Integrated head-based data and charging antenna for implantable medical devices

Abstract

An integrated head-based data and charging antenna for an implantable medical device is disclosed. Disclosed is an implantable medical device having a single antenna structure at its head, capable of receiving power from an external charger by near-field magnetic induction, and capable of communicating data with an external communication system by far-field radio frequency (RF) waves. The antenna structure preferably includes a stamped conductive sheet, and is generally toroidal. In one example, the antenna includes an end connection and a center connection acting as an RF feed, although the antenna may have only two connections. If desired, an algorithm operable at least in the HMD may time-multiplex data and charging operations of the antenna, and may configure circuitry of the IMD to operate in a charging mode or a data communication mode.

Description

[0001] This application is a divisional application of patent application No. 2024800391134, filed on May 8, 2024, entitled "Integrated Head-Based Data and Charging Antenna for Implantable Medical Devices". Technical Field

[0002] This invention relates generally to medical devices, and more specifically, to antenna structures and circuits that can be used in such devices. Background Technology

[0003] Implantable neurostimulatory devices are devices that generate and deliver electrical stimulation to the body's nerves and tissues to treat a variety of biological disorders, such as pacemakers for treating arrhythmias, defibrillators for treating fibrillation, cochlear stimulators for treating deafness, retinal stimulators for treating blindness, muscle stimulators for generating coordinated limb movements, spinal cord stimulators for treating chronic pain, cortical and deep brain stimulators for treating motor and psychological disorders, and other neurostimulators for treating urinary incontinence, sleep apnea, shoulder subluxation, etc. The following description will generally focus on the use of the invention in spinal cord stimulation (SCS) systems, such as those disclosed in U.S. Patent 6,516,227. However, the invention can be found in any implantable medical device (IMD) system.

[0004] like Figure 1As shown, an SCS system typically includes an implantable pulse generator (more generally, an IMD) 10, which includes a biocompatible device housing 12 formed, for example, of a conductive material such as titanium. The housing 12 typically houses the circuitry and power supply (e.g., a battery, not shown) required for the operation of the IMD 10, although the IMD can also be continuously powered via an external source and an external charger, and therefore may lack a battery. The IMD 10 is coupled to electrodes 16 via one or more electrode leads 18, such that the electrodes 16 form an electrode array 20. The electrodes 16 are carried on a flexible body 22, which also houses a separate signal line 24 connected to each electrode. In the illustrated embodiment, there are eight electrodes (Ei) on two leads 18, for a total of sixteen electrodes 16, although the number of leads and electrodes is application-specific and can therefore vary. The conductive housing 12 may also include electrodes. The leads 18 are connected to the IMD 10 using lead connectors 26, which are secured in a non-conductive head material 28, which may include, for example, a non-conductive epoxy resin. The contacts at the proximal end of lead 18 connect to contacts in lead connector 26, which in turn connect to feed conductor 29 passing through a sealed feedthrough 31 positioned between head 28 and housing 12. Feed conductor 29 connects to circuitry (e.g., a circuit board) within housing 12. Head 28, although shown as being on top of the IMD, can be located anywhere relative to housing 12.

[0005] IMD 10 may include different antennas. For example, IMD 10 may include one or more telemetry antennas 34a and / or 34b for transmitting to / from an external communication system 100 (such as... Figure 2 The external controller 60, clinician programmer 70, or system 80 shown wirelessly transmits / receives data. The IMD 10 may also include a charging antenna 36 for wirelessly receiving power from an external charger 90 to power the IMD or charge its battery. The IMD 10 is shown with two telemetry antennas 34a and 34b, although typically the IMD 10 will only have one of these antennas, and specifically an antenna with a format compatible with the antennas in the external communication system 100 to which they communicate.

[0006] The telemetry antenna 34a includes a coil, a winding of copper (e.g., Litz) wire, and communicates data with an external communication system 100 via a near-field bidirectional magnetic induction (MI) data link 104a. Figure 1The telemetry antenna 34a is shown inside the housing 12 of the IMD 10, but it could also be present in the head 28 with the lead connector 26. The telemetry antenna 34a can communicate with an external communication system 100 via a protocol such as frequency shift keying (FSK), using a modulation frequency centered at 125 kHz, along the MI data link 104a, as described in U.S. Patent Application Publication 2015 / 0080982. This is just one example, and other data modulation schemes can also be used. The telemetry antenna 34a can communicate (and be inductively coupled) with similar coils 64a, 74a, and 84a in the controller 60, programmer 70, and system 80, respectively, via the MI data link 104a. As is known, communication along the MI data link 104a involves exciting one of the coils (e.g., 64a) with modulated data, thereby forming the MI data link 104a into a modulated magnetic field, which is received as an induced current at another coil (e.g., 34a), where it can then be demodulated to recover the data. Because magnetic induction operates over shorter distances for communication, the effective communication distance of the MI data link 104a (i.e., the distance between the IMD 10 and an external system) can include up to about 2 feet.

[0007] In contrast, the telemetry antenna 34b in IMD 10 includes a far-field RF antenna, which is used to communicate with external systems via far-field electromagnetic waves through a bidirectional RF data link 104b. The telemetry antenna 34b may include a monopole or a dipole and may be configured as a wire, slot, or patch antenna. Figure 1 The telemetry antenna 34b is shown within the head 28 of the IMD 10, but it may also be present within the housing 12. The telemetry antenna 34b and the RF data link 104b can operate according to short-range RF communication protocols such as Bluetooth, Bluetooth Low Energy (BLE), WiFi, MICS, Zigbee, etc., as described in U.S. Patent Application Publication 2016 / 0051825. Such communication on the RF data link 104b typically occurs at frequencies from 10 MHz to 10 GHz (e.g., 2.4 GHz in the case of Bluetooth). The telemetry antenna 34b can communicate via the RF data link 104b with similar antennas 64b, 74b, and 84b in the controller 60, programmer 70, and system 80, respectively. Far-field communication on the RF data link 104b operates over longer distances than communication via magnetic induction, and therefore the effective communication range of the RF data link 104b (i.e., the distance between the IMD 10 and external systems) can include up to approximately 25 feet.

[0008] The charging antenna 36 in the IMD 10 receives wireless power via a magnetic induction power link 106 supplied from an external charger 90. Similar to the telemetry antenna 34a, the charging coil 36 comprises a coil wound with copper (e.g., lizard) wire. The charging antenna 36... Figure 1 The primary charging coil 96 in the charger 90 is shown inside the housing 12 of the IMD 10, but it could also be present in the head 28. When the IMD is being charged or powered, the primary charging coil 96 in the charger 90 is energized, thereby generating a magnetic charging field along the MI power link 106, which is received by the charging antenna 36 in the IMD 10, where the received power is rectified and used to power the IMD 10 or charge its battery. (The link 106 may also include a data-modulated magnetic field, thus enabling the supply of both data and power to the IMD 10). The magnetic charging field provided by the MI power link 106 can be approximately 80 kHz in one example. Again, since magnetic induction operates over short distances, the effective communication range of the MI power link 106 may include at most about 2 feet, although typically the primary charging coil 96 is brought closer to the IMD 10 (e.g., within 1 cm–3 cm) to improve charging efficiency and accelerate charging of the IMD. Figure 2 In the example shown, the charging coil 96 of the charger 90 is positioned within a charging head 94, which is coupled to an electronics module 92 via a cable, as described in USP 10,603,501. However, the charging coil 96 and associated electronics can also be integrated into a single housing, as disclosed, for example, in USP 7,979,126.

[0009] As already introduced, Figure 2 Various external communication systems 100 capable of wirelessly communicating data with the IMD 10 are shown, as well as an external charger 90 for powering or charging the IMD 10. The external communication system 100 can be used to wirelessly transmit stimulation programs to the IMD 10—that is, to program its stimulation circuitry to generate stimulation with desired amplitude and timing at electrode 16. This system can also be used to adjust one or more stimulation parameters of the stimulation program currently being executed by the IMD 10, and / or to wirelessly receive information from the IMD 10, such as various status information. While the external charger 90 for powering / charging the IMD 10... Figure 2 The external communication system 100 used for communicating data with the IMD 10 is shown separately, but in other examples, this power supply / charging and data communication may be integrated into a single external device or system. See, for example, USP 8,498,716 and 8,335,569.

[0010] For example, external controller 60 may be as described in U.S. Patent Application Publication 2015 / 0080982 and may include a portable handheld controller specifically designed to work with IMD 10. External controller 60 may also include a general-purpose mobile electronic device, such as a mobile phone, which has been programmed with a Medical Device Application (MDA) to allow it to function as a wireless controller for IMD 10, as described in U.S. Patent Application Publication 2015 / 0231402. As already described, external controller 60 may include MI antenna 64a and / or RF antenna 64b capable of communicating with IMD 10 along MI data link 104a and / or RF data link 104b. External controller 60 is typically designed for patient use and, like other external systems, enables patients to adjust stimulation parameters and perform other forms of control and monitoring of IMD 10, although it may have limited functionality compared to systems 70 and 80 (described below) typically used by clinicians.

[0011] The clinician programmer 70 is further described in U.S. Patent Application Publication 2015 / 0360038 and may include computing devices such as desktop computers, laptops or notebook computers, tablets, mobile smartphones, personal data assistant (PDA) type mobile computing devices, etc. Figure 2 In the image, the computing device is shown as a laptop computer, which includes typical computer user interface devices (e.g., monitor, buttons, mouse, keyboard, speakers, stylus, printer, etc.), although not all of these are shown for convenience. Figure 2 Also shown are accessory devices for the Clinician Programmer 70, which are typically specific to its operation as an IMD controller. For example, a communication “stick” 76 that can be coupled to a suitable port on a computing device is shown. Typically, the stick 76 will include an MI antenna 74a capable of communicating with an MI antenna 34a in the IMD 10, wherein the stick 76 can be positioned close to the IMD 10 to allow communication to occur along the MI data link 104a. The Clinician Programmer 70 (or stick 76) may also include one or more RF antennas 34b to communicate with the RF antennas 34b in the IMD 10 over longer distances via the RF data link 104b. The Clinician Programmer 70 may also communicate wirelessly or via a wired link provided at an Ethernet or network port with other devices and networks, such as the Internet.

[0012] External system 80 includes another device that communicates with and controls IMD 10 via network 85 (which may include the Internet). Network 85 may include a server 86 programmed with communication and control capabilities, and may include other communication networks or links, such as WiFi, cellular, or landline telephone links. Network 85 is ultimately connected to an intermediate device 82 with antennas (such as near-field MI coil antenna 84a and / or far-field RF antenna 84b) suitable for communicating with antennas 34a and / or 34b of the IMD. Intermediate device 82 may typically be located close to IMD 10 (within effective distance of data links 104a and 104b). Network 85 can be accessed by any user terminal 87, which typically includes computer equipment associated with a display and associated computer peripherals. External system 80 allows a remote user at terminal 87 to communicate with and control IMD 10 via intermediate device 82.

[0013] U.S. Patent Application Publication 2023 / 0173273 describes in more detail the external systems 60, 70, and 80 and IMD10, as well as the circuitry inherent in these systems. Summary of the Invention

[0014] In a first example, an implantable medical device (IMD) is disclosed, which may include: a housing; a non-conductive head attached to the housing; an antenna within or on the head, wherein the antenna is configured to operate in a first mode for far-field radio frequency (RF) data communication with an external system and in a second mode for receiving a near-field magnetic charging field to power the IMD; and control circuitry within the housing configured to time-multiplex the operation of the antenna in the first and second modes.

[0015] In one example, the antenna is inside the head. In one example, the head encapsulates the antenna. In one example, the head also includes at least one lead connector, into which at least one lead can be inserted. In one example, the antenna is formed in a plane. In one example, the plane is perpendicular to the top of the housing to which the head is attached. In one example, the plane is offset within the head in a direction parallel to the top of the housing. In one example, the antenna includes at least one planar metal sheet. In one example, the antenna is coated, plated, or covered with a conductive material. In one example, the antenna is three-dimensional. In one example, the antenna does not include wires. In one example, the antenna is loop-shaped. In one example, the antenna does not include a continuous loop. In one example, the antenna includes a top horizontal portion, a right vertical portion, and a left vertical portion. In one example, the antenna also includes at least one bottom horizontal portion. In one example, the IMD also includes a feedthrough between the head and the housing. In one example, the IMD also includes a plurality of electrical connections to the antenna, wherein the plurality of electrical connections pass through the feedthrough. In one example, a first electrical connection and a second electrical connection among the electrical connections are connected to a first end and a second end of the antenna. In one example, the IMD also includes a resonant capacitor, wherein the inductance between the first and second ends and the resonant capacitor form a resonant cavity to generate an AC voltage between the first and second ends in response to a magnetic charging field in a second mode, wherein the AC voltage provides power to the IMD. In one example, during the first mode, the control circuitry configures a third electrical connector in the electrical connections to operate as an RF feeder for RF data communication. In one example, during the first mode, the first and second electrical connectors are capacitively coupled to the housing, which acts as a ground plane. In one example, in either the first or second mode, none of the first, second, or third electrical connectors is directly connected to the housing. In one example, during the second mode, the third electrical connector is inactive. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes by configuring the charging circuitry and / or telemetry circuitry in the housing. In one example, the control circuitry is configured to control the operation of the antenna in the first and second modes via a time-multiplexing algorithm programmed in the control circuitry. In one example, the control circuitry is configured to operate in the first mode by default. In one example, the control circuitry is configured to receive a charging request to switch to operation in the second mode. In one example, the antenna is configured to receive charging requests. In another example, the IMD also includes a charging sensor from which charging requests are provided. In one example, the control circuitry is configured to operate in the second mode by default. In yet another example, the control circuitry is configured to automatically switch operation to the first mode after a certain duration.In one example, the IMD also includes a battery, wherein in the second mode, the received magnetic charging field is used to power the IMD by charging the battery. In one example, the radio frequency (RF) data communication in the first mode includes Bluetooth short-range communication.

[0016] In a second example, an implantable medical device (IMD) is disclosed, which may include: an antenna having a first connector to a first end of the antenna, a second connector to a second end of the antenna, and a third connector to the antenna; wherein the antenna is operable in a first mode for using the third connector as an RF feeder to perform far-field radio frequency (RF) data communication with an external system, and wherein the antenna is operable in a second mode for receiving a magnetic charging field to power the IMD, thereby inducing an AC voltage between the first and second connectors via near-field magnetic induction to provide power to the IMD.

[0017] In one example, the IMD also includes control circuitry configured to configure the operation of the antenna in a first mode and a second mode. In one example, the IMD also includes a housing in which the control circuitry is housed. In one example, in either the first or second mode, none of the first, second, or third electrical connectors is directly connected to the housing. In one example, during the first mode, the first and second electrical connectors are capacitively coupled to a ground plane including the housing. In one example, the IMD also includes a non-conductive head attached to the housing. In one example, the antenna is located within or on the head. In one example, the head overlays the antenna. In one example, the head also includes at least one lead connector, into which at least one lead can be inserted. In one example, the antenna is formed in a plane. In one example, the plane is perpendicular to the top of the housing to which the head is attached. In one example, the plane is offset within the head in a direction parallel to the top of the housing. In one example, the antenna is three-dimensional. In one example, the IMD also includes a feedthrough between the head and the housing. In one example, the first, second, and third electrical connectors pass through the feedthrough. In one example, in the first mode, the antenna is configured as a first monopole antenna between the third connector and the first connector, and a second monopole antenna between the third connector and the second connector. In one example, the antenna includes at least one planar metal sheet. In one example, the antenna is coated, plated, or covered with a conductive material. In one example, the antenna does not include a wire. In one example, the antenna is loop-shaped. In one example, the third connector is connected to the middle of the antenna between the first end and the second end. In one example, the antenna does not include a continuous loop. In one example, the antenna includes a top horizontal portion, a right vertical portion, and a left vertical portion. In one example, the antenna also includes at least one bottom horizontal portion. In one example, the IMD also includes a resonant capacitor, wherein the inductance between the first end and the second end and the resonant capacitor constitute a resonant cavity in the second mode. In one example, the third connector to the antenna is between the first connector and the second connector. In one example, the third electrical connector is inactive during the second mode. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes by configuring the charging circuitry and / or telemetry circuitry of the IMD. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes in a time-multiplexed manner. In one example, the control circuitry is configured to control the antenna's operation in both a first and a second mode via a time-multiplexing algorithm programmed within the control circuitry. In another example, the control circuitry is configured to operate in the first mode by default. In yet another example, the control circuitry is configured to receive a charging request to switch to operation in the second mode.In one example, the antenna is configured to receive charging requests. In one example, the IMD also includes a charging sensor from which charging requests are provided. In one example, the control circuitry is configured to operate by default in a second mode. In one example, the control circuitry is configured to automatically switch operation to a first mode after a certain duration. In one example, the IMD also includes a battery, wherein in the second mode, the received magnetic charging field is used to power the IMD by charging the battery. In one example, radio frequency (RF) data communication in the first mode includes Bluetooth short-range communication.

[0018] In a third example, an implantable medical device (IMD) is disclosed, which may include: an antenna having only a first connector to a first end of the antenna and a second connector to a second end of the antenna; wherein the antenna is configured to operate in a first mode to use the first connector as an RF feeder for far-field radio frequency (RF) data communication with an external system, wherein the antenna is configured to operate in a second mode to receive a magnetic charging field to power the IMD, thereby inducing an AC voltage between the first and second connectors via near-field magnetic induction to provide power to the IMD; and a control circuit configured to configure the operation of the antenna in the first and second modes.

[0019] In one example, the IMD also includes a housing, within which control circuitry is housed. In one example, in either the first or second mode, neither the first nor the second electrical connector is directly connected to the housing. In one example, during the first mode, the second electrical connector is capacitively coupled to a ground plane including the housing. In one example, the IMD also includes a non-conductive head attached to the housing. In one example, the antenna is located within or on the head. In one example, the head encapsulates the antenna. In one example, the head also includes at least one lead connector, into which at least one lead can be inserted. In one example, the antenna is formed in a plane. In one example, the plane is perpendicular to the top of the housing to which the head is attached. In one example, the plane is offset within the head in a direction parallel to the top of the housing. In one example, the antenna is three-dimensional. In one example, a feedthrough is included between the head and the housing. In one example, the first and second electrical connectors pass through the feedthrough. In one example, the antenna includes at least one planar metal sheet. In one example, the antenna is coated, plated, or covered with a conductive material. In one example, the antenna does not include a wire. In one example, the antenna is loop-shaped. In one example, the antenna does not include a continuous loop. In one example, the antenna includes a top horizontal portion, a right vertical portion, and a left vertical portion. In one example, the antenna also includes at least one bottom horizontal portion. In one example, the IMD also includes a resonant capacitor, wherein the inductance between the first end and the second end and the resonant capacitor constitute a resonant cavity in the second mode. In one example, during the first mode, a first electrical connection is coupled to telemetry circuitry. In one example, during the second mode, the first electrical connection does not include an RF feed. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes by configuring the charging circuitry and / or telemetry circuitry in the housing. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes in a time-multiplexed manner. In one example, the control circuitry is configured to control the operation of the antenna in the first and second modes via a time-multiplexing algorithm programmed in the control circuitry. In one example, the control circuitry is configured to operate in the first mode by default. In one example, the control circuitry is configured to receive a charging request to switch to operation in the second mode. In one example, the antenna is configured to receive a charging request. In one example, the IMD also includes a charging sensor, wherein the charging request is provided from the charging sensor. In one example, the control circuitry is configured to operate in the second mode by default. In another example, the control circuitry is configured to automatically switch operation to the first mode after a certain duration. In yet another example, the IMD also includes a battery, wherein in the second mode, the received magnetic charging field is used to power the IMD by charging the battery.In one example, radio frequency (RF) data communication in the first mode includes Bluetooth short-range communication.

[0020] In the fourth example, an implantable medical device (IMD) is disclosed, which may include: an antenna including at least one planar metal sheet and having a plurality of connections, including a first connector to a first end of the antenna and a second connector to a second end of the antenna; wherein the antenna is operable in a first mode for far-field radio frequency (RF) data communication with an external system using one of the plurality of connectors as an RF feeder, wherein the antenna is operable in a second mode for receiving a magnetic charging field to power the IMD, thereby inducing an AC voltage between the first and second connectors via near-field magnetic induction to provide power to the IMD.

[0021] In one example, the IMD also includes control circuitry configured to configure the operation of the antenna in a first mode and a second mode. In one example, the IMD also includes a housing within which the control circuitry is housed. In one example, in either the first or second mode, none of the plurality of electrical connections is directly connected to the housing. In one example, the IMD also includes a non-conductive head attached to the housing. In one example, the antenna is located within or on the head. In one example, the head encapsulates the antenna. In one example, the head also includes at least one lead connector, into which at least one lead can be inserted. In one example, the antenna is formed in a plane. In one example, the plane is perpendicular to the top of the housing to which the head is attached. In one example, the plane is offset within the head in a direction parallel to the top of the housing. In one example, the antenna is three-dimensional. In one example, the IMD also includes a feedthrough between the head and the housing. In one example, a plurality of electrical connections pass through the feedthrough. In one example, the antenna is coated, plated, or covered with a conductive material. In one example, the antenna is loop-shaped. In one example, the antenna does not include a continuous loop. In one example, the antenna includes a top horizontal portion, a right vertical portion, and a left vertical portion. In one example, the antenna further includes at least one bottom horizontal portion. In one example, the IMD also includes a resonant capacitor, wherein the inductance between the first end and the second end and the resonant capacitor constitute a resonant cavity in the second mode. In one example, the plurality of connections also includes a third connector to the antenna. In one example, the third electrical connector includes an RF feed in the first mode. In one example, the third electrical connector is inactive during the second mode. In one example, the first electrical connector includes an RF feed in the first mode. In one example, the first electrical connector does not include an RF feed during the second mode. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes by configuring the charging circuitry and / or telemetry circuitry in the housing. In one example, the control circuitry is configured to configure the operation of the antenna in the first and second modes in a time-multiplexed manner. In one example, the control circuitry is configured to control the operation of the antenna in the first and second modes via a time-multiplexing algorithm programmed in the control circuitry. In one example, the control circuitry is configured to operate in the first mode by default. In one example, the control circuitry is configured to receive a charging request to switch to operation in the second mode. In one example, the antenna is configured to receive a charging request. In one example, the IMD also includes a charging sensor from which charging requests are received. In one example, the control circuitry is configured to operate in the second mode by default. In another example, the control circuitry is configured to automatically switch operation to the first mode after a certain duration.In one example, the IMD also includes a battery, wherein in the second mode, the received magnetic charging field is used to power the IMD by charging the battery. In one example, the radio frequency (RF) data communication in the first mode includes Bluetooth short-range communication. Attached Figure Description

[0022] Figure 1 An implantable pulse generator (an IMD) according to the prior art and the manner in which an electrode array is connected to the IMD are shown.

[0023] Figure 2 An external communication system and an external charger, based on existing technology, are shown that are capable of communicating with and powering an IMD.

[0024] Figures 3A to 3D An example of a single antenna structure in the header of an IMD that implements both data communication and charging of the IMD according to an example of the present invention is shown.

[0025] Figure 4 The circuitry in the IMD is shown, including charging and telemetry circuitry, and includes a time multiplexing algorithm to configure the IMD for data communication or charging.

[0026] Figure 5 It shows the ability to interact with Figures 3A to 4 The external communication system and external charger that communicate with and power the IMD.

[0027] Figure 6 A first example of a time multiplexing algorithm for controlling the operation of the IMD in data communication mode and charging mode is shown.

[0028] Figure 7 A second example of a time multiplexing algorithm is shown, in which the pattern is implemented as interleaved charging and telemetry periods.

[0029] Figure 8 A third example of a time multiplexing algorithm is shown, where the operation defaults to the charging mode in the IMD.

[0030] Figures 9A to 9D An example is shown in which the antenna structure includes various extensions to improve data communication performance.

[0031] Figures 10A to 10E An example is shown in which the antenna structure can be made three-dimensional in shape to improve data communication performance.

[0032] Figures 11A to 11D An example is shown where the antenna structure includes only two connection points.

[0033] Figure 12The circuit modification is shown when only two connection points are used.

[0034] Figure 13 An expandable penile implant (an IMD) is shown, which can be combined with any publicly available antenna structure, associated circuitry, and algorithms. Detailed Implementation

[0035] The inventors found that, unfortunately, IMDs, such as the IMD 10 described above, typically require two separate antennas: one (34a and / or 34b) for data communication with an external communication system 100 (e.g., 60, 70, 80) (e.g., IMD control and / or monitoring); and the other (e.g., 36) to allow the IMD 10 to be powered or charged by an external charger 90. Having two separate antennas complicates the design and manufacture of the IMD and increases its cost.

[0036] The inventors also discovered that, unfortunately, at least some IMD designs place one or more of the antennas within the housing 12 of the IMD 10. As previously mentioned, this housing 12 is typically conductive, which tends to attenuate the MI or RF fields transmitted to or from these antennas (MI data link 104a, RF data link 104b, MI power link 106). This reduces the operational distance of these links or requires them to operate at higher power to compensate for this. Alternatively, placing the antennas within the housing 12 may require increasing the size (e.g., area) of the antennas to compensate for this attenuation and increase signal strength. This is not preferred, as the IMD is preferably as small as possible to minimize inconvenience to the patient.

[0037] In the inventors' view, it is preferable to position the antenna within the head 28 of the IMD. As previously discussed, the head 28 typically comprises a non-conductive dielectric material, such as epoxy or plastic, which does not significantly attenuate the MI or RF field. This allows the antenna to be made smaller, thereby reducing the IMD size and allowing for lower power for the supported communication links.

[0038] However, placing the antenna in the head 28 has disadvantages. The head 28 is preferably small to reduce the IMD size and typically includes other structures that occupy a significant volume, such as the lead connector 26. Figure 1 Therefore, there is limited space in the header 28 to accommodate antennas, especially if the header 28 needs to accommodate multiple antennas, such as RF antennas (e.g., 34a or 34b) for data communication (on data link 104a or 104b) and charging antenna 36 for receiving power (on MI power link 106). USP 8,929,986 provides an example where separate data and charging antennas are provided in the header of the IMD.

[0039] USP 9,750,930 provides a different example where a single antenna is provided in the IMD header, providing both data and charging functions. While this approach includes improvements in using only a single antenna structure in the header, it requires complex filtering circuitry to prevent data communication and charging from interfering with each other—specifically, preventing power received at the antenna from interfering with the data telemetry circuitry and preventing data transmission and reception from interfering with the charging circuitry. Because of the presence of a rectifier in the charging circuitry, the adequacy of the filtering circuitry in resolving interference between data communication and charging functions may be potentially compromised. In the GHz frequency range used for RF data communication in the '930 patent, parasitic capacitance in the rectifier may unintentionally shorten this data communication. This could negatively impact the power delivery efficiency of the RF data communication, potentially affecting overall performance.

[0040] The inventors' antenna structure 200 and related circuitry for the IMD 150 improve upon these previous methods. (As in...) Figures 3A to 3D As shown first in the various views, the disclosed antenna structure 200 is operable for both bidirectional data communication and IMD charging / power reception. As explained in detail later, complex filtering circuitry is not required to prevent interference between data and charging functions. A time-multiplexing scheme can be used, in which the IMD 150 is controlled to enable data communication and charging at different times. Time multiplexing can be enabled by using a time-multiplexing algorithm 300 operable at least in the IMD 150, as described later. This use of time multiplexing in the antenna structure 200 may include a better and more organized way of handling potential conflicts between IMD data communication and power reception compared to relying on the use of filtering circuitry. While the use of time multiplexing in the disclosed antenna structure is useful, it is not strictly required, as explained further below.

[0041] like Figure 3A and Figure 3B As shown in the side view, the antenna structure 200, together with the previously mentioned lead connector 26, is positioned within the head 28 of the IMD 150, with the two lead connectors in... Figure 3A It is shown in the image, and four lead connectors are in... Figure 3B It is shown in the side view. As shown, the antenna structure 200 is preferably offset within the head 28 (in Figure 3BWhen implanted in a patient, the IMD is preferably positioned outwards (closer to the external system with which it communicates), facing to the right. This is preferred to minimize electrical interference with communication with the antenna structure 200, i.e., to minimize interference with other conductive structures in the head 28 (e.g., lead connector 26). That said, the antenna structure 200 can also be located in different positions within the head 28. For example, the plane of the antenna structure 200 can be parallel to and close to the top or any of the four sides of the head 28. The antenna structure 200 can also be placed on the outer surface of the head. In other IMD designs that do not include leads, the head 28 may not include the lead connector 26, or may include other structures or ports.

[0042] Although not shown, the antenna structure 200 can also be housed within the housing 12, but as previously discussed, this is less desirable if the housing is conductive, as this would attenuate communication with the antenna. That said, not all IMD housings 12 are conductive (e.g., some are ceramic), and therefore do not significantly attenuate this communication.

[0043] Antenna structure 200 preferably does not include wound coils and is preferably not made of wire (e.g., wire with a circular cross-section), although it may. Instead, antenna structure 200 preferably comprises at least one planar metal sheet formed (e.g., by stamping or milling) into the desired shape. Antenna structure 200 can take different shapes, as discussed later. Antenna structure 200 can be made of any number of conductive materials or alloys (such as those containing titanium, copper, gold, silver, and the like). Antenna structure 200 may also comprise combinations of alloys formed in different layers and may be coated, plated, or clad with a conductive material such as gold. Regardless of how it is manufactured, antenna structure 200 is preferably biocompatible. Because antenna structure 200 is preferably planar and formed of a sheet of conductive material, it is thin and, as Figure 3B As best shown, the antenna structure 200 advantageously does not occupy significant space in the head 28. Preferably, the plane of the antenna structure 200 is perpendicular to the top 12a of the housing to which the head 28 is attached. That said, the antenna structure 200 may also be three-dimensional in other examples, as shown later. Although not shown, the antenna structure 200 may also be formed on a substrate, such as a printed circuit board.

[0044] Antenna structure 200 is preferably entirely contained within head 28. For example, and like lead connector 26, antenna structure 200 is preferably overmolded with a material used to form head 28 (e.g., epoxy resin). To aid in this overmolding and to additionally mechanically stabilize the electrical components in head 28 during the manufacture of IMD 150, antenna structure 200 may be permanently or temporarily stabilized using support structures. For example, Figure 3B The diagram illustrates the use of a clamp 210 to stabilize the antenna structure 200 within the head 28 prior to overmolding. This clamp 210 preferably holds the antenna structure 200 to a lead connector 26, which is relatively rigidly secured to the IMD 150 via a feedthrough wire 29. Support structures for the antenna structure 200 can also rigidly secure the antenna structure to the housing 12, to the top 12a of the housing, or to other IMD structures. While useful, the support structure for the antenna 200 is not strictly required, as the electrical connections 202, 204a, and 204b (described later) to the antenna structure 200 can provide sufficient mechanical stability. While overmolding is preferred for forming the head 28, the head can also be pre-formed separately as a solid piece, which is then placed within the head 28 onto a structure (e.g., lead connector 26; antenna structure 200; any support structure) and then secured to the housing 12, preferably in a medical-sealed manner.

[0045] Because the antenna structure 200 is located within the non-conductive dielectric head 28 and not within the conductive housing 12, communication (data, power) with the antenna structure is not significantly attenuated. Therefore, the antenna structure 200 can more easily (and over greater distances and / or with lower power) transmit and send data and receive power from external systems, as explained later.

[0046] The head 28 can be relatively rounded in shape to improve patient comfort, such as... Figures 3B to 3D As best shown in the image. The antenna structure 200 can also be relatively rounded in shape, for example, to match the rounded contours of the head 28, such as... Figure 3C and Figure 3D As best shown in the diagram. Additionally, the shape of the antenna structure 200 can be modified to accommodate other aspects of the head 28. For example, in Figure 3D In this embodiment, the head 28 of the IMD 150 includes a suture hole 212 to allow the IMD 150 to be secured (via sutures, not shown) to a specific location within the patient's tissue. This suture hole 212 is located essentially at the midpoint of the head 28, and to accommodate this, the antenna structure 200 includes a recess 214 to route the antenna structure 150 below this suture hole 212. This is similar to... Figure 3C Compared to the antenna structure 200 shown, it lacks the seam hole 212. From an electrical and performance perspective, Figure 3C and Figure 3D The examples shown are not substantially different.

[0047] like Figure 3AThe antenna structure 200 shown is typically ring-shaped, comprising a top horizontal portion 200a, left and right vertical portions 200b and 200c, and one or more bottom horizontal portions 200d. These portions may not be perfectly straight, or perfectly horizontal or vertical. They may also not be perfectly continuous (e.g., in the case of portion 200d). That is, the antenna structure 200 may not include a continuous loop, although it is possible to include a loop with multiple turns. In one example, the length L of the top horizontal portion 200a is approximately in the range of 20mm-30mm, while the lengths of the left and right vertical portions 200b and 200c are approximately in the range of 10mm-15mm. The length of the bottom horizontal portion 200d can be variable, and these portions can be of different lengths.

[0048] In the illustrated example, antenna structure 200 includes three electrical connectors 202, 204a, and 204b. Connectors 202, 204a, and 204b, like the feed passage 29 described above, are connected to the relevant electrical circuitry within housing 12 via feed passage 31 at the top 12a of housing 12, as explained below.

[0049] Connectors 204a and 204b are preferably connected to the ends of antenna structure 200 (e.g., to the end of portion 200d). During power reception, and similar to conventional power receiving coils, antenna structure 200 is magnetically coupled to charger 270 via MI power link 250, and includes region A ( Figure 3C To capture the magnetic flux of the link. This region A may not be entirely defined by a portion of the antenna structure 200; for example, as shown, gaps G may exist between portions 200d in the antenna structure. Figure 3C The gap G may also appear at other locations in the antenna structure 200 (parts 200a, b, or c). Nevertheless, the antenna structure 200 typically defines region A to capture the magnetic flux provided by the MI power link 250. During power reception, the connector 202 is not involved and is disabled (e.g., suspended), as explained further below.

[0050] As shown in the circuit diagram Figure 4As shown, connectors 204a and 204b are connected in parallel with resonant capacitor 239, although a series connection can also be used. The resonant capacitor 239 is preferably located within the housing 12 of the IMD 150, but can also be located in the head 28, as explained, for example, in U.S. Patent Application Publication 2022 / 0088396. The antenna structure 200 and the resonant capacitor 239 together form a resonant cavity that resonates at a frequency set by the capacitance of the resonant capacitor (e.g., 8.5 nF) and the inductance of the antenna structure between connectors 204a and 204b (e.g., in the range of 60 nH-70 nH). Preferably, the resonance is matched to the frequency of the MI power link 250 provided by the charger 270, which in one example includes 6.78 MHz within the Industrial, Scientific, and Medical (ISM) radio band. Generally, the frequency used for power transmission along the MI power link 250 can vary in the range of approximately 20 kHz to 20 MHz. Charging at a higher frequency within this range is beneficial because it reduces heating in the housing 12 by reducing the effect of eddy currents formed in the housing 12 in response to the AC magnetic charging field on the MI power link 250.

[0051] Power received via the MI power link 250 establishes an AC voltage between connectors 204a and 204b at the ends of antenna structure 200. This AC voltage is rectified by rectifier circuit 216 to establish a DC voltage Vdc. As shown in circuit 218, Vdc can be stabilized by a storage capacitor, and a Zener diode can be provided to ensure that Vdc does not exceed a specific threshold. Vdc can be provided to battery charging and protection circuit 220, which can then control the charging of battery 222 by providing battery charging current Ibat and / or battery voltage Vbat. As previously mentioned, IMD 150 may also lack battery 222, and in this case, Vdc can be more generally used to power IMD 150. Battery monitoring circuit 236 can monitor the charging process, such as by monitoring battery voltage Vbat, charging current Ibat provided to the battery, or other relevant charging information (e.g., temperature), and can report this charging information to IMD control circuit 230, which is discussed further below. Circuits 216, 218, and 220 can be collectively referred to as charging circuit 221.

[0052] IMD 150 may also include circuitry for communicating the battery's status back to charger 270 during power reception. While this communication can occur in different ways (including through the use of RF telemetry circuitry 228 described later), IMD 150 may also use load shift keying to communicate this status information back to the charger. Figure 5 The diagram shows an LSK data link 252. For example, Load Shift Keying (LSK) for communication with a charger is described in U.S. Patent Application Publication 2013 / 0096652. LSK involves modulating the impedance of antenna structure 200 by serially transmitting data bits (“LSK”) provided by control circuitry 230 from IMD 150 to external charger 270 along LSK data link 252. For example, and depending on the logic state of the bits to be transmitted, the ends of antenna structure 200 can be selectively shorted to each other via switch 231 to modulate the impedance of the antenna structure. The impedance of antenna structure 200 can be modulated in other ways.

[0053] At the external charger 270, and as Figure 5 As shown, LSK demodulator 280 ( Figure 5 The magnitude of the AC voltage developed across the coil 96 of the external charger (when the coil generates a magnetic charging field on the MI power link 250) is evaluated to determine whether a logic '0' or '1' has been transmitted from the IMD 150. In effect, modulating the antenna structure 200 in the IMD 150 in this way can be considered as creating a reflection along the magnetic charging field of the MI power link 250, which the charger 270 can evaluate to recover the LSK data. As shown, the demodulated data (LSK) can be reported to the control circuitry 272 of the external charger for analysis. This LSK reverse telemetry from the IMD 150 to the charger 270 can provide the external charger 50 with useful data about charging, such as the capacity of the battery 14 in the IMD, whether charging of the battery 14 is complete, and whether the operation of the external charger 270 and the generation of the magnetic charging field on the MI power link 250 can be stopped. As discussed earlier, the battery monitoring circuitry 236 can provide such charging information to the control circuitry 230.

[0054] Connector 202 is preferably attached at or near the middle of antenna structure 200, such as at the middle of top portion 202a, although connector 202 can also be located anywhere along the antenna between connectors 204a and 204b. Connector 202 includes an RF feed element used during data transmission and reception along the bidirectional RF link. Figure 5 As shown, multiple such data RF links can be supported by the IMD 150, such as RF data link 254 with external communication system 100 (e.g., external controller 60, clinician programmer 70, and / or external system 80), and / or RF data link 256 with charger 270. RF data links 254 and 256 can be established according to short-range RF communication protocols such as Bluetooth (at 2.4 GHz).

[0055] The physics involved in RF data transmission and reception using antenna structure 200 differs from that during charging. While antenna structure 200 operates as a loop during power reception to capture magnetic flux via magnetic induction along the MI power link 250, antenna structure 200 instead operates as a far-field EM antenna during data communication and therefore does not operate on the principle of magnetic induction. As further explained below, during data communication, connectors 204a and 204b can remain suspended, using housing 12 (e.g., top 12a and feedthrough 31) as a ground plane. In this respect, connectors 204a and 204b include parasitic capacitance 205 to housing 12, which in Figure 4 The dashed lines in the diagram are shown. The housing 12 then, and as... Figure 4 As shown, it can be coupled to system ground (GND) via a low-value capacitor 235 (e.g., 12 pF). Capacitors 205 and 235 essentially act as a short circuit at higher frequencies (e.g., 2.4 GHz) where data communication operates, thus allowing housing 12 to operate as a ground plane at these frequencies. During the reception of low-frequency magnetic charging fields via MI power link 250, the impedance of parasitic capacitance 205 will be high, and it will essentially operate as an open circuit.

[0056] In an alternative, during data communication, connectors 204a and 204b can be actively coupled to system ground or housing 12 via optional switches 233 or 237, as shown by dashed lines. These switches 233 or 237 can be controlled via control signal X, as explained further below.

[0057] The RF feed 202 establishes the antenna structure 200 as two monopole antennas operating in parallel: one between the RF feed 202 and the connector 204a, and one between the RF feed 202 and the connector 204b. In this example, each of these monopole antennas has the same length B. Figure 3C Although these lengths can also be different, for example, by not precisely connecting connector 202 in the middle of the top portion 200a, or by changing the lengths of the previously discussed portions 200a-200d. Length B is typically between approximately 1 cm and 5 cm, which generally corresponds to a quarter wavelength of the frequency used on RF data links 254 and 256. For example, if Bluetooth is used on these links (e.g., 2.4 GHz), this would be equivalent to approximately 2 cm-3 cm, consistent with length B. Those skilled in the art will understand that length B can be adjusted to obtain better performance at the frequencies in question. For example, gap G ( Figure 3C It can be made longer or shorter to affect the length B.

[0058] like Figure 4As shown, the IMD 150 includes RF telemetry circuitry 228 operable according to a short-range RF protocol in use, and may include a typical Bluetooth chipset. Interface circuitry 226 is situated between the RF telemetry circuitry 228 and the RF feeder 202. This interface circuitry 226 may include necessary matching networks and / or balun circuitry, as those skilled in the art will understand. Typically, the RF telemetry circuitry 228 communicates digital data with the IMD's control circuitry 230. That is, the RF telemetry circuitry 228 provides demodulated digital data (e.g., new or updated stimulation parameters for the IMD) received from an external system to the IMD's control circuitry 230, and modulates data received from the control circuitry 230 (e.g., IMD status information) for transmission to the external system. The RF telemetry circuitry 228 and associated circuitry such as the interface circuitry 226 are collectively referred to as telemetry circuitry 223.

[0059] Advantageously, the housing 12 of the IMD can still be used as a stimulation electrode during power reception or data communication. The frequency at which stimulation occurs at the electrode (e.g., 10 kHz or lower) is significantly lower than the frequencies involved in the RF data links 254 and 256 (e.g., 2.4 GHz) and the MI power link 250 (e.g., 6.78 MHz). At these lower frequencies, the capacitor 235 between the system ground and the housing 12 will effectively act as an open circuit. Therefore, the housing 12 can continue to be used as a stimulation electrode without shorting the housing 12 to the system ground.

[0060] As previously mentioned, data and charging access to antenna structure 200 can be time-multiplexed. This time multiplexing is preferably controlled by a time multiplexing algorithm 300 programmed in the control circuitry 230 of the IMD (e.g., as firmware). In some examples, the time multiplexing algorithm 300 can also operate at least partially in the external charger 270 (as firmware in its control circuitry 272), as referenced below. Figure 7As further explained. Control circuits 230 and 272 may, for example, include a microcontroller, such as the part number MSP430 manufactured by Texas Instruments, which is described in a datasheet accessible on the Internet. Other types of control circuitry may also be used instead of a microcontroller, such as a microprocessor, FPGA, DSP, or a combination thereof. Control circuits 230 and 272 may also be formed integrally or partially in one or more application-specific integrated circuits (ASICs), such as those described in U.S. Patent Application Publications 2012 / 0095529, 2012 / 0092031, and 2012 / 0095519. Those skilled in the art will understand that, in addition to the operation of the time multiplexing algorithm 300, these control circuits may also provide general functionality in the IMD 150 and charger 270. For example, control circuit 230 may include or interface with stimulation circuitry in the IMD 150 (which provides stimulation to the electrodes), as previously described.

[0061] Time multiplexing algorithm 300 determines whether the antenna structure 200 of IMD 150 can be used for data communication or power reception at any given time, and issues a control signal X accordingly (e.g., X=1 during data communication and X=0 during power reception). In one example, algorithm 300 may default to data reception (X=1), meaning that algorithm 300 will normally configure the circuitry of the IMD to allow antenna structure 200 to be used for data communication. When charging is needed or requested, algorithm 300 may instead configure the circuitry for power reception (X=0). As further explained below, control signal X can selectively enable or disable charging circuitry 221 or telemetry circuitry 223 in different ways. While it is preferred that algorithm 300 set data communication as the default mode, it may also set charging as the default mode, as further explained below.

[0062] The state of control signal X can be set in different ways by time multiplexing algorithm 300. In one example, a request to charge IMD 150 can be sent as data by an external system (such as charger 270). Figure 5The signal is transmitted to IMD 150, allowing algorithm 300 to configure the IMD's circuitry for charging (X=0). Alternatively, IMD 150 can detect the presence of a magnetic charging field already established by charger 270 along MI power link 250. For this option, IMD 150 includes a charging sensor 238 operable to detect the presence of a magnetic charging field on MI power link 250. In one example, charging sensor 238 may include a magnetic field detector (e.g., a Hall or Reed sensor) that can report the detection of a magnetic charging field to algorithm 300. In another example, charging sensor 238 may receive information from charging circuitry 221 indicating that a magnetic charging field is being received. For example, the reception of a charging field may cause rectifier circuitry 216 to generate a significant voltage Vdc, and therefore this voltage can be reported to charging sensor 238. In either case, charging sensor 238 can report the presence of a magnetic charging field to algorithm 300, which can then set a control signal X for charging (X=0).

[0063] When algorithm 300 configures IMD 150 for power reception (X=0), charging circuit 221 in IMD can be enabled, and telemetry circuit 223 can be disabled. In the depicted example, charging circuit 221 can be enabled by disconnecting switch 241 coupled to Vdc ground via control signal X, thereby allowing Vdc to form. Battery charging and protection circuit 220 can also be specifically enabled via control information X, although this is not shown. Switches 233 and 237, if present, will also be disconnected. Connectors 204a and 204b are preferably left floating during power reception, which is desirable for proper resonance and ultimately establishes Vdc to the appropriate value as previously described. Telemetry circuit 223 can also be disabled. In the depicted example, this occurs by disconnecting switch 234 coupled to ground via control signal X, which disables interface circuit 226. Control signal X can also be used to enable or disable RF telemetry circuit 228, although this is not shown. Disabling telemetry circuit 223 in this way allows RF feed connector 202 to be left floating during power reception.

[0064] When algorithm 300 configures IMD 150 for data communication (X=1), charging circuit 221 in IMD can be disabled, and telemetry circuit 223 can be enabled. In the depicted example, control signal X can close switch 241, which grounds Vdc to prevent charging. Although not shown, control signal X can also disable charging and protection circuit 220. Switches 233 and 237, if present, can also be closed to disable charging by preventing resonant voltage from building between connectors 204a and 204b (if a magnetic charging field (along the MI power link 250) is present). Telemetry circuit 223 is enabled by closing switch 234, allowing interface circuit 226 and / or RF telemetry circuit 228 to operate and generate or receive RF feed signals at connector 202. The depicted algorithm 300 and control signal X can be used to selectively enable or disable charging circuit 221 or telemetry circuit 223 in just one example. Examples of other enable or disable mechanisms are possible.

[0065] Figure 5 This has been discussed extensively, but various communication links involved in communicating with and powering the IMD 150, which has the antenna structure 200 and circuitry just described, are shown. When the IMD 150 operates in charging mode (X=0) to receive power, the MI power link 250 from the charger 270 is active, as is the LSK data link 252, to communicate charging information back to the charger. When the IMD 150 operates in data communication mode (X=1, preferably its default state), the IMD 150 can communicate with conventional external communication systems 100 (e.g., 60, 70, and / or 80) on the RF data link 254. As shown, these external systems will include RF telemetry circuitry 264 and RF antennas 266 (e.g., 64b, 74b, 84b) conforming to short-range RF protocols (such as Bluetooth) supported by the IMD 150. Similar to IMD 150, the RF telemetry circuitry 264 in these external systems may include interface circuitry between the telemetry circuitry 264 and the antenna 266, but this detail is not shown. These external systems will also include control circuitry 262.

[0066] The IMD 150 can also communicate with the charger 270 over the RF data link 256 in data communication mode (X=1). In this regard, the charger 270 can similarly include an RF telemetry circuit 274 and an RF antenna 276 conforming to the short-range RF protocol supported by the IMD 150. Preferably, the charger 270 includes the RF telemetry circuit 274 to communicate with the IMD 150 via the RF data link 256, as this facilitates the operation of the time multiplexing algorithm 300 described below. That said, this is not strictly required, and instead, the IMD 150 can communicate with the charger 270 via different means, such as by modulating the MI power link 250 and / or via the LSK data link 252.

[0067] Figure 6 A first example of the steps involved in the operation of time multiplexing algorithm 300 is described. As previously described, at step 302, algorithm 300 defaults to a data communication mode (X=1), where IMD 150 configures the circuitry to enable antenna structure 200 to be used for bidirectional RF communication on RF data links 254 and 256. In this mode, various switches in the IMD can be closed or opened as previously described to enable telemetry circuitry 223 and / or disable charging circuitry 221. At this step, and assuming the use of a short-range protocol such as Bluetooth, telemetry circuitry 228 of IMD 150 can periodically broadcast advertising data on links 254 and 256, which external communication system 100 and external charger 270 can detect to establish a data communication session with the IMD. The use of advertising data in this context is further discussed in USP 11,576,223, which is assumed to be familiar to the reader.

[0068] At this point, the external communication system 100 or charger 270 can transmit a connection request to IMD 150, which can acknowledge the request to establish a communication session, during which telemetry data can be transmitted between the devices. In layman's terms, this means of establishing a communication session can be referred to as a "handshake" between the relevant external device and IMD 150. When in data communication mode, the external communication system 100 can, for example, send new or updated stimulus parameters for IMD 150 to execute, or IMD 150 can send status information to those systems. More relevant to the subsequent steps in algorithm 300, charger 270 can also transmit a request to IMD 150 to begin charging the IMD via MI power link 250, as discussed below.

[0069] IMD 150 receives a request from charger 270 to begin charging IMD 150. This can occur in different ways, as shown in steps 304 and 305. In a preferred example of step 304, charger 270 may transmit the charging request via RF data link 256. This request may be generated at charger 270 without the user's knowledge. For example, a user of charger 270 may simply turn on charger 270 or otherwise select input from the user interface of charger 270 to begin charging. This may automatically result in charger 270 automatically “handshaking” with IMD 150 via RF data link 256 to send the charging request (via the operation of charger control circuitry 272). Alternatively, the transmission of the charging request may be manual, with the user using the user interface of charger 270 to transmit the charging request.

[0070] At step 304, once a charging request has been received at IMD 150, algorithm 300 can determine whether charging can be enabled at IMD 150, and therefore determine whether charger 270 can begin generating its magnetic charging field. Typically, algorithm 300 will allow IMD charging to occur upon request, but if algorithm 300 understands that IMD 150 is not currently in a position where charging is permitted, it may not do so (or may not do so immediately). For example, algorithm 300 may understand that IMD 150 is currently engaged in a data communication session with external communication system 100; in this case, algorithm 300 will reject or delay action regarding the charging request until the data communication session ends. Finally, if or when algorithm 300 determines that charging can occur, the algorithm can cause IMD 150 to transmit confirmation that charging can begin to charger 270 via RF link data 256. In response, external charger 270 can then automatically begin generating a magnetic charging field on MI power link 250.

[0071] In the example of step 305, the charging request at step 304 can appear in the form of a magnetic charging field generated by the charger 270 via the MI power link 250. In this example, the algorithm 300 detects this magnetic field and interprets it as a charging request. As previously described, the algorithm 300 can detect the presence of the magnetic charging field via the charging sensor 238, as explained previously. If charging is requested in this manner, there is no need for the IMD 150 to send a confirmation that charging can begin back to the charger 270, because the charger 270 is already providing the magnetic charging field.

[0072] Regardless of the method of charging request, algorithm 300 can configure the IMD's circuitry to operate in charging mode at step 306. Therefore, algorithm 300 can set X=0 to close or open various switches to disable telemetry circuit 223 and / or enable charging circuit 221. Charging of the IMD 150 thus begins (or continues) at step 306.

[0073] Once the MI power link 250 is generated, step 308 monitors the charging of the IMD 150. This monitoring can occur using battery monitoring circuitry 236 (which can, for example, determine charging information such as Vbat, Ibat, and temperature) and / or charging sensor 238 (which determines whether the magnetic charging field still exists). As relevant here, the monitoring at step 238 may include two queries: whether the battery 222 is fully charged (e.g., whether Vbat has risen above the threshold Vt indicating that the battery is full); and whether the MI power link 250 is still being supplied from the charger 270. Although Figure 6 Not described herein, but those skilled in the art will understand that the IMD 150 can also telemetry charging information to the charger 270 via the LSK data link 252 as needed during battery charging.

[0074] If algorithm 300 determines that battery 222 is fully charged (e.g., Vbat > Vt) and the magnetic charging field is still being generated from charger 270 on MI power link 250, the algorithm can proceed to step 310. At this step, algorithm 300 can cause control circuitry 230 to transmit information to charger 270 via LSK link 252 to prevent further generation of the magnetic charging field on MI power link 250. Such information may include specific instructions for shutting off the magnetic charging field to the charger, or it may include information that allows charger 270 itself to determine whether the magnetic charging field should stop. For example, the information transmitted at step 310 may include the charging information discussed earlier (e.g., Vbat), when Vbat reaches Vt, charger 270 stops generating the magnetic charging field on MI power link 250. In either case, the algorithm at the next step 312 can verify that MI power link 250 has actually stopped, which can be re-enacted using either or both of battery monitoring circuitry 236 and / or charging sensor 238.

[0075] At this point, algorithm 300 knows that charging no longer occurs (or is not needed) and can continue to step 302 to put IMD back into data communication mode (X=1) to prepare for potential future communication with external communication system 100 and / or charger 270.

[0076] If, at step 308, algorithm 300 learns that a magnetic charging field is no longer generated on the MI power link 250, algorithm 300 can also configure IMD 150 for data communication. This may occur if the patient turns off the charger or removes the charger from the vicinity of IMD 150. In this case, charger 270 will again need to be invoked via a new charging request (steps 304, 305). To prevent a too-rapid switch to data communication, for example in the case of a temporary interruption of only the magnetic charging field, algorithm 300 can determine that the MI power link 250 has been inactive for a period of time (e.g., a few seconds) before returning to the data communication mode at step 302.

[0077] Note that Algorithm 300 time-multiplexes the data communication and charging functions, specifically determining when to operate in either mode and appropriately configuring IMD 160 to control the operation of antenna structure 200, charging circuit 221, and telemetry circuit 223. Under this control method, filtering of the received signal is unnecessary because conflicts between data communication (at 2.4 GHz) and charging (e.g., at 13.56 MHz) should not occur. For example, data received during charging does not need to be filtered because telemetry circuit 223 can be disabled when IMD operates in charging mode (X=0). Similarly, the magnetic charging field received during data communication does not need to be filtered because charging circuit 221 can be disabled when IMD operates in data communication mode (X=1). Figure 6 In the example, the time multiplexing algorithm 300 can only run within the IMD 150.

[0078] Figure 7 Algorithm 300 can be operated in another way, and in this example, algorithm 300 can operate at least partially within charger 270. Figure 7 In the example, the charging session is time-multiplexed into multiple charging periods of duration D, with intervening telemetry periods provided to determine whether charging needs to continue or can be terminated. For example... Figure 7 The algorithm 300 shown relies solely on RF data communication between the charger 270 and the IMD 150 along RF data link 256 to control and synchronize charging. Communication along LSK link 252 is not required.

[0079] Step 302 is as described above, where algorithm 300 sets the IMD to the default data communication mode. Step 304 is also as described above, where the IMD 150 receives a request to start charging from the charger 270 via RF data link 256. As previously mentioned, this request can be automatically sent from the charger without the user's knowledge, for example, by turning on the charger. A "handshake" will occur in this step. In this example, it is assumed that the charger 270 cannot simply begin to generate a magnetic charging field on the MI link 250, where this field is used as a charging request (compare step 305, Figure 6 Although this is also possible. Once a charging request has been received at IMD 150, algorithm 300 running in IMD 150 can determine whether charging can be initiated at IMD 150, and therefore determine whether charger 270 can begin generating its magnetic charging field. As previously stated, if IMD is busy with another task, algorithm 300 can reject or delay the request. When algorithm 300 determines that charging can occur, it can cause IMD 150 to transmit confirmation that charging can begin to charger 270 via RF link data 256.

[0080] At step 318, algorithm 300 running in IMD 150 initiates a charging mode (X=0), and charger 270 can then automatically begin generating a magnetic charging field on MI power link 250. This charging will occur within a set charging period duration D, which is preferably known (e.g., programmed into) by algorithm 300 running in both IMD 150 and charger 270 for proper synchronization. Duration D can include a period of time that is typically too short to fully charge the battery 222 of IMD 150. For example, duration D can range from a few seconds to a few minutes.

[0081] Step 320 queries whether the duration D has been exceeded; if not, charging can continue. When the duration D has been exceeded, the IMD 150 and charger 270 re-establish a data communication session at step 322 to exchange necessary charging information and determine whether charging should continue. More specifically, the charger 270 stops generating a magnetic charging field on the power link 250, and the IMD defaults back to data communication mode (X=1). After the handshake and establishment of communication on the RF data link 256, charging information can be transmitted from the IMD 150 to the charger. For example, the IMD 150 can transmit the battery voltage Vbat to the charger, and may also transmit other relevant charging information such as Ibat and temperature.

[0082] At step 324, one of the devices in the system - charger 270 or IMD 150 - determines whether further charging is needed. If charger 270 is to make this determination, then IMD 150 will need to have transmitted relevant charging information to the charger (e.g., Vbat, at step 322). If, in contrast, IMD 150 is to make this determination, then no further data can be transmitted to charger 270. In any case, the device making this determination will evaluate the charging information (e.g., Vbat v. Vt) and determine whether further charging is needed.

[0083] If no further charging is needed (e.g., Vbat > Vt), then the device making this determination can notify the other device of this decision in step 326, effectively allowing the two devices to confirm or understand that no further charging is needed. This confirmation can occur using the RF data link 256 that has been established between the two devices. The current data communication between charger 270 and IMD 150 can then end, and algorithm 300 can return to step 302 to allow IMD 150 to establish other communication sessions in the future. Since charger 270 has stopped generating a magnetic charging field on the MI power link 250 (step 322), the charger can simply be turned off or otherwise notify the user that charging is complete.

[0084] If further charging is needed at step 324 (e.g., Vbat < Vt), then the device making this determination can notify the other device of this decision in step 328, effectively allowing the two devices to confirm and understand that further charging is needed. In this case, the data communication session can end, and algorithm 300 can return to step 318. As previously discussed, at this point, the algorithm running in IMD 150 places it in the charging mode (X = 0), and the algorithm running in charger 270 can again begin generating a magnetic charging field on the MI power link 250. As before, this charging will occur for the duration D discussed previously (step 320), after which a new data communication is established to determine and communicate whether further charging is needed (322 to 328). Through this iterative process, eventually no further charging will be needed (as Vbat increases during charging), and charging will stop.

[0085] The duration D of a charging session can be fixed during the charging session, or it can vary as algorithm 300 runs. For example, the duration D may initially be longer, but may shorten as charging progresses (i.e., as the battery charge increases). The extent to which algorithm 300 can adjust the duration D can depend on charging information (e.g., Vbat, Ibat, temperature). For example, if the temperature is high, or if Vbat is close to the full charge threshold (Vt), the duration D may be shortened. Conversely, the charging duration D can also be extended over time if desired.

[0086] In short, Figure 7 In the example, algorithm 300 runs on both IMD 150 and charger 270 to interleave telemetry periods (322 to 328) between each of the charging periods (318, 320) of duration D. Note that the interleaved telemetry periods are quite short (one-tenth of a second) compared to the charging period duration D. In this respect, when Figure 7 When Algorithm 300 is running, the magnetic charging field is almost always on, and the staggered telemetry periods do not significantly increase the time required to fully charge the battery 222 of the IMD 150.

[0087] Although the example of time multiplexing algorithm 300 shown so far configures IMD 150 to operate by default in data communication mode (X=1), this is not strictly necessary, and instead, the algorithm can configure IMD 150 to charging mode (X=0) by default. This example in... Figure 8 As shown in the diagram. At step 350, algorithm 300 configures IMD 150 to operate in charging mode by default (X=0). Therefore, data communication cannot (has not yet) occur on RF data links 254 and 256.

[0088] At step 352, algorithm 300 queries whether a charging request has been received. In this example, the charging request includes generating a magnetic charging field from charger 238 on MI power link 250, which can be sensed by charging sensor 238. If the charging request has been received, and as shown in step 354, charging can begin and be monitored. As previously stated... Figure 6 and Figure 7 As outlined in the text, this can happen in different ways. For example, Figure 6 Steps 308 to 312 can occur. Therefore, charging can begin / continue, where algorithm 300 monitors whether the battery is fully charged and / or whether the magnetic charging field on MI link 250 has stopped (308). When the battery is fully charged, the IMD can transmit this fact to the charger 270 via LSK link 252 (310) so that the charger can shut off the charging field. Alternatively, Figure 7Steps 320 to 328 can occur, which, as previously described, interleave the charging period on the MI power link 250 with the data communication period on the RF data link 256 to determine when charging should end. Afterward (or if the magnetic charging field has stopped for some reason), algorithm 300 can return to step 350, where IMD 150 defaults back to charging mode (X=0).

[0089] If no charging request is received at step 352, algorithm 300 can move to step 356 to inquire whether a delay X has been exceeded. This delay X is set to allow IMD 150 to periodically configure itself for data communication and check for the need for data communication. Therefore, when delay X is exceeded, and as shown in step 358, algorithm 300 puts IMD 150 into data communication mode (X=1). Thus, and as previously described, IMD 150 can begin advertising its presence on RF data links 254 and 256 and check for data communication requests from external communication system 100 or charger 270 (step 360). If no communication request is received, the algorithm can inquire whether a delay period Y has been exceeded (362). The delay period Y determines how long IMD 150 will remain in data communication mode and checks for the need for RF data communication with external devices. If delay period Y expires without a data communication request, the algorithm can return to step 350 and once again set IMD 150 into charging mode (X=0). It should be noted that the delay periods X (356) and Y (362) are a matter of design choice, where the value for each depends on whether it is more important to allow charging to occur quickly upon request (in which case period X would be relatively longer compared to period Y), or whether it is more important to allow data communication to occur quickly upon request (and vice versa).

[0090] If a communication request is received at step 360 (and after the handshake), algorithm 300 may inquire whether the request includes a charging request from external charger 270, as received on data link 356. This step is not necessary because, as previously stated, charger 270 can simply request charging by activating its magnetic charging field (in step 352). Nevertheless, charger 270 may also request charging via RF data link 356. If this occurs, algorithm 300 may configure IMD to charging mode (X=0) and proceed to step 354 to charge and monitor IMD 150. If at step 364 the communication request is not a charging request, it may be a request from external communication system 100 on RF data link 254 (or some other form of communication request from charger 270 on RF data link 256). In this case, at step 368 the devices have their communication session (on either RF data link 254 or 252) until that session ends and is completed. At that point, the algorithm can go back to step 350 to set the (default) charging mode (X=0).

[0091] While time multiplexing of antenna structure 200 using, for example, algorithm 300 may be beneficial, such time multiplexing is not strictly required, and instead, charging and data communication can occur simultaneously without definitively enabling / disabling telemetry and charging circuits 221 / 223. Higher frequency data communication received at or transmitted from antenna structure 200 will not be affected by the rectifier circuit 216 of charging circuit 221. Figure 4 The parasitic effects of the RF feed are mitigated because the RF feed 202 is not directly supplied at connectors 204a or 204b. This prevents high-frequency signals at connector 202 from being shorted to ground at rectifier 216 (i.e., through the inherent capacitance in the rectifier). Furthermore, the interface circuit 226 within the telemetry circuit 223 can be designed to filter the lower-frequency charging signals received at antenna structure 200.

[0092] Various modifications to the antenna structure 200 are possible and are shown in the following figures. Those skilled in the art will recognize that the various modifications shown can be combined in different ways. Not all of these combinations are explicitly shown.

[0093] exist Figure 9AIn the antenna structure 200, an extension 215 is included, to which the RF feed 202 is connected. The extension 215 can operate as a patch antenna. The patch has a region C as shown and can be sized to facilitate efficient data communication at frequencies used for data communication on RF data links 254 / 256. In the example shown, the extension 215 is largely circular in region, although this is not strictly necessary, and other shapes (rectangular, square, etc.) are also possible. Although not shown, the extension 215 may also include a slot and operate at least partially as a slotted antenna. Note that adding the extension 215 to the antenna structure 200 can change the length B of the monopole antenna formed when the RF feed 202 is active. Figure 3C This can be useful for tuning the antenna structure 200 to operate at the frequencies involved (e.g., Bluetooth). Extension 215 is significantly involved during data communication mode; it is not involved in charging mode when the antenna structure 200 is induced with current by the magnetic charging field (MI link 250) between connectors 204a and 204b. This is because, as shown, extension 215 is not significantly within the current path formed between connectors 204a and 204b. Figure 9A In the example shown, the extension 215 is planar with the rest of the antenna structure 200 and can be formed of the same conductive material sheet as the rest of the antenna structure.

[0094] Figure 9B The use of extension 215 is also shown, although in this case the extension is largely linear with no substantial region C. Nevertheless, extension 215 still affects the length B of the formed monopole antenna, which, as just noted, can be useful in tuning the antenna. Figure 9B In the middle, the extension 215 is centered and connected to the middle portion (e.g., the top portion 200a) of the antenna structure 200 between the ends where connectors 204a and 204b are connected. Figure 9C In the antenna structure 200, the extension 215 is not centered, which results in two monopole antennas having different lengths—length B between connectors 202 and 204a and length B' between connectors 202 and 204a. Antennas with different lengths can be useful for increasing the bandwidth or efficiency of the antenna structure 200 in data communication mode.

[0095] exist Figure 9D In this configuration, the extension 215 is not located within region A defined by the loop between connectors 204a and 204b, which reduces interference when the antenna structure 200 receives a magnetic charging field via the MI power link 250. This configuration also forms monopole antennas with different lengths B and B', as shown in the figure.

[0096] exist Figures 9A to 9D In the example shown, the extension 215 is planar with the rest of the antenna structure 200 and can be formed of the same material. Various examples of the extension 215 can also be made of different materials and connected to the general loop shape of the antenna structure 200.

[0097] In particular, the efficiency of data communication can be further improved by providing some three-dimensionality to the antenna structure 200, and Figures 10A to 10E Examples illustrate various possible three-dimensional structures of the antenna structure 200. In these examples, the general loop shape of the antenna structure 200 remains planar (in the xy plane), and therefore power reception during charging mode is unaffected. However, the antenna structure 200 also has a significant length in the z-direction. For example, in Figure 10A In this configuration, the antenna structure 200 has a substantial thickness t (in the z-direction). This can be achieved either by forming the antenna structure 200 using a particularly thick conductive sheet, or by forming the antenna structure 200 as several thinner layers.

[0098] exist Figures 10B to 10E In this embodiment, the antenna structure 200 is made three-dimensional by including extensions 215 that substantially protrude in the z-direction at different locations. As in the previous example, these extensions 215 are connected to the RF feed 202. However, this is not strictly necessary. Although not shown, the extensions 215 can also be connected to connectors 204a or 204b, where the RF feed 202 is instead connected to one of the ends of the loop (instead of 204a or 204b). That is, the three connection points of the antenna structure 200 can vary between 202, 204a, and 204b according to user preference. The extensions 215 shown in these figures can be formed by bending the conductive material of the antenna structure 200, although, as mentioned earlier, these extensions can also be made of a separate material and also fixed to the antenna structure.

[0099] The examples of antenna structure 200 and related circuitry shown so far assume that antenna structure 200 has three connections—connectors 204a and 204b coupled to the ends of the loop of charging circuit 221, and RF feed 202 coupled to telemetry circuit 223. However, this is not strictly required, and on the contrary, antenna structure 200 may have only two connections, as one of the loop end connections can also be used as an RF feed.

[0100] The antenna structure 200, capable of operating in both data communication and charging modes but with only two connection points, is first... Figure 11A As shown in the figure, where... Figure 12The IMD circuit shown has been modified. Only connectors 204a and 204b at the ends of antenna structure 200 are present. These connectors 204a and 204b, as in the previous example, are connected to charging circuit 221 and, as previously described in charging mode (X=0), are used to capture the magnetic flux provided by MI power link 250 to provide power to IMD 150 via magnetic induction.

[0101] Unlike the previous example, RF feed connector 202 is absent, and instead, connector 204a at the end of antenna structure 200 selectively acts as an RF feed and is coupled to telemetry circuit 223, being active in data communication mode (X=1). As before, switch 234 can be used to enable telemetry circuit 223 and activate the RF feed. To prevent high-frequency data signals on the antenna structure from shorting through resonant capacitor 239, switch 411 can be added in series with the capacitor, which is disconnected in data communication mode, effectively disabling charging circuit 221 (in addition to or in place of switch 241). Switch 411 can be controlled by the inverse of control signal X, i.e., X*. In data communication mode, an optional switch 410 between telemetry circuit 223 and connector 204a can also be closed, although this switch 410 is not needed if telemetry circuit 223 is enabled and disabled using switch 234. When in data communication mode, antenna structure 200 is constructed as a single monopole antenna of length B (basically... Figure 11A The entire length of the antenna structure is fed at connector 204a and parasiticly grounded at connector 204b. As previously explained, this grounding (to the housing 12, which acts as the ground plane) is affected by capacitors 205 and 235.

[0102] During the charging mode (X=0), switch 411 is closed to connect resonant capacitor 239 to antenna structure 200. Switch 410, if present, can also be opened to disable telemetry circuit 223, thereby allowing connector 204a to float, as this is preferred during receiving the magnetic charging field and establishing AC voltage across connectors 204a and 204b. Other switches described above (e.g., 234, 241, 233, 237, 233) can be used as before to effectively enable and disable telemetry circuit 223 and charging circuit 221 in the corresponding operating mode (X) set by time multiplexing algorithm 300. Time multiplexing algorithm 300 can operate in any of the ways described above (see...). Figures 6 to 8 ).

[0103] Modifications to the two connection point examples of antenna structure 200 are possible. For example, Figure 11B The use of extension 215 is shown, similar to the previous description. Figure 9AThe details discussed will not be repeated here. In the example shown, the extension 215 is located at the connector 204a, although this is not strictly necessary, and instead the extension 215 may be located at other points along the length of the antenna structure 200 (including at the connector 204b). Figure 11C An extension 215 is shown at the midpoint of the length along the antenna structure 200. Note that this may alter (shorten) the effective length B of the monopole antenna, which may parasitically ground to the housing 12 at the end of the extension 215. Figure 11D In, and in conjunction with the previously discussed Figure 9D Similarly, the extension 215 is not located within region A defined by the loop between connectors 204a and 204b, which reduces interference when the antenna structure 200 receives a magnetic charging field via the MI power link 250. This also alters (shortens) the effective length B of the monopole antenna, which can be parasitically grounded back to the housing 12 at the end of the extension 215.

[0104] Figures 11A to 11D The examples all show the antenna structure 200 as a planar plane. However, and although not shown, modifications discussed earlier can also be used (see...). Figures 10A to 10E This allows these antenna structures to present a three-dimensional form, which, as mentioned earlier, can particularly improve performance in data communication modes.

[0105] Although the disclosed structure provides both RF data communication and charging functions, the example of the disclosed antenna structure 200 can also be used in the IMD to provide only one of these functions, i.e., only RF data communication or only charging. In other words, the antenna structure 200 is not required to implement both functions in the IMD.

[0106] Although examples of the invention are described for implantable stimulation device systems, such as spinal cord stimulation systems as indicated above, the antennas, circuitry, and algorithms described herein can be used in other implantable medical device systems. For example, in some embodiments, an implantable medical device may include an electric pump configured to move fluid within the device to inflate or deflate an expandable member. For example, in some embodiments, an implantable medical device may be an expandable penile implant. In some cases, expandable penile implants have been used to help address erectile dysfunction.

[0107] like Figure 13As shown, the expandable penile implant 400 (an implantable medical device, IMD) includes a fluid reservoir 440 configured to be placed in a patient's pelvic region and one or more expandable members 450 configured to be placed within the patient's penis. The expandable penile implant 400 also includes a housing 460 (including a housing and a head) operatively coupled to the fluid reservoir 440 and the one or more expandable members 450. The housing 460 may house a power source (such as a rechargeable battery) and one or more pumps (such as one or more piezoelectric pumps) configured to move fluid to and from the one or more expandable members 450 to place them in an expanded or compressed configuration. The housing 440 may also house an antenna and circuitry, such as those described herein, to allow control of the expandable penile implant 400 from an external communication system 100 located outside the patient's body and to provide the power source for the expandable penile implant 400 to be recharged by an external charger 270.

[0108] As discussed earlier, the various algorithms described in this paper (e.g., 300, see...) Figures 6 to 8 The instructions can be implemented as firmware or software, and these instructions can be embodied in non-transitory computer-readable media, such as solid-state storage (e.g., control circuitry 230 in IMD 150 and / or 272 in charger 270), optical discs or disks, and the like. These media can be within IMD 150, charger 270, or in an external system, such as on various Internet servers (e.g., 86, ...), in a manner downloadable to IMD 150 and / or charger 270. Figure 2 Portable or fixed disks, and the manufacture of computer systems and the like.

Claims

1. An implantable medical device (IMD), comprising: case; The non-conductive head is attached to the housing; An antenna inside or on the head, wherein the antenna is configurable to operate in a first mode for far-field radio frequency (RF) data communication with an external system and in a second mode for receiving a near-field magnetic charging field to power the IMD. as well as The control circuitry within the housing is configured to time-multiplex the operation of the antenna in the first and second modes.

2. The IMD according to claim 1, wherein the antenna is inside the head, or wherein the head covers the antenna in a molded manner.

3. The IMD according to claim 1, wherein, The head also includes at least one lead connector, and at least one lead can be inserted into the at least one lead connector.

4. The IMD according to claim 3, wherein, The antenna is formed in a planar shape.

5. The IMD according to claim 4, wherein, The plane is perpendicular to the top of the housing to which the head is attached.

6. The IMD according to claim 4, wherein, The antenna includes at least one planar metal sheet.

7. The IMD according to claim 1, wherein, The antenna is ring-shaped.

8. The IMD according to claim 1, wherein, The antenna includes a top horizontal section, a right vertical section, and a left vertical section.

9. The IMD according to any one of claims 1 to 9, further comprising a feedthrough between the head and the housing, and further comprising a plurality of electrical connections to the antenna, wherein the plurality of electrical connections pass through the feedthrough.

10. The IMD according to claim 12, further comprising a resonant capacitor, wherein, The inductance between the first end and the second end and the resonant capacitor form a resonant cavity to generate an AC voltage between the first end and the second end in response to a magnetic charging field in the second mode, wherein the AC voltage provides power to the IMD.

11. The IMD according to claim 13, wherein, During the first mode, the control circuit configures the third electrical connection in the electrical connections to operate as an RF feeder for RF data communication.

12. The IMD according to claim 14, wherein, In either the first or second mode, none of the first, second, or third electrical connectors is directly connected to the housing.

13. The IMD according to claim 14, wherein, During the second mode, the third electrical connection is inactive.

14. The IMD according to claim 13, wherein, The control circuit is configured to operate in the first mode by default, and the control circuit is configured to receive a charging request to switch to operating in the second mode.

15. The IMD according to claim 13, wherein, The control circuit is configured to operate in the second mode by default, and the control circuit is configured to automatically switch the operation to the first mode after a certain duration.

16. An implantable medical device (IMD), comprising: An antenna having only a first connector to a first end of the antenna and a second connector to a second end of the antenna; The antenna can be configured to operate in a first mode to use the first connector as an RF feeder for far-field radio frequency (RF) data communication with an external system. The antenna can be configured to operate in a second mode to receive a magnetic charging field to power the IMD, thereby inducing an AC voltage between the first and second connectors via near-field magnetic induction to provide power to the IMD; and A control circuit configured to configure the operation of the antenna in the first mode and the second mode.

17. The IMD of claim 16, further comprising a housing, wherein the control circuitry is located within the housing.

18. The IMD according to claim 17, wherein, In either the first or second mode, neither the first nor the second electrical connector is directly connected to the housing.

19. The IMD according to claim 18, wherein, During the first mode, the second electrical connection is capacitively coupled to the ground plane including the housing.

20. The IMD of claim 17, further comprising a non-conductive head attached to the housing, wherein the antenna is inside or on the head.

21. The IMD according to claim 20, wherein, The head also includes at least one lead connector, and at least one lead can be inserted into the at least one lead connector.

22. The IMD according to claim 20, wherein, The antenna is formed in a plane, wherein the plane is perpendicular to the top of the housing to which the head is attached.

23. The IMD of claim 30, further comprising a feedthrough between the head and the housing, wherein, The first and second electrical connectors pass through the feedthrough.

24. The IMD according to claim 16, wherein, The antenna includes at least one planar metal sheet.

25. The IMD according to claim 16, wherein, The antenna is ring-shaped.

26. The IMD according to claim 16, wherein, During the first mode, the first electrical connector is coupled to the telemetry circuit, wherein during the second mode, the first electrical connector does not include the RF feeder.

27. The IMD according to claim 26, wherein, The control circuit is configured to configure the antenna operation in the first and second modes in a time-multiplexed manner.

28. The IMD according to claim 27, wherein, The control circuit is configured to operate in the first mode by default.

29. The IMD according to claim 28, wherein, The control circuit is configured to receive a charging request to switch to operation in the second mode.

30. The IMD according to claim 29, wherein, The control circuit is configured to operate in the second mode by default.

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