Implantable medical device antenna

Abstract

An implantable medical device (IMD) includes a housing, communication circuitry within the housing, and an antenna. The antenna includes: a forming portion of the housing; a first metal portion adjacent to the non-conductive feature on a first side of the non-conductive feature; a second metal portion adjacent to the non-conductive feature on a second side of the non-conductive feature; and a plurality of switchable contacts, the plurality of switchable contacts being configured to couple the dielectric antenna to the communication circuit, wherein the plurality of switchable contacts are configurable according to a selected one of a plurality of excitation modes to connect the communication circuitry to the antenna via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

Description

[0001] This application is an international application with provisional priority to U.S. Provisional Patent Application No. 63 / 381,366, filed Oct. 28, 2022, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] This disclosure relates to medical device communication and, more particularly, to antennas for implantable medical devices (IMDs). BACKGROUND

[0003] A variety of IMDs have been clinically implanted or proposed for effectively treating and / or monitoring one or more physiological conditions of a patient. Such devices can be adapted to monitor or treat conditions or functions related to the heart, muscle, nerve, brain, stomach, endocrine organs, or other organs and their associated functions. Advancements in the design and manufacture of miniaturized electronic and sensing devices have enabled the development of IMDs capable of having therapeutic as well as diagnostic capabilities, such as pacemakers, cardioverters, defibrillators, biochemical sensors, implantable loop recorders, and pressure sensors, among others. Such devices can be associated with leads that position electrodes or sensors at desired locations, or such devices can be leadless with electrodes or sensors integrated into the device housing. These devices can have the ability to communicate wirelessly with another device implanted within the patient and / or another device positioned outside the patient.

[0004] Although implantation of some devices requires a surgical procedure, other devices can be small enough to be delivered in a minimally invasive manner (such as via a percutaneous delivery catheter) or transvenously and placed at the intended implantation location. By way of illustrative example, implantable monitors have been proposed and used to monitor heart rate and rhythm as well as other physiological parameters, such as patient posture and activity level. Such direct in vivo measurements of physiological parameters can provide important information to clinicians to facilitate diagnostic and treatment decisions. Additionally, miniaturized pacemakers have been developed that can be directly implanted within a patient's heart, with or without leads to position electrodes, and are adapted to provide pacing and other electrotherapies to the patient.

[0005] For most of these devices, the ability to communicate wirelessly with the device after implantation is important. These exemplary devices need to communicate with external devices and / or other devices implanted within the patient. For example, these devices can send information indicative of sensed data and / or treatment data. These devices can receive information such as treatment parameters and sensed parameters as well as other information that can define an operating mode. SUMMARY

[0006] The present disclosure describes an antenna integrated with a housing of an IMD, where the antenna can be used to provide communication between the IMD and one or more other devices. In some examples, an IMD that may advantageously include an antenna according to the present disclosure can be a small device and may have been implanted subcutaneously or relatively deeper within a patient, such as above or within the patient's heart. An example of such an IMD is a self - contained pacemaker that is designed to be implanted internally within a patient's heart and in some cases does not require external leads coupled to the device to provide pacing to the heart. Self - contained pacemaker.

[0007] One solution to extend the mission life of an IMD is to provide a larger power source, such as a larger - sized battery, within the device prior to implantation. However, a larger power source may require an increase in the overall size of the implantable medical device. Since there is a need to miniaturize implantable medical devices so that these implantable medical devices can be implanted in a desired location (such as within the heart), while maintaining a small size to minimize any obstruction (e.g., obstruction to blood flow) caused by the device once implanted, an increase in the power source size and thus the overall size of the implantable medical device can be counterproductive for many applications.

[0008] The IMD described in the present disclosure includes an antenna that includes a non - conductive component between a first metal portion and a second metal portion that forms part of the housing of the device. The non - conductive component provides the IMD with the required level of telemetry and communication functionality and frees up valuable space that would otherwise be allocated to a conventional microstrip or patch antenna. This provides an advantage because, compared to a device with a conventional microstrip or patch antenna, a device of the same size can be configured to include a larger battery, or the IMD can have an overall smaller size and a mission life with a similarly - sized battery. A longer mission life and / or a smaller overall device size provides benefits to both the patient and the clinician who implants the device and / or treats the patient after the device is implanted. For example, a longer life can increase the time between when the device is implanted and when it needs to be replaced, and thus extend that time and / or can eliminate the need for additional surgical procedures required to implant a replacement device. Miniaturization of implantable medical devices can allow physicians to perform less invasive implantation procedures, such as by using a percutaneous delivery catheter or implanting transvenously, and a smaller implant volume within the patient's body.

[0009] In addition, some IMDs are implanted deeper within a patient, such that signal strength is a consideration for reliable communication. Also, some types of IMDs may be more difficult to orient within a patient, such that a known orientation of an antenna of the IMD within the patient may be difficult to achieve. In some examples, an antenna (e.g., a non-conductive component) may be annular, and an IMD antenna as described herein may be capable of providing substantially uniform signal strength along multiple axes for RF communication signals between the IMD and other devices, and / or may be configured to adaptively or selectively direct RF communication signals in different directions to achieve reliable communication regardless of the orientation of the IMD within the patient.

[0010] In one example, an implantable medical device (IMD) includes a housing, communication circuitry within the housing, and an antenna that includes: a non-conductive component that forms part of the housing; a first metallic portion of the housing that is adjacent to the non-conductive component on a first side of the non-conductive component; a second metallic portion of the housing that is adjacent to the non-conductive component on a second side of the non-conductive component; and a plurality of switchable contacts configured to connect the first metallic portion and the second metallic portion to the communication circuitry, wherein the plurality of switchable contacts are configurable, according to a selected excitation mode of a plurality of excitation modes, to connect the communication circuitry to the first metallic portion and the second metallic portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0011] In another example, a pacemaker includes: a housing configured to be implanted within a patient's heart chamber; a plurality of electrodes integrated into the housing; a sensing circuit within the housing and configured to sense an electrocardiogram via the one or more electrodes; a therapy delivery circuit within the housing and configured to deliver pacing pulses via the one or more electrodes; a communication circuit within the housing; and an antenna. The antenna includes: a non-conductive member forming part of the housing; a first metallic portion of the housing adjacent to the non-conductive member on a first side of the non-conductive member; a second metallic portion of the housing adjacent to the non-conductive member on a second side of the non-conductive member; and a plurality of switchable contacts configured to connect the first metallic portion and the second metallic portion to the communication circuit, wherein the plurality of switchable contacts are configurable, according to a selected excitation mode of a plurality of excitation modes, to connect the communication circuit to the first metallic portion and the second metallic portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0012] In another example, a method includes: configuring, by processing circuitry within a housing of an implantable medical device (IMD), a plurality of switchable contacts of an antenna of the IMD according to a selected excitation mode of a plurality of excitation modes; and exciting, by a communication circuit within the housing of the IMD, the antenna via the plurality of switchable contacts. The antenna includes: a non-conductive member forming part of the housing; a first metallic portion of the housing adjacent to the non-conductive member on a first side of the non-conductive member; and a second metallic portion of the housing adjacent to the non-conductive member on a second side of the non-conductive member. The method further includes communicating, by the IMD and via radio frequency (RF) wireless communication, with an external device using the excited antenna.

[0013] In another example, an implantable medical device (IMD) includes a housing, communication circuitry within the housing, and an antenna. The antenna includes: a ring-shaped non-conductive member that forms part of the housing; a first ring-shaped metal portion of the housing that is adjacent to the non-conductive member on a first side of the non-conductive member; a second ring-shaped metal portion of the housing that is adjacent to the non-conductive member on a second side of the non-conductive member, wherein the first ring-shaped metal portion and the second ring-shaped metal portion have a common longitudinal axis with each other and with the ring-shaped non-conductive member; and a plurality of switchable contacts that are circumferentially distributed around the IMD and are configured to connect the first ring-shaped metal portion and the second ring-shaped metal portion to the communication circuitry, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuitry to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0014] This disclosure is intended to provide an overview of the subject matter described in this disclosure. This summary is not intended to provide an exclusive or exhaustive explanation of the systems, devices, and methods described in detail in the following drawings and specification. Further details of one or more examples of the disclosure are set forth in the following drawings and specification. Other features, objectives, and advantages will be apparent from the specification, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a conceptual diagram showing an exemplary medical device system coupled to a patient in accordance with various examples described in this disclosure.

[0016] Figure 2A is a diagram showing an exemplary IMD having an antenna in accordance with one or more techniques described in this disclosure.

[0017] Figure 2B is a diagram showing in more detail Figure 2A a portion of the exemplary IMD.

[0018] Figure 2C is a cross-sectional view of the IMD taken along line C-C Figure 2A of the IMD.

[0019] Figure 3A is a diagram showing another exemplary IMD having an antenna in accordance with one or more techniques described in this disclosure.

[0020] Figure 3B is in accordance with one or more techniques described in this disclosure Figure 3AConceptual diagram of the features of an exemplary IMD.

[0021] Figure 3C is a functional block diagram showing an exemplary configuration of an IMD that illustrates one or more techniques described in the present disclosure Figure 3A and Figure 3B of the IMD.

[0022] Figure 4 is a conceptual diagram showing an example of antenna radiation with an exemplary antenna operating in two complementary excitation modes that illustrates one or more techniques described in the present disclosure.

[0023] Figure 5 is a plot showing the antenna gain in the azimuth plane of an exemplary antenna that illustrates the techniques described in the present disclosure, where the antenna operates in a unidirectional excitation mode and a bidirectional excitation mode.

[0024] Figure 6 is a plot showing the antenna gain in the elevation plane of an exemplary antenna that illustrates the techniques described in the present disclosure, where the antenna operates in a unidirectional excitation mode and a bidirectional excitation mode.

[0025] Figure 7 is a flowchart showing an exemplary operation of an IMD including an antenna that illustrates one or more techniques described in the present disclosure.

[0026] Figure 8A and Figure 8B are a perspective view and a cross-sectional view, respectively, showing an exemplary antenna and an exemplary interconnect device of an IMD that illustrate the techniques described in the present disclosure.

[0027] Figure 9A and Figure 9B are a cross-sectional view and a perspective view, respectively, showing another exemplary antenna and another exemplary interconnect device of an IMD that illustrate the techniques described in the present disclosure.

[0028] Figure 10 is a cross-sectional view showing another exemplary antenna and another exemplary interconnect device of an IMD that illustrate the techniques described in the present disclosure. Detailed Description

[0029] The present disclosure generally relates to an antenna that is formed as part of the housing of an IMD. The antenna can include a plurality of switchable contacts to a metal portion adjacent to a non-conductive component for coupling the antenna to a communication circuit of the IMD, which can include switches and / or signal feeds to selectively connect the contacts to the communication circuit. The antenna is configured to be excited to provide RF wireless communication, such as Bluetooth Low Energy signals, between the IMD and one or more other devices, such as an external device or another IMD.

[0030] Exemplary non-conductive components can be formed as part of the housing of a medical device such that when the IMD is implanted, the non-conductive components are in contact with patient fluids and / or tissue. Accordingly, the present disclosure describes examples of antennas that can be formed as part of the housing of a medical device such that the antennas utilize or do not utilize a relatively small volume within the housing. This can enable a smaller overall medical device compared to other medical devices having headers that house the antennas, which is beneficial for implantation. This can also enable a medical device to have a similar size to existing devices, but the medical device can include more space for a larger power source or other components.

[0031] Figure 1 is a conceptual diagram showing examples of some components of a medical device system 100 in combination with a patient 102 in accordance with various examples described in the present disclosure. The systems, devices, and techniques described in the present disclosure provide an IMD that includes antennas arranged in a manner further described throughout the present disclosure to communicatively link the IMD with one or more external devices 110 and / or with each other, as further described below.

[0032] System 100 can include one or more IMDs implanted within patient 102, such as one or more of IMDs 101A, 101B, and 101C (collectively referred to as "IMD 101"). In various examples, at least one of the IMDs 101 in system 100 includes an antenna configured as described in the present disclosure. Although the exemplary techniques are described with respect to devices for monitoring the heart and / or delivering therapy to the heart and, in some cases, devices implanted within the heart, the exemplary techniques are not limited thereto. For example, the exemplary techniques described in the present disclosure can extend to non-cardiac medical devices that provide wireless communication with other devices (e.g., devices for pain stimulation, brain stimulation, pelvic stimulation, spinal stimulation, etc., and devices such as implanted drug pumps). Additionally, although system 100 shows IMDs 101A, 101B, and 101C implanted together within patient 102, the system need not include each of these IMDs 101 and can include any one or more of IMDs 101.

[0033] System 100 can include an intracardiac pacing device IMD 101A. In the illustrated example, IMD 101A is implanted within the right ventricle of patient 102, e.g., inside the heart 104 of patient 102. In some examples, one or more IMDs similar to IMD 101A ( Figure 1(not specifically shown) may additionally or alternatively be implanted in other chambers of the heart 104 or epicardially attached to the heart. The IMD 101A may be configured to sense the electrical activity of the heart 104 and / or deliver stimulation therapies to the heart 104, such as pacing therapies, e.g., bradycardia pacing therapy, cardiac resynchronization therapy (CRT), antitachycardia pacing (ATP) therapy, and / or post-shock pacing.

[0034] The IMD 101A may be attached to the inner wall 108 of the heart 104 via one or more tissue-penetrating fixation mechanisms. As described herein, the fixation mechanism may secure the IMD 101A to the heart tissue and retain one or more electrodes (e.g., a cathode or an anode) on the housing of the IMD 101A that is in contact with the heart tissue. In addition to delivering pacing pulses, the IMD 101A may also be capable of sensing electrical signals using the electrodes carried on the housing of the IMD 101A. These electrical signals may be electrical signals generated by the myocardium and indicative of depolarization and repolarization of the heart 104 at different times during the cardiac cycle. In various examples, the IMD 101A is configured to wirelessly communicate with one or more external devices 110 as Figure 1 exemplarily shown.

[0035] System 100 may include IMD 101B, which may be implanted at different locations of patient 102 outside the ventricles of the heart 104 of patient 102. IMD 101B may include an implantable pressure sensing device, which may be implanted in the left or right pulmonary artery of the patient. IMD 101B may include a pressure sensing circuit configured to measure cardiovascular pressure within the pulmonary artery of patient 102. In some examples, IMD 101B may include a wireless communication circuit, such as a TCC and / or RF telemetry circuit, configured to receive a trigger signal at an electrode or antenna provided in IMD 101B (e.g., an antenna such as an example of the antennas described in the present disclosure) from an external device 110, IMD 101C, and / or IMD 101A. The pressure sensing circuit of IMD 101B may be configured to measure the cardiovascular pressure of patient 102 in response to receiving the trigger signal. In either case, IMD 101B may be configured to wirelessly transmit the measured pressure value to external device 110, IMD 101C, and / or IMD 101A. For example, IMD 101B may transmit to IMD 101C, IMD101A, and / or external device 110 the measurement values and data related to pulmonary artery pressure acquired by IMD 101B and other information generated by IMD 101B. In various examples, IMD 101B includes an antenna for communication between IMD 101B and other devices of system 100, which is arranged using the examples of antennas described throughout the present disclosure or any equivalents thereof.

[0036] As Figure 1 shown, system 100 includes IMD 101C, which may be an insertable cardiac monitor (ICM) capable of sensing and recording electrogram (EGM) signals from locations outside the heart 104 via electrodes ( Figure 1 not shown). In some examples, IMD 101 includes or is coupled to one or more additional sensors, such as an accelerometer, which generate one or more signals that vary based on patient movement and / or posture, blood flow, or respiration. Examples of IMD 101C may monitor physiological parameters indicative of the patient's state, such as posture, heart rate, activity level, and / or respiratory rate. IMD101C may be implanted outside the thorax of patient 102, such as subcutaneously or submuscularly, such as Figure 1 the chest location shown. In some examples, IMD 101C may take the form of a Reveal ICM commercially available from Medtronic plc, of Dublin, Ireland.

[0037] In various examples, the IMD 101 is configured to wirelessly communicate with one or more external devices 110, such as illustrated by Figure 1 exemplarily shown, via a communication link 112. The external device 110 can be a computing device (e.g., for use in a home, outpatient, clinic, or hospital environment) to wirelessly communicate with the IMD 101. For example, the external device 110 can be a patient monitor, such as MyCareLink TM patient monitor, or a programming instrument, such as SmartSync TM system, available from Medtronic Inc., a subsidiary of Medtronic plc, of Dublin, Ireland. In another example, the external device 110 can be a mobile computing device, such as a smart phone, tablet, smart watch, or other wearable or portable device. For example, the external device 110 can include a mobile application, such as MyCareLink Heart TM mobile application, available from Medtronic Inc., a subsidiary of Medtronic plc, of Dublin, Ireland, enabling the external device 110 to communicate with the IMD 101. The external device 110 can be coupled to a remote patient monitoring system, such as CareLink TM network, available from Medtronic Inc., a subsidiary of Medtronic plc, of Dublin, Ireland. As an example, the external device 110 can be a programmer, an external monitor, or a consumer device, such as a smart phone. For example, the external device 110 can be used to program commands or operating parameters into the IMD 101 to control the functions of the IMD. The external device 110 can be used to interrogate the IMD 101 to retrieve data, including device operation data and physiological or neurological data accumulated in the memory of the IMD. The interrogation can be automatic, e.g., according to a schedule, or in response to a remote or local user command. One or more of these external devices 110 can also be referred to as an "instrument" or a set of instruments.

[0038] Examples of communication technologies used by the IMD 101 and the external device 110 include, but are not limited to, any specific communication technology or communication protocol, such as the Bluetooth Low Energy communication protocol. In other examples, tissue conductance communication (TCC) or RF telemetry can be used, and the TCC or RF telemetry can be an RF link established via WiFi or the Medical Implant Communication Service (MICS). The IMD 101 can utilize an antenna or its equivalent arranged as described in this disclosure to perform communications associated with the IMD in order to provide any of these features and perform any of the functions ascribed to the IMD.

[0039] In various examples, Figure 1One or more of the IMDs in IMD 101 may include an antenna arranged in accordance with an example of an antenna described in the present disclosure and any equivalents thereof to facilitate communication between one or more of the IMDs 101 of system 100 and / or one or more of the IMDs 101 and / or an external device 110.

[0040] For the remainder of the present disclosure, a general reference to a medical device system may collectively refer to any instance including medical device system 100, as described above with respect to Figure 1 and any equivalents thereof. Further, for the remainder of the present disclosure, a general reference to an IMD may collectively refer to any example including IMD 101A, IMD 101B, and / or IMD 101C, as described above with respect to Figure 1 and any equivalents thereof.

[0041] Figure 1 Exemplary IMDs include a housing configured to house at least one of a communication circuit and a stimulation and sensing circuit on an inner side of the housing. For example, a battery such as a lithium / iodine cell may be coupled to a motherboard or flexible circuit hosting one or more semiconductor chips and other electronic circuits. In some examples, the communication circuit and / or the stimulation and sensing circuit may be part of the one or more semiconductor chips.

[0042] Figure 2A An example of an IMD 201 in accordance with the techniques of the present disclosure is shown. Figure 2B is a diagram that more particularly shows a portion of IMD 201 corresponding to block 209 in Figure 2A An IMD 201 is a sectional view of IMD 201 taken along line C-C in Figure 2C viewed in the direction of housing portion 220 and with certain components within the internal space defined by metal portions 203 and 205 and non-conductive member 207 removed. Figure 2A

[0043] Figure 1 IMD 201 may be an example of IMD 101A of Figure 1 such as an intracardiac pacing device, such as a Medtronic Micra TM Transcatheter pacing system. As shown, IMD 201 may include a generally cylindrical housing that includes housing portion 220, annular non-conductive member 207, and annular metal portions 203 and 205. Housing portion 220 may house the battery of IMD 201, while the electronics of IMD 201 (such as the communication circuit) are housed within the internal space defined by non-conductive member 207 and annular metal portions 203 and 205 and the upper surface of housing portion 220. IMD 201 may include a fixing mechanism 213, which may be asFigure 2A shown as helical and for holding the IMD in place by attaching the IMD to heart tissue. The fixation mechanism 213 or a part thereof can act as an electrode for sensing cardiac signals and delivering pacing pulses. In some examples, the fixation mechanism 213 includes one or more tucks or one or more barbs as shown in Figure 3A and Figure 3B . In some examples, the fixation mechanism 213 includes multiple components of one or more types, such as multiple helices, multiple barbs, or multiple tucks.

[0044] The housing portion 220 and the annular metal portions 203 and 205 can but need not be formed of common metals such as titanium, cobalt, chromium, nickel, their alloys, or stainless steel. The non-conductive component 207 and the portions 203, 205, 220 have a common axis, which is the longitudinal axis 215 of the IMD 201. The portions 203 and 205 can be used as a ground plane and a feed point on each side of the non-conductive component 207. The non-conductive component 207 can be formed of a material that is transparent or at least partially transparent to RF waves, such as sapphire or ceramic, for example, alumina ceramic or zirconia ceramic. An annular non-conductive component such as the non-conductive component 207 can include a continuous ring, tube, or cylinder of non-conductive material, or can include multiple non-conductive material segments arranged in a ring, for example, arranged in a ring around the longitudinal axis 215. The segments of the non-conductive component 207 can be separated, for example, by the same material as the material forming the metal portions 203 and 205 or other materials. In some examples, the non-conductive component of the antenna according to the present disclosure can be formed as a partial ring rather than a complete ring. In some examples, the non-conductive component of the antenna according to the present disclosure can be formed as a "window" in the housing of the IMD, and the "window" has an outer boundary shape that can be (by way of example) polygonal or elliptical.

[0045] The IMD 201 can also include a plurality of contacts or feed points 225A to 225H (collectively referred to as "contacts 225"), which can act as signal feeders for coupling the antenna 211 to a communication circuit within the housing via the metal portions 203 and 205. In some examples, two or more of the contacts 225 are positioned near each of the sides or ends of the non-conductive component 207. In some examples, the contacts 225 on opposite sides of the non-conductive component 207 are arranged in pairs, for example, each arranged on a corresponding side. In some examples, the contacts 225 are distributed around the lateral perimeter (e.g., circumference) of the IMD 201, for example, evenly distributed. For example, referring to Figure 2B , Figure 2B and Figure 2CThe size and shape of the contact portion 225 therein are for illustrative purposes, and the contact portion 225 can have any size / shape configured to provide an electrical connection.

[0046] The non-conductive member 207 and the metal portions 203 and 205 together with the contact portion 225 form an antenna 211, which is configured to be excited to provide RF wireless communication between the IMD 201 and one or more other devices in conjunction with a communication circuit. The IMD 201 (e.g., the communication circuit) can include switches respectively associated with one or more contact portions 225. For example, based on the configuration of the switches, each contact portion 225 can switch back and forth between a short circuit, an open circuit, or being connected to an RF signal feed, as described more fully below. In some examples, a subset of the contact portions 225 can be non-switchable and can be fixed in one of a short circuit state, an open circuit state, or a connected state (e.g., one or more fixed shorting members and one or more fixed feed points). In some examples, a subset of the contact portions 225 are fixed as shorting members, while other contact portions can be switched between open and connected to configure the excitation mode. When arranged in pairs on opposite sides of the non-conductive member 207, a pair of contact portions 225 can be switched / configured together. For example, a pair of contact portions 225D and 225H can both be connected, both be open, or both be shorted. When a pair of contact portions 255 are switched / configured together to be connected (e.g., as a signal input and a ground), they can be used to drive the metal portions 203 and 205 to excite the antenna 211, where the non-conductive member 207 acts as a gap between the metal portions 203 and 205. In some examples, to excite the antenna 211, the contact portions 225 are configured to provide an input and a ground on opposite sides of the non-conductive member 207, and one or more switched or fixed shorting members across the non-conductive member 206 define a path for the RF current signal to flow around the non-conductive member.

[0047] Based on the selection of different configurations of the switches, multiple excitation modes can be provided to provide spatial diversity for the RF signal. In one example, pairs 225D / 225H and 225B / 225F that are 180 degrees apart from each other can be configured to be shorted, and pairs 225A / 225E and 225C / 225G that are 180 degrees apart from each other can be connected to the signal. One of pairs 225A / 225E or 225C / 225G can be selected to provide the directivity of the RF signal. The wireless communication can be a Bluetooth Low Energy (BLE) signal or another communication protocol as previously described.

[0048] Figure 3A An exemplary IMD 301 according to the techniques of the present disclosure is shown. The IMD 301 can also be Figure 1 an example of the IMD101A. Except as noted herein, similarly numbered elements of the IMD 301 can be configured to be substantially similar toFigures 2A to 2C The corresponding components of the IMD 201 in

[0049] The IMD 301 may include a housing that includes a generally cylindrical portion 320, an annular (e.g., tubular or cylindrical) non-conductive member 307, and annular (e.g., tubular or cylindrical) metal portions 303 and 305 having a common axis. Figures 2A to 3A The dimensions of the non-conductive members 207, 307 shown in

[0050] are merely examples. In the longitudinal direction, the lengths of the non-conductive members 207, 307 may range from 1 millimeter (mm) to 5 mm, such as about 2 mm. The diameters of the non-conductive members 207, 307 may range from 3 mm to 9 mm, such as in the range from 5 mm to 7 mm. The communication range of the antennas 211, 311 may range from 1 meter to 10 meters. Figure 3A The portions 303 and 305 may be used as a ground plane and a feed point on each side of the non-conductive member 307. The antenna including the non-conductive member 307 may include Figure 2B and Figure 2C contact portions 225 not shown in

[0051] The IMD 301 includes electrodes 304 and 316, which may be integrally formed with the housing. In Figure 3A the example of

[0052] In Figure 3A the example of Figure 3AAs shown, the flexible circuit 330 can be disposed within the housing, for example, beneath the non-conductive member 307 such that the flexible circuit substantially conforms to the inner surface of the non-conductive member 307, for example, wound / bent into a loop shape. In some examples, the flexible circuit 330 can maintain contact with the non-conductive member 307 and / or the metal portions 303 and 305, such as electrical contact. For example, the flexible circuit 330 can be glued or bonded to one or more of these elements. In some examples, a mechanism (e.g., a compressible material on the inner surface of the flexible circuit 330) can radially outwardly bias the flexible circuit 330 against these components. In some examples, the flexible circuit 330 can include a mechanism on the outer surface of the flexible circuit 330, such as a spring or other elastically compressible element, that can flexibly maintain electrical contact between the circuit 330 and the metal portions 303 and 305.

[0053] The flexible circuit 330 can include traces that serve as contacts 225 ( Figure 2B and Figure 2C ), and these traces, together with the dielectric resonator 307, serve as an antenna to provide RF wireless communication. In some examples, the flexible circuit 330 includes or is coupled to switches that selectively couple the contacts to the communication circuitry of the IMD 301. Switching which contacts (e.g., which portion of the flexible circuit 330) are coupled to the antenna as the feed for the communication signal can provide directivity of the transmitted signal. In some examples, the flexible circuit 330 includes some of the communication circuitry in all of the communication circuitry. The flexible circuit 330 can include an RF system on a chip. In some examples, the flexible circuit 330 includes additional circuitry of the IMD 301, for example, as described with respect to Figure 3C stated.

[0054] Figure 3B is a conceptual diagram further illustrating exemplary components of the IMD 301 in accordance with the techniques described in the present disclosure. The IMD 301 includes the dielectric resonator 307 of the DRA 310 (the ground plane and contacts are omitted in Figure 3B for clarity). The IMD 301 also includes a power supply 318 (e.g., within the housing portion 320) and electronic circuitry 312 (e.g., within the housing portion partially defined by the non-conductive member 307). The power supply 318 can be a battery coupled to and providing power to the electronic circuitry 312. The IMD 301 defines a longitudinal axis 315.

[0055] The electronic circuit 312 can include components on the flexible circuit 330, and / or components, for example, within a space in a housing defined by the header 308, housing portions 303 and 305, non-conductive component 307, and housing portion 320, on one or more boards or substrates. Traces on the flexible circuit can lead to the contact 225 and thus provide signal lines to the antenna 310. The flexible circuit can also include other circuit components, such as an RF system-on-a-chip (SOC), RF switches, components such as those described above, etc. A communication circuit (such as Figure 3C the communication circuit 348 shown in Figure 1 can be configured to provide excitation of the antenna 310 and communication signals for wireless communication between the IMD 301 and one or more external devices and / or other IMDs, as described with respect to Figures 4 to 6 The antenna 310 is configured to provide efficient wireless communication using a predetermined frequency or frequency range (such as the BLE communication frequency). In terms of performance, the antenna 310 can have a radiation efficiency and gain comparable to much larger devices at a similar implantation depth (e.g., as shown with respect to Figures 4 to 6 ).

[0056] As an example, the contact 225 can be configured to act as an RF switch by sometimes coupling to the communication circuit 348 and sometimes coupling to ground (e.g., the metal of the housing) or disconnecting and then switching back and forth between the two states. In this way, the antenna 310 can be excited and RF signals can be routed via the antenna. Different switching modes and switching frequencies can be used to select different excitation modes.

[0057] The communication circuit 348 can include a transmitter, a receiver, or a transceiver. That is, the communication circuit 348 can provide two-way communication (e.g., transmit and receive communication) or one-way communication (e.g., receive but not transmit data or transmit but not receive data). The communication circuit 348 can be configured to output a modulated signal that causes the antenna 310 to radiate an electromagnetic signal carrying the data to be transmitted by the IMD 301. For reception, the electromagnetic signal can induce a signal on the antenna 310, and the communication circuit 348 receives the signal and demodulates it to determine the data transmitted to the IMD 301.

[0058] The antenna 310 can be configured to communicate according to one or more wireless communication protocols (such as WiFi or Medical Implant Communication Service (MICS)). That is, the antenna 310 can be configured to have a resonant frequency approximately equal to the frequency (or frequencies) for one or more exemplary communication protocols. Here, approximately means that the resonant frequency of the antenna 310 is within the frequency range that conforms to the exemplary communication protocol.

[0059] Figure 3Cis a functional block diagram showing an exemplary configuration of an IMD 301 in accordance with the techniques described in the present disclosure. Figures 2A to 2C The IMD 201 can be similarly configured.

[0060] As Figure 3C shown, the IMD 301 includes a power source 318 that is coupled to electronic circuitry 312 disposed within the IMD 301 and is configured to provide power to components of the electronic circuitry 312. As Figure 3C shown, the electronic circuitry 312 includes a processing circuit 350, a memory 352, a sensing circuit 342, a therapy delivery circuit 344, and a sensor 340. The sensor 340 can include one or more position and / or motion sensing sensors (such as an accelerometer) and / or other physiological sensors. The electronic circuitry 312 also includes a communication circuit 348 coupled to an antenna 310.

[0061] The electronic circuitry 312 and the devices included within the electronic circuitry 312 can be disposed on one or more structures, such as a flexible circuit 330, one or more printed circuit boards, etc. As Figure 3C shown, the power source 318 includes a power connection 362 that is electrically connected to one terminal (voltage level) of the power source 318. An electrical contact 360 can be electrically coupled to electrical conductors and electronic components of the electronic circuitry 330 and is configured to provide a flow of current that is provided by the power source 318 and flows through the power connection 362 to the electronic circuitry 330. In various examples, a connection 358 can be electrically coupled to a reference voltage (second terminal) of the power source 318 to provide a return path for the current provided from the power source 318 to the electronic circuitry 330. In various examples, the connection 358 is coupled to the housing 320 of the IMD 301, where the housing is coupled to the reference voltage 354 of the power source 318, thereby using the housing of the IMD 301 as a return path for the current provided from the power source 318 to the power electronic circuitry 330.

[0062] In the example shown, the IMD 301 includes a processing circuit 350 and associated memory 352, a sensing circuit 342, a therapy delivery circuit 344, one or more sensors 340, and a communication circuit 348 coupled to an antenna 310 via a switch 370, as described above. However, the IMD 301 need not include all of these components, or can include additional components. For example, some examples of the IMD 301 do not provide therapy, such that the therapy delivery circuit 344 may not be included in the IMD 301.

[0063] Memory 352 includes computer-readable instructions that, when executed by processing circuitry 350, cause IMD 301 and the processing circuitry 350 to perform the various functions attributed herein to IMD 301 and the processing circuitry 350 (e.g., prepare and transmit information and data wirelessly from IMD 301 using communication circuitry 348 and antenna 310 prepared by the processing circuitry 350, receive wireless communications at antenna 310 and via the communication circuitry 348, and process the received communications using, for example, the processing circuitry 350). The memory 352 can include any volatile medium, non-volatile medium, magnetic medium, optical medium, or electrical medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital or analog medium. The memory 352 can store one or more thresholds for time of day, posture, heart rate, activity level, respiratory rate, and other parameters. The memory 352 can also store data indicative of cardiovascular pressure measurements. The memory 352 can store data, instructions, and / or parameters for use by the processing circuitry 350 and / or the communication circuitry 348 in performing the telemetry and communication functions of the IMD. The processing circuitry 350 can be configured to access the data and / or instructions stored in the memory 352 to perform any of these functions and provide any of the features attributed to IMD 301 throughout this disclosure and any equivalents thereof.

[0064] The processing circuitry 350 can include fixed-function circuitry and / or programmable processing circuitry. The processing circuitry 350 can 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 analog logic circuitry. In some examples, the processing circuitry 350 can 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 herein to the processing circuitry 350 can be embodied as software, firmware, hardware, or any combination thereof.

[0065] The sensing circuit 342 and the therapy delivery circuit 344 are coupled to the electrodes 304 and 316 of the IMD 301. The sensing circuit 342 can monitor signals from the electrodes 304, 316 to monitor the electrical activity, impedance, or some other electrical phenomenon of the heart. Sensing of the cardiac electrical signals can be performed to determine heart rate or heart rate variability or to detect arrhythmias (e.g., tachyarrhythmias or bradycardia) or other electrical signals. In some examples, the sensing circuit 342 can include one or more filters and amplifiers for filtering and amplifying the signals received from the electrodes 304, 316. In some examples, the sensing circuit 342 can sense or detect physiological parameters such as heart rate, blood pressure, respiration, and other physiological parameters associated with the patient.

[0066] The resulting cardiac electrical signals can be transmitted to a cardiac event detection circuit that detects a cardiac event when the cardiac electrical signals exceed a sensing threshold. The cardiac event detection circuit can include a rectifier, filters and / or amplifiers, a sense amplifier, a comparator, and / or an analog-to-digital converter. The sensing circuit 342 outputs an indication to the processing circuit 350 in response to sensing a cardiac event (e.g., a detected P wave or R wave).

[0067] In Figure 3C the example of, the IMD 301 includes one or more sensors 340 coupled to the sensing circuit 342. Although shown as being included within the IMD 301 in Figure 3C , one or more of the sensors 340 can be external to the IMD 301, e.g., coupled to the IMD 301 via one or more leads, or configured to communicate wirelessly with the IMD 301. In some examples, the sensors 340 convert signals indicative of patient parameters, which can be amplified, filtered, or otherwise processed by the sensing circuit 342. In such examples, the processing circuit 350 determines the values of the patient parameters based on these signals. In some examples, the sensors 340 determine the patient parameter values and transmit them to the processing circuit 350, e.g., via a wired or wireless connection.

[0068] The therapy delivery circuit 344 is configured to generate electrotherapy and deliver the electrotherapy to the heart. The therapy delivery circuit 344 may include one or more pulse generators, capacitors, and / or other components capable of generating and / or storing energy for delivery as pacing therapy, defibrillation therapy, cardioversion therapy, other therapies, or a combination of therapies. In some cases, the therapy delivery circuit 344 may include a first set of components configured to provide pacing therapy and a second set of components configured to provide anti-tachyarrhythmia shock therapy. In other cases, the therapy delivery circuit 344 may utilize the same set of components to provide both pacing therapy and anti-tachyarrhythmia shock therapy. In still other cases, the therapy delivery circuit 344 may share some components of the pacing therapy components and the shock therapy components, while using only other components for pacing or shock delivery.

[0069] The therapy delivery circuit 344 may include a charging circuit, one or more charge storage devices (such as one or more capacitors), and a switching circuit that controls when to discharge one or more capacitors to the electrodes. Charging the capacitor to the programmed pulse amplitude and discharging the capacitor to the programmed pulse width may be performed by the therapy delivery circuit 344 in accordance with control signals received from the processing circuit 350, which are provided by the processing circuit 350 based on parameters stored in the memory 352. The processing circuit 350 controls the therapy delivery circuit 344 to deliver the generated therapy to the heart via one or more electrode combinations, for example, in accordance with parameters stored in the memory 352. The therapy delivery circuit 344 may include a switching circuit to select which of the available electrodes to use for delivering therapy, for example, as controlled by the processing circuit 350.

[0070] The communication circuit 348 includes any suitable hardware, firmware, software, or any combination thereof for communicating with another device (such as an external device or another IMD or sensor, such as Figure 1 the IMD shown). Under the control of the processing circuit 350 as shown in Figure 3C , the communication circuit 348 may receive downlink telemetry from an external device or another device and transmit uplink telemetry to an external device or another device via the antenna 310, which may be arranged in accordance with any of the exemplary antennas described herein or any equivalent thereof. In some examples, the communication circuit 348 may communicate with a local external device, for example, via one or more of the external devices 110 ( Figure 1 ), and the processing circuit 350 may communicate with a networked computing device via the local external device and a computer network (such as the network developed by Medtronic, Inc. of Dublin, Ireland).

[0071] A clinician or other user may retrieve data from the IMD 301 using an external device 110 ( Figure 1 ) or another local or networked computing device configured to communicate with the processing circuit 350 via the communication circuit 348. The clinician may also use the external device 110 ( Figure 1 ) or another local or networked computing device to program parameters of the IMD 301.

[0072] In various examples, the processing circuit 350 is configured to receive signals from the sensing circuit 342, the sensors 340, and / or sensor signals provided by sensors external to the IMD 301 to process the sensor signals to generate one or more input parameters directly based on or derived from the sensor signals. The input parameters are associated with current values of one or more physiological parameters associated with the patient. The physiological parameters associated with the input parameters may include activity counts, respiratory rate, movement, posture, and posture changes associated with the patient. The current values associated with these input parameters may be values measured directly according to the input parameters or values derived for the input parameters. For example, a value of the heart rate measured, for example, in beats per minute or cardiac cycle length may be determined as the current value (e.g., the most recent value) of an input parameter associated with the patient's heart rate measured over a certain predetermined period of time. Similarly, a value of the respiratory rate measured, for example, in breaths per minute or respiratory cycle length may be determined as the current value (e.g., the most recent value) of an input parameter associated with the patient's respiratory rate measured within a certain predetermined period of time.

[0073] Similarly, current values of other input parameters, such as activity counts (e.g., based on the patient's movement measured, for example, in steps taken per minute by the patient), body temperature, and current values of, for example, the patient's posture (e.g., lying down, standing, sitting) may be determined. In some instances, the current value of a physiological parameter may be an average or median value of measurements over a period of time. These sensed and determined parameters associated with the patient may be used to control the therapy delivery circuit 344 when delivering electrical stimulation therapy (e.g., pacing and / or shock therapy) to the patient.

[0074] Figure 4 is a conceptual diagram showing an example of the radiation performance of the antenna 310 for two different antenna excitation modes (such as by using different switching modes for a switch), where the two different modes produce radiation patterns that are spatially complementary to each other. This dual-mode operation of the excitation shows spatial diversity in the radiation pattern with respect to the longitudinal axis 415 of the IMD, which may be similar to Figure 2A and Figure 3B the longitudinal axes 215 and 315 shown in Figure 4An example is shown in which feeding a signal to antenna 310 via each of two locations on opposite sides of a longitudinal plane including longitudinal axis 415 allows the resulting radiation to be beamformed to a respective half of a transverse plane passing through the longitudinal plane. In some examples, antenna 310 may include two sub-antennas with respective feeding locations. By operating the antenna in dual mode with complementary excitation modes, the RF radiation signal may be approximately constant in all directions, such as in Figure 5 and Figure 6 In some examples, processing circuitry of the IMD or processing circuitry of an external device that communicates with the IMD can save energy for the IMD by selecting one feeding position or another based on which portion (e.g., half) of antenna 310 provides better (or acceptable) communication performance (e.g., based on the orientation of the IMD relative to the patient or external computing device).

[0075] Specifically, these figures show a comparison of the spatial gain of an antenna excited with dual modes versus an antenna excited with a single mode in both the azimuth and altitude planes. Figure 5 and Figure 6 The single-mode results shown in FIG. 1 reflect the excitation of one or more feed locations on one circumferential half of the IMD (e.g., excitation of one sub-antenna) from the IMD. Figure 4 The radiation pattern shown in is effectively absent in one of the directions or lobes 480A and 480B. By using dual-mode excitation (i.e., with spatial diversity), radiation nulls can be substantially eliminated so that radiation can be emitted in an approximately uniform manner in all directions. In this way, the radiation gain for RF wireless communication with an external device is approximately the same regardless of the orientation of the IMD when implanted in a patient. However, in some examples, communication quality feedback can be used to select a single excitation mode that provides sufficient quality (e.g., corresponding to one of lobes 480A or 480B) by selecting one feed position or another feed position via a switch as described above. In this way, the increased power consumption associated with driving the entire antenna to provide dual-mode operation can be avoided.

[0076] Figure 7 is a flow chart illustrating example operation of an IMD (eg, IMD 301) including an antenna (eg, antenna 310) according to one or more techniques described in this disclosure. Figure 7 For example, the processing circuit 350 of the IMD 301 may determine two or more excitation modes of the antenna 310 (eg, Figures 4 to 6The value (500) of the communication metric corresponding to two spatial excitation modes). In some examples, the processing circuit 350 can test the excitation mode by controlling the communication circuit 348 to excite the antenna 310 with various configurations of the switch 370 and determining the corresponding metric value (e.g., the ability to make a connection, or signal strength, packet rate, packet error rate, bit rate, bit error rate, or another metric of link quality if a connection is made). In some examples, the excitation mode can include: the two modes that feed different physical parts of the antenna (e.g., a half or side with respect to the longitudinal axis) to respectively generate a radiation pattern including Figure 4 one of the lobes 480A and 480B in; and in some cases, the dual mode that feeds two positions to generate a radiation pattern corresponding to both lobes 480A and 480B. In some examples, the processing circuit 350 can control each single excitation mode of the antenna 310 by controlling the communication circuit 348 to drive a pair of contacts 225 (as signal and ground) on opposite sides of the non-conductive member 307, where circumferentially adjacent contacts are shorted across the non-conductive member, such as a shorting member spaced approximately 90 degrees from the driven contact pair across the non-conductive member. The processing circuit 350 can determine the communication metric value via communication with the external device 12.

[0077] The processing circuit 350 selects one of the excitation modes (502) based on the metric value (e.g., based on a corresponding metric value that meets a threshold or is the "best" (highest or lowest) of the determined values). The processing circuit 350 controls the communication circuit 348 to excite the antenna 310 according to the selected excitation mode (e.g., via the associated configuration of the switch 370) (504). The IMD 301 communicates with the external device 12 via the excited antenna (506).

[0078] Figure 7 The exemplary operations can be performed at various times. In some examples, Figure 7 the operations can be performed during the implantation procedure of the IMD 10, e.g., to identify the excitation mode to be subsequently used by the IMD 10. In some examples, the orientation of the IMD 10 can be relatively stable after implantation.

[0079] In some examples, multiple excitation modes can be identified for use under certain conditions, and the processing circuit 350 of the IMD 10 can automatically switch between such modes based on detecting such conditions (e.g., the time of day, the patient's posture or activity level (e.g., as indicated by an accelerometer or other sensor 340), or the phase of the patient's cardiac cycle). In some examples, the processing circuit 350 can perform Figure 7operations, or otherwise automatically switch to a different excitation mode based on detecting a communication loss or inability to establish communication.

[0080] Figure 8A and Figure 8B are perspective and cross-sectional views showing an exemplary antenna 610 and an interconnect device 682 of an IMD according to the techniques described in the present disclosure. As Figure 8A and Figure 8B shown, the antenna 610 can include a non-conductive member 607 between adjacent metal portions 603 and 605 on opposite longitudinal sides of the non-conductive member 607, similar to Figures 2A to 2C and Figure 3A and Figure 3B the metal portions 203, 303 and 205, 305 and the non-conductive members 207, 307. The antenna 610 also includes one or more flexible circuits 630 configured to provide electrical contact portions with the metal portions 603 and 605.

[0081] In Figure 8A and Figure 8B the example shown, the IMD includes an interconnect device 682 and a circuit 690, such as within an internal space within the housing of the IMD defined by the metal portions 603 and 605 and the non-conductive member 607, on one or more stacked printed circuit boards. The interconnect device 682 can provide circuit paths (e.g., traces) to connect the metal portions 603 and 605 to communication signals and electrical ground from a communication circuit 348. The interconnect device 682 can be a molded device configured to include such metal connection components. In some examples, one or more circuit boards of the circuit 690 may not be stacked within the internal space within the housing of the IMD defined by the metal portions 603 and 605 and the non-conductive member 607.

[0082] A gap 688 may exist between the interconnect device 682 and the flexible circuit 630 or between the flexible circuit 630 and the metal portions 603 and 605, and the gap can be bridged by an elastically deformable connector 684 (e.g., a conductive spring). In some examples, as an alternative or supplement to the flexible circuit 630 and / or the connector 684, the metal portions 603 and 605 can be connected to the circuit 690 and ground via other portions of the housing of the IMD that are electrically common with the metal portions 603 and 605, such as portions 694 and portion 692. Figure 8A An electrical shorting member 686 is also shown, which can electrically isolate portions of the antenna 610, such that each portion can separately act as a corresponding directional antenna when individually excited. In some examples, Figure 8A the two shorting members 686 shown in Figures 4 to 6The two single-excitation modes and the dual-excitation mode described above.

[0083] Figure 9A and Figure 9B are a cross-sectional view and a perspective view, respectively, showing another exemplary antenna 710 and another exemplary interconnect device 782 of an IMD according to the techniques described in the present disclosure. As Figure 9A and Figure 9B shown, the antenna 710 may include a non-conductive member 707 between adjacent metal portions 703 and 705 on opposite longitudinal sides of the non-conductive member 707, similar to Figures 2A to 2C and Figure 3A and Figure 3B the metal portions 203, 303 and 205, 305 and the non-conductive members 207, 307. The IMD also includes an interconnect device 782 and a circuit 790, which are similar to the interconnect device 682 and the circuit 690 described above with respect to Figure 8A and Figure 8B The antenna 710 does not necessarily include one or more flexible circuits configured to provide electrical contact with the metal portions 703 and 705. In some examples, one or more circuit boards of the circuit 790 may be stacked within an internal space within the housing of the IMD defined by the metal portions 703 and 705 and the non-conductive member 707. In some examples, one or more circuit boards of the circuit 790 may not be stacked within an internal space within the housing of the IMD defined by the metal portions 703 and 705 and the non-conductive member 707.

[0084] Figure 9B An electrical shorting member 786 is shown, which can electrically isolate portions of the antenna 710, such that each portion can separately act as a corresponding directional antenna when individually excited. The shorting member 786 can provide functionality regarding the antenna 710, as described above with respect to the shorting member 686 of the antenna 610 and Figure 8A described above. Figure 9B Also shown are resiliently deformable connectors 794A and 794B (collectively referred to as "connectors 794") for redundantly connecting a battery or other power source of the IMD to the circuit 790 via the interconnect device 782.

[0085] Additionally, as Figure 9A and Figure 9BAs shown, the IMD may include resiliently deformable connectors 784A and 784B (collectively referred to as "connectors 784"). The connectors 784 may be fixedly connected to the interconnect device 782 and are configured to make electrical and physical contact with the metal portion 705. The connectors 784 are configured to be spring-like, for example due to their material and the way they are bent or otherwise formed, and elastically deform when the interconnect device 782 is inserted into the housing and the connectors 784 engage the metal portion 705, for example elastically deforming inwardly towards the longitudinal axis of the IMD. The connectors 784 may be considered, for example, conductive springs.

[0086] Each of the connectors 784 may be selectively coupled to a respective section (e.g., a circumferential section) of the metal portion 705 that is electrically separated from other sections of the metal portion 705 by two shorting members 686. In the example shown, the two shorting members 686 separate the antenna 710 (including the metal portion 705) into two hemispherical sections or sub-antennas. Each of the connectors 784A and 784B may be connected (e.g., via the interconnect device 782) to an RF signal to excite its respective section of the antenna 710.

[0087] Figure 10 is a cross-sectional view showing another exemplary antenna 810 and another exemplary interconnect device 882 of the IMD according to the techniques described in the present disclosure. As Figure 10 shown, the antenna 810 may include a non-conductive member 807 between adjacent metal portions 803 and 805 on opposite longitudinal sides of the non-conductive member 807, similar to Figures 2A to 2C and Figure 3A and Figure 3B the metal portions 203, 303 and 205, 305 and the non-conductive members 207, 307. The IMD also includes an interconnect device 882, a circuit 890, and (although not shown in Figure 10 ) shorting members, similar to the interconnect device 682, the circuit 690, and the shorting members 686 described above with respect to Figure 8A and Figure 8B . The antenna 810 does not necessarily include one or more flexible circuits configured to provide electrical contact with the metal portions 803 and 805.

[0088] Figure 10 Also shown are resiliently deformable connectors 894A and 894B (collectively referred to as "connectors 894") for redundantly connecting a battery or other power source of the IMD to the circuit 890 via the interconnect device 882. In Figure 10In the example of, the IMD includes connectors 884A and 884B (collectively referred to as "connector 884"), which flexibly establish electrical contact between the electrically common portion of the IMD housing (in this case, the battery housing 892) and the RF signal source via the interconnecting device 882, rather than a connector that flexibly makes electrical contact with a metal portion (e.g., connector 784 having a metal portion 705 as described with respect to Figure 9A and Figure 9B . For ease of assembly, the connector 884 can be fixedly coupled to either (but not both) the interconnecting device 882 and the housing 892. The connector 884 can be configured to be elastically deformable, e.g., the distance between the interconnecting device 882 and the housing 892 decreases to flexibly maintain electrical contact. The connector 884 can selectively electrically connect the circuit 890 to the battery housing (ground) to power the IMD and is also used to connect the RF signal to the housing to excite the antenna 810.

[0089] The techniques described in this disclosure may be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, aspects of the described techniques may be implemented within one or more processors, which include one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combination of such components. The term "processor" or "processing circuitry" generally may refer to any of the foregoing logic circuitry alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also perform one or more of the techniques of this disclosure.

[0090] Such hardware, software, and firmware may be implemented within the same device or in separate devices to support the various operations and functions described in this disclosure. Additionally, any of the described units, modules, or components may be implemented together or separately as discrete but interoperable logic devices. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Instead, the functionality associated with one or more modules or units may be performed by separate hardware or software components, or integrated in common or separate hardware or software components.

[0091] The techniques described in this disclosure may also be embedded or encoded in a computer-readable medium (such as a computer-readable storage medium) that contains instructions. The instructions embedded or encoded in the computer-readable storage medium may cause a programmable processor or other processor to perform the method, for example, when the instructions are executed. The computer-readable storage medium may include random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette tape, a magnetic medium, an optical medium, or other computer-readable media.

[0092] The following examples illustrate the techniques described herein.

[0093] Example 1: An implantable medical device (IMD) includes a housing; a communication circuit within the housing; and an antenna that includes a non-conductive component that forms part of the housing; a first metal portion of the housing that is adjacent to the non-conductive component on a first side of the non-conductive component; a second metal portion of the housing that is adjacent to the non-conductive component on a second side of the non-conductive component; and a plurality of switchable contacts configured to connect the first metal portion and the second metal portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0094] Example 2: The IMD according to Example 1, wherein the non-conductive component is formed of at least one of sapphire or ceramic.

[0095] Example 3: The IMD according to Example 1 or 2, wherein the non-conductive component is at least partially transparent to RF waves.

[0096] Example 4: The IMD according to any one or more of Examples 1 to 3, wherein the non-conductive component has a polygonal or oval outer boundary.

[0097] Example 5: The device according to any one or more of Examples 1 to 3, wherein the non-conductive component is in a ring shape.

[0098] Example 6: The IMD according to Example 5, wherein the non-conductive component includes a continuous ring or a plurality of segments arranged as a ring.

[0099] Example 7: The IMD according to Example 5 or 6, wherein the first metal part and the second metal part are annular and have a common longitudinal axis with each other and with the non-conductive component.

[0100] Example 8: The IMD according to any one or more of Examples 5 to 7, wherein the plurality of switchable contacts are circumferentially distributed around the IMD.

[0101] Example 9: The IMD according to any one or more of Examples 1 to 8, wherein the plurality of switchable contacts include a first subset of the plurality of switchable contacts on the first side of the non-conductive component and a second subset of the plurality of switchable contacts on the second side of the non-conductive component.

[0102] Example 10: The IMD according to Example 9, wherein the first subset of the plurality of switchable contacts is formed on the first metal part and the second subset of the plurality of switchable contacts is formed on the second metal part.

[0103] Example 11: The IMD according to Example 8 and Example 9 or 10, wherein each contact in the first subset of the plurality of switchable contacts forms a pair with a corresponding contact in the second subset of the plurality of switchable contacts, and each pair is located at a corresponding position on the circumference of the IMD.

[0104] Example 12: The IMD according to Example 11, wherein two pairs of the contact pairs are spaced 180 degrees apart from each other.

[0105] Example 13: The device according to any one or more of Examples 1 to 12, wherein the RF wireless communication includes Bluetooth Low Energy signals.

[0106] Example 14: The IMD according to any one or more of Examples 1 to 13, the IMD further comprising one or more additional contacts fixed in a short-circuit configuration.

[0107] Example 15: The IMD according to Example 14, wherein the one or more additional contacts fixed in a short-circuit configuration are used to short-circuit the first metal part to the second metal part.

[0108] Example 16: The IMD according to any one or more of Examples 1 to 15, wherein each of the plurality of excitation modes is associated with a corresponding radiation pattern among a plurality of radiation patterns that are complementary to each other.

[0109] Example 17: The IMD according to any one or more of Examples 1 to 16, the IMD further comprising a processing circuit, the processing circuit being within the housing, the processing circuit being configured to configure the plurality of switchable contacts.

[0110] Example 18: The IMD according to Example 17, wherein the processing circuit is configured to: determine a metric of the wireless communication with the external device for at least two of the plurality of excitation modes; select an excitation mode from the at least two excitation modes based on the metric of the wireless communication for the at least two excitation modes; and configure the plurality of switchable contacts to provide the selected excitation mode.

[0111] Example 19: The IMD according to any one or more of Examples 1 to 18, the IMD further comprising one or more flexible circuits, the one or more flexible circuits being within the housing, the one or more flexible circuits being configured to conform to an inner surface of the antenna, wherein the one or more flexible circuits include the plurality of switchable contacts.

[0112] Example 20: The IMD according to any one or more of Examples 1 to 19, the IMD further comprising an interconnect device, the interconnect device being configured to connect the plurality of contacts to the communication circuit.

[0113] Example 21: The IMD according to any one or more of Examples 1 to 20, wherein the IMD is configured such that when the IMD is implanted within the patient, the antenna contacts at least one of the patient's tissue or fluid.

[0114] Example 22: The IMD according to any one or more of Examples 1 to 21, the IMD further comprising one or more electrodes integrated into the housing.

[0115] Example 23: The IMD according to Example 22, wherein the IMD includes a pacemaker, the pacemaker including a sensing circuit, the sensing circuit being within the housing, the sensing circuit being configured to sense an electrocardiogram via the one or more electrodes; and a therapy delivery circuit, the therapy delivery circuit being within the housing, the therapy delivery circuit being configured to deliver pacing pulses via the one or more electrodes, wherein the housing is configured for implantation within a heart chamber of the patient.

[0116] Example 24: A pacemaker includes: a housing configured for implantation within a patient's heart chamber; a plurality of electrodes integrated into the housing; a sensing circuit within the housing and configured to sense an electrocardiogram via the one or more electrodes; a therapy delivery circuit within the housing and configured to deliver pacing pulses via the one or more electrodes; a communication circuit within the housing; and an antenna including a non-conductive member forming part of the housing; a first metallic portion of the housing adjacent to the non-conductive member on a first side of the non-conductive member; a second metallic portion of the housing adjacent to the non-conductive member on a second side of the non-conductive member; and a plurality of switchable contacts configured to connect the first and second metallic portions to the communication circuit, wherein the plurality of switchable contacts are configurable, according to a selected excitation mode of a plurality of excitation modes, to connect the communication circuit to the first and second metallic portions via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0117] Example 25: The pacemaker of Example 24, wherein the non-conductive member and the first and second metallic portions are annular, the first and second metallic portions have a common longitudinal axis with each other and with the non-conductive member, and wherein the plurality of contacts include a first subset of the plurality of contacts formed on the first metallic portion on the first side of the non-conductive member and a second subset of the plurality of contacts formed on the second portion on the second side of the non-conductive member.

[0118] Example 26: A method includes: configuring, by a processing circuit within a housing of an implantable medical device (IMD), a plurality of switchable contacts of an antenna of the IMD according to a selected excitation mode of a plurality of excitation modes; exciting, by the communication circuit within the housing of the IMD, the antenna via the plurality of switchable contacts, the antenna including a non-conductive member forming part of the housing; a first metallic portion of the housing adjacent to the non-conductive member on a first side of the non-conductive member; and a second metallic portion of the housing adjacent to the non-conductive member on a second side of the non-conductive member; and communicating, by the IMD and via radio frequency (RF) wireless communication, with an external device using the excited antenna.

[0119] Example 27: The method of Example 26, wherein the non-conductive member is formed of at least one of sapphire or ceramic.

[0120] Example 28: The method according to Example 26 or 27, wherein the non-conductive component is at least partially transparent to RF waves.

[0121] Example 29: The method according to any one or more of Examples 26 to 28, wherein the non-conductive component has a polygonal or elliptical outer boundary.

[0122] Example 30: The method according to any one or more of Examples 26 to 28, wherein the non-conductive component is annular.

[0123] Example 31: The method according to Example 30, wherein the non-conductive component comprises a continuous ring or a plurality of segments arranged as a ring.

[0124] Example 32: The method according to Example 30 or 31, wherein the first metal part and the second metal part are annular and have a common longitudinal axis with each other and with the non-conductive component.

[0125] Example 33: The method according to any one or more of Examples 30 to 32, wherein the plurality of switchable contacts are circumferentially distributed around the IMD.

[0126] Example 34: The method according to any one or more of Examples 26 to 33, wherein the plurality of switchable contacts comprises a first subset of the plurality of switchable contacts on the first side of the non-conductive component and a second subset of the plurality of switchable contacts on the second side of the non-conductive component.

[0127] Example 35: The method according to Example 34, wherein the first subset of the plurality of switchable contacts is formed on the first metal part and the second subset of the plurality of switchable contacts is formed on the second metal part.

[0128] Example 36: The method according to Example 33 and Example 34 or 35, wherein each contact in the first subset of the plurality of switchable contacts forms a pair with a corresponding contact in the second subset of the plurality of switchable contacts, wherein each pair is located at a corresponding position on the circumference of the IMD.

[0129] Example 37: The method according to Example 36, wherein two pairs of contacts in these pairs of contacts are spaced 180 degrees apart from each other.

[0130] Example 38: The method according to any one or more of Examples 26 to 37, wherein communicating via RF wireless communication comprises communicating via Bluetooth Low Energy signals.

[0131] Example 39: The method according to any one or more of Examples 26 to 38, wherein the IMD includes one or more additional contacts fixed in a shorted configuration for shorting the first metal portion to the second metal portion.

[0132] Example 40: The method according to any one or more of Examples 26 to 39, wherein each of the plurality of excitation modes is associated with a corresponding radiation pattern among a plurality of radiation patterns that are complementary to each other, the method further comprising: determining a metric for the wireless communication with the external device for at least two of the plurality of excitation modes; selecting an excitation mode from the at least two excitation modes based on the metric for the wireless communication for the at least two excitation modes; and configuring the plurality of switchable contacts to provide the selected excitation mode.

[0133] Example 41: The method according to any one or more of Examples 26 to 40, wherein the IMD is implanted into a patient's body, and wherein the antenna is in contact with at least one of the patient's tissue or fluid.

[0134] Example 42: The method according to any one or more of Examples 26 to 41, wherein the IMD is implanted into a heart chamber, the method further comprising sensing an electrocardiogram through the IMD; and delivering pacing pulses through the IMD.

[0135] Example 43: An implantable medical device (IMD) includes a housing; a communication circuit within the housing; and an antenna that includes: an annular non-conductive member that forms part of the housing; a first annular metal portion of the housing that is adjacent to the non-conductive member on a first side of the non-conductive member; a second annular metal portion of the housing that is adjacent to the non-conductive member on a second side of the non-conductive member, wherein the first annular metal portion and the second annular metal portion have a common longitudinal axis with each other and with the annular non-conductive member; and a plurality of switchable contacts that are circumferentially distributed around the IMD and are configured to connect the first annular metal portion and the second annular metal portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0136] Example 44: The IMD according to Example 43, wherein the non-conductive member is formed of at least one of sapphire or ceramic.

[0137] Example 45: The IMD according to Example 43 or 44, wherein the non-conductive component is at least partially transparent to RF waves.

[0138] Example 46: The IMD according to any one or more of Examples 43 to 45, wherein the non-conductive component comprises a continuous ring or a plurality of segments arranged as a ring.

[0139] Example 47: The IMD according to any one or more of Examples 43 to 46, wherein the plurality of switchable contacts comprises a first subset of the plurality of switchable contacts on the first side of the non-conductive component and a second subset of the plurality of switchable contacts on the second side of the non-conductive component.

[0140] Example 48: The IMD according to Example 47, wherein the first subset of the plurality of switchable contacts is formed on the first metal part, and the second subset of the plurality of switchable contacts is formed on the second metal part.

[0141] Example 49: The IMD according to Example 47 or 48, wherein each contact in the first subset of the plurality of switchable contacts forms a pair with a corresponding contact in the second subset of the plurality of switchable contacts, and each pair is located at a corresponding position on the circumference of the IMD.

[0142] Example 50: The IMD according to Example 49, wherein two pairs of the contact pairs are spaced 180 degrees apart from each other.

[0143] Example 51: The device according to any one or more of Examples 43 to 50, wherein the RF wireless communication comprises Bluetooth Low Energy signals.

[0144] Example 52: The IMD according to any one or more of Examples 43 to 51, the IMD further comprising one or more additional contacts fixed in a short-circuit configuration.

[0145] Example 53: The IMD according to Example 52, wherein the one or more additional contacts fixed in a short-circuit configuration are used to short-circuit the first metal part to the second metal part.

[0146] Example 54: The IMD according to any one or more of Examples 43 to 53, wherein each of the plurality of excitation modes is associated with a corresponding radiation pattern among a plurality of radiation patterns that are complementary to each other.

[0147] Example 55: The IMD according to any one or more of Examples 43 to 54, the IMD further comprising a processing circuit, the processing circuit being within the housing and being configured to configure the plurality of switchable contacts.

[0148] Example 56: The IMD according to Example 55, wherein the processing circuit is configured to: determine a metric of the wireless communication with the external device for at least two of the plurality of excitation modes; select an excitation mode from the at least two excitation modes based on the metric of the wireless communication for the at least two excitation modes; and configure the plurality of switchable contacts to provide the selected excitation mode.

[0149] Example 57: The IMD according to any one or more of Examples 43 to 56, the IMD further comprising one or more flexible circuits within the housing, the one or more flexible circuits being configured to conform to the inner surface of the antenna, wherein the one or more flexible circuits include the plurality of switchable contacts.

[0150] Example 58: The IMD according to any one or more of Examples 43 to 57, the IMD further comprising an interconnect device configured to connect the plurality of contacts to the communication circuit.

[0151] Example 59: The IMD according to any one or more of Examples 43 to 58, wherein the IMD is configured such that the antenna contacts at least one of the patient's tissue or fluid when the IMD is implanted in the patient's body.

[0152] Example 60: The IMD according to any one or more of Examples 43 to 59, the IMD further comprising one or more electrodes integrated into the housing.

[0153] Example 61: The IMD according to Example 60, wherein the IMD includes a pacemaker, the pacemaker including a sensing circuit within the housing, the sensing circuit being configured to sense an electrocardiogram via the one or more electrodes; and a therapy delivery circuit within the housing, the therapy delivery circuit being configured to deliver pacing pulses via the one or more electrodes, wherein the housing is configured for implantation within a heart chamber of the patient.

[0154] Example 1A: An implantable medical device (IMD) includes: a housing; a communication circuit within the housing; and an antenna that includes a non-conductive component that forms part of the housing; a first metal portion of the housing that is adjacent to the non-conductive component on a first side of the non-conductive component; a second metal portion of the housing that is adjacent to the non-conductive component on a second side of the non-conductive component; and a plurality of switchable contacts configured to connect the first metal portion and the second metal portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0155] Example 2A: The IMD according to Example 1A, wherein the non-conductive component is formed of at least one type of ceramic material.

[0156] Example 3A: The IMD according to any one of Example 1A or 2A, wherein the non-conductive component is at least partially transparent to RF waves.

[0157] Example 4A: The IMD according to any one or more of Example 1A to 3A, wherein the non-conductive component has a polygonal or elliptical outer boundary.

[0158] Example 5A: The IMD according to any one or more of Example 1A to 3A, wherein the non-conductive component is annular.

[0159] Example 6A: The IMD according to Example 5A, wherein the non-conductive component includes a continuous ring or a plurality of segments arranged as a ring.

[0160] Example 7A: The IMD according to any one of Example 5A or 6A, wherein the first metal portion and the second metal portion are annular and have a common longitudinal axis with each other and with the non-conductive component.

[0161] Example 8A: The IMD according to any one or more of Example 5A to 7A, wherein the plurality of switchable contacts are circumferentially distributed around the IMD.

[0162] Example 9A: The IMD according to any one or more of Example 1A to 8A, wherein the plurality of switchable contacts include a first subset of the plurality of switchable contacts on the first side of the non-conductive component and a second subset of the plurality of switchable contacts on the second side of the non-conductive component.

[0163] Example 10A: The IMD according to Example 9A, wherein the first subset of the plurality of switchable contacts is formed on the first metal part, and the second subset of the plurality of switchable contacts is formed on the second metal part.

[0164] Example 11A: The IMD according to any one or more of Examples 1A to 10A, the IMD further comprising one or more additional contacts fixed in a short - circuit configuration, wherein the one or more additional contacts fixed in the short - circuit configuration are for short - circuiting the first metal part to the second metal part.

[0165] Example 12A: The IMD according to any one or more of Examples 1A to 11A, wherein each of the plurality of excitation modes is associated with a corresponding radiation pattern among a plurality of radiation patterns that are complementary to each other.

[0166] Example 13A: The IMD according to any one or more of Examples 1A to 12A, the IMD further comprising processing circuitry within the housing, the processing circuitry being configured to configure the plurality of switchable contacts.

[0167] Example 14A: The IMD according to Example 13A, wherein the processing circuitry is configured to: determine a metric of the wireless communication with the external device for at least two of the plurality of excitation modes; select an excitation mode from the at least two excitation modes based on the metric of the wireless communication for the at least two excitation modes; and configure the plurality of switchable contacts to provide the selected excitation mode.

[0168] Example 15A: The IMD according to any one or more of Examples 1A to 14A, the IMD further comprising one or more flexible circuits within the housing, the one or more flexible circuits being configured to conform to an inner surface of the antenna, wherein the one or more flexible circuits include the plurality of switchable contacts.

[0169] Example 16A: The IMD according to any one or more of Examples 1A to 15A, the IMD further comprising an interconnecting device configured to connect the plurality of contacts to the communication circuitry.

[0170] Example 17A: The IMD according to Example 16A, the IMD further comprising one or more elastically deformable connectors configured to connect the interconnecting device to one of the first metal part or the second metal part.

[0171] Example 18A: An IMD according to any one or more of Examples 1A to 17A, the IMD further comprising a sensing circuit within the housing, the sensing circuit configured to sense an electrocardiogram via the one or more electrodes; and a therapy delivery circuit within the housing, the therapy delivery circuit configured to deliver pacing pulses via the one or more electrodes, wherein the housing is configured for implantation within a heart chamber of a patient.

[0172] Example 19A: A pacemaker comprises: a housing configured for implantation within a heart chamber of a patient; a plurality of electrodes integrated into the housing; a sensing circuit within the housing, the sensing circuit configured to sense an electrocardiogram via the one or more electrodes; a therapy delivery circuit within the housing, the therapy delivery circuit configured to deliver pacing pulses via the one or more electrodes; a communication circuit within the housing; and an antenna comprising a non-conductive member forming part of the housing; a first metal portion of the housing adjacent to the non-conductive member on a first side of the non-conductive member; a second metal portion of the housing adjacent to the non-conductive member on a second side of the non-conductive member; and a plurality of switchable contacts configured to connect the first metal portion and the second metal portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode of a plurality of excitation modes, to connect the communication circuit to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0173] Example 20A: An implantable medical device (IMD) includes: a housing; a communication circuit within the housing; and an antenna that includes: an annular non-conductive member that forms part of the housing; a first annular metal portion of the housing that is adjacent to the non-conductive member on a first side of the non-conductive member; a second annular metal portion of the housing that is adjacent to the non-conductive member on a second side of the non-conductive member, wherein the first annular metal portion and the second annular metal portion have a common longitudinal axis with each other and with the annular non-conductive member; and a plurality of switchable contacts that are circumferentially distributed around the IMD and are configured to connect the first annular metal portion and the second annular metal portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

[0174] Various embodiments have been described. These and other examples are within the scope of the appended claims.

Claims

1. An implantable medical device (IMD), the IMD comprising: a housing; a communication circuit within the housing; and an antenna, the antenna comprising: a non-conductive component that forms part of the housing; a first metal portion of the housing adjacent to the non-conductive component on a first side of the non-conductive component; a second metal portion of the housing adjacent to the non-conductive component on a second side of the non-conductive component; and a plurality of switchable contacts configured to connect the first metal portion and the second metal portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metal portion and the second metal portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

2. The IMD according to claim 1, wherein the non-conductive component is formed of at least one type of ceramic material.

3. The IMD according to claim 1 or 2, wherein the non-conductive component is at least partially transparent to RF waves.

4. The IMD according to any one or more of claims 1 to 3, wherein the non-conductive component has a polygonal or oval outer boundary.

5. The IMD according to any one or more of claims 1 to 3, wherein the non-conductive component is annular.

6. The IMD according to claim 5, wherein the non-conductive component comprises a continuous ring or a plurality of segments arranged as a ring.

7. The IMD according to claim 5 or 6, wherein the first metal portion and the second metal portion are annular and have a common longitudinal axis with each other and with the non-conductive component.

8. The IMD according to any one or more of claims 5 to 7, wherein the plurality of switchable contacts are circumferentially distributed around the IMD.

9. The IMD according to any one or more of claims 1 to 8, wherein the plurality of switchable contacts include a first subset of the plurality of switchable contacts on the first side of the non-conductive component and a second subset of the plurality of switchable contacts on the second side of the non-conductive component.

10. The IMD according to claim 9, wherein the first subset of the plurality of switchable contacts is formed on the first metal portion and the second subset of the plurality of switchable contacts is formed on the second metal portion.

11. The IMD according to any one or more of claims 1 to 10, the IMD further comprising one or more additional contacts fixed in a shorted configuration, wherein the one or more additional contacts fixed in the shorted configuration are for shorting the first metal portion to the second metal portion.

12. The IMD according to any one or more of claims 1 to 11, wherein each of the plurality of excitation modes is associated with a corresponding radiation pattern among a plurality of radiation patterns that are complementary to each other.

13. The IMD according to any one or more of claims 1 to 12, the IMD further comprising a processing circuit, the processing circuit being within the housing, the processing circuit being configured to configure the plurality of switchable contacts.

14. The IMD according to claim 13, wherein the processing circuit is configured to: Determine a metric of the wireless communication with the external device for at least two of the plurality of excitation modes; Select an excitation mode from the at least two excitation modes based on the metric of the wireless communication for the at least two excitation modes; and Configure the plurality of switchable contacts to provide the selected excitation mode.

15. The IMD according to any one or more of claims 1 to 14, the IMD further comprising one or more flexible circuits, the one or more flexible circuits being within the housing, the one or more flexible circuits being configured to conform to an inner surface of the antenna, wherein the one or more flexible circuits include the plurality of switchable contacts.

16. The IMD according to any one or more of claims 1 to 15, the IMD further comprising an interconnecting device, the interconnecting device being configured to connect the plurality of contacts to the communication circuit.

17. The IMD according to claim 16, the IMD further comprising one or more elastically deformable connectors, the one or more elastically deformable connectors being configured to connect the interconnecting device to one of the first metal portion or the second metal portion.

18. The IMD according to any one or more of claims 1 to 17, the IMD further comprising one or more electrodes integrated into the housing, wherein the IMD includes a pacemaker, the pacemaker comprising: A sensing circuit, the sensing circuit being within the housing, the sensing circuit being configured to sense an electrocardiogram via the one or more electrodes; and A therapy delivery circuit, the therapy delivery circuit being within the housing, the therapy delivery circuit being configured to deliver pacing pulses via the one or more electrodes, wherein the housing is configured for implantation within a heart chamber of a patient.

19. A pacemaker, the pacemaker comprising: A housing, the housing being configured for implantation within a heart chamber of a patient; A plurality of electrodes, the plurality of electrodes being integrated into the housing; A sensing circuit, the sensing circuit being within the housing, the sensing circuit being configured to sense an electrocardiogram via the one or more electrodes; A therapy delivery circuit, the therapy delivery circuit being within the housing, the therapy delivery circuit being configured to deliver pacing pulses via the one or more electrodes; A communication circuit, the communication circuit being within the housing; and An antenna, the antenna comprising: A non-conductive component, the non-conductive component forming a part of the housing; a first metallic portion of the housing, the first metallic portion being adjacent to the non-conductive component on a first side of the non-conductive component; a second metallic portion of the housing, the second metallic portion being adjacent to the non-conductive component on a second side of the non-conductive component; and a plurality of switchable contacts configured to connect the first metallic portion and the second metallic portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metallic portion and the second metallic portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

20. An implantable medical device (IMD), the IMD comprising: a housing; a communication circuit within the housing; and an antenna, the antenna comprising: an annular non-conductive component forming part of the housing; a first annular metallic portion of the housing, the first annular metallic portion being adjacent to the non-conductive component on a first side of the non-conductive component; a second annular metallic portion of the housing, the second annular metallic portion being adjacent to the non-conductive component on a second side of the non-conductive component, wherein the first annular metallic portion and the second annular metallic portion have a common longitudinal axis with each other and with the annular non-conductive component; and a plurality of switchable contacts circumferentially distributed around the IMD and configured to connect the first annular metallic portion and the second annular metallic portion to the communication circuit, wherein the plurality of switchable contacts can be configured, according to a selected excitation mode among a plurality of excitation modes, to connect the communication circuit to the first metallic portion and the second metallic portion via a selected one or more of the plurality of contacts to excite the antenna to provide radio frequency (RF) wireless communication between the IMD and an external device.

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