, the apparatus comprising: a first electrode; a second electrode; and a biocompatible circuit board configured to be disposed about a housing of the implantable medical device, the biocompatible circuit board comprising a plurality of traces, wherein a first trace of the plurality of traces is coupled to the first electrode and configured to be electrically coupled to a first feedthrough of the implantable medical device, and a second trace of the plurality of traces is coupled to the first electrode and configured to be electrically coupled to a second feedthrough of the implantable medical device.

[0033] In Example 28, the apparatus of Example 27, the circuit board further comprising an antenna, wherein a third trace of the plurality of traces is electrically coupled to the antenna and configured to be coupled to a third feedthrough of the implantable medical device.

[0034] In Example 29, the apparatus of Example 28, wherein the biocompatible circuit board comprises a plurality of layers, and the plurality of traces is disposed between two layers of the plurality of layers.

[0035] In Example 30, the apparatus of Example 29, further comprising a barrier layer disposed between the antenna and one of the plurality of layers.

[0036] In Example 31, the apparatus of Example 27, wherein the biocompatible circuit board is made of a flexible material.

[0037] In Example 32, a method for constructing an implantable medical device, the method comprising: disposing an antenna, a first electrode, and a second electrode on a circuit board substrate; disposing a plurality of traces on the circuit board substrate, wherein a first trace of the plurality of traces is coupled to the first electrode, wherein a second trace of the plurality of traces is coupled to the second electrode, and a third trace of the plurality of traces is coupled to the antenna; coupling the first trace to a first feedthrough of a housing of the implantable medical device; coupling the second trace to a second feedthrough of the housing of the implantable medical device; coupling the third trace to a third feedthrough of the housing of the implantable medical device; and disposing the circuit board substrate about the housing of the implantable medical device.

[0038] In Example 33, the method of Example 32, wherein disposing the circuit board substrate about the housing of the implantable medical device comprises: aligning the antenna with a non-conductive window of the housing of the implantable medical device.

[0039] In Example 34, the method of Example 32, further comprising disposing a barrier layer between the antenna and the housing of the implantable medical device.

[0040] In Example 35, the method of Example 32, further comprising adhering the circuit board substrate to the housing of the implantable medical device with an epoxy.

[0041] While several embodiments have been disclosed, other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the subject matter disclosed herein. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature rather than restrictive. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a schematic diagram of a system with an implantable medical device (IMD) and a receiving device according to embodiments of the present disclosure.

[0043] Figure 2 is a perspective view of a housing of an IMD according to embodiments of the present disclosure.

[0044] Figure 3A is a perspective view of a flexible circuit of an IMD according to embodiments of the present disclosure. Figure 2

[0045] Figure 3B is a perspective view of a flexible circuit according to embodiments of the present disclosure in a partially curved or folded configuration. Figure 3A

[0046] Figure 4 is a schematic diagram of an electrical subassembly according to embodiments of the present disclosure.

[0047] Figure 5 is a schematic diagram of an electrical subassembly and an IMD operating with a receiving device according to embodiments of the present disclosure.

[0048] Figure 6A is a perspective view of an IMD according to embodiments of the present disclosure.

[0049] Figure 6B is another perspective view of a housing of an IMD according to embodiments of the present disclosure. Figure 6A

[0050] While the subject matter disclosed herein can be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail herein. However, it should be understood that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the subject matter disclosed herein as defined by the appended claims.

[0051] Although the term "block" can be used herein to connote different elements employed in the illustrative methodology, the term should not be interpreted as implying any requirement that the various steps be performed in the order shown or that the various steps be performed at all, unless and except as explicitly recited in the independent claims. DETAILED DESCRIPTION​​​

[0052] Implantable medical devices (IMDs) are limited in size due to being implanted within a patient’s body. Due to these size limitations, the power source of the IMD can be a limiting factor of how much functionality can be incorporated into the IMD. As such, it can be useful to transmit sensor measurements to an external device for processing of the sensor measurements. To transmit the sensor measurements, the IMD typically includes a header made of a non-conductive material, such as epoxy. However, due to the positioning and size of the header, including the header further reduces the size of the power source that can be included in the IMD. Embodiments disclosed herein provide a solution to this problem.

[0053] Figure 1 is a schematic diagram of a system 100 including an IMD 102 implanted within a patient’s body 104 and configured to communicate with a receiving device 106. In embodiments, the IMD 102 can be implanted subcutaneously within an implant location or pocket of a patient’s chest or abdomen and can be configured to monitor (e.g., sense and / or record) physiological parameters associated with a patient’s heart 108. In embodiments, the IMD 102 can be an implantable cardiac monitor (ICM) (e.g., an implantable diagnostic monitor (IDM), an implantable loop recorder (ILR), etc.) configured to record physiological parameters such as, for example, one or more cardiac activation signals, heart sounds, blood pressure measurements, oxygen saturation, and / or the like.

[0054] In embodiments, the IMD 102 can be configured to monitor physiological parameters that can include one or more signals indicative of a patient’s physical activity level and / or metabolic level, such as an acceleration signal. In embodiments, the IMD 102 can be configured to monitor physiological parameters associated with one or more other organs, systems, and / or the like. The IMD 102 can be configured to sense and / or record at regular intervals, continuously, and / or in response to a detected event. In embodiments, such a detected event can be detected by one or more sensors of the IMD 102, another IMD (not shown), an external device (e.g., the receiving device 106), and / or the like.

[0055] In addition, IMD 102 can be configured to detect a variety of physiological signals that can be used in conjunction with various diagnostic, therapeutic, and / or monitoring implementations. For example, IMD 102 can include sensors or circuitry for detecting respiratory system signals, cardiac system signals, and / or signals related to patient activity. In embodiments, IMD 102 can be configured to sense intrathoracic impedance from which a variety of respiratory parameters can be derived, including, for example, tidal volume and minute ventilation. Sensors and associated circuitry can be incorporated with IMD 102 in conjunction with detecting one or more body motion or body posture and / or position related signals. For example, an accelerometer and / or GPS device can be used to detect patient activity, patient positioning, body orientation, and / or torso position.

[0056] For purposes of illustration and not limitation, various embodiments of devices that can be used in accordance with the present disclosure to record physiological parameters are described herein in the context of an IMD implantable under the skin in a patient's thoracic region.

[0057] As shown, IMD 102 can include a housing 110 Figure 2 In embodiments, IMD 102 can include any number of electrodes (and / or other types of sensors, such as, for example, thermometers, barometers, pressure sensors, optical sensors, motion sensors, and / or the like) in any number of various types of configurations, and housing 110 can include any number of different shapes, sizes, and / or features. In embodiments, IMD 102 can be configured to sense physiological parameters and record physiological parameters. For example, IMD 102 can be configured to activate (e.g., periodically, continuously, upon detection of an event, and / or the like), record a specified amount of data (e.g., physiological parameters) in memory, and transmit the recorded data to receiving device 106. For example, in the case of an IDM, IMD 102 can activate, record cardiac signals for a certain period of time, deactivate, and activate to transmit the recorded signals to receiving device 106.

[0058] In embodiments, receiving device 106 can be, for example, a programmer, a controller, a patient monitoring system, and / or the like. Although in the example shown in FIG. 1, receiving device 106 is shown as a separate device from IMD 102, in embodiments, receiving device 106 can be incorporated with IMD 102. Figure 1The receiving device 106 is shown as an external device, but the receiving device 106 can include an implantable device configured to communicate with the IMD 102, which can be, for example, a control device, another monitoring device, a pacemaker, an implantable defibrillator, a cardiac resynchronization therapy (CRT) device, and / or the like, and can be an implantable medical device known in the art or later developed for providing therapy and / or diagnostic data regarding the patient and / or the IMD 102. In embodiments, the IMD 102 can be a pacemaker, an implantable cardioverter defibrillator (ICD) device, or a cardiac resynchronization therapy (CRT) device. In embodiments, the IMD 102 can include defibrillation and pacing / CRT capabilities (e.g., a CRT-D device).

[0059] According to embodiments of the present disclosure, the system 100 can be used to implement coordinated patient measurement and / or monitoring, diagnosis, and / or therapy. The system 100 can include, for example, one or more patient internal medical devices, such as the IMD 102, and one or more patient external medical devices, such as the receiving device 106. The receiving device 106 can be configured to perform monitoring, and / or diagnosis and / or therapy functions external to the patient (i.e., not invasively implanted within the patient). The receiving device 106 can be positioned on the patient, near the patient, or at any location external to the patient.

[0060] The IMD 102 and the receiving device 106 can communicate over a wireless link. For example, the IMD 102 and the receiving device 106 can be coupled through a short-range radio link, such as Bluetooth, IEEE 802.11, and / or a proprietary wireless protocol. The communication link can facilitate one-way and / or two-way communication between the IMD 102 and the receiving device 106. Data and / or control signals can be sent between the IMD 102 and the receiving device 106 to coordinate the functions of the IMD 102 and / or the receiving device 106. Patient data can be downloaded from one or more of the IMD 102 and the receiving device 106 periodically or on command. A physician and / or the patient can communicate with the IMD 102 and the receiving device 106, for example, to obtain patient data or to initiate, terminate, or modify recording and / or therapy.

[0061] As shown, because the IMD 102 does not include a header and an antenna disposed at an end of the IMD 102, the housing 110 of the IMD 102 can include a larger volume than for the same size IMD 102 that includes a header and an antenna. Figure 2 As such, the IMD 102 can include more electronics and / or power sources. However, because the IMD 102 does not include a header with an antenna, embodiments disclosed herein include alternative embodiments for equipping the IMD 102 with an antenna for transmission, as explained below.

[0062] Figure 1 The illustrative system 100 shown in the Figure 1 The illustrative system 100 shown in the Figure 1 Any one or more of the components depicted in the Figure 1 The illustrative system 100 depicted in the

[0063] Figure 2 is a perspective view of the housing 110 according to embodiments disclosed herein.

[0064] According to embodiments, the IMD 102 includes a non-conductive window 200 on an outer surface 216 of the housing 110. In embodiments, the window 200 is located on a frontward facing portion 210 of the outer surface 216. In embodiments, the window 200 can be located on a rearward facing portion 212 of the outer surface 216. In embodiments, if there are two antennas 206 facing in opposite directions from each other, the window 200 can be located on both the frontward facing portion 210 and the rearward facing portion 212 (e.g., have two windows instead of one). The IMD 102 has a longitudinal axis 214 along which components of the IMD 102 (e.g., the components shown in the Figure 4 The window 200 is made of any suitable non-conductive material, such as ceramic, glass, sapphire, etc. In some examples, the window 200 can be transparent or translucent.

[0065] At least one feedthrough 202 is arranged along the longitudinal axis 214 at or near one or more ends of the housing 110. In some examples, the housing 110 can include one feedthrough 202, and in some other examples, the housing 110 can include two or more feedthroughs 202. In the example shown in Figure 3A and Figure 3B In the example shown in the

[0066] The non-conductive window 200 serves to isolate the antenna 206 from the conductive surface of the housing 110. Additionally or alternatively, the isolation can be performed by inserting an isolation layer (not shown) between the housing 110 and the antenna 206. In some examples, the isolation layer is formed from any non-conductive material, such as a suitable polymer, using any suitable method of polymer deposition. The non-conductive window 200 can be advantageous over inserting an additional non-conductive isolation layer between the antenna 206 and the housing 110, as the window 200 can reduce the profile (i.e., thickness) of the IMD 102 compared to when implementing an additional layer. However, this example is not meant to be limiting, and in embodiments, both a window 200 and a non-conductive substrate can be used.

[0067] Figure 3A is a perspective view of a circuit board 204 for use in the IMD 102 according to embodiments disclosed herein. The circuit board 204 can be biocompatible. In some examples, the circuit board 204 can be flexible, while in some other examples, the circuit board 204 can be rigid. The circuit board 204 can be opaque and made from any suitable material, including but not limited to liquid crystal polymer (LCP). The circuit board 204 includes two surfaces, a front surface 204A and a back surface 204B. Additionally or alternatively, the circuit board 204 can include multiple layers.

[0068] In embodiments, the antenna 206 can be disposed on the front surface 204A, embedded in the circuit board 204, and / or disposed between layers of the circuit board 204. In embodiments, the antenna 206 can be disposed proximate to the window 200 to prevent the material of the housing 110 from interfering with wireless data transmission by the antenna 206. The antenna 206 can be configured to wirelessly communicate data with the receiving device 106.

[0069] Additionally or alternatively, the traces 208 can be disposed on the front surface 204A, embedded in the circuit board 204, and / or disposed between layers of the circuit board 204. There can be any number of traces 208 as needed, such that the traces 208 electrically couple the feedthroughs 202 with each component disposed on the circuit board 204. For example, there are five (5) traces 208, each connected to one of the five (5) feedthroughs 202. And, these five feedthroughs 202 are connected to four (4) electrodes and a single antenna of the IMD 102 (for a total of five separate internal components). If there are fewer electrodes or more antennas, the number of feedthroughs 202 can change accordingly. In embodiments, the traces 208 are made from any suitable conductive material, such as, for example, gold, silver, or platinum alloys. The traces 208 are printed on the circuit board 204 to electrically couple the feedthroughs 202 with each of the first electrode 112A, the second electrode 114A, the third electrode 112B, the fourth electrode 114B, and / or the antenna 206.

[0070] In embodiments, an epoxy layer or any other suitable non-conductive polymer can be applied over the front surface 204A to prevent the traces 208 and / or the antenna 206 from contacting each other and / or the patient’s body 104.

[0071] In embodiments, the circuit board 204 can be coupled to the first electrode 112A and / or the second electrode 114A. In embodiments, the first electrode 112A and the second electrode 114A can be incorporated into the circuit board 204. The first electrode 112A and the second electrode 114A can be disposed on the front-facing portion 210 of the housing 110.

[0072] Additionally or alternatively, the circuit board 204 can be coupled to the third electrode 112B and / or the fourth electrode 114B. In embodiments, the third electrode 112B and the fourth electrode 114B can be incorporated into the circuit board 204. The third electrode 112B and the fourth electrode 114B can be disposed on the rear-facing portion 212 of the housing 110. In embodiments, the electrodes 112, 114 can be used to monitor (e.g., sense and / or record) physiological parameters associated with the patient’s body 104.

[0073] In embodiments, the circuit board 204 can wrap around the housing 110 by, for example, bending or folding the circuit board 204 around the housing 110, as shown in Figure 2 In embodiments, the circuit board 204 can wrap around the housing 110 by, for example, bending or folding the circuit board 204 around the housing 110, as shown in Figure 2 It is shown that the electrodes 112A, 114A or the electrodes 112B, 114A can overlap with the circles 116 and 118 of Figure 2 As used herein, the term “overlap” can be when the electrodes 112A, 114A at least partially cover one of the circles 116, 118 when viewed from an angle perpendicular to the longitudinal axis of the IMD.

[0074] Figure 4 It is shown that the electrodes 112A, 114A or the electrodes 112B, 114A can overlap with the circles 116 and 118 of

[0075] The subassembly 300 can also include one or more connector blocks 314 secured in the housing 110 such that when the connector blocks 314 are attached to the feedthrough 202 at the housing 110 of the IMD 102, the contacts 302 within the connector blocks 314 are in electrical contact with the traces 208 of the IMD 102. The number of contacts 302 can be the same as the number of traces 208 such that each contact 302 makes a one-to-one connection with each trace 208.

[0076] The sub-assembly 300 can also include control circuitry, such as a microcontroller 308, and one or more application specific integrated circuits (ASICs) 310, as appropriate. The one or more ASICs 310 can include current generation circuitry for providing stimulation pulses at one or more of the electrodes 112 and 114, and can also include telemetry modulation and demodulation circuitry for enabling bidirectional wireless communication at the antenna 306, battery charging and protection circuitry that can be coupled to the charging coil 306, decoupling capacitors in each current path to the electrodes 112 and 114, and the like. The components within the housing 110 are integrated via a printed circuit board (PCB) 312.

[0077] Figure 5 Further shown are the above-referenced external components (e.g., the receiving device 106), which can be used to communicate with the IMD 102. The receiving device 106 can include an external charger 318 and an external controller 320. The external controller 320 can be used to control and monitor the IMD 102 via a bidirectional wireless communication link 324 through the patient’s tissue. For example, the external controller 320 can be used to monitor measurements made by the electrodes 112 and 114.

[0078] Communications over the wireless communication link 324 can occur via magnetic induction coupling between an antenna (not shown) in the external controller 320 and the antenna 206 in the IMD 102. The magnetic field comprising the link 324 can be modulated via frequency shift keying (FSK) or the like to encode the transmitted data. Other methods can also be employed, including but not limited to short-range RF telemetry (e.g., Bluetooth, WiFi, Zigbee, MICS, etc.).

[0079] When the battery 304 is rechargeable, the external charger 318 can provide power to recharge the battery 304. Such power transfer can occur by exciting a charging coil (not shown) in the external charger 318, which produces a magnetic field 322 that then excites the charging coil 306 in the sub-assembly 300, which is rectified, filtered, and used to recharge the battery 304.

[0080] Further, the antenna 206, as well as the window 200, can be positioned to face tissue, or positioned at a location closest to the skin side or outer side of the patient’s body, so as to minimize or avoid RF interference by having less body tissue to transmit wireless data through. Further, in some examples, the integrated circuit includes a Kelvin connection to the first electrode 112 and the second electrode 114. In certain cases, the sub-assembly 300 can include an accelerometer to determine whether the IMD 102 has been turned or flipped over. The accelerometer can determine periods of electrode inactivity to determine a stable signal and select between the first electrode 112 and the second electrode 114.

[0081] Figure 6A and Figure 6B Perspective views of IMD 102 are shown from two different angles according to embodiments as disclosed herein. Housing 110 of IMD 102 includes a window 200 embedded in housing 110 such that window 200 is positioned proximate to antenna 206 and is shown overlapping antenna 206. Flexible biocompatible circuit board 204 is wrapped around an outer surface 216 of housing 110 such that feedthrough 202 is in contact with contacts 302 in connector block 314 and first electrode 112A overlaps circle 116 and second electrode 114A overlaps circle 118. In addition, third electrode 112B and fourth electrode 114B are located on facing back portion 212.

[0082] In some examples, housing 110 can be formed by combining or joining two separate housing portions (e.g., one defining facing front portion 210 and the other defining facing back portion 212) together into one assembly. In some examples, the combined portions can be laser welded or ultrasonically welded together onto housing 110. In some examples, the combined portions can be brazed together using any suitable metal, such as a gold alloy, to form housing 110. In some examples, the combined portions can be attached together using a suitable adhesive to form housing 110.

[0083] In some examples, the combined portions can be shrink-wrapped with circuit board 204 using any suitable polymer, including but not limited to PVC, polyolefins, polyethylene, and polypropylene, to form IMD 102. In some examples, an epoxy can be placed on housing 110 such that circuit board 204 is immovably secured around housing 110 when circuit board 204 is disposed around housing 110. In some examples, IMD 102 is sealed to ensure hermiticity using any one or more of the methods outlined above.

[0084] The functionality of first electrode 112A, second electrode 114A, third electrode 112B, and / or fourth electrode 114B can be controlled by an integrated circuit (e.g., microcontroller 308 and / or ASIC 310). For example, the integrated circuit can be configured to select between electrodes 112, 114. In addition, the integrated circuit can be configured to measure the sensing capabilities of electrodes 112, 114.

[0085] In some cases, the integrated circuit can be configured to select between one or more of the first electrode 112A, the second electrode 114A, the third electrode 112B, and / or the fourth electrode 114B in response to determining which of the one or more electrodes 112, 114 has the greatest sensing capability. The integrated circuit can be configured to measure impedance on the sensed signal of the electrodes 112, 114 to determine the sensing capability of the electrodes 112, 114. The integrated circuit configured to select between the electrodes 112, 114 can increase sensing capability and signal capture by selecting whichever of the electrodes 112, 114 has the strongest signal for sensing.

[0086] The illustrative components shown in the figures are not intended to suggest any limitation as to scope of use or functionality of embodiments of the disclosed subject matter. Neither should the illustrative components be interpreted as having any dependency or requirement for one another. Furthermore, one or more of the components depicted in the figures can be integrated with various other components depicted therein (and / or components not depicted) in embodiments of the disclosed subject matter, all of which are considered to be within the scope of the disclosed subject matter.

[0087] Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments that do not include all of the features described above. Thus, embodiments of the present disclosure can include only a subset of the features described above, and the scope of the disclosure is intended to encompass all such alternative, modified, and equivalent embodiments, as well as any and all equivalents thereof.

Claims

1. An implantable medical device, comprising: a housing including a non-conductive window and a plurality of feedthroughs extending through the housing; a first electrode; a second electrode; a biocompatible circuit board disposed about an outer surface of the housing, the biocompatible circuit board including a plurality of traces, wherein a first trace of the plurality of traces is coupled to the first electrode and a first feedthrough of the plurality of feedthroughs, and a second trace of the plurality of traces is coupled to the first electrode and a second feedthrough of the plurality of feedthroughs; and an antenna, wherein a third trace of the plurality of traces is coupled to the antenna, wherein the antenna is positioned proximate to the non-conductive window.

2. The implantable medical device of claim 1, wherein, The first electrode and the second electrode are integrated into the biocompatible circuit.

3. The implantable medical device of claim 1, wherein, The biocompatible circuit board includes a plurality of layers, and the plurality of traces is disposed between two layers of the plurality of layers.

4. The implantable medical device of any of claims 1-3, wherein, The biocompatible circuit board is a flexible circuit board.

5. The implantable medical device of any of claims 1-3, wherein, The housing is formed of a conductive material.

6. The implantable medical device of claim 1, wherein, The non-conductive window is formed of sapphire.

7. The implantable medical device of any of claims 6, further comprising an isolation layer disposed between the antenna and the housing.

8. The implantable medical device of any of claims 1-3, further comprising a third electrode and a fourth electrode.

9. The implantable medical device of any of claims 1-3, further comprising a power source disposed substantially along an entire length of the housing.

10. A method for constructing an implantable medical device, the method comprising: disposing an antenna, a first electrode, and a second electrode on a circuit board substrate; and disposing a plurality of traces on the circuit board substrate, wherein a first trace of the plurality of traces is coupled to the first electrode, wherein a second trace of the plurality of traces is coupled to the second electrode, and a third trace of the plurality of traces is coupled to the antenna; coupling the first trace to a first feedthrough of an implantable medical device housing; coupling the second trace to a second feedthrough of an implantable medical device housing; coupling the third trace to a third feedthrough of an implantable medical device housing; and disposing the circuit board substrate about the implantable medical device housing and aligning the antenna with a non-conductive window of the implantable medical device housing.

11. The method of claim 10, further comprising disposing an isolation layer between the antenna and the implantable medical device housing.

12. The method of claim 10 or 11, further comprising adhering the circuit board substrate to the implantable medical device housing with an epoxy.

Images