Receive coil configuration for implantable medical devices

Abstract

Systems, devices, and methods allow for inductive recharging of a power source positioned within or coupled to an implantable medical device while the device is implanted in a patient. In some instances, the implantable medical device includes a receive antenna configuration that may include at least one infinity-shaped receive coil. One or more of the receive coils may be formed with a curved shape that conforms to a curvature on an inner surface of a portion of a housing of the implantable medical device, such that the one or more receive coils may be positioned adjacent to, and in some instances directly contacting, a portion of the curved inner surface.

Description

Technical Field

[0001] The present disclosure relates to devices and systems for recharging a power source positioned within a medical device that has been implanted in a patient. Background Art

[0002] Various implantable medical devices have been implanted or proposed clinically to treat or monitor one or more physiological and / or neurological conditions of patients with curative effect. Such devices may be suitable for monitoring or treating conditions or functions related to heart, muscle, nerve, brain, stomach, endocrine organs or other organs and their related functions. The advancement of the design and manufacture of miniaturized electronics and sensing devices enables the development of implantable devices with therapeutic functions and diagnostic functions, such as pacemakers, cardioversion devices, defibrillators, biochemical sensors, implantable loop recorders and pressure sensors, etc. Such devices may be associated with leads that position electrodes or sensors at desired locations, or may be leadless with electrodes integrated into the device housing. These devices may have the ability to wirelessly transmit data to another device implanted in the patient or another instrument positioned outside the patient's body or both.

[0003] Although implanting some devices requires surgical procedures (e.g., pacemakers, defibrillators, etc.), other devices can be small enough to be delivered in a relatively non-invasive manner (such as through a percutaneous delivery catheter) or intravenously and placed at the intended implantation location. By way of illustrative example, implantable microsensors have been proposed and used in blood vessels to directly measure diastolic, systolic and mean blood pressures as well as the patient's body temperature and cardiac output. As an example, patients with chronic cardiovascular conditions (particularly patients with chronic heart failure) can benefit from the use of implantable sensors suitable for monitoring blood pressure. As another example, a subcutaneously implantable monitor has been proposed and used to monitor heart rate and rhythm and other physiological parameters, such as patient posture and activity level. Such direct in vivo measurements of physiological parameters can provide important information to clinicians to facilitate diagnostic and therapeutic decisions. In addition, a miniaturized pacemaker that can be directly implanted in the heart of a patient with or without an external lead has been proposed and established and is suitable for providing both pacing and other electrical therapies to the patient. Summary of the invention

[0004] The present disclosure describes implantable medical devices, systems including receiving antenna configurations and associated techniques for implantable medical devices, structures, and assemblies configured to provide recharging of power sources positioned within a medical device that has been implanted in a patient. Implantable medical devices that contain these power sources to be recharged are typically small devices that have been implanted relatively deep within a patient's body (e.g., internally implanted within a patient's heart). One example of such a device is a device that is designed to be implanted internally, such as within a chamber of a patient's heart, and in various instances does not require external leads coupled to the device in order to provide pacing and electrical stimulation to the heart. Micra TM Self-contained pacemaker.

[0005] An implantable medical device may include a receiving antenna comprising one or more receiving coils positioned within a portion of a housing of the device. The individual receiving coils may be made of windings that may be formed of individual electrical conductors that are individually coupled to a recharging circuit system and configured to induce current into one or more of the coil windings to provide a recharging current for recharging a power source of the implantable medical device. Configurations that may be used to arrange electrical conductors (such as multiple strands of wire) into the receiving coil of the receiving antenna include flat spirally wound coils and coils formed in the shape of an infinity symbol or a figure eight that may include coil windings formed into two or three loops. The configuration may further include a dual winding coil configuration forming a two-loop coil winding. Examples of receiving antennas as described herein provide compact and efficient receiving antenna configurations that may be positioned within a housing of an implantable medical device, including versions of miniaturized implantable medical devices, such as Micra TM Self-contained pacemaker.

[0006] In some instances, a receive coil of a receive antenna can have a curved shape corresponding to an inner surface of a housing that is a portion of an implantable medical device. In some instances, one or more receive coils can be placed in direct contact with the inner surface of the housing such that the windings of the one or more receive coils extend around and surround the longitudinal axis of the device. This arrangement of receive coils allows a high level of inductive coupling efficiency to be achieved between the one or more receive coils and an externally generated magnetic field applied to the receive coils, which can be for the purpose of providing inductive recharging of a power source (such as a battery or supercapacitor) positioned within the implantable medical device.

[0007] When it is necessary to recharge the power supply of an implantable medical device including an example of a receiving antenna configuration as described in the present disclosure, the device including the receiving antenna configuration can be placed in a magnetic field generated by an externally powered device and one or more recharging coils (or in a composite magnetic field formed by multiple magnetic fields) so that the magnetic field (or composite magnetic field) is applied to the receiving antenna configuration of the implantable medical device. The one or more magnetic fields applied to the device can be arranged to induce one or more currents into one or more coil windings of the coil windings of the receiving antenna. The one or more induced currents can be used to recharge the power supply of the implantable medical device and / or provide power for directly operating the device. The examples of receiving antennas as described in the present disclosure can provide at least a minimum level of recharging current induced into one or more coil windings of the receiving antenna for a given energy level of a magnetic field applied to a multi-axis antenna over a wide range of relative orientations between the implantable device and the direction of the one or more magnetic fields applied to the device.

[0008] In some instances, the changing magnetic field strength flux through the receiving coil contains an electromotive force (emf) that can drive a charging current for a power source for recharging purposes regardless of the orientation of the direction of one or more magnetic fields applied to the device relative to the orientation of the device and the receiving antenna. This capability can allow the use of a simplified recharging system to recharge an implantable medical device. In some instances, the recharging of an implantable medical device can be accomplished using only a single planar recharging coil that generates one or more magnetic fields or, for example, only a single pair of recharging coils that generate one or more magnetic fields to achieve rapid recharging of an implantable medical device without the need for a carefully designed orientation procedure and / or complex orientation equipment. In addition, this feature can allow the implantable device to be recharged when the exact position and / or orientation of the device may not be precisely known or may change, for example, due to movement of the device or changes in the orientation of the device after implantation and / or during a recharging session performed on the device. The receiving antenna configuration as described in the present disclosure is particularly useful in recharging a deep implantable device (e.g., a device implanted three centimeters or more than three centimeters from the nearest outer surface of the patient). As an example, a receive antenna configuration as described in the present disclosure can provide a high level of inductive coupling efficiency between one or more externally generated and applied magnetic fields applied to an implantable device that has been implanted within or external to cardiac tissue of a patient's heart, where heartbeats and other cardiac activity associated with cardiac tissue at or near the implantation site may cause the position and / or orientation of the implanted device to change or vary during a time period during which a recharging process is performed on the implanted device.

[0009] Examples described in the present disclosure relate to an implantable medical device, the implantable medical device comprising: a rechargeable power source coupled to one or more circuits positioned within a housing of the implantable medical device, the rechargeable power source configured to provide power to the one or more circuits; a receiving antenna configuration comprising at least one receiving coil, the at least one receiving coil comprising an electrical conductor forming a coil winding, the coil winding being positioned within an inner cavity surrounded by the housing of the implantable medical device, the coil winding being formed into a curved shape conforming to a curvature of an inner surface of the housing that at least partially surrounds at least a portion of the inner cavity, the coil winding being positioned adjacent to the curvature of the inner surface such that the coil winding is disposed along the at least a portion of the inner surface. The curvature is curved and positioned adjacent to the curvature, the receiving coil being configured to generate a current induced into the at least one receiving coil when an externally generated magnetic field is applied to the at least one receiving coil; and a recharging circuit system, the recharging circuit system coupled to the at least one receiving coil and to the rechargeable power source, the recharging circuit system configured to receive the current induced into the at least one receiving coil and provide a recharging current to the rechargeable power source, wherein the at least one receiving coil and the recharging circuit system are configured to provide at least a minimum level of recharging current for a given level of magnetic field strength provided by the magnetic field applied to the at least one receiving coil for multiple orientations of the magnetic field direction relative to the orientation of the implantable medical device.

[0010] Examples described in the present disclosure also include a method for forming a receive antenna configuration for an implantable medical device, the method comprising: forming an electrical conductor into at least one receive coil, the at least one receive coil comprising a first set of coil windings forming a first loop, a second set of coil windings forming a second loop, and coupling the coil windings of the first loop with the coil windings of the second loop to form the at least one receive coil into an intersection region of an infinite shape; attaching the at least one receive coil comprising the infinite shape to an inner surface of an antenna window portion of a housing of the implantable medical device such that a curvature of a longitudinal axis of the at least one receive coil conforms to a curvature of the inner surface; electrically coupling the at least one receive coil to a recharging circuit system of the implantable medical device; and coupling the antenna window to one or more additional portions of the housing to enclose the at least one receive coil and the recharging circuit system within the housing of the implantable medical device.

[0011] Examples described in the present disclosure also include a system for recharging a power source in an implantable medical device positioned within a patient's body, the system comprising: a power source; at least one recharging coil coupled to the power source and configured to generate a magnetic field having a magnetic field direction when electrically excited by the power source; a receiving antenna configuration comprising at least one receiving coil, the at least one receiving coil comprising an electrical conductor forming a coil winding, the coil winding being positioned within an inner cavity surrounded by the shell of the implantable medical device, the coil winding being formed into a curved shape conforming to a curvature of an inner surface of the shell that at least partially surrounds at least a portion of the inner cavity, the coil winding being positioned adjacent to the curvature of the inner surface such that the coil winding is bent along the curvature of the at least a portion of the inner surface and is positioned adjacent to the curvature, the receiving coil being configured to bend at an outer a recharging circuit system coupled to the receiving antenna configuration, the recharging circuit system being configured to sum the currents induced into the at least one receiving coil and generate a recharging current to recharge the power source positioned in the implantable medical device; and a switching device coupled to the multi-axis antenna and the power source of the implantable medical device, the switching device being configured to be controlled by the recharging circuit, the recharging circuit being used to couple the recharging current to the power source to recharge the electrical energy stored in the power source, wherein the at least one receiving coil and the recharging circuit system are configured to provide at least a minimum level of recharging current for a given level of magnetic field strength provided by the magnetic field applied to the at least one receiving coil for a plurality of orientations of the magnetic field direction relative to the orientation of the implantable medical device.

[0012] Examples described in the present disclosure also include a method for recharging a power source in an implantable medical device positioned within a patient's body, the method comprising: receiving, at a receive antenna configuration of the implantable medical device, a magnetic field generated by at least one recharging coil positioned outside the patient's body, wherein the magnetic field comprises one or more currents in at least one receive coil forming the receive antenna configuration, wherein at least one of the receive coils comprises a coil winding positioned within an inner cavity surrounded by the housing of the implantable medical device, the coil winding being formed into a curved shape conforming to a curvature of at least a portion of an inner surface of the housing at least partially surrounding the inner cavity, the coil winding being positioned adjacent to the curvature of the inner surface such that the coil winding is bent along and positioned adjacent to the curvature of at least a portion of the inner surface; generating one or more currents induced into the at least one receive coil when an externally generated magnetic field is received at the at least one receive coil using the receive antenna configuration; summing, by a recharging circuit system, the one or more currents to form a recharging current; and applying, by the recharging circuit system, the recharging current to the power source of the implantable medical device to recharge an energy level stored in the power source.

[0013] This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the devices and methods described in detail in the following figures and descriptions. Details of one or more aspects of the disclosure are set forth in the following figures and descriptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The details of one or more examples of the present disclosure are set forth in the accompanying drawings and the description that follow. Other features, objects, and advantages of the present disclosure will become apparent from the description and drawings, and from the claims.

[0015] Figure 1 is a conceptual diagram illustrating an example medical device system in conjunction with a patient according to various examples described in the present disclosure.

[0016] Figure 2A is a conceptual diagram illustrating an example configuration of an implantable medical device according to various examples described in the present disclosure.

[0017] Figure 2B is a conceptual diagram illustrating another example configuration of an implantable medical device according to various examples described in the present disclosure.

[0018] Figure 3A According to the various examples described in this disclosure, Figure 2A-2B A cross-sectional view of a receiving antenna configuration of an implantable medical device.

[0019] Figure 3B According to the various examples described in this disclosure, Figure 2A-2B Another cross-sectional view of a receiving antenna configuration of an implantable medical device.

[0020] Figures 4A-4B Electrical conductors configured to form a receiving coil for an implantable medical device according to various examples described in the present disclosure are shown.

[0021] Figures 5A-5C Electrical conductors configured to form a receiving coil for an implantable medical device according to various examples described in the present disclosure are shown.

[0022] Figure 5D Examples of electrical conductors configured to form a receiving coil for an implantable medical device according to various examples described in the present disclosure are presented.

[0023] Figure 6 is another cross-sectional view of an example receive antenna configuration for an implantable medical device according to various examples described in the present disclosure.

[0024] Figure 7A-7B A series of operations performed on an electrical conductor to form a receiving coil for an implantable medical device according to various examples described in the present disclosure are presented.

[0025] Figure 7C Example receive antenna configurations for implantable medical devices according to various examples described in this disclosure are shown.

[0026] Fig. 8A Cross-sectional and exploded views of example receive antenna configurations for implantable medical devices according to various examples described in the present disclosure are shown.

[0027] Figure 8B is included Fig. 8A A cross-sectional view of an implantable medical device with a receiving antenna configuration.

[0028] Fig. 9A Cross-sectional and exploded views of example receive antenna configurations for implantable medical devices according to various examples described in the present disclosure are shown.

[0029] Fig. 9B is included Fig. 9A A cross-sectional view of an implantable medical device with a receiving antenna configuration.

[0030] Fig.10 is a functional block diagram showing an intracardiac pacing device according to various examples described in the present disclosure.

[0031] Fig.11 is a schematic diagram of a receiving coil including a rechargeable power source coupled to an implantable medical device according to various examples described in the present disclosure.

[0032] Fig.12 is a functional block diagram illustrating an example configuration of a system for inductively recharging an implantable medical device according to various examples described in the present disclosure.

[0033] Fig.13 Graphs illustrating representative waveforms that may be generated by a signal generator and applied to one or more recharging coils of a recharging system according to various examples described in the present disclosure.

[0034] Fig.14 is a flowchart illustrating methods according to various examples described in the present disclosure.

[0035] Fig.15 is a flowchart illustrating another method according to various examples described in the present disclosure.

[0036] In the accompanying drawings, the use of the same reference numerals or the same reference numerals with letter extensions may be used to indicate the same or corresponding devices or elements when used in the same or different drawings. In addition, unless otherwise indicated, devices and / or other objects such as patients, implantable medical devices, or electrical devices (such as electrical coils) are not necessarily shown to scale relative to each other and / or relative to actual examples of the items shown. Specifically, the various figures provided by the present disclosure show "patients" represented by human-shaped outlines, and unless otherwise explicitly indicated in the drawings, such as by size indicators or otherwise described, such as in the text of the present disclosure, it should not be considered that it is drawn to scale relative to actual human patients or relative to other objects shown in the same figure. DETAILED DESCRIPTION

[0037] Once the device has been implanted in the patient, conventional pacemakers, neurostimulators, and implantable loop recorders can use primary batteries with limited energy as an internal power source to power the operating power of the device. In various instances of implantable medical devices, the primary (non-rechargeable) battery has a limited energy storage that limits its operating life based on its size and energy density (for a given energy usage rate). This limits the useful duration of the implanted device. Once the primary battery is exhausted, the device may need to be replaced, and although replacing the device is minimally invasive, it may still cause trauma to the patient. For example, there is a risk of pocket infection in the area of ​​the implant, which in turn may result in longer hospital stays and increased cost burdens for patients and / or insurance companies.

[0038] Additionally, limitations on available battery energy may result in limitations on therapy options for the device and / or the patient. Further, issues associated with implantable medical devices may result in the need for more energy consuming device configurations, which may further shorten the operating life of the implantable device. For example, for a certain percentage of patients, such as twenty-five percent of patients implanted with left ventricular (LV) leads, the patient does not respond to cardiac resynchronization therapy (CRT) due to suboptimal lead placement, which results in the need to apply higher levels of stimulation thresholds, resulting in excessive battery consumption and reduced implantable device life.

[0039] The use of rechargeable batteries or other rechargeable power sources that can be positioned within an implantable medical device and used to power the operation of the device is not a novel concept for overcoming the problems of primary batteries with limited energy. However, the use of rechargeable batteries or other rechargeable power sources can include additional technical challenges, particularly if the device is deeply implanted in the patient's body (e.g., more than three centimeters). Rechargeable batteries conceptually provide semi-infinite energy storage, where the size of the battery and the energy density of the charge determine the recharge frequency rather than the working life (under the assumption of negligible battery capacity decay). A result of the semi-infinite energy source is the opportunity to provide additional features and functions that may otherwise be limited or unusable under the constraints of a limited energy source. Another result of this semi-infinite energy source is the potential reduction or elimination of the need for surgical invasive device replacement procedures that need to be performed due to exhaustion of the capacity of a primary (i.e., non-rechargeable) battery.

[0040] In some instances, conventional inductive power transfer to implantable medical devices may be limited to devices implanted at a depth of about two inches or less from a patient's surface (e.g., skin). Small, deeply implanted devices (e.g., Micra TM Rapid recharging of an implantable device such as a pacemaker presents a number of challenges. These challenges include providing sufficient magnetic field strength and frequency at the implant site so that rapid recharging can be achieved without exceeding electric and magnetic field exposure safety limits for the patient, while also considering the uncontrolled orientation of the implanted device, and while considering the true spatial position of the device in addition to the device / antenna orientation.

[0041] Further, after the device is implanted, the exact orientation of the device itself may be unknown and / or may change after the implantation procedure. Therefore, implantable medical devices that include receiving antennas such as unidirectional antennas or planar antennas that may be sensitive to the alignment of the direction of an applied magnetic field with the orientation of the antenna's axis may require more elaborate procedures and / or more complex recharging equipment to achieve efficient levels of inductive coupling between the magnetic field and the receiving antenna. This requirement may require the use of more elaborate alignment procedures to align the direction of the magnetic field with the orientation of the receiving antenna, or may require the use of more complex arrangements of multiple pairs of recharging coils to achieve acceptable levels of inductive coupling efficiency between the magnetic field and the receiving antenna during the recharging procedure.

[0042] The devices, systems, and methods described in this disclosure address many of the challenges associated with recharging these power sources within implantable medical devices. The systems, devices, and methods described in this disclosure provide examples of receive antenna configurations that include one or more receive coils that can be incorporated into an implantable medical device. These receive antenna configurations can allow for recharging of small, deeply implanted medical devices such as Micra. TM In some instances, a system for recharging can use a single recharging coil, or in some instances a single pair of recharging coils, to generate a magnetic field for recharging an implantable device. A receive antenna configuration as described in the present disclosure can be arranged to generate at least a minimum level of recharging current for a given level of power applied to the receive antenna configuration by the magnetic field over a wide range of variations in the orientation of the magnetic field relative to the orientation of the implantable device. Thus, the use of a receive antenna configuration as described in the present disclosure can reduce or eliminate the need for complex alignment procedures and / or more complex arrangements of one or more recharging coils in order to achieve a minimum level of inductive coupling efficiency between an implantable medical device and one or more magnetic fields applied to the device as part of a recharging procedure.

[0043] It is thus possible to establish a directional recharging current in the receiving coil of a receiving antenna configuration as provided in an example implantable medical device as described in the present disclosure that can be independent of the recharging magnetic field applied to the receiving antenna configuration, and thus provide a high level of inductive coupling efficiency between the receiving antenna and the magnetic field applied to the device using only a single external recharging coil or only a single pair of external recharging coils for the purpose of recharging the device's power supply.

[0044] The systems, devices, and methods described herein provide a means of allowing one or more magnetic fields to efficiently induce electrical energy (e.g., current) into a receiving antenna configuration contained within an implantable medical device with minimal need for complex alignment and orientation between the receiving antenna and the magnetic field. The induced electrical energy can be used to recharge a power source of the implantable medical device using an externally provided magnetic field, and / or to power an electronic circuit system contained within or coupled to the implantable medical device, the electronic circuit system including a device that can be considered to be deeply implanted in a patient (e.g., a device implanted more than two to three centimeters below the patient's skin or external surface).

[0045] The ability to quickly recharge the power source of an implantable medical device (e.g., within a one-hour recharge period on a monthly or yearly cycle) without the need for an externally implanted device to recharge allows for at least the benefits described above, including the use of a smaller power source to help miniaturize the implantable medical device itself, and allowing more power and therefore greater functionality for the implantable medical device by using a smaller sized power source to provide an overall longer operating life for the device. An example of a receive antenna configuration for providing a recharge current in a device implanted approximately fifteen centimeters within the patient's body and for safely delivering more than 30 milliwatts of power to a rechargeable battery of an implantable device as described in the present disclosure has been shown. Such an example includes a pair of infinity-shaped receive coils positioned along the curvature of the inner surface of the antenna window portion of the housing of the implantable medical device.

[0046] Throughout this disclosure, references to a "receive coil" refer to a coil winding formed of electrical conductors that may or may not be coupled to one or more additional "receive coils" to form a receive antenna for an implantable medical device. The use of the term "receive antenna" may be used in place of or interchangeably with the term "receive coil" in any context involving a coil winding that is coupled to recharging circuitry of an implantable medical device and that may be configured to have current induced into the coil winding for the purpose of providing electrical energy to recharge a rechargeable power source of the implantable medical device and / or to provide electrical power to operate circuitry of the implantable medical device for the purpose of operating the device.

[0047] Throughout this disclosure, reference is made to a "magnetic field" in the context of one or more magnetic fields generated externally to an implantable medical device and applied to an implantable medical device for the purpose of inducing current into one or more coil windings of a receiving antenna configuration of the implantable medical device. Fig.13Examples of waveforms that can represent one or more parameters of one or more magnetic fields are shown and described. However, examples of one or more magnetic fields are not limited to having Fig.13 Throughout this disclosure, the term "magnetic field" or "magnetic fields" is used to contemplate any one or more magnetic fields having parameters (e.g., amplitude or phase) of a magnetic field that vary with time or whose magnetic field direction varies with time relative to the magnetic field so as to produce a time rate of change in the net magnetic flux intensity applied to the coil windings of the receiving antenna configuration and a corresponding change in the electromotive force (emf) configured to generate one or more currents in the one or more coil windings.

[0048] Figure 1 1 is a conceptual diagram showing an example medical device system 10 in combination with a patient 12 according to various examples described in the present disclosure. The systems, devices, and methods described in the present disclosure may include being positioned within an implanted medical device and providing for access to such internal and, in some cases, deeply implanted medical devices (e.g., reference Figure 1 Examples of a single antenna or multiple antennas for charging an IMD 15A, IMD 15B, and / or sensor circuit 18 as shown and described. For purposes of this specification, knowledge of cardiovascular anatomy is assumed, and details are omitted except to the extent necessary or desired to explain the context of the technology disclosed herein. The systems, devices, and methods described herein can provide efficient inductive coupling of an externally generated recharging power source to circuitry within the IMD 15A, IMD 15B, and / or sensor circuit 18 even when the devices are deeply implanted in a patient. The implantable device can include multi-axis antennas and / or multi-directional antennas that are not necessarily orientation-specific with respect to the inductive coupling efficiency between a receiving antenna of the device being inductively recharged and the orientation of one or more recharging coils used to provide one or more magnetic fields applied to the device for the purpose of inductively recharging a power source (such as a battery) positioned within the device. In various examples, IMD 15A and / or IMD 15B may represent an example of a defibrillator, a cardiac resynchronization pacemaker / defibrillator, or a pacemaker. Medical device system 10 typically includes facilities for interrogating these devices via wireless or other communication protocols using an external "instrument" (such as external device 11) that includes an antenna external to the patient and a software / firmware interface for collecting data.

[0049] In some existing examples of implantable medical devices, techniques for keeping the size of one or more implantable devices as small as possible include the use of planar antennas (receive / transmit antennas), such as antennas that include conductive traces printed on a planar surface (such as a substrate) disposed within the implantable medical device. One possible advantage of a planar antenna design, compared to, for example, an antenna having multiple directional axes, is that a unidirectional or planar format of the antenna may take up less space within the device and may be more easily packaged into the device when size and space are a concern. The main disadvantage associated with planar antennas may be that the efficiency of inductive coupling relative to received power transmitted from outside the patient to the receiving antenna may be orientation-specific. For example, the orientation of electromagnetic and magnetic fields applied to an implantable medical device relative to the orientation of a planar type receiving antenna within the implantable medical device (e.g., the normal axis of the orientation) may have an impact on the inductive coupling and, therefore, the efficiency of transferring power from the electromagnetic and magnetic fields to the receiving antenna.

[0050] For some implantable devices, the orientation of the implantable device and therefore the orientation of the receiving antenna within the device may not be precisely known or may be offset at a certain point in time after the device is implanted in the patient's body. This positioning offset may include the movement of the implantable device itself during the time when the recharging of the implantable device is performed. This positioning offset may be caused by the movement of tissue in the implanted area (such as cardiac activity including the heartbeat of the patient's heart) and / or the movement of the patient itself (including the movement of the patient when the patient lies down) when the patient walks, stands or changes position. When trying to inductively recharge a power source (such as a battery) positioned in an implantable medical device, this orientation change of the implantable medical device may cause problems including changes in power transfer efficiency. When the implantable device is inductively powered for the purpose of operating the device, for example, when the implantable device does not include an internal power source for operating the device and relies on inductively coupled electrical energy to power the operation of the device, similar problems may also exist.

[0051] Examples of compact receiving antennas and receiving antenna configurations as described in the present disclosure can overcome some or all of these directional issues related to coupling efficiency and recharging of implantable medical devices. For example, using a receiving antenna as described in the present disclosure within an implantable medical device can minimize or even eliminate issues related to the orientation of one or more receiving antennas relative to one or more recharging coils used to provide a magnetic field that induces current in the receiving antenna, while providing a compact antenna configuration that can be assembled within the housing of the implantable medical device. Because the examples of receiving antennas as described in the present disclosure are generally not orientation-specific, such as they may be like planar antennas, the recharging process performed on an implantable medical device having a receiving antenna configuration described herein can be performed by a single external coil (such as a planar recharging coil, a simply wound non-planar coil, a spiral planar or non-planar coil) or by a single pair of recharging coils arranged as, for example, a Helmholtz coil. Regardless of the relative orientation of the recharging coil with respect to one or more receiving antennas of the implantable medical device, a higher level of coupling efficiency can be achieved between one or more recharging coils and the receiving antenna of the implantable medical device during the recharging process, for example compared to an implantable medical device having a unidirectional antenna and the same relative orientation between the unidirectional antenna and the one or more recharging coils.

[0052] exist Figure 1 In the illustrated example, the medical device system 10 includes an implantable medical device (IMD) 15A coupled to a ventricular lead 22 and an atrial lead 21. The IMD 15A may include an example of a receive antenna or multiple receive antennas as described herein, the receive antenna or multiple receive antennas being configured to have current induced into windings of these antennas by one or more magnetic fields provided externally to the patient 12, the induced current being used to recharge a power source within the IMD 15A. In various examples, the IMD 15A is an implantable cardioverter-defibrillator (ICD) capable of delivering pacing therapy, cardioversion therapy, and defibrillation therapy to the heart 13 of the patient 12. The ventricular lead 22 and the atrial lead 21 are electrically coupled to the IMD 15A and extend into the heart 13 of the patient 12. The ventricular lead 22 includes an electrode ( Figure 1 The atrial lead 21 includes electrodes (not labeled) on the lead positioned in the right atrium (RA) of the patient 12 for sensing ventricular electrogram (EGM) signals and pacing in the RV. Figure 1 The ventricular lead 22 and / or the atrial lead 21 may also include coil electrodes for delivering cardioversion and defibrillation shocks.

[0053] The term "anti-tachyarrhythmia shock" may be used herein to refer to both a cardioversion shock and a defibrillation shock. The IMD 15A may use both a ventricular lead 22 and an atrial lead 21 to acquire electrocardiogram (EGM) signals from the patient 12 and deliver therapy in response to the acquired data. The medical device system 10 is shown as having a dual-chamber IMD configuration, but other instances may include one or more additional leads, such as a coronary sinus lead that extends into the right atrium, through the coronary sinus, and into the cardiac veins to position an electrode along the left ventricle (LV) for sensing LV EGM signals and delivering pacing pulses to the LV. In other instances, the medical device system may be a single-chamber system or otherwise not include an atrial lead 21. Although Figure 1 Not specifically shown, but in addition to or in lieu of intravascular leads 21 and 22, IMD 15A may be coupled to one or more extravascular leads, including one or more epicardial leads, substernal leads, and / or subcutaneous leads, or some combination thereof.

[0054] Processing circuitry, sensing circuitry, a receiving antenna configuration, a rechargeable power source, and other circuitry configured to perform the techniques described herein or otherwise attributed to IMD 15A can be housed within sealed housing 23. Housing 23 (or a portion thereof) can be conductive so as to serve as an electrode for pacing or sensing or as an active electrode during defibrillation. Therefore, housing 23 is also referred to herein as "housing electrode" 23. Housing 23 can include one or more electrodes having a high capacitance portion and a low capacitance portion. The high capacitance portion and the low capacitance portion can be formed using two different materials.

[0055] IMD 15A may transmit EGM signal data and cardiac rhythm episode data, as well as data related to therapy delivered by IMD 15A, to external device 11. External device 11, which may also be referred to as an "instrument," may include any of the devices described throughout this disclosure as a device positioned outside the patient's body, and in some instances may include a portion of a recharging system configured to recharge a battery or other power source disposed within IMD 15A. For example, Figure 1 The external device 11 shown in FIG. 1 may be a computing device used to communicate with the IMD 15A via wireless telemetry, for example, in a residential, outpatient, clinic, or hospital environment. The external device 11 may be coupled to a remote patient monitoring system, such as the one available from Medtronic plc of Dublin, Ireland. As examples, external device 11 may be a programmer, an external monitor, or a consumer device such as a smartphone.

[0056] External device 11 may be used, for example, when configured as a programmer for IMD 15A, to program commands or operating parameters into IMD 15A to control its operation. External device 11 may be used to interrogate IMD 15A to retrieve data, including device operating data as well as physiological data accumulated in IMD 15A memory. Interrogation may be automatic, such as on a schedule or in response to a remote or local user command. Examples of communication technologies used by IMD 15A and external device 11 may include tissue conductance communication (TCC) and / or radio frequency (RF) telemetry (which may be via RF link established), WiFi, or Medical Implant Communications Service (MICS).

[0057] like Figure 1 As shown in , the medical device system 10 may also include an intracardiac pacing device IMD 15B. IMD 15B may include an example of a receiving antenna configuration as described herein, wherein the receiving antenna configuration is configured to induce current into one or more receiving antennas through one or more magnetic fields provided externally to the patient 12, and the induced current is used to recharge the power supply within IMD 15B. In the example shown, IMD 15B is implanted in the right ventricle of the patient 12, for example, inside the heart 13 of the patient 12. In some examples, one or more IMDs such as IMD 15B ( Figure 1 ) may additionally or alternatively be implanted within another chamber of the heart 13 (such as the left ventricle) or epicardially attached to the heart.

[0058] IMD 15B may be configured to sense the electrical activity of heart 13 and deliver pacing therapy, such as bradycardia pacing therapy, cardiac resynchronization therapy (CRT), anti-tachycardia pacing (ATP therapy), and / or post-shock pacing, to heart 13. ... Figure 1 The IMD 15B may be attached to the inner wall of the heart 13 (not shown). These fixation elements may secure the IMD 15B to the cardiac tissue and retain electrodes (e.g., cathodes or anodes) on the housing of the IMD 15B in contact with the cardiac tissue. In addition to delivering pacing pulses, the IMD 15B may also be able to sense electrical signals using electrodes carried on the housing of the IMD 15B. These electrical signals may be electrical signals generated by the myocardium and indicate depolarization and repolarization of the heart 13 at different times during the cardiac cycle of the heart 13.

[0059] In some instances, IMD 15A and IMD 15B can be configured to deliver pacing therapy. In such instances, IMD 15A and IMD 15B can deliver pacing therapy to the right ventricle and / or left ventricle of heart 13, respectively, to provide CRT pacing. Additionally, IMD 15A and IMD 15B can be configured to detect tachyarrhythmias and deliver anti-tachyarrhythmia therapy. IMD 15A and IMD 15B can be configured to coordinate its cardiac rhythm detection and treatment activities. In some instances, IMD 15A and IMD 15B can carry out wireless communication between IMD 15A and IMD 15B to promote such coordinated activities. Wireless communication can be through TCC, and can be one-way communication in which one device is configured to transmit a communication message and another device is configured to receive the message or two-way communication in which each device is configured to transmit and receive a communication message.

[0060] In various instances, IMD 15B is configured to communicate directly with external device 11 wirelessly using any of the communication protocols described above with reference to IMD 15A. As an example, external device 11 can be a programmer, external monitor, or consumer device, such as a smart phone, that can be used to program commands or operating parameters into IMD 15B to control the operation of the device. External device 11 can be used to query IMD 15B to retrieve data, including device operating data and physiological data or neurological data accumulated in the memory of IMD 15B. Querying can be automatic, such as according to a schedule or in response to a remote or local user command. In some instances, communication between IMD 15B and external device 11 can occur through IMD 15A, where IMD 15B communicates with IMD 15A and IMD 15A communicates with external device 11. Examples of communication technologies used by IMD 15A and / or 15B and external device 11 are not limited to any particular communication technology or communication protocol and in some instances TCC or RF telemetry (which can be through RF link established), WiFi, or Medical Implant Communications Service (MICS).

[0061] In various examples, communications provided from IMD 15A and / or IMD 15B may include data and / or other information related to inductive charging of the devices. For example, when an electromagnetic or magnetic field is applied to IMD 15A and / or IMD 15B for the purpose of inductively charging the devices, information related to coupling efficiency of the inductive coupling to the devices and / or, for example, charging status (e.g., percentage charged relative to a full charge) may be transmitted from one or both of IMD 15A and / or IMD 15B to external device 11 as part of the recharging process. Other information such as full charge time, recharge rate, and temperature of the device may also be provided as transmitted information from the device or devices being recharged. In some instances, such information can be used to: adjust parameters, such as field strength of one or more magnetic fields used to induce energy in an antenna used to recharge IMD 15A and / or IMD 15B; adjust the relative orientation of one or more recharging coils that provide one or more magnetic fields; and / or provide information for, for example, reconfiguring electrical parameters of one or more coils used to energize fields for inductively coupled recharging of these devices.

[0062] Additionally, information may be provided by IMD 15A and / or IMD 15B indicating the level of recharging of one or both of IMD 15A and / or IMD 15B that has been achieved or completed, which level may then be used to determine when to further adjust, stop, or otherwise terminate the recharging process. For example, during the recharging process, IMD 15A and / or IMD 15B may each transmit data or other information indicating that the device has been fully recharged. The indication may then be provided by providing a field ( Figure 1 An external device (not shown) may be used to stop the charging process, which may include removing the field used to recharge IMD 15A and / or IMD 15B from being applied to these devices. In addition, because overheating of implanted devices due to the recharging process may damage the devices or pose safety issues to the patient, it may be important to monitor the temperature of these devices. Adjustments to the strength of the field applied to one or more devices and / or termination of the recharging process altogether can be made based on the monitored temperature of the device being recharged as part of the recharging process.

[0063] In various examples, one or more additional sensor circuits may be positioned external to or separately relative to IMD 15A and / or IMD 15B. These one or more additional sensor circuits are illustratively represented by sensor circuit 18. Sensor circuit 18 may include a single sensor circuit configured to sense a particular physiological parameter or neurological parameter associated with patient 12, or may include a plurality of sensor circuits that may be positioned at various and / or different locations relative to patient 12 and / or relative to each other and that may be configured to sense one or more physiological parameters associated with patient 12.

[0064] For example, sensor circuit 18 may include a sensor operable to sense the body temperature of patient 12 in the location of sensor circuit 18 or at the location of the patient where a temperature sensor is positioned by leads coupled to sensor circuit 18. In another example, sensor circuit 18 may include a sensor configured to sense motion, such as the number of steps taken by patient 12 and / or changes in positioning or posture of patient 12. In various examples, sensor circuit 18 may include a sensor configured to detect respirations taken by patient 12. In various examples, sensor circuit 18 may include a sensor configured to detect a heartbeat of patient 12. In various examples, sensor circuit 18 may include a sensor configured to measure systemic blood pressure of patient 12.

[0065] In some examples, one or more of the sensors comprising sensor circuit 18 may be implanted within patient 12 (i.e., implanted below at least the level of the patient's skin). In some examples, one or more of the sensors of sensor circuit 18 may be positioned external to patient 12, for example as part of a cuff or as a wearable device, such as a device embedded in clothing worn by patient 12. In various examples, sensor circuit 18 may be configured to sense one or more physiological parameters associated with patient 12 and transmit data corresponding to the sensed one or more physiological parameters to IMD 15A, as represented by the lightning line coupling sensor circuit 18 to IMD 15A.

[0066] In various instances, data transmission from sensor circuit 18 to IMD 15A may be performed via wireless transmission using, for example, any of the formats for wireless communication described above. In various instances, data transmission from one or more of the sensors including sensor circuit 18 to IMD 15A may be performed via a wired connection between sensor circuit 18 and IMD 15A. When sensor circuit 18 is an implantable device implanted in patient 12, one or more of the sensor circuits may include any instance of one or more receiving antennas described in the present disclosure, and the recharging techniques described throughout the present disclosure may also be used to recharge a power source (e.g., a battery) positioned within one or more implanted sensors, the power source being configured to provide power to operate the sensor and / or to provide power to operate the device.

[0067] In various examples, IMD 15A and / or IMD 15B may be coupled to an external device (eg, one or more instruments) other than or in addition to external device 11, such as Figure 1 The transceiver 16 shown in FIG. communicates wirelessly. In various examples, as shown in FIG. Figure 1 The transceiver 16 shown in FIG. 1 is used to provide IMD 15A and / or IMD 15B with a network (such as reference Fig.12 An access point for a wireless communication link between the network 237 shown and described (such as reference Fig.12 The access point 235 is shown and described. In various examples, the transceiver 16 is Fig.12 , wherein the communication circuitry of recharging circuitry 231 is configured to communicate with IMD 15A and / or IMD 15B during the recharging process of these devices, as further described below. Figure 1 Examples of communication technologies used by any of the described devices and transceiver 16 may include radio frequency (RF) telemetry (which may be via established RF link), WiFi, or Medical Implant Communications Service (MICS).

[0068] For the remainder of this disclosure, general references to medical device systems may collectively refer to any instance including medical device system 10, general references to IMD 15 may collectively refer to any instance including IMD 15A and / or IMD 15B, general references to sensor circuits may collectively refer to any instance including sensor circuit 18, general references to external devices may collectively refer to any instance of external device 11, and general references to transceivers may collectively refer to any instance of transceiver 16.

[0069] Figure 2Ais a conceptual diagram illustrating an example configuration of an implantable medical device 30 according to various examples described in the present disclosure. Figure 2A A diagram of a three-axis coordinate system 49 is included, wherein the three-axis coordinate system is included in Figure 2A The Y axis extending vertically in the middle, perpendicular to the Y axis and spanning Figure 2A An X-axis extending horizontally and a Z-axis perpendicular to both the Y-axis and the X-axis, the Z-axis extending in and out Figure 2A In the figure page. Figure 2A , the Y axis corresponds to the longitudinal axis 46 of the device 30, and any plane containing the X axis and the Z axis may be a cross-section of the device 30 taken perpendicular to the Y axis and the longitudinal axis 46. References to these axes of the three-axis coordinate system 49 may be used in the description of the device 30 and in additional figures of the present disclosure to help describe the various features and techniques described in the present disclosure related to implantable medical devices.

[0070] In some examples, device 30 is an intracardiac pacing device designed to be implanted in a chamber of a patient's heart. In some examples, device 30 is as described in reference Figure 1 The IMD 15B shown and described. The device 30 may be configured to be implanted as Figure 1 In the right ventricle of the patient's heart as depicted in or in some other chamber of the patient's heart. Figure 2A As shown and described, device 30 may be an example of an implantable medical device that includes a receive antenna 43 that may be used to provide a recharging current induced into the coil of the antenna for the purpose of recharging a power source (such as battery 39) within device 30. Device 30 may include a second antenna 44 arranged as part of the receive antenna configuration of device 30. Second antenna 44 may be used to provide some or additional recharging current induced into the coil of second antenna 44 to the circuitry of device 30 for the purpose of recharging a power source (such as battery 39) within device 30. In some examples, device 30 was developed by Medtronic plc of Dublin, Ireland. Micra TM Transcatheter pacing system.

[0071] like Figure 2A As shown in FIG. 1 , the device 30 includes a first housing portion 31, an antenna window 40, a second housing portion 36, and an end cap 34 that are coupled together to form an exterior portion of the device 30. The first housing portion 31, the antenna window 40, the second housing portion 36, and the end cap 34 may be as shown in FIG. Figure 2A30 to form a hermetically sealed housing surrounding the battery 39, receiving antenna 43, and electronic circuit system 45 of the device 30. If a second antenna 44 is included as part of the device 30, the housing may also surround the second receiving antenna. As used herein, "sealingly coupled" or "sealingly joined" refers to two or more separate pieces of material that are mechanically coupled to each other at a joint or along a seam formed to provide a hermetic seal at the joint or a seam between two or more components. Figure 2A The device 30 shown in FIG. 3 may further include an electrode 32, an electrode 33, a fixing mechanism 35, and a flange 38 including an opening 37. Each of the first housing portion 31, the second housing portion 36, and the end cap 34 may be formed of an electrically insulating material, and / or may be coated with a polymer material such as polyparaxylene (generally “PARYLENE”). In some examples, one or both of the first housing portion 31 and the second housing portion 36 may be formed of the same material (including titanium in some examples). In some examples, the end cap 34 may be formed in whole or in part of an electrically insulating material (such as a plastic material).

[0072] Although device 30 is generally described as including one or more electrodes, device 30 may generally include at least two electrodes (e.g., electrodes 32 and 33) to transmit electrical signals (e.g., a therapy such as cardiac pacing) and / or provide at least one sensing vector. Electrode 32 is carried on the portion of device 30 indicated as first housing portion 31, and electrode 33 is carried at an upper portion or distal portion of end cap 34. In the sense that electrodes 32 and 33 are not coupled to device 30 or a housing portion of device 30 by leads, the electrodes can be considered leadless electrodes. Figure 2A In an example, electrode 32 can be a ring electrode or a cylindrical electrode disposed on the outer surface of the first shell portion 31, and electrode 33 can be disposed on the outer surface of the end cap 34. Electrode 33 can be a circular electrode positioned to contact cardiac tissue when the device 30 is implanted. Electrode 33 can be used as a cathode and electrode 32 can be used as an anode or vice versa for delivering cardiac pacing, such as bradycardia pacing, cardiac resynchronization therapy (CRT), anti-tachycardia pacing (ATP) or post-shock pacing. However, electrodes 32 and 33 can be used in any stimulation configuration. In addition, electrodes 32 and 33 can be used to detect intrinsic electrical signals from myocardial tissue. When the device 30 is implanted in the patient's heart, electrode 33 can be configured to contact cardiac tissue, such as the inner wall of the right ventricle.

[0073] The fixation mechanism 35 may be arranged to attach the device 30 to the cardiac tissue. The fixation mechanism 35 may be an active fixation fork, a screw, a clamp, an adhesive member, or any other mechanism for attaching the device to the tissue. Figure 2AAs shown in the example of , the fixing mechanism 35 can be constructed of a memory material (such as a shape memory alloy (e.g., nickel titanium)) that retains a preformed shape. During implantation, the fixing mechanism 35 can be flexed forward to pierce the tissue, and then allowed to flex backward toward the second housing portion 36. In this way, the fixing mechanism 35 can be embedded in the target tissue to fix the device 30 in a suitable position relative to the target tissue. The flange 38 can be set on one end of the device 30, for example, extending from the first housing portion 31 to achieve the tethering and / or extraction of the device 30. For example, a suture or other device can be inserted around the flange 38 and / or through the opening 37 and attached to the tissue. In this way, the flange 38 can provide a second attachment structure to tie or retain the device 30 in, for example, the heart. Once the device needs to be removed (or removed) from the patient's body, if such an action is necessary, the flange 38 and / or the opening 37 can also be used to extract the device 30.

[0074] The electronic circuit system 45 (including communication and / or recharging circuit systems coupled to the receiving antenna 43) and the power source (such as the battery 39) can be enclosed within the housing of the device 30. When the second antenna 44 is provided as part of the device 30, the second antenna 44 is also electrically coupled to the electronic circuit system 45. The power source of the device 30 is not limited to any particular type of power source, and in some instances is a rechargeable battery coupled to the electronic circuit system 45 and configured to provide power to the electronic circuit system. The electronic circuit system 45 of the device 30 is not limited to any particular type or arrangement of electronic devices, and can include any one or more types of devices arranged to perform any of the functions attributed to the device 30. For example, the electronic circuit system 45 can include electronic devices configured to perform any of the patient monitoring functions and / or provide electrical stimulation therapy through the electrodes (e.g., electrodes 32 and 33) of the device 30.

[0075] The electronic circuit system 45 may further include a circuit configured to provide the device 30 with other devices (such as those described above, for example, with reference to Figure 1 The communication circuitry of device 30 may utilize a receive antenna 43 for transmitting signals transmitted from device 30 and for receiving signals transmitted to device 30 from one or more devices external to device 30. In other examples, device 30 includes a separate telemetry antenna ( 43 ) coupled to the communication circuitry of device 30 and for receiving and transmitting wireless communications to and from device 30, respectively. Figure 2A Not shown, but for example Figure 3A Antenna 67 shown in FIG.

[0076] Reference again Figure 2A, the receiving antenna 43 can be configured to receive electrical energy applied to the device 30 in the form of one or more magnetic fields and use the energy from these fields inductively coupled to the receiving antenna 43 to recharge the battery 39, which can also be referred to as wireless power transfer. In order to achieve a high level of inductive coupling efficiency between the receiving antenna 43 and the one or more magnetic fields applied to the device 30 for the purpose of recharging the battery 39, the receiving antenna 43 can be arranged as a multi-directional antenna that allows current to be induced into the receiving antenna 43 when a magnetic field that can have a magnetic field direction oriented in one of various possible orientations relative to the orientation of the device 30 is applied to the receiving antenna, for example, arranged as an infinite loop coil as described in the present disclosure. Examples of "receiving coils" including but not limited to infinite loop coils configured as one or more receiving antennas of an implantable medical device (such as the device 30) as described throughout the present disclosure can provide a high level of inductive coupling efficiency between the receiving antenna configuration and the magnetic field applied to the implanted device over a wide range of changes in the relative orientation between the one or more magnetic field directions of the one or more applied magnetic fields and the orientation of the implanted device.

[0077] like Figure 2A , the receiving antenna 43 is positioned within the device 30 in alignment with a portion of the antenna window 40 and, in some instances, surrounded by the portion of the antenna window. The receiving antenna 43 can be attached to the ferrite sheet, or can be attached directly to a portion of the inner surface of the antenna window 40. The receiving antenna 43 and / or the ferrite sheet (when provided) can have a height dimension 48 corresponding to the orientation of the longitudinal axis 46. The antenna window 40 can extend along the Y axis and surround the Y axis so that the inner cavity 53 extending along the Y axis (longitudinal axis 46) of the device 30 has a circular cross-sectional shape and has a diameter corresponding to the longitudinal axis 46. Figure 2A The shaped body is formed in the shape of a right cylinder having a height of the longitudinal dimension 47 shown in FIG.

[0078] When the receiving antenna 43 is configured to have a winding of an antenna formed in a curved shape corresponding to the curvature of the inner surface of the antenna window 40, additional space is provided within the inner cavity 53 in a portion of the cavity not occupied by the receiving antenna 43, such as an area around the center of the inner cavity. The additional space can be used for one or more additional antennas configured to provide additional inductive current for recharging and / or operating the device 30, such as the second antenna 44. The additional space can also be used for additional antennas (such as the second antenna 44) that can be configured to support transmission and reception of wireless communications between the device 30 and other devices external to the device 30. Figure 2AExamples of receive coils and arrangements of these receive coils as one or more receive antennas for improving inductive recharging of an implantable device may provide a compact and efficient arrangement of one or more antennas to allow recharging of the device, wherein these antennas and antenna configurations are implemented in a smaller size implantable device while eliminating or minimizing directional issues that may exist in similar devices utilizing unidirectional antennas or a single planar receive antenna.

[0079] As further described below, the antenna window 40 can be formed of a material (e.g., a material having a high value relative to resistivity) that allows electromagnetic energy applied to the device 30 for recharging purposes to be transmitted to penetrate and pass through the antenna window 40 and reach the receiving antenna 43 and the second antenna 44 when the second antenna is set. The antenna window 40 can be referred to as being formed of a "radio-transmissive" material that also provides a low relative dielectric constant (i.e., a high relative resistivity) and a low magnetic permeability. Resistivity can be represented by the Greek letter ρ (rho), and in the International System (SI), the units are measured in ohm-meters (Ω-m), and the resistivity can vary for a given material based on temperature. An example of a material (such as certain metals) that can be considered a good electrical conductor and therefore has a low resistivity value is copper, which has a ρ value of approximately 1.68×10 at 20 degrees Celsius (°C). -8 Ω-meter. Examples of materials that can be considered to be poor electrical conductors and therefore have high ρ values ​​(e.g., electrical insulators) can include glass, which has a ρ value in the range of 1×10 10 to 1×10 14 Ω-meter. Another example of a material with a high ρ value is sapphire, which in some instances has a ρ value in the range of 1×10 14 Ω-cm. Examples of materials with low dielectric constant, high resistivity, and low magnetic permeability that can be used for portions of the housing that contain the receive antenna configuration according to the examples described in the present disclosure can include titanium alloys of grades 5, 9, 23, 36 that can provide adequate radio transmittance levels at lower frequencies (such as up to 200KHz) or ceramic materials that can provide radio transmittance at these lower frequencies and at frequencies above the 200kHz frequency range (e.g., a frequency range up to 10MHz). Metal ceramics made using a metal injection molding process can also be used for a wide range of frequencies similar to the operating frequency range of ceramics.

[0080] To allow the higher frequency magnetic field to penetrate the housing of the device 30 and reach the receiving antenna 43, at least the antenna window 40 portion of the device can be formed of a material (e.g., sapphire) that has a high resistivity value at least at temperatures typically experienced by the device after implantation in a patient that may occur when the device is recharged (e.g., temperatures that do not typically exceed 39 to 40° C. on the outer surface of the implanted device, even for a short period of time). To allow the use of higher frequency magnetic fields for the purpose of recharging the device 30, the antenna window 40 can be formed of a material having a high resistivity (e.g., in the range of 1×10 11 to 1×10 16 ohm-cm) and low magnetic permeability. A wide range of materials will meet these requirements, including commonly used examples such as sapphire, glass materials or polymer materials with a dielectric constant ranging from about 1 to 12. Relative to other materials that may not provide the same level of resistivity or high resistivity values, the use of sapphire or glass materials for antenna window 40 can allow higher frequencies of the induced magnetic field to be transmitted through antenna window 40 and applied to receiving antenna 43. For example, by using an antenna window 40 made of sapphire, a magnetic field with a frequency range of about 100KHz to 10MHz can be applied to device 30, wherein sapphire allows one or more applied magnetic fields with frequencies within this range to pass through antenna window 40 and induce current in the electrical conductors that form the windings of receiving antenna 43.

[0081] The ability to use a higher frequency magnetic field allows more energy, and therefore a greater current, to be induced into the electrical conductors forming the windings of the receiving antenna 43 at any given time or for a particular period of time during which the higher frequency is applied to the device 30 compared to using a lower frequency magnetic field. The antenna window 40 is not limited to being formed from a visually transparent material. Examples of materials for forming the antenna window 40 may include any type of material having a minimum resistivity value (e.g., a good electrical insulator with a low dielectric constant value) and a low magnetic permeability and meeting other manufacturing requirements and complying with any other applicable regulatory requirements for use with an implantable medical device (e.g., biocompatibility requirements).

[0082] In a similar manner as described above with reference to antenna 43, second antenna 44 (when provided as part of device 30) may also be positioned within antenna window 40 and, for example, surrounded by the antenna window. When one or more externally generated and applied magnetic fields are applied to second antenna 44, currents may be induced into electrical conductors forming windings of second antenna 44. In some examples, second antenna 44 is a unidirectional antenna that will have a maximum level of current generated in electrical conductors forming windings of the second antenna for a given level of magnetic field strength when the direction of the magnetic field applied to the second antenna is aligned with a normal axis of the second antenna. The normal axis is typically a line perpendicular to a plane or a set of coplanar planes in which the windings of the second antenna lie.

[0083] In some examples, the positioning of the second antenna 44 and the directional orientation of the normal axis of the second antenna 44 can be arranged to allow the normal axis of the second antenna to be aligned with a direction of a magnetic field applied to the device 30 that would otherwise provide a lower level of inductive coupling efficiency associated with the orientation of the receiving antenna 43. As a result, the second antenna 44 can be able to provide a higher level of induced current to the electronic circuit system 45, as would be provided based on the induced current level that can be provided by the receiving antenna 43 alone for the specific orientation of the magnetic field induced to the device 30 at any specific time. In other words, the second antenna 44 is specifically oriented within the device 30 to have the most efficient inductive coupling level with a magnetic field having a magnetic field orientation that does not necessarily efficiently provide some higher or most efficient inductive coupling level with the receiving antenna 43. Therefore, the combination of the receiving antenna 43 and the second antenna 44 allows for a wide range of orientations of the magnetic field direction of the magnetic field applied to the device 30 that still produces some minimum current level induced into the combination of the receiving coils forming the receiving antenna 43 and the second antenna 44.

[0084] The electronic circuit system 45 of the device 30 coupled to each of the receiving antenna 43 and the second antenna 44 may include a device such as a diode ( Figure 2A 43 and the second antenna 44 for a given level of magnetic field strength applied to the device.

[0085] like Figure 2A, the first housing portion 31 (which may also be referred to as a "battery housing") is sealingly coupled to the antenna window 40 at a first seam 41. The antenna window 40 is sealingly coupled to the second housing portion 36 of the device 30 at a second seam 42. The antenna 43 can be positioned within the portion of the device 30 surrounded by the antenna window 40. The electronic circuit system 45 can be positioned within the portion of the device 30 surrounded by the second housing portion 36. In some examples, one or more components of the electronic circuit system 45 can also be positioned within a portion of the interior cavity 53 to take advantage of the space provided by positioning the receiving antenna 43 around the periphery of the inner surface of the antenna window 40. The end cap 34 can be sealingly coupled to the end of the second housing portion 36 opposite the end of the second housing portion 36 coupled to the antenna window 40.

[0086] Examples of antenna window 40 are not limited to being formed of a material different from the first housing portion 31 and / or different from the second housing portion 36. In some examples, antenna window 40 and second housing portion 36 may be formed of the same material (e.g., sapphire) that is a different material from that used to form first housing portion 31. In some examples, first housing portion 31 and second housing portion 36 are formed of the same material (e.g., titanium or a titanium alloy) and may be formed as separate components that are sealingly joined together using antenna window 40 as a coupling component. In various examples, first housing portion 31, antenna window 40, and second housing portion 36 may be formed of a biocompatible ceramic material.

[0087] As further described below, instances of the receiving antenna 43 may be configured as a multi-axis antenna or a multi-directional antenna. In this way, regardless of the relative orientation of the device 30 and the orientation of the one or more applied magnetic fields, or at least over a wide range of the relative orientation and the orientation, the direction (e.g., the orientation of the one or more applied magnetic fields to the receiving antenna 43) can effectively provide a minimum level of inductive coupling between the antenna and the one or more magnetic fields. In other words, the receiving antenna 43 itself may not be orientation-specific relative to the specific orientation of the field applied to the device 30 for the purpose of inductive power transfer that can be used to recharge the battery 39. For example, for some instances of the receiving antenna configuration included in the device 30, any angle of the direction of the magnetic field applied to the device 30 can induce a certain current level in the receiving antenna 43 for a given level of magnetic field strength applied to the device 30 and therefore also applied to the receiving antenna 43. In some instances, due to the multi-directional configuration of the receiving antenna 43, a specific angle of the magnetic field direction of the magnetic field applied to the device may not be associated with inducing a minimum current level in the receiving antenna 43 for a given energy level of one or more magnetic fields.

[0088] In some instances, various other aspects of the device 30 itself, such as interference with the transmission of one or more magnetic fields produced by the first housing portion 31 and / or the second housing portion 36, or, for example, by materials used to form a portion of the device 30 (e.g., titanium material used to form a cover for the battery 39), may produce lower levels of induced currents when the magnetic field is applied at certain angles relative to the device 30 as compared to other angles used to apply the magnetic field to the device. For an implantable medical device, certain angles of the direction of the magnetic field applied to the device may cause interference with the inductive coupling of the magnetic field with the device's multi-directional antenna as compared to other angles of the direction of the magnetic field that may be applied to the device, and some level of one or more currents may still be induced into the device's receiving antenna, but may, for example, provide a lower level of induced current. In such a case, a feedback signal provided by the device having a multi-directional antenna and indicative of the level of one or more induced currents generated by the receiving antenna may be used to redirect the direction of the magnetic field applied to the device relative to the device. Based on the monitoring feedback signals, different relative angles between the implantable device and the direction of the magnetic field can be arranged, for example by moving the positioning of one or more recharging coils providing the magnetic field and / or repositioning the patient relative to one or more transmitting coils, and thereby providing a better level of inductive coupling between the magnetic field and one or more receiving antennas of the implantable device.

[0089] Based on the ability of the receive antenna 43 to provide at least a minimum level of induced current from the receive antenna for a given power level of the magnetic field applied to the receive antenna regardless of the incident (orientation) angle of the magnetic field within a range determined by other physical factors related to the device itself, a specific orientation or a narrow limited range of orientations between the receive antenna 43 and the direction of the incident magnetic field applied to the receive antenna 43 is not required. The minimum current level can be induced into one or more of the receive coils of the multi-directional receive antenna 43 regardless of the specific orientation of the incident magnetic field and the relative orientation of the receive antenna to the one or more magnetic fields. Because the minimum level of recharging current can be induced into the receive antenna of the device without the need for elaborate or complex alignment procedures to direct the magnetic field to a specific orientation of the device and the receive antenna, this feature is useful when performing a recharging operation on an implantable device that includes a multi-directional antenna within the device. For deeply implanted devices whose exact orientation may not be known or whose positioning may have shifted or may actually shift during a recharging session of the device, the feature of not having to precisely determine this relative orientation can allow the use of less expensive, less complex and less time consuming techniques to efficiently recharge a power source positioned within the implanted device.

[0090] Although the example of inducing current as described above has been described with reference to recharging a power source positioned within the device, the receiving antenna configuration and the features of transferring induced power to the device via current induced in one or more receiving antennas of the receiving antenna configuration of the implanted device may also be applied when inducing current into the receiving antenna configuration for the purpose of providing power to directly power the operation of the implanted device itself, such as in a passive device that can operate only when powered by an external power source and may not include a rechargeable power source (such as a battery) that can continue to power the device once the externally provided magnetic field is no longer applied to the device. One advantage of a passive device is that because a rechargeable power source is not required, the space typically occupied by such a rechargeable power source is not required, and may therefore allow for further miniaturization relative to the overall size required for the housing of the device.

[0091] like Figure 2A As shown in FIG. 1 , a power source (battery) 39 occupies a portion of the device 30, such as the first housing portion 31. The receiving antenna 43 is positioned within the interior space surrounded by the antenna window 40, and the electronic circuit system 45 is positioned substantially within the interior space of the device 30 formed by the second housing portion 36. Examples of the arrangement of components within the housing of the device 30 are not limited to the following. Figure 2A , and other arrangements of devices and components included in device 30 are contemplated for use with the multi-directional receive antenna configurations described in this disclosure. Figure 2A , the receiving antenna 43 is arranged proximate to the inner surface of the antenna window 40. The second antenna 44 (when provided) may be a planar antenna formed on a substrate such as a ferrite sheet and positioned in a central portion of the area forming the inner cavity 53 surrounded by the antenna window 40. An electrical conductor may extend from the receiving coil of one or more receiving antennas and be electrically coupled to one or more terminals of the electronic circuit system 45 and / or the battery 39.

[0092] In some examples of device 30, first housing portion 31, antenna window 40, and second housing portion 36 may not be separately formed components, but may be one component of a housing that is formed of the same type of material and sealingly coupled to end cap 34 to form a hermetically sealed housing of device 30. In such examples, antenna window 40 is not provided as a separate piece of material, but is considered to be formed of the same material that forms one piece of material that forms the housing portion of device 30. Device 30 is not limited to devices having a housing of any particular shape. Figure 2A, for any plane perpendicular to the longitudinal axis 46 that passes through the first housing portion 31, the antenna window 40, and the second housing portion 36, the device 30 has a generally circular cross-sectional shape along the longitudinal axis 46. In some examples, the diameter of the circular cross-sectional shape of the device is about six millimeters. However, the device 30 is not limited to having a circular cross-sectional shape as described above, and the cross-section of a portion of the device 30 relative to the longitudinal axis 46 may have other shapes, including a rounded square shape, a rounded rectangular shape, or an elliptical shape.

[0093] like Figure 2A As shown in , the shape of the device 30 can allow the device 30 to be delivered to the implantation site (such as the interior portion of the chamber of the patient's heart) by a tubular-shaped delivery tool (such as a catheter). The desire to keep the device 30 as small as possible to allow such delivery and implantation techniques while still providing sufficient levels of functionality and features and acceptable levels of on-board power available from a power source (such as battery 39) may limit the space available for one or more receiving antennas within the device itself. The receiving coils and arrangements of the receiving coils that form one or more receiving antennas as described in the present disclosure provide a compact arrangement for a receiving antenna configuration that can not only be packaged into these miniature types of implantable medical devices, but also still solve many problems related to inductive coupling efficiency and directional problems related to the directionality of the orientation of one or more receiving antennas and devices during the recharging process performed on the device after implantation. Additional examples of multi-directional receiving antenna configurations that can be set as receiving antennas 43 and one or more additional antennas (such as second antenna 44) in implantable medical devices (such as device 30) and systems and techniques for recharging these devices are further illustrated and described below.

[0094] Figure 2B is a conceptual diagram showing another example configuration of an implantable medical device 30A according to various examples described in the present disclosure. Figure 2B As shown in FIG. 1 , the implantable medical device 30A includes the same Figure 2A The same or similar components of the implantable medical device 30 shown and described above are described below as variations of the implantable medical device 30A. These same or similar components of the implantable medical device 30A are retained for identification purposes. Figure 2A The same reference numerals are used for corresponding components of implantable medical device 30 in FIG. 1 , with any exceptions being further described below.

[0095] like Figure 2BAs shown in FIG. 1 , the implantable medical device 30A includes a first housing portion 31 that at least partially surrounds a battery 39 and includes an electrode 32, a flange 38, and an opening 37. A second housing portion 36 at least partially surrounds an electronic circuit system 45 and is coupled to an end cap 34 at one end of the second housing portion. The end cap 34 includes an electrode 33 and a fixing mechanism 35. Figure 2B As shown in FIG. 1 , the end of the second housing portion 36 opposite the end cap 34 is not used to form an antenna window at the seam 42 (as shown in FIG. 1 ). Figure 2A In the case of the intermediate and separate material piece of the antenna window 40 shown and described, it is “sealingly coupled” directly to the end of the first housing portion 31 opposite the flange 38 .

[0096] like Figure 2B As shown in , the receiving antenna 43 is at least partially surrounded by a portion of the second housing portion 36 that forms the inner cavity 53A. In addition, in the example of the implantable medical device 30A provided with the second antenna 44, the second receiving antenna can also be positioned relative to the receiving antenna 43 to be at least partially surrounded by the second housing portion 36. Figure 2B , the inner cavity 53A of the implantable medical device 30A in which the receiving antenna 43 (and the second antenna 44 when provided) is located is located within and at least partially surrounded by the second housing portion 36, and some remaining portion of the second housing portion 36 at least partially surrounds the electronic circuit system 45. Thus, the second housing portion 36 is formed of a material (such as sapphire) that allows energy in the form of a magnetic field applied to the implantable medical device 30A from a source external to the device 30A to pass through the second housing portion 36 and be applied to the one or more receiving antennas contained within the inner cavity 53A of the second housing portion 36 as described above.

[0097] The second housing portion 36 is not limited to being formed of any particular material, and may be formed of any type of one or more materials that allow a magnetic field to pass through the second housing portion at a certain frequency or within a certain range of frequencies and at a strength level required to generate an induced current to one or more receiving antennas positioned within the inner cavity 53A. In addition to the example of using sapphire, in other examples, the second housing portion 36 may be formed of a biocompatible ceramic material or glass material that still allows a higher frequency (e.g., 100kHz to 10MHz) magnetic field to pass through the second housing portion and be applied to a receiving coil (such as the receiving antenna 43 and / or the second antenna 44). For lower frequency applications (e.g., magnetic fields with a frequency of 200kHz or less), the second housing portion may be formed of a material (including a titanium alloy) that allows magnetic fields with these lower frequencies to pass through the second housing portion and be applied to a receiving coil (such as the receiving antenna 43 and / or the second antenna 44).

[0098] Seam 42 is used to "sealingly couple" second housing portion 36 to first housing portion such that first housing portion 31, second housing portion 36, and end cap 34 form a hermetically sealed housing for components contained within implantable medical device 30A. Seam 42 is not limited to any particular type of seam formed using any particular technique for forming a seam, and may include any type of seam suitable for joining together the type of material or materials used to form first housing portion 31 and second housing portion 36. In some examples, by not using a separate antenna window section (e.g., a portion containing antenna window 40) when forming a housing for implantable medical device 30A, Figure 2A The overall length dimension of implantable medical device 30A along longitudinal axis 46 may be reduced compared to implantable medical device 30A of the same embodiment. The smaller longitudinal dimension of implantable medical device 30A may provide advantages with respect to a smaller space in which the device may be implanted and / or with respect to a reduced effect on the flow of fluids (e.g., blood flow) around or in the area of ​​the patient in which the device is implanted.

[0099] For several examples of receive antenna configurations including one or more receive coils positioned within an implantable medical device described throughout the remainder of this disclosure, the one or more receive antennas are described as being positioned within an antenna window (e.g., Figure 2A The antenna window 40 of the implantable medical device 30 is partially surrounded by and / or attached to the antenna window. However, unless otherwise specifically described, any of these receive antenna configurations and any equivalents thereof may be disposed within the lumen 53A and at least partially surrounded by the antenna window 40 of the implantable medical device 30 as described above with reference to the reference antenna. Figure 2B The illustrated and described implantable medical device 30A is disposed within a second housing portion 36 of the implantable medical device in the same or similar manner as described above.

[0100] Figure 3A According to the various examples described in this disclosure, Figure 2A 4. Although described with reference to the device 30 having the antenna window 40, as will be described below with reference to Figure 3A One or more of the described receiving antenna configurations may also be provided in a configuration not including the device as described above. Figure 2B In the device shown and described 30A) a separate antenna window is part of the housing. For example, the following reference Figure 3A The one or more receiving antennas described above may be attached to Figure 2B A portion of the second housing portion 36 is shown and described as being positioned within that portion of the second housing portion.

[0101] Figure 3A The cross-sectional view AA in FIG. 1 is viewed from a plane cut through the device 30 at the midpoint of the antenna window 40 along the longitudinal axis 46 of the device 30, wherein the longitudinal axis is perpendicular to the plane cut through the device. Figure 3A In the cross-sectional view AA shown in FIG. 1 , the device 30 is shown viewed in the same direction as the orientation of the Y axis, wherein the X axis extends in a left-right (horizontal) orientation and the Z axis extends in an up-down (vertical) orientation in the view. Figure 3A As shown in , the antenna window 40 includes an outer surface 50 having a circular cross-section, and an inner surface 51 also having a circular cross-section positioned within the outer surface 50, such that the wall thickness 52 of the antenna window 40 surrounds the Y axis (and the longitudinal axis 46) of the device 30, thereby surrounding and at least partially enclosing the cylindrical inner cavity 53. The dimension value of the wall thickness 52 can range from 0.15 to 0.5 mm. The dimension value of the radius 54 extending from the center point of the Y axis of the inner cavity 53 to the inner surface 51 can range from 2 to 10 mm. The antenna window 40 can extend along the Y axis and around the Y axis, so that the inner cavity 53 is formed along the Y axis (longitudinal axis 46) and has a shape corresponding to the shape of the inner cavity 53. Figure 2A The interior surface 51 of the right cylindrical shape extends within the height of the longitudinal dimension 47 shown in FIG.

[0102] Reference again Figure 3A , one or more receiving coils forming a receiving antenna of device 30 can be positioned within interior cavity 53 of antenna window 40. For example, receiving coil 55 can be positioned adjacent to a portion of inner surface 51 of antenna window 40. Receive coil 55 can be electrically coupled to the recharging circuitry ( Figure 3A Not shown, but for example Fig.10 ) and is configured to induce a current into the coil winding of the receive antenna when one or more magnetic fields are applied to the receive antenna. For the purpose of inducing the recharging current into the coil winding of the receive coil 55, the one or more magnetic fields applied to the receive coil 55 may be provided by the external recharging circuit system ( Figure 3A Not shown, but for example Fig.12 The external recharging circuit system 231 in the embodiment of the present invention generates and is generated by the recharging coil ( Figure 3A Not shown, but for example Fig.12 The receiving coil 55 may be formed by an electrical connector (e.g., a recharging coil 232 and / or a recharging coil pair 232, 233) that is shaped to form a conductor having electrical connections that are electrically coupled to each end of the electrical conductor forming the receiving coil. Figure 3AThe coil winding of the electric conductor (such as a wire or a plurality of electric conductors) is formed. It can be used to form Figure 3A Examples of coil windings for the receiving coil 55 in the configuration shown in FIG. 5 include those shown in FIG. Figures 4A-4B The coil winding 70 shown and described and as referenced Figure 5A A single loop receive coil 90 is shown and described. The current induced in the coil windings of receive coil 55 may be provided to recharging circuitry of device 30 for the purpose of recharging power from a power source located within or electrically coupled to device 30, as further described below.

[0103] like Figure 3A As shown in , the receiving coil 55 is positioned on the ferrite sheet 56 so that the curved shape of the receiving coil 55 conforms to the curved shape of the ferrite sheet 56. The curved shapes of the receiving coil 55 and the ferrite sheet 56 conform to the curvature of the inner surface 51 of the antenna window 40 over an angular range 62 extending from a first radial position 60 to a second radial position 61 around the inner surface 51. The first radial position 60 is separated from the second radial position 61 along the inner surface 51 by a certain angle value of the angular range 62. The angular value of the angular range 62 can range from 30 to 180 degrees. As shown in FIG. Figure 3A As shown in FIG. 1 , the first side of the ferrite sheet 56 is attached to the inner surface 51 of the antenna window 40 along the portion of the inner surface 51 extending between the first radial location 60 and the second radial location 61. The ferrite sheet 56 may also have a height dimension 48 ( 100 ft ) extending in a direction corresponding to the orientation of the Y axis. Figure 2A )(For example, from Figure 3A The pages in the figure look inwards and extend outwards. Figure 3A As shown in FIG. 1 , the receiving coil 55 is positioned adjacent to a second side of a ferrite sheet 56, the second side of the ferrite sheet 56 being opposite to and separated from the first side of the ferrite sheet by a thickness dimension 57 of the ferrite sheet 56. The dimensional value of the thickness dimension 57 of the ferrite sheet 56 may range from 0.01 to 5 millimeters.

[0104] Further, the material used to form the ferrite sheet is not limited to a particular type of material, and in some instances is a ferrite material including a compound that includes iron oxide and may be combined with a nickel compound, a zinc compound, and / or a manganese compound. The ferrite material may be referred to as a "soft ferrite" having a low coercivity (magnetization in the material can be easily reversed in direction without generating a large level of hysteresis losses) and having a high resistivity that helps reduce eddy currents flowing in the material. The ferrite sheet may include one or more material layers, including a polyethylene terephthalate (PET) layer as a first surface of the ferrite sheet and an adhesive layer on a second surface of the ferrite sheet opposite the first surface.

[0105] The electrical conductors forming the receiving coil 55 may be arranged so that each of the individual windings of the electrical conductors forming the receiving coil 55 is located within the same curved planar region having a thickness dimension 58 extending across the entire area occupied by the coil windings. In some examples, the thickness dimension 58 may be a thickness value of the electrical conductor itself, such as a cross-sectional diameter of the electrical conductor used to form the windings of the receiving coil 55. In some examples, portions of the windings of the electrical conductors used to form the receiving coil 55 may cross or overlap each other, and at these portions of the receiving coil 55, the thickness dimension 58 may be greater than the thickness dimension at other portions of the receiving antenna. For example, the thickness dimension 58 at a portion of the receiving coil where the electrical conductors cross or overlap may be equal to or slightly greater than the thickness of each of the overlapping electrical conductors combined together. In other examples, the windings of the electrical conductors used to form the receiving coil 55 may include multiple layers of windings stacked one on top of another in a direction extending away from the ferrite sheet 56. When the electrical conductors forming the receive coil 55 are stacked one on top of another, the thickness dimension 58 of the receive coil 55 may have a value approximately equal to the thickness of the individual windings combined.

[0106] Regardless of the actual value of the thickness 58 across the area occupied by the windings forming the receiving coil 55, the contour of the windings conforms to the contour of the ferrite sheet 56 and, therefore, to the contour of the inner surface 51 of the antenna window 40 over the angular extent 62 and in the height dimension 48 ( Figure 2A ) in a direction corresponding to the Y axis (and longitudinal axis 46) of device 30. In the example where receiving coil 55 is attached to ferrite sheet 56, the outermost winding of the electrical conductor forming the receiving antenna may extend to a position slightly smaller than the outer edge of ferrite sheet 56. For example, Figure 3A, the uppermost portion of the ferrite sheet 56 near the first radial location 60 extends slightly further along the inner surface 51 of the antenna window 40 relative to the uppermost portion of the receiving coil 55 closest to the first radial location 60. Similarly, the lower portion of the ferrite sheet 56 near the second radial location 61 extends slightly further along the inner surface 51 of the antenna window 40 relative to the lower portion of the receiving coil 55 closest to the second radial location 61. In addition, the outermost extension of the winding forming the receiving coil 55 relative to the Y-axis (e.g., the longitudinal axis 46) of the device 30 can be in the height dimension 48 ( Figure 2A ) in the direction of the receiving coil 55 to a distance slightly less than the corresponding dimension of the ferrite sheet 56, thereby maintaining these portions of the receiving coil 55 within the area defined by the second surface of the ferrite sheet 56 to which the windings forming the receiving coil 55 are attached.

[0107] Based on Figure 3A In the configuration of the receiving coil 55 shown in FIG. 1 , the electrical conductors forming the windings of the receiving antenna can provide a minimum level of inductive coupling current for a given level of magnetic field strength induced by one or more magnetic fields having a large change in magnetic field direction applied to the receiving coil. For example, when the magnetic field applied to the receiving coil has a value of Figure 3A The receiving coil 55 can provide a high level of inductive coupling when any of the magnetic field directions indicated by arrows 63 in FIG. 5 is in the magnetic field direction, and thus provides a minimum level of induced current generated in the receiving coil for a given level of magnetic field strength. Figure 3A As shown in , the magnetic field direction can include a magnetic field having an orientation pointing toward the Y-axis of the device 30 and an angular orientation extending anywhere between the first radial location 60 and the second radial location 61 .

[0108] like Figure 3A , any magnetic field applied to the receive coil 55 having a magnetic field direction coplanar with a plane containing the X-axis and Z-axis of the device 30 at the antenna window 40 and the angular orientation between the first radial location 60 and the second radial location 61 will provide a minimum level of inductive coupling efficiency between the applied magnetic field and the receive coil 55. In other words, due at least in part to the curved configuration of the receive coil 55, the coupling efficiency of the receive coil 55 with respect to one or more magnetic fields applied to the receive coil is not unidirectional and may provide the same or similar level of inductive coupling efficiency with one or more magnetic fields applied to the receive coil over a range of relative orientations of the magnetic fields as illustratively represented by arrow 63.

[0109] In addition to magnetic fields having magnetic field directions that are coplanar with the X-axis and Z-axis as described above, the receiving coil 55 may also provide the same or similar levels of inductive coupling efficiency as magnetic fields having magnetic field directions that are not coplanar with the X-axis and Z-axis of the device relative to the device 30. For example, a magnetic field having a magnetic field direction that is not perpendicular to the Y-axis (longitudinal axis) and intersects the plane containing both the X-axis and Z-axis of the device at some angle other than zero degrees may also provide the same or similar levels of inductive coupling efficiency between the magnetic field and the receiving coil 55 as compared to the level of inductive coupling efficiency achieved for the coplanar magnetic field represented by arrow 63. For more extreme angles of incidence, such as magnetic field directions that intersect the plane of the X-axis and Z-axis at an angle greater than, for example, 45 degrees above the plane, the level of coupling efficiency may be reduced to a level less than that achieved for a magnetic field having a magnetic field direction that is within the range indicated by arrow 63 but is also perpendicular to the Y-axis.

[0110] In some examples, the incident angle of the magnetic field direction can include an incident angle perpendicular to a plane containing both the X-axis and the Z-axis of device 30, such as an incident angle of the magnetic field that is co-linear with the orientation of the Y-axis (longitudinal axis 46) of device 30. For some of these non-coplanar orientation angles between the magnetic field and device 30, portions of device 30 (such as Figure 2A The first shell portion 31, the second shell portion 36 and / or the end cap 34 shown in the figure can reduce the overall inductive coupling efficiency level for the orientation angle between the magnetic field and the receiving coil 55 at some larger incident angles (for example, incident angles that are more closely aligned with the Y-axis (longitudinal axis) of the device 30).

[0111] As described above, the magnetic fields represented by arrows 63 and the angle of incidence of these magnetic fields as described above generally vary from the outer region to the inner region. Figure 3A The left side of the device shown in FIG. 5 is directed toward the device 30. Therefore, the direction of the magnetic field can pass through the ferrite sheet 56 before reaching the receiving coil 55. Figure 3A Positioning the ferrite sheet 56 on one side of the receive coil 55 as shown in , results in an overall level of inductive coupling between the magnetic field and the receive coil 55 that is greater than that achieved for the same magnetic field strength in the absence of the ferrite sheet. Additionally, a magnetic field having a magnetic field direction such that the magnetic field is applied to the receive coil 55 without first passing through the ferrite sheet 56 can still induce similar current levels into the coil windings of the receive coil 55.

[0112] For example, Figure 3A As shown in Figure 3AA range of incident angles of a magnetic field with a magnetic field direction extending between the third radial location 60A and the fourth radial location within the angular range 62A shown in FIG. 6A may also be applied to the receiving coil 55. The third radial location 60A, the fourth radial location 61A, and the angular range 62A may represent a mirror image of the first radial location 60, the second radial location 61, and the angular range 62, but are arranged on the opposite side of the Z axis relative to these corresponding elements ( Figure 3A In addition to the orientation angle of the magnetic field represented by arrow 63A which may be located in a plane containing both the X-axis and the Z-axis, other incident angles which are not perpendicular to the Y-axis as described above with reference to arrow 63 may also be set as the magnetic field direction represented by arrow 63A.

[0113] Because the change in angle of incidence represented by arrow 63A may not pass through ferrite sheet 56 before being applied to receiving coil 55, the overall inductive coupling level achieved for a given level of magnetic field strength may be less than the level achieved for the same level of magnetic field strength having a corresponding but opposite magnetic field direction represented by arrow 63. For certain directions of the applied magnetic field (such as a magnetic field having a direction illustratively represented by arrow 64 and / or arrow 64A), lower or no induced current levels may be generated in the coil windings forming receiving coil 55. However, a high or sufficient level of inductive coupling efficiency may still be achieved between receiving coil 55 and a magnetic field having a magnetic field direction represented by arrow 63A, thereby further increasing the overall range of magnetic field directions that may be applied to device 30 and produce sufficient inductive coupling levels between the device and one or more magnetic fields to provide efficient recharging of a rechargeable power source located within the device. This feature further reduces the need to achieve a specific orientation or a narrow range of relative orientations between the receiving antenna of device 30 and the direction of the magnetic field applied to the device while still achieving sufficient levels of inductive coupling efficiency during a recharging session performed on the device.

[0114] In some embodiments of the device 30, an additional receiving coil or a second receiving coil 65 is also positioned within the lumen 53. Figure 3A , the receiving coil 65 may be a flat planar coil or a spirally wound planar coil. The receiving coil 65 may be a unidirectional antenna having a normal axis oriented corresponding to the orientation of the Z axis of the device 30 and having windings located in a plane or a set of coplanar planes coplanar with a plane containing both the X axis and the Y axis of the device 30. Figure 3A As shown in , the receiving coil 65 can be positioned at a distance offset relative to the center point of the inner cavity 53. In addition, the coil winding forming the receiving coil 65 can extend at least partially into the region of the inner cavity located on the left hand side of the arc 69 drawn between the first radial location 60 and the second radial location 61. Figure 3A The proportions, positioning, and relative spacing between the receive coil 65 and the receive coil 55 shown in are intended as non-limiting examples, and other sizes and types of coil configurations for the receive coil 65 and alternative physical positioning of the receive coil 65 within the lumen 53 are possible and contemplated by the examples of the device 30 as described in the present disclosure.

[0115] like Figure 3A 3 , the receive coil 65 can be attached to a ferrite sheet 66 on the side of the receive coil 65 that faces the upper portion of the view in FIG. 3 . In various examples, the ferrite sheet 66 can include a thickness dimension 66A, with the thickness of the ferrite sheet ranging from 0.01 to 5 millimeters. In other examples, the receive coil 65 can be attached to some other type of substrate, such as a circuit board or other type of insulating material. In still other examples, the coil windings of the receive coil 65 are not attached to any type of additional sheet or substrate and are self-supporting within the inner cavity 53. As shown in FIG. Figure 3A , magnetic fields having magnetic field directions illustratively represented by arrow 64 that are perpendicular to the Y axis (longitudinal axis) and aligned with the orientation of the Z axis are also aligned with the normal axis of the receiving coil 65. Additionally, these same magnetic fields having magnetic field directions illustrated by arrow 64 will pass through ferrite sheet 66 before being applied to the receiving coil 65. Due to the alignment between the orientation of arrow 64 and the normal axis of the receiving coil 65, a high level of inductive coupling efficiency can be achieved between the magnetic field having the magnetic field direction indicated by arrow 64 and the receiving coil 65. The placement of ferrite sheet 66 (when provided) can further increase the level of inductive coupling efficiency achieved between the magnetic field having the magnetic field direction indicated by arrow 64 and the receiving coil 65.

[0116] The change in the orientation of the magnetic field direction, illustrated by arrow 64, relative to the radial orientation of the magnetic field direction while maintaining a perpendicular orientation relative to the Y axis is illustratively represented by arrow 64B. Additional changes in the orientation of the magnetic field direction, illustrated by arrow 64, may also produce relative arrows 64 that have non-perpendicular orientations relative to the Y axis and intersect a plane containing both the X axis and the Z axis at some non-zero angle. While these changes in the relative orientation of the direction of the magnetic field, represented by arrow 64B, potentially reduce the level of inductive coupling efficiency that is initially achieved between the magnetic field and the receiving coil 65, some level of inductive coupling and, therefore, some level of induced current in the receiving coil 65 may still be provided.

[0117] In a similar manner, magnetic fields having magnetic field directions illustratively represented by arrow 64A that are perpendicular to the Y axis (longitudinal axis) and aligned with the orientation of the Z axis of device 30 are also aligned with the normal axis of receive coil 65. While these same magnetic fields having magnetic field directions demonstrated by arrow 64A will not pass through ferrite sheet 66 prior to being applied to receive coil 65, the magnetic fields can provide a high level of inductive coupling efficiency between the magnetic field having the magnetic field direction indicated by arrow 64A and receive coil 65. Variations in the direction of the orientation of the magnetic field, as represented by arrow 64C, and variations in the direction of the orientation of arrow 64A that can include orientations that are not perpendicular to the Y axis or a plane that includes both the X axis and the Z axis, can still provide some level of inductive coupling and, therefore, some level of induced current in receive coil 65.

[0118] like Figure 3A As shown in , the placement and orientation of the second receiving antenna in the lumen 53 of the device 30 can provide a certain level of inductive coupling between the receiving coil 55 and a magnetic field having an orientation as described above with reference to arrows 64, 64A and which is not necessarily a better orientation with respect to inductive coupling efficiency. Therefore, the range of changes in the direction of the magnetic field that provide a certain minimum induced current level for a given level of magnetic field strength can be increased while still maintaining a compact arrangement of the receiving antennas within the device 30. This compact arrangement with a wide range of angles over which high levels of inductive coupling efficiency can be achieved is particularly suitable for allowing efficient and safe recharging of power supplies contained within small implantable medical devices (such as device 30), especially when the orientation is unknown or a constant orientation is not necessarily maintained. The same benefits also apply when a magnetic field is applied to a device (such as device 30) for the purpose of powering the operation of the device from the current induced into one or more receiving antennas. The use of only two receive coil windings forming receive coils 55 and 65 also reduces to two sets the number of components required to provide rectification and summing of one or more currents that may be induced into these coils during a recharging session performed on device 30, thereby minimizing the amount of space and circuit real estate required to perform these functions. Further, as Figure 3A The receiving antenna configuration including the curved-shaped receiving coil 55 shown in the figure allows the receiving antenna configuration of the device to be encapsulated within a device having, for example, a circular cross-section, at least for example at the portion of the device including the antenna window 40, so that the device can be advanced through and / or implanted using a tubular-shaped delivery tool (such as a catheter).

[0119] In various examples of the device 30, the receiving coil 55 and / or the second receiving coil 65 can also be configured to operate as a telemetry antenna to allow wireless communication signals to be transmitted from and received by one or more antennas of the implanted device. Figure 3AThe telemetry antenna 67 can be positioned within the inner cavity 53 and surrounded by the antenna window 40 to allow wireless communication signals between the device 30 and one or more external devices ( Figure 3A Not shown, but for example Figure 1 The telemetry antenna 67 may be coupled to a substrate 68 (such as a circuit board or ceramic substrate), or in the alternative, may be configured as a self-supporting structure.

[0120] Figure 3B According to the various examples described in this disclosure, Figure 2A Another cross-sectional view of the receiving antenna configuration of the implantable medical device 30. Figure 3B The examples of implantable medical devices 30 shown and described may include reference Figure 3A Any of the examples and variations of one or more implantable medical devices shown and described, but the following description is intended to Figure 3B Further, although described with reference to the device 30 having the antenna window 40, as will be described below with reference to Figure 3B One or more of the described receiving antenna configurations may also be provided in a configuration not including the device as described above. Figure 2B In the device shown and described 30A) a separate antenna window is part of the housing. For example, below with reference to Figure 3B The one or more receiving antennas described above may be attached to Figure 2B A portion of the second housing portion 36 is shown and described as being positioned within that portion of the second housing portion.

[0121] like Figure 3B As shown in FIG. 4 , the device 30 includes a ferrite sheet 56 attached to a portion of the inner surface 51 of the antenna window 40 and a receiving coil 55 attached to a surface of the ferrite sheet 56 opposite to the surface of the ferrite sheet 56 attached to the inner surface 51. Figure 3A Compared with the example of the ferrite sheet shown in FIG. 5 and the receiving coil 55, as shown in FIG. Figure 3B The ferrite sheet and receiving coil shown in FIG. Figure 3A The angle range 62 shown in FIG. 6 extends around the angle range 62C of the inner surface 51 which is much larger than the angle range 62C shown in FIG. The angle range 62C may have an angle value ranging from 180 to 360 degrees. Figure 3B Examples of coil windings that can be used to form the receiving coil 55 include Figure 5B-5C The infinitely large coil winding 90 shown in FIG. Figure 5D1. The current induced in the coil windings of the receiving coil 55 may be provided to the recharging circuitry of the device 30 for the purpose of recharging power from a power source located within or electrically coupled to the device 30, as further described below.

[0122] like Figure 3B As shown in , the ferrite sheet 56 extends along the inner surface 51 from the second radial position 61 to the fourth radial position 61A. The receiving coil 55 extends along the surface of the ferrite sheet 56 opposite the surface of the ferrite sheet 56 attached to the inner surface 51 of the antenna window 40, and in some instances has an angular range that is equal to or slightly less than the angular range 62C of the ferrite sheet. The extension of the infinitely shaped coil winding or dual winding coil configuration used to form the receiving coil 55 places the loops of these coil windings in different planes relative to each other, and thereby allows the magnetic field applied to the ether loop of the coil to provide a current generated in the coil winding that can be used to recharge the power supply of the device and / or power the operation of the device. As shown in FIG. Figure 3B As shown in FIG. 6 , the arrangement of the ferrite sheet 56 positioned between the antenna window 40 and the receiving coil 55 can be directed to a magnetic field having a magnetic field direction over a range indicated by the angle range 62C. Figure 3B The ferrite sheet / receive coil assembly shown in FIG. 5 provides a "preferred orientation" that in some examples may extend 360 degrees around the Y axis around the entire inner surface 51. This may include magnetic fields having magnetic field directions that are perpendicular and / or non-perpendicular to the Y axis of device 30 over an angular range 62C as illustratively represented by arrows 63, 64, and 63A.

[0123] exist Figure 3B In the example shown in , the coil windings forming the receive coil 55 can be formed as an infinitely shaped coil winding or a dual winding coil configuration, with the longitudinal axis formed in a curved shape to conform to the curvature of the surface of the ferrite sheet to which the receive coil is attached. Thus, the "preferred orientation" of the ferrite sheet receive coil assembly including the receive coil 55 can extend over the entire angular range 62C. Thus, the benefits of the increased level of magnetic field coupling efficiency imparted to the assembly by using the ferrite sheet 56 can be achieved in applications where the receive coil is applied such as Figure 3B The receiving antenna configuration of the device 30 shown in the figure is achieved over a wide range of magnetic field directions of the magnetic field.

[0124] like Figure 3BAs further shown in FIG. 6 , an example of a device 30 having a ferrite sheet 56 and a Reeve coil 55 arrangement extending over an angular range 62C may also include one or more additional receive coils that may also be attached to one or more ferrite sheets and coupled to the recharging circuitry of the device 30 to further enhance a level of inductive coupling efficiency achieved by applying one or more magnetic fields to the device. For example, an additional receive coil 69A attached to a ferrite sheet 69B may be positioned as shown in FIG. Figure 3B 30 is shown in the inner cavity 53 of the device 30. In some examples, the receiving coil 69A can be a flat spiral wound coil. Because the ferrite sheet 69B is attached to the receiving coil 69A facing the Figure 3B 62C, so the ferrite sheet 69B and the receiving coil 69A can be considered to have a "preferred orientation" that favors inductive coupling with a magnetic field having a magnetic field direction pointing toward the bottom side of the device 30 as illustratively represented by arrow 64A. Because this bottom portion of the device 30 can include areas that are not necessarily within the angular range 62C and therefore do not necessarily provide a preferred orientation relative to the receiving coil 55, the addition of the ferrite sheet 69B and the receiving coil 69A can enhance the overall level of one or more currents induced into the receiving antenna configuration of the device 30 through magnetic sensation having a magnetic field orientation outside of the angular range 62C, for example. Thus, the addition of the receiving coil 69A can increase the variation in the orientation of the direction of the magnetic field that can be applied to the device and still provide a minimum level of one or more induced currents into the receiving antenna configuration of the device.

[0125] like Figure 3B As shown in FIG. 6 , some examples of device 30 include a receiving coil 65 attached to a ferrite sheet 66 in addition to or in lieu of the ferrite sheet 69B and receiving coil 69A in device 30. In some examples, the receiving coil can be formed as a flat spirally wound coil. As shown, the ferrite sheet 66 and receiving coil 65 have a configuration that is advantageously aligned with the receiving coil having a direction as illustratively represented by arrow 64. Figure 3B The addition of receive coil 65 can further increase the variation in one or more orientations of one or more directions of the magnetic field that can be applied to device 30 and still provide a minimum level of one or more induced currents into the receive antenna configuration of the device.

[0126] like Figure 3BAs shown in , ferrite sheets 56, 66, and 69B can be formed from one or more of the materials described above for ferrite sheets, including compounds of iron oxide that may or may not be mixed with some other metal or compound. In some examples, one or more of these ferrite sheets can include a flexible material that can be bent or otherwise formed into some non-planar shape for the sheet. In some examples, one or more of the receiving coils 55, 65, and 69A can also operate as one or more telemetry antennas to provide wireless communication to and from device 30. In other examples, in addition to Figure 3B In addition to the receiving coil shown in Figure 3B ) is also included in the device 30.

[0127] Figures 4A-4B An electrical conductor 71 configured to form a receiving coil 70 for an implantable medical device according to various examples described in the present disclosure is shown. Figure 4A , the electrical conductor 71 is formed into a coil winding having a substantially rectangular shape. The outermost winding of the electrical conductor 71 extends along a length dimension 74 and along a width dimension 75. The length dimension 74 has the same orientation as the orientation of a longitudinal axis 76 extending across the receiving coil 70 parallel to the length dimension 74. The first end of the electrical conductor 71 is electrically coupled to a first lead 72. The second end of the electrical conductor 71 is electrically coupled to a second lead 73. The first lead 72 and the second lead 73 can extend to the receiving coil 70 and connect the receiving coil to the recharging circuit system of the implantable medical device (in Figure 4A Not shown, but for example Fig.10 This allows the current induced into the receiving coil 70 by one or more magnetic fields applied to the receiving coil 70 to be used to recharge the power supply of the implantable medical device coupled to the receiving coil or to power the operation of the circuit system of the device.

[0128] like Figure 4AAs shown in , the windings of the receiving coil 70 extending from the first lead 72 form the outermost windings of the receiving coil, wherein additional windings are progressively formed within the previous windings as the electrical conductor 71 extends toward the second lead 73. Therefore, the overall thickness dimension of the receiving coil 70 (e.g., the thickness dimension of the receiving coil 70 that is orthogonal to both the length dimension 74 and the width dimension 75) can be the thickness of the diameter of the electrical conductor 71. In other words, the coil windings of the receiving coil 70 can be configured as a flat wound coil having a generally rectangular shape in the length dimension and the width dimension. The changes in the shape of the coil windings of the electrical conductor 71 can include corners that change the direction of the electrical conductor from the longitudinal direction to the transverse direction, including rounded corner shapes or curved shapes, as illustratively shown by the corner radius 78. Further, the number of turns or windings included in the receiving coil 70 is not limited to a specific number of turns, and in some examples includes ten turns, wherein each turn includes a portion of the four-sided winding of the electrical conductor forming the receiving coil 70.

[0129] like Figure 4A As shown in FIG, the first lead 72 and the second lead 73 are coupled to the electrical conductor 71 at the same corner of the coil winding, so that the first lead 72 and the second lead 73 extend from the coil winding in close proximity to each other. However, the positioning of the first lead 72 and the second lead 73 is not limited to any particular arrangement, such as Figure 4A In some examples, leads 72 and 73 may extend from other locations of the coil winding of receive coil 70, including extending first lead 72 and second lead 73 from different portions of the coil winding such that the leads do not extend from portions of the receive coil that are immediately adjacent to each other.

[0130] The electrical conductor 71 is not limited to being formed of any particular type of material, and may be formed of a conductive metal (such as copper) that is easily formed into a wire and that can be easily bent to form the desired shape of the coil windings for forming the receiving coil 70. In some instances, the electrical conductor used to form the receiving coil 70 may include an insulating material (such as enamel) coated on the outer surface of the conductor to provide an insulating layer between the individual coil windings. In various instances, the electrical conductor used to form the receiving coil 70 is a multi-strand conductor (such as Litz wire), wherein the electrical conductor used to form each winding is insulated along the outer surface of the electrical conductor, for example, using a coating (such as enamel) to reduce the skin effect of the electrical conductor. The skin effect is a property of current flowing through an electrical conductor that causes the flow of current in the electrical conductor to travel through the outer portion (e.g., the "skin" of the conductor) rather than through the inner portion of the electrical conductor. At higher frequencies, the skin effect is more pronounced. The use of Litz wire helps to reduce the skin effect in the electrical conductor at higher frequencies.

[0131] The instance of the receiving coil 70 may be retained as in Figure 4A and used as a receiving antenna in an implantable medical device, for example as shown in reference Figure 3A-3B The receiving coil 65 of the implantable medical device 30 is shown and described. In other examples, the receiving coil 70 can be formed into a curved shape, as described below with reference to Figure 4B When formed into a curved shape, the receiving coil 70 may or may not be attached to the ferrite sheet and is positioned so that the curvature of the receiving coil 70 corresponds to the inner surface 51 of the antenna window 40 of the implantable medical device 30, thereby forming, for example, a reference Figure 3A The receiving coil 55 of the implantable medical device 30 is shown and described.

[0132] like Figure 4B , the receive coil 70 is curved along the length of the longitudinal axis 76 such that the length dimension 74 of the receive coil forms a corner radius 78. The amount of curvature along the longitudinal axis 76 can correspond to the curvature of the inner surface 51 on the antenna window 40 of the device 30, such that the receive coil 70 can be attached along a portion of the inner surface 51 of the antenna window 40 and positioned directly adjacent to the portion. Figure 3A In the example of the ferrite sheet 56 shown and described, a certain amount of curvature of the receiving coil 70 is formed so that the receiving coil 70 can be attached to a surface of the ferrite sheet, and the surface of the ferrite sheet opposite the surface to which the receiving coil is attached can be attached to contact with and directly adjacent to a portion of the inner surface 51 of the antenna window 40, as shown by Figure 3A The positioning of the receiving coil 55 is shown in FIG.

[0133] In the example where the receiving coil 70 is not attached to the ferrite sheet, the receiving coil 70 may be arranged along a Figure 4B , and is attached to be in direct contact with and directly adjacent to the inner surface 51 of the antenna window 40 of the device 30. Whether the receive coil 70 is attached to the inner surface 51 through the ferrite sheet or directly to the inner surface, the curvature of the receive coil 70 is configured so that the ferrite sheet and the receive coil or a separate receive coil can be positioned to be in contact with and directly adjacent to the curved portion of the inner surface 51 of the antenna window.

[0134] Figures 5A-5C An electrical conductor 91 configured to form a receiving coil 90 for an implantable medical device according to various examples described in the present disclosure is shown. Figure 5AAs shown in FIG. 1 , the electrical conductor 91 is formed into a coil winding having a circular or elliptical shape. A first end of the electrical conductor 91 is electrically coupled to a first lead 92 and a second end of the electrical conductor 91 is electrically coupled to a second lead 93. The first lead 92 and the second lead 93 may be configured to extend to the receiving coil 90 and connect the receiving coil to the recharging circuit system (in the implantable medical device) of the implantable medical device. Figure 5A Not shown, but for example Fig.10 This allows the current induced into the receiving coil 90 by one or more magnetic fields applied to the receiving coil 90 to be used to recharge the power supply of the implantable medical device coupled to the receiving coil or to power the operation of the device's circuit system.

[0135] like Figure 5A As shown in FIG. 1 , the windings of the receiving coil 90 extending from the first lead 92 form the outermost windings of the receiving coil, wherein additional windings are gradually formed within the previous windings as the electrical conductor 91 extends toward the second lead 93. Therefore, the overall thickness dimension of the receiving coil 90 (e.g., the thickness dimension of the receiving coil 90) can be the thickness of the diameter of the electrical conductor 91. In other words, as Figure 5A The coil windings of the receive coil 90 shown in the figure can be configured as a flat wound planar coil having a generally circular or elliptical shape. The number of turns or windings included in the receive coil 90 is not limited to a specific number of turns, and in some examples includes ten turns, wherein each turn includes a portion of an electrical conductor forming a generally circular or elliptical winding of the receive coil.

[0136] like Figure 5A As shown in FIG. 1 , the first lead 92 and the second lead 93 are coupled to the electrical conductor 91 at the same relative location of the respective coil windings to which these leads are attached, so that the first lead 92 and the second lead 93 extend from the coil windings in close proximity to each other. However, the positioning of the first lead 92 and the second lead 93 is not limited to any particular arrangement, such as Figure 5A In some examples, leads 92 and 93 may extend from other locations of the coil winding of receive coil 90, including extending first lead 92 and second lead 93 from different portions of the coil winding such that the leads do not extend from portions of the receive coil that are immediately adjacent to each other.

[0137] The electrical conductor 91 is not limited to being formed of any particular type of material, and may be formed of any type of electrical conductor described above with reference to the electrical conductor 71, including conductive metals such as copper, that is easily formed into a wire and can be easily bent to form a desired shape for forming the coil windings of the receiving coil 70. In some examples, the electrical conductor 91 may be formed of a conductive metal such as copper. Figure 5AThe electrical conductor of the receiving coil 90 in the embodiment may include an insulating material (such as enamel) coated on the outer surface of the conductor to provide an insulating layer between the individual coil windings. In various examples, the electrical conductor used to form the receiving coil 90 is a multi-strand conductor (such as Litz wire), wherein the electrical conductor used to form each winding is insulated along the outer surface of the electrical conductor, for example using a coating (such as enamel) to reduce the skin effect of the electrical conductor.

[0138] like Figure 5A The receiving coil 90 shown in FIG. 1 can be manipulated to include a single half twist of a portion of the receiving coil 90 so that the receiving coil is formed as shown in FIG. Figure 5B The shape of the infinite loop shown in . Figure 5B , the windings of the electrical conductor 91 form a first loop 94 and a second loop 96 coupled to the first loop at a crossover region 95. The winding of the receiving coil 90, whose end is coupled to the first lead 92, extends from the first lead 92 and around the outermost winding of the first loop 94, and then reaches the crossover region 95. This same winding extends from the crossover region 95 to form a portion of the winding contained in the second loop 96 before returning to the crossover region 95 again. The windings of the receiving coil 90 continue to form a progressive series of windings that form a portion of the winding in the first loop 94, extend to the crossover region 95, and form a winding in the second loop 96 before returning to the crossover region 95 again until reaching the end of the conductor 91 coupled to the second lead 93. The total number of turns formed by the windings passing around the first loop 94, through the crossover region 95, and around the second loop 96 is not limited to any particular number of turns, and some examples may be ten turns.

[0139] The receiving coil 90 in the infinite loop shape is firstly as follows Figure 5A In the example of a circular or elliptical winding shape as shown in FIG, all electrical conductors 91 aligned in intersection region 95 may be above or below all other portions of electrical conductors 91 that are aligned with each other and pass through the intersection region. For example, all portions of electrical conductors 91 that are surrounded by dashed ellipse 98 and that are aligned with each other when entering and leaving intersection region 95 are above all conductors surrounded by dashed ellipse 99 (e.g., in FIG. Figure 5B Thus, the thickness dimension of the infinity-shaped coil at the intersection region 95 may be greater than the thickness dimension of the combined two or more portions of the electrical conductor 91 .

[0140] As first, the receiving coil 90 is formed as follows Figure 5A The single loop shown in and then twisted to form Figure 5B An alternative to the portion of the loop of the infinitely shaped coil shown in, Figure 5B The infinitely shaped coil may be initially wound in a figure-eight pattern to form the infinitely shaped coil. In various instances of winding the figure-eight pattern to form the infinitely shaped coil, the winding in the outermost winding of the electrical conductor 91 around the first loop 94 may be arranged as the innermost winding of the electrical conductor 91 around the second loop 96. The routing of the electrical conductor 91 may continue in a manner such that the second outermost portion of the electrical conductor 91 within the first loop 94 continues like the second innermost portion of the electrical conductor 91 formed within the second loop 96. By continuing to use this outermost to innermost pattern relative to the first loop 94 and the second loop 96 to alternatively form the windings of the receiving coil 90, the thickness of the winding at the intersection region 95 may be maintained to not exceed the thickness dimension of two windings in the combined winding of the electrical conductor 91. Therefore, this pattern may provide a flatter or less thick coil winding in the portion of the electrical conductor 91 that crosses each other within the intersection region 95.

[0141] Whether the receive coil 90 is formed into an infinitely shaped coil by twisting a circular or elliptical shaped coil or by winding the receive coil in a figure eight pattern, the receive coil 90 can then be formed as shown in reference Figure 5C The curved shape shown and further described. When formed into Figure 5C When the receiving coil 90 is in a curved shape, the receiving coil 90 may or may not be attached to the ferrite sheet and is positioned so that the curvature of the receiving coil 90 corresponds to, for example, the inner surface 51 of the antenna window 40 of the implantable medical device 30, thereby forming, for example, a reference Figure 3B The receiving coil 55 of the implantable medical device 30 is shown and described.

[0142] like Figure 5C , the receiving coil 90 is bent along the length of the longitudinal axis 100 so that a curved shape 97 is formed corresponding to the longitudinal dimension of the longitudinal axis 100 of the receiving coil. A certain amount of curvature along the longitudinal axis 100 can correspond to the curvature of the inner surface 51 on the antenna window 40 of the device 30, so that the receiving coil 90 can be attached along a portion of the inner surface 51 of the antenna window 40 and be positioned directly adjacent to the portion. When the receiving coil 90 is attached to the ferrite sheet (such as, for example, reference Figure 3B In the example of the ferrite sheet 56 shown and described, a certain amount of curvature of the receiving coil 90 is formed so that the receiving coil 90 can be attached to a surface of the ferrite sheet, and the surface of the ferrite sheet opposite the surface to which the receiving coil is attached can be attached to contact with and directly adjacent to a portion of the inner surface 51 of the antenna window 40, as shown by Figure 3B The positioning of the receiving coil 55 is shown in FIG.

[0143] In the example where the receiving coil 90 is not attached to the ferrite sheet, the receiving coil 90 may be arranged along a Figure 5C 1 and is attached to be in direct contact with and directly adjacent to the inner surface 51 of, for example, the antenna window 40 of the device 30. Whether the receiving coil 90 is attached to the inner surface 51 via the ferrite sheet or directly to the inner surface, the curvature of the receiving coil 90 is configured so that the ferrite sheet and the receiving coil or a separate receiving coil can be positioned to be in direct contact with the inner surface 51 of the antenna window or as shown in reference Figure 2B The curved portion shown and described, for example, of the inner surface 51 of the second housing portion 36 is in contact with and directly adjacent to the curved portion.

[0144] Figure 5D Examples of electrical conductors configured to form a receiving coil for an implantable medical device according to various examples described in the present disclosure are shown. Figure 5D As shown in FIG. 1 , the first electrical conductor is formed into a first coil winding indicated by bracket 103, the first electrical conductor having a first end 103A at one end of the coil winding and a second end 103B at an end of the electrical conductor opposite the first end 103A. The first coil winding can be made of any type of electrical conductor, including conductive wire (such as Litz wire) as described throughout this disclosure. The first coil winding can be made in the same manner as in reference 104. Figure 4A The coil 70 shown and described is formed in a similar or identical manner to that described.

[0145] like Figure 5D As shown in FIG. 1 , the first electrical conductor is formed into a second coil winding indicated by bracket 104, the second electrical conductor having a first end 104A at one end of the coil winding and a second end 104B at an end of the electrical conductor opposite to the second end 103B. The first coil winding can be made of any type of electrical conductor, including conductive wire (such as Litz wire) as described throughout this disclosure. The second coil winding can be made of the same type as described in reference 104. Figure 4A The illustrated and described coil 70 is formed in a similar or identical manner as described. The type of material used, overall dimensions, and number of turns used to form the second coil winding are the same or similar to the type of material used, overall dimensions, and number of turns used to form the first coil winding.

[0146] The first coil winding and the second coil winding can be attached to a ferrite sheet or a separate ferrite sheet, wherein the ferrite sheet can then be attached to the inner surface of the inner cavity of the implantable medical device. The inner surface of the inner cavity of the implantable medical device can form a curved surface, wherein the first coil winding and the second coil winding can be positioned adjacent to each other so that a longitudinal axis extending through each of the first coil winding and the second coil winding extends around or along the periphery of the inner surface and conforms to the curvature of the inner surface of the implantable medical device (illustratively represented by the double-headed arrow 106). The curvature separates the two loops of the dual-winding coil configuration into separate planes, and thus allows the dual-winding coil configuration to generate an induced current when a magnetic field is applied to one or both of the coil windings.

[0147] The second end 103B of the first coil winding is electrically coupled to the second end 104B of the second coil winding. In some examples, the connection coupling the second end 103B to the second end 104B can be on a circuit board or hybrid substrate ( Figure 5D ), thereby allowing each of the first coil winding and the second coil winding to be coupled together before or after the coil has been attached to the appropriate position within the housing of the implantable medical device. Figure 5D As shown in FIG. 1 , the second end 103B of the first coil winding extends to form the outermost winding of the first coil winding, and the innermost winding of the second coil winding extends to the second end 104B directly coupled to the second end 103B. The first end 103A of the first coil winding and the first end 104A of the second coil winding are configured to be coupled to the recharging circuit system (as shown in FIG. Fig.10 Recharging circuit system 206) as shown and described.

[0148] like Figure 5D The first coil winding and the second coil winding shown in can be referred to as a dual-winding coil configuration forming a two-loop coil winding. Figure 5D The dual winding coil configuration shown and described may be included in place of one or more infinity shaped coils in any of the receive antenna configurations described throughout this disclosure. Figure 5D The dual winding coil configuration shown in the reference Figure 3B The infinitely shaped receiving coil 55 shown and described. Figure 5D The pair of double winding coil configurations shown in the reference Figures 8A-8BA pair of infinity shaped receive coils 164, 174 are shown and described. In the same manner as described above with reference to the use of infinity shaped coil windings, the dual winding coil configuration can provide a recharging current induced into one or both of the coil windings when a magnetic field is applied to the dual winding coil configuration from a variety of different magnetic field directions relative to the orientation of the dual winding coil configuration, as long as the two loops of the dual winding coil configuration are positioned in different planes relative to each other.

[0149] Figure 6 FIG. 2 is another cross-sectional view AA of an example receive antenna configuration for an implantable medical device 30 according to various examples described in the present disclosure. Figure 6 In, with reference to e.g. Figure 3A Items having the same reference numerals as those shown and described correspond to the same or similar items and may contain any of the features and provide the same as those for Figure 3A Although described with reference to the device 30 having the antenna window 40, as described below with reference to Figure 3A One or more of the described receiving antenna configurations may also be provided in a configuration not including the device as described above. Figure 2B In the device shown and described 30A) a separate antenna window is part of the housing. For example, below with reference to Figure 6 The one or more receiving antennas described above may be attached to Figure 2B A portion of the second housing portion 36 is shown and described as being positioned within that portion of the second housing portion.

[0150] like Figure 6 The example of the device 30 shown in FIG. 1 includes a device 30 as shown in FIG. Figure 3A The receiving coil 55 and the ferrite sheet 56 are arranged along a portion of the inner surface 51 of the antenna window 40 in the same or similar manner as shown and described. The receiving coil 55 can include any single loop coil winding formed in any of the coil winding configurations for the coil windings of the curved shape described throughout the present disclosure, including as described in reference Figures 4A-4B The receiving coil 70 shown and described and as referenced Figure 5A The single loop coil version shown and described. Figure 6 The example of the device 30 shown in FIG. 1 also includes a Figure 3A A receiving coil 65 is attached to a ferrite sheet 66 and a telemetry antenna 67 is coupled to a substrate 68 in the same or similar manner as shown and described. Figure 6In the example of the device 30 shown in FIG. 1 , each of the receiving coil 55, the receiving coil 65 and the telemetry antenna 67 can be, for example, referenced to the device 30 and Figure 3A Any of the example configurations shown and described are arranged and provided, and may be configured to perform any of the functions and provide functions attributed to the apparatus 30 and Figure 3A any of the features of .

[0151] In addition, if Figure 6 As shown in , the device 30 includes a second curved shaped receiving coil 112 attached to a ferrite sheet 111. The ferrite sheet 111 is attached to a portion of the inner surface 51 extending between a third radial location 113 and a fourth radial location 114 of the inner surface of the antenna window 40. The ferrite sheet 111 is in contact with and directly adjacent to the portion of the inner surface 51 extending between the third radial location 113 and the fourth radial location 114, so that the surface of the ferrite sheet 111 forms a curved surface corresponding to the curvature of the inner surface 51 in the area extending between the third radial location 113 and the fourth radial location 114. The thickness dimension 118 of the ferrite sheet 111 can have the same value as the value of the thickness dimension 57 of the ferrite sheet 56. The receiving coil 112 is attached to the surface of the ferrite sheet 111 opposite to the surface of the ferrite sheet 111 in contact with the inner surface 51. Receive coil 112 is also bent to form a curvature of the windings forming receive coil 112 that conforms to the curvature of inner surface 51 between third radial location 113 and fourth radial location 114. Thickness dimension 117 of receive coil 112 may have the same or similar value as thickness dimension 58 of receive coil 55.

[0152] In some examples, the receiving coil 112 may not be attached to the ferrite sheet (eg, Figure 6 111) and may instead be directly attached to the inner surface 51 of the antenna window 40 in an area of ​​the inner surface extending between the third radial location 113 and the fourth radial location 114. The receiving coil 112 may include any single loop coil winding formed in any of the coil winding configurations for the coil windings of the curved shape described throughout the present disclosure, including as described in reference Figures 4A-4B The receiving coil 70 shown and described and as referenced Figure 5A A single loop coil version is shown and described. Figure 6 In some examples of the apparatus 30 shown in , the receiving coil 112 is configured using the same arrangement of coil windings used to form the coil as used to form the receiving coil 55. In other examples, the configuration of the coil windings used to form the receiving coil 112 may be different from the configuration of the coil windings used to form the receiving coil 55.

[0153] In such Figure 6 In some examples of the device 30 shown in FIG, one or both of the receiving coil 65 and the telemetry antenna 67 may not be present in the device. In such examples where the telemetry antenna 67 is not present, one or some combination of the receiving coils 112, 55, and / or 65 (when the receiving coil 65 is provided as part of the device 30) may be used to provide for communication to and from the device 30 to an external device (e.g., as referenced in FIG. 1 ). Figure 1 The transmission and / or reception functionality of any telemetry communications of the external device 11 and / or transceiver 16 shown and described, or any other external device that wirelessly communicates with an example of device 30 described throughout this disclosure.

[0154] Reference again Figure 6 , the positioning of the receiving coil 112 along the inner surface 51 of the antenna window 40 between the third radial position 113 and the fourth radial position 114 can allow a high level of inductive coupling efficiency to be achieved between the receiving coil 112 and one or more magnetic fields applied to the receiving coil 112 having a magnetic field direction incident on the receiving coil 112 over an angular range 115 (including angles of one or more magnetic fields that may be tilted (non-perpendicular) relative to the Y axis and over the angular range 115) in a manner similar to that described above with reference to the angular range 62 and the receiving coil 55. The positioning of the ferrite sheet 111 between the receiving coil 112 and the inner surface 51 of the antenna window 40 can increase the level of inductive coupling between the receiving coil 112 and the magnetic field having a magnetic field direction indicated by arrow 116. Although the inductive coupling level can also be increased between the receiving coil 112 and the magnetic field having a magnetic field direction indicated by arrow 116, the inductive coupling level can be increased. Figure 6 63 in the receiving coil 112, for a given same magnetic field strength level, the level of coupling between the magnetic field having the magnetic field direction indicated by arrow 63 and the receiving coil 112 may be a lower level than for a magnetic field having the magnetic field direction indicated by arrow 116. For example, other devices such as the receiving coil 65, the ferrite sheet 66, the telemetry antenna 67 and the substrate 68, the ferrite sheet 56 and / or the receiving coil 55 may reduce the level of inductive coupling efficiency that can be achieved between the receiving coil 112 and the magnetic field having the magnetic field direction indicated by arrow 63 applied to the receiving coil 112. Further, because any magnetic field having the magnetic field direction indicated by arrow 63 will be directly applied to the receiving coil 112 without passing through the ferrite sheet 111 in the process, the level of inductive coupling between these magnetic fields and the receiving coil 112 for these magnetic fields may be lower than the level of inductive coupling achieved for a magnetic field having the same magnetic field strength but having the magnetic field direction indicated by arrow 116 applied to the receiving coil 112.

[0155] By including Figure 6 , and due at least in part to the curvature of the receiving coil 112, a higher level of inductive coupling efficiency can be achieved relative to the device 30 and the magnetic field applied to the device 30 having a magnetic field direction indicated by one or more of the arrows 63 and / or 116. This higher level of inductive coupling can be achieved for a portion of the inner surface 51 extending between the third radial location 113 and the fourth radial location 114 and parallel to the device 30. Figure 6 115 in the XZ plane shown in . In addition, high levels of inductive coupling efficiency may also be achieved between the receive coil 112 and a magnetic field applied to the device 30 having a magnetic field direction indicated by arrow 116 extending between the third radial location 113 and the fourth radial location 114 but also "tilted" at a non-perpendicular incidence angle relative to the Y axis (longitudinal axis) of the device 30. In the example of the device 30, the inclusion of a second receive coil 112 in addition to the receive coil 55 may further increase the variation in angles and angular ranges over which magnetic fields may be applied to the device 30 while achieving a minimum level of inductive coupling efficiency between the device's receive antenna and a magnetic field applied to the device.

[0156] Figure 7A-7B A series of operations for using an electrical conductor 131 to form a receiving coil 130 for an implantable medical device according to various examples described in the present disclosure are shown. Fig. 7A As shown in FIG. 130A in FIG. 130A , the electrical conductor 131 is formed into a coil winding including three loops. The first loop of the receiving coil 130 is generally indicated by bracket 134 (hereinafter referred to as “first loop 134”), the second loop is generally indicated by bracket 136 (hereinafter referred to as “second loop 136”), and the third loop is generally indicated by bracket 138 (hereinafter referred to as “third loop 138”). The first end of the electrical conductor 131 is electrically coupled to the first lead 132 and the second end of the electrical conductor 131 is electrically coupled to the second lead 133. The first lead 132 and the second lead 133 can be configured to extend to the receiving coil 130 and connect the receiving coil to the recharging circuit system of the implantable medical device (in Fig. 7A Not shown, but for example Fig.10 This allows the current induced into the receiving coil 130 by one or more magnetic fields applied to the receiving coil to be used to recharge the power supply of the implantable medical device coupled to the receiving coil or to power the circuit system of the implantable medical device.

[0157] As shown in FIG. 130A , the electrical conductor 131 of the receiving coil 130 extends from the first lead 132 and forms a first half of the winding of the first loop 134. The electrical conductor 131 extends from the first half of the winding of the first loop 134 to the first intersection region 135, and extends away from the first intersection region 135 to form the first half of the winding of the second loop 136. The electrical conductor 131 extends from the first half of the winding of the second loop 136 to the second intersection region 137, and extends away from the second intersection region 137 to form the entire winding of the third loop 138, and then returns to the second intersection region 137. The electrical conductor 131 exits the second intersection region 137 to complete the second half of the winding of the second loop 136, continues to and exits the first intersection region 135, and completes the second half of the winding of the first loop 134, thereby extending a single winding of the electrical conductor through each side of the loops 134, 136, and 138 and through each of the intersection regions 135 and 137. This or similar routing of the electrical conductor 131 may be repeated a number of times that is some positive integer "N", where the value of "N" represents the number of turns included in the completed receiving coil 130. After completing the desired number of turns for the receiving coil 130, the electrical conductor 131 may exit the first loop 134 and form the second lead 133.

[0158] The number of turns or windings included in receiving coil 130 is not limited to a particular number of turns, and in some examples includes ten turns, wherein each turn includes a portion of an electrical conductor forming two halves of a loop in each of loops 134, 136, and 138. Fig. 7A 130A , the first lead 132 and the second lead 133 are arranged in the same relative position relative to the first loop 134, so that the first lead 132 and the second lead 133 extend from the coil winding in close proximity to each other. However, the positioning of the first lead 132 and the second lead 133 is not limited to any particular arrangement, such as the arrangement shown in FIG. 130A . In some instances, the leads 132 and 133 can extend from other locations (such as the intersection region 135 or the intersection region 137) of the coil winding of the receiving coil 130. In other instances, the first lead 132 and the second lead 133 extend relative to each other from different portions of the coil winding, so that these leads do not extend from portions of the receiving coil that are in close proximity to each other.

[0159] The electrical conductor 131 is not limited to being formed from any particular type of material, and may be formed from any type of electrical conductor described throughout the present disclosure, including conductive metals such as copper, that are easily formed into a wire and that can be easily bent to form the desired shape of the coil winding. In some examples, the electrical conductor used to form the receiving coil 130 may include an insulating material such as enamel coated on the outer surface of the conductor to provide an insulating layer between individual coil windings. In various examples, the electrical conductor used to form the receiving coil 130 is a multi-strand conductor such as Litz wire, where the electrical conductor used to form each winding is insulated along the outer surface of the electrical conductor using a coating such as enamel to reduce the skin effect of the electrical conductor.

[0160] The receiving coil 130 may be initially formed as a circular or elliptical winding (eg, Figure 5A The receiving coil 90 shown in FIG. 1 is then twisted at two locations to produce the following Fig. 7A 130A shows a first intersection region 135 and a second intersection region 137. In other examples, as Fig. 7A The receiving coil 130 shown in FIG. 130A can be as shown by Fig. 7A The initial pattern shown forms loops 134, 136 and 138 and crossover regions 135 and 137. Any of the winding techniques described throughout this disclosure may be used for windings from a Fig. 7A The loop and crossover region depicted by the receiving coil 130 in FIG.

[0161] When the receiving coil 130 is configured as Fig. 7A 130A , the longitudinal axis 140 of the receive coil may extend through each of the loops 134, 136, and 138 and intersect a point within each of the intersection regions 135 and 137 such that a mirror image of a half loop of each of the loops 134, 136, and 138 appears on each side of the longitudinal axis 140, respectively, except for the positioning of the first lead 132 and the second lead 133. As shown in FIG. 130A , the electrical conductor 131 forming the winding of the receive coil 130 lies in a plane or a set of coplanar planes containing the longitudinal axis 140 and a second axis 141 perpendicular to the longitudinal axis 140 as shown in FIG. 130A . A third axis 142 perpendicular to both the longitudinal axis 140 and the second axis 141 is also perpendicular to the plane or a set of planes within which the winding of the receive coil lies as shown in FIG. 130A .

[0162] Fig. 7A130B shows the steps of forming the receiving coil 130 as shown in FIG. 130A. As shown in FIG. 130B, the third loop 138 of the receiving coil 130 is twisted at the second intersection region 137 so that the third loop 138 is rotated about the longitudinal axis 140 by approximately 90 degrees, as represented by arrow 144. As shown in FIG. 130B, when this step is completed, the winding of the electrical conductor 131 forming the third loop 138 generally lies in a plane or a set of coplanar planes that contain the longitudinal axis 140 and the third axis 142 and are perpendicular to the one or more planes in which the first loop 134 and the second loop 136 generally lie.

[0163] Fig. 7A FIG. 130C of FIG. 130B shows another step of forming the receiving coil 130 as shown in FIG. 130B. As shown in FIG. 130C, after being twisted so that the third loop 138 of the receiving coil 130 is substantially perpendicular to the second loop 136 and the first loop 134, the third loop 138 is folded upward so that the third loop 138 rotates around the second axis 141 using the second intersection region 137 as a rotation center point, as shown by arrow 145. As shown in FIG. 130C, the processing of the third loop 138 can make the end of the third loop 138 opposite the second intersection region 137 close to the first intersection region 135. In FIG. 130C, the orientation of the winding of the third loop 138 remains generally perpendicular to the orientation of the winding of the second loop 136 and the first loop 134.

[0164] Figure 7B FIG. 130D shows the formation of Fig. 7A Another step of the receiving coil 130 shown in FIG. 130C. Figure 7B 130D of , while maintaining the third loop 138 in a plane containing the longitudinal axis 140, the first loop 134 and the second loop 136 are compressed such that the end of the first loop 134 containing the first lead 132 and the second lead 133 moves along the longitudinal axis 140 toward the end of the third loop 138. Thus, the portion of the longitudinal axis 140 that initially extends through the first loop 134, the first intersection region 135, and the second loop 136 assumes a curvature that generally corresponds to the shape of a portion of the third loop 138 and extends from the end of the first loop 134 containing the leads 132, 133, through the first intersection region 135, through the second loop 136, and to the second intersection region 137 as shown in FIG. 130D as a dashed curve 140A.

[0165] When formed as shown in FIG. 130D , the first loop 134 and the second loop 136 extend in an arcuate shape, thereby at least partially surrounding a portion of the winding forming the third loop 138 of the electrical conductor 131. As shown in FIG. 130D , the curvature of the arcuate shape formed by the first loop 134 and the second loop 136 corresponds to the curved longitudinal axis 140A, wherein the curvature of the arcuate shape of the first loop 134 and the second loop 136 extends around and at least partially surrounds a cylindrical shaped volume having a circular cross-sectional shape and centered on a central axis 140B extending along the height dimension of the cylindrical shaped volume. The third loop 138 is positioned in a plane or a set of coplanar planes perpendicular to the central axis 140B, wherein a cross-section taken in the plane or a set of coplanar planes in which the winding forming the third loop 138 is located is cylindrical in shape, and wherein the outer perimeter of the third loop 138 is also circular. The cross-sectional dimensions of the cylindrically shaped volume enclosed by the first loop 134 and the second loop 136 generally correspond to the same diameter dimensions of the circularly shaped windings forming the third loop 138, and are just smaller than the internal cross-sectional dimensions of a portion of the housing of the implantable medical device within which the receiving coil 130 is arranged to be positioned as configured in FIG. 130D.

[0166] Figure 7B FIG. 130E shows the formation of Figure 7B 130D of the present invention. As shown in FIG. 130E, the receiving coil 130 having the configuration shown in FIG. 130D is positioned within a portion of the housing of the implantable medical device, such as the antenna window 40 of the implantable medical device 30 (e.g., Figure 2A ).like Figure 7B 130E, the first loop 134 and the second loop 136 are attached to the inner surface 51 of the antenna window 40 so that the curvature of the first loop and the second loop along the axis 140A corresponds to the curvature of the inner surface 51 and at least partially surrounds the central axis 140B, which is now aligned with and corresponds to the longitudinal axis 46 extending through the center point of the diameter of the antenna window 40 in the cross section. In addition, the third loop 138 is positioned so that the winding forming the third loop 138 extends around the inner surface 51 of the antenna window 40, thereby forming a coil having a normal axis aligned with the central axis 140B.

[0167] When the receiving coil 130 is arranged as shown in FIG. 130E to be used as an implantable medical device (eg, device 30- Figure 2A), the first loop 134 and the second loop 136 can operate as an infinite shape or a figure eight coil as described throughout the present disclosure, and can provide a magnetic field applied to the antenna window 40 in the range of magnetic field directions described throughout the present disclosure (such as with the above reference Figure 6 130E).

[0168] Thus, regardless of the orientation of the magnetic field direction during the recharging session and / or the orientation of the implantable medical device, many of the orientations of the magnetic field applied to an implantable medical device having a receiving coil arranged as shown in FIG. 130E for the purpose of recharging a power source within the implantable medical device can provide a minimum level of inductive coupling efficiency between the applied magnetic field and the implantable medical device. This feature of the receiving coil 130 is particularly important for performing recharging operations on deeply implanted medical devices and / or when the precise orientation of the implanted device may not be known and / or constant, for example due to movement of the device and / or movement of the patient or within the patient's body. In addition to providing a wide range of possible orientations for the applied magnetic field that provides inductive coupling with the receiving coil winding, another advantage of the multi-loop coil described in the present disclosure, such as the receiving coil 130, or any other multi-loop coil winding, also includes that a certain number of additional electronic components that may need to be coupled to the multi-loop coil may only require a set of tuning capacitors, diodes, and smoothing caps that are required as rectifier components for the receiving coil. This feature of having a single set of rectifier components that need to be coupled to multiple loop coils provides additional space and real estate savings on, for example, a hybrid circuit, where such electrical components are located within an implantable medical device, thereby further helping to miniaturize the overall size required for the electronic circuit system and / or the housing of the implantable medical device.

[0169] Figure 7C An example receiving antenna configuration for an implantable medical device according to various examples described in the present disclosure is shown. Figure 7C As shown in FIG. 130F, having Figure 7B 130E is positioned within a portion of the housing of the implantable medical device, such as the antenna window 40 of the implantable medical device 30 (e.g., Figure 2A ).like Figure 7C 130F, the first loop 134 and the second loop 136 are attached to the inner surface 51 of the antenna window 40 so that the curvature of the first loop and the second loop along the axis 140A corresponds to the curvature of the inner surface 51 and at least partially surrounds the central axis 140B, which is now aligned with and corresponds to the longitudinal axis 46 extending through the center point of the diameter of the antenna window 40 in the cross section. The third loop 138 is positioned so that the winding forming the third loop 138 extends around the inner surface 51 of the antenna window 40, thereby forming a coil having a normal axis aligned with the central axis 140B.

[0170] In FIG. 130F , a second receiving coil 139 is also disposed within a portion of the housing of the implantable medical device shown in the figure. The second receiving coil 139 may include a single loop coil winding, such as positioned at, for example, a reference Figure 3B The coil winding 70 ( Figures 4A-4B The second receiving coil 139 may be connected to the lead wires ( Figure 7C ) and is separately coupled to a recharging circuit system (eg, recharging circuit system 206- Fig.10 ). In other examples, the second receiving coil 139 is a fourth loop formed by the same electrical conductor used to form the first loop, the second loop, and the third loop of the receiving antenna, and is coupled to the first loop, the second loop, and the third loop by, for example, twisting or additional crossing areas formed during winding of the electrical conductor 131.

[0171] The second receiving coil 139 may be attached to a ferrite sheet (e.g., Figure 3B The ferrite sheet 69B in the embodiment may be attached to a ferrite sheet, and / or may be self-supporting or may be supported by a substrate such as a circuit board ( Figure 7C130F). In various examples, the normal axis of the second receiving coil 139 is oriented such that the normal axis is directed in a first direction to the intersection region 135 between the first loops 134 and 136, and in a second direction toward the gap between the first loop 134 and the second loop 136 farthest from the intersection region 135. Such orientation of the normal axis of the second receiving coil 139 can allow the second receiving coil to have maximum coupling efficiency with one or more magnetic fields having one or more magnetic field directions that are not necessarily optimal for inducing one or more currents into one or more of the loops of the receiving coil 130. In addition to increasing the range of magnetic field directions that can provide a high level of inductive coupling efficiency with the device, the receiving antenna configuration shown in FIG. 130F requires only two sets of rectifying components (one set for the coil 130 and the other set for the coil 139), thereby saving the amount of substrate real estate required for the rectifying circuitry associated with the receiving antenna configuration and the overall number of components required.

[0172] Fig. 8A A cross-sectional and exploded view 160 of an example receive antenna configuration for an implantable medical device 30 is shown according to various examples described in the present disclosure. Fig. 8A An illustrative depiction of an antenna window 40 is included with a first housing portion 31 and a second housing portion 36 on opposite sides (top and bottom) of the antenna window 40. Fig. 8A , antenna window 40 has been illustratively separated from first housing portion 31 at first seam 41 and moved away from the first housing portion and illustratively separated from second housing portion 36 at second seam 42 and moved away from the second housing portion. In addition, antenna window 40 has been illustratively cut along illustrative axis 161 to form illustrative edges 162 and 163 along the cut line of axis 161. Edges 162 and 163 have been illustratively separated from each other to show the structure depicted as Fig. 8A The inner surface 51 of the antenna window 40 is a flat surface facing in an outward direction as viewed in FIG.

[0173] like Fig. 8AAs shown in , the first receiving coil 164 and the second receiving coil 174 are attached to the inner surface 51 of the antenna window 40. Each of the receiving coils 164 and 174 includes a separate electrical conductor formed into an infinitely shaped coil having a first loop and a second loop configured in a figure eight pattern. For example, the first receiving coil 164 including the first loop 166, the intersection area 168, and the second loop 167 can be formed using the electrical conductor 165. The first receiving coil 164 can be formed by the electrical conductor 165 and arranged in a curved shape so that the axis 164A extending from one end of the first loop 166 opposite to the intersection area 168 through the intersection area 168 and to the end of the second loop 167 opposite to the intersection area 168 has a curvature corresponding to the curvature of the inner surface 51 of the antenna window 40. Similarly, the second receiving coil 174 including the first loop 170, the intersection area 172, and the second loop 171 can be formed using the electrical conductor 169. The second receiving coil 174 can be formed using an electrical conductor 169 arranged in a curved shape so that an axis 168A extending from one end of the first loop 170 opposite the intersection region 172, through the intersection region 172 and to the end of the second loop 171 opposite the intersection region 172 has a curvature corresponding to the curvature of the inner surface 51 of the antenna window 40. The receiving coils 164, 174 can use coils as described throughout this disclosure for infinite shapes and any equivalents thereof (including but not limited to reference Figure 5B-5C 90) described herein. Although described with reference to an infinitely shaped coil, in some examples, coils 164 and 174 may each be formed using any of the materials, winding configurations, and techniques described herein or any combination thereof. Figure 5D The dual winding coil configuration 102 shown and described is formed.

[0174] Reference again Fig. 8A , the curvature of axes 164A and 164B allows receiving coils 164 and 174 to be attached to inner surface 51 of device 30 and take on the shape of the curvature of the inner surface. As previously described, the curvature of inner surface 51 can surround a cylindrically shaped inner cavity with a circular cross-section. In some examples, receiving coils 164 and 174 can be attached directly to inner surface 51 of antenna window 40. In some examples, receiving coils 164 and 174 can be attached to one or more ferrite sheets ( Fig. 8A It is not shown in the figure, but for example, they are respectively as follows Figure 8B , wherein the one or more ferrite sheets are then attached to the inner surface 51 such that the one or more ferrite sheets are respectively positioned between the receiving coil and the inner surface 51.

[0175] like Fig. 8A As shown in FIG. 1 , the portions of the loops included in the receiving coils 164 and 174 can extend into the antenna window 40 to a height dimension close to the height dimension 47 of the antenna window itself. In addition, the second loop 167 of the receiving coil 164 extends to be adjacent to the first loop 170 of the receiving coil 174, but not in contact therewith. When arranged in the antenna window 40 in a practical state (e.g., along the direction shown in FIG. 1 ), the receiving coils 164 and 174 can extend into the antenna window 40 to a height dimension close to the height dimension 47 of the antenna window itself. In addition, the second loop 167 of the receiving coil 164 extends to be adjacent to the first loop 170 of the receiving coil 174, but not in contact therewith. Fig. 8A The edges 162, 163 shown in the figure for illustrative purposes only are not separated), and the first loop 166 of the receiving coil 164 extends to the second loop 171 of the receiving coil 174 adjacent to it but not in contact with it. Fig. 8A , the axis 164A of the receiving coil 164 is aligned with the axis 168A of the receiving coil 174 relative to the height dimension 47 of the antenna window 40. Therefore, a majority of the inner surface 51 around the entire perimeter of the inner surface 51 falls within the region into which one of the loops of the first receiving coil 164 or the second receiving coil 174 extends. When a pair of receiving coils 164 and 174 are arranged as shown in FIG. Fig. 8A When placed within the antenna window of an implantable medical device as shown in FIG. , the pair of coils provides a wide range of relative angular orientations between the magnetic field applied to the device and the device, which enables a high level of inductive coupling efficiency to be achieved between the applied magnetic field and the receiving coil, as described below with reference to FIG. Figure 8B Further described. It should be understood that Fig. 8A The depiction of the flat shape of the antenna window 40 shown in FIG. 4 is for illustrative purposes only and is not intended to represent an actual shape or configuration that may be used on or incorporated into an implantable medical device in actual practice (e.g., as Fig. 8A , which can be split apart and then reassembled).

[0176] Figure 8B is included Fig. 8A A cross-sectional view 160A of an example implantable medical device with a receiving antenna configuration is shown. View 160A shows the device 30 viewed from a plane cut through the device 30 at the midpoint of the antenna window 40 along the longitudinal axis 46 of the device 30, wherein the longitudinal axis is perpendicular to the plane cut through the device. Figure 8B In view 160A shown in FIG. 1 , the device 30 is shown viewed in the same direction as the orientation of the Y axis, with the X axis extending in a left-right (horizontal) orientation and the Z axis oriented in an up-down (vertical) orientation.

[0177] like Figure 8B The example of the device 30 shown in FIG. 1 includes Fig. 8A160A and 160B illustrate a first receiving coil 164 and a second receiving coil 174 arranged along a portion of the inner surface 51 of the antenna window 40 in a manner that is the same or similar to that shown and described in view 160 of FIG. As shown in view 160A, the first loop 166 of the first receiving coil 164 is positioned along the inner surface 51 of the antenna window 40 such that the windings forming the first loop 166 extend to both sides of the X-axis along the side of the antenna window pointed to by arrow 63. The second loop 167 of the first receiving coil 164 is positioned along the inner surface 51 of the antenna window 40 such that the windings forming the second loop 167 extend to both sides of the Z-axis along the side of the antenna window pointed to by arrow 64. The crossover region 168 of the first receiving coil 164 is positioned along the inner surface 51 at approximately the midpoint between the X-axis and the Z-axis. As further shown in view 160A, the first loop 170 of the second receiving coil 174 is positioned along the inner surface 51 of the antenna window 40 so that the windings forming the first loop 170 extend to both sides of the X-axis along the side of the antenna window pointed to by arrow 63A. The second loop 171 of the second receiving coil 174 is positioned along the inner surface 51 of the antenna window 40 so that the windings forming the second loop 171 extend to both sides of the Z-axis along the side of the antenna window pointed to by arrow 64A. The crossover region 172 of the second receiving coil 174 is positioned along the inner surface 51 at approximately the midpoint between the X-axis and the Z-axis.

[0178] In some examples, the receiving coils 164 and 174 are directly attached to the inner surface 51 of the antenna window 40. In some alternative examples, the first receiving coil 164 is attached to the ferrite sheet 177 and the second receiving coil 174 is attached to the ferrite sheet 178. Then, as shown in view 160A, the ferrite sheets 177 and 178 are respectively attached to the inner surface 51 on the antenna window. Regardless of whether the ferrite sheets 177, 178 are included in the given example as shown in view 160A or whether the receiving coils 164, 174 are directly attached to the inner surface 51, the outer extents of the loops forming each receiving coil are located in close proximity to each other so that at least some portion of the windings forming the receiving coils are arranged around the Y axis (the longitudinal axis of the device 30) to almost a full 360 degrees around the inner surface 51.

[0179] For example, as shown in view 160A, a portion of the first loop 166 of the first receiving coil 164 that extends farthest from the intersection region 168 is positioned in close proximity to a portion of the second loop 171 of the second receiving coil 174 that extends farthest from the intersection region 172. The arrangement leaves only a small gap 175, or in some instances, no gap is required between the first loop 166 and the second loop 171 along the axis 173. In some instances, a portion of the first loop 166 touches a portion of the loop 171, resulting in no gap between these coil loops. Similarly, a portion of the second loop 167 of the first receiving coil 164 that extends farthest from the intersection region 168 is positioned in close proximity to a portion of the first loop 170 of the second receiving coil 174 that extends farthest from the intersection region 172. This arrangement leaves only a small gap 176, or in some instances, no gap is required between the second loop 167 and the first loop 170 along the axis 173. In some examples, a portion of first loop 167 touches a portion of loop 170, resulting in no gap between these coil loops. In addition to gaps 175 and 176 (if such gaps exist), inner surface 51 also contains a portion of the winding forming one of receiving coils 164 and 174 around the Y axis of device 30.

[0180] The arrangement of two receiving coils using coils configured as infinity shapes as illustrated in views 160 and 160A provides a wide range of relative orientations between the device 30 and one or more magnetic fields applied to the device 30, which can result in a high level of inductive coupling efficiency between the one or more applied magnetic fields and the receiving coils 164 and / or 174. For example, any magnetic field having a magnetic field direction that lies in a plane containing both the X-axis and the Z-axis (e.g., as illustrated by arrows 63, 63A, 64, 64A) can provide a high level of inductive coupling efficiency with one or both of the receiving coils 164, 174. Additionally, variations in the angle of incidence of the magnetic field, including a magnetic field having a magnetic field direction that intersects the plane containing the X-axis and the Z-axis of the device 30 at some non-zero angle (e.g., not perpendicular to the Y-axis), can also provide a high level of inductive coupling efficiency between one or more magnetic fields and one or both of the receiving coils 164 and 174. Additionally, because this arrangement requires only two infinite loops of coil windings, only two sets of rectifier components (e.g., tuning capacitors, diodes) (one set for each infinite loop) may be required to provide the additional components required for the rectification circuitry associated with each coil. Reducing the requirement for additional components can help reduce the real estate required to perform these functions, for example, on a hybrid circuit and / or can help reduce the overall size of the housing of the device in which the infinite loop coils are located.

[0181] Fig. 9AA cross-sectional and exploded view 180 of an example receive antenna configuration for an implantable medical device according to various examples described in the present disclosure is shown. Fig. 9A An illustrative depiction of an antenna window 40 is included with a first housing portion 31 and a second housing portion 36 on opposite sides (top and bottom) of the antenna window 40. Fig. 9A , antenna window 40 has been illustratively separated from first housing portion 31 at first seam 41 and moved away from the first housing portion and illustratively separated from second housing portion 36 at second seam 42 and moved away from the second housing portion. In addition, antenna window 40 has been illustratively cut along illustrative axis 181 to form illustrative edges 182 and 183 along the cut line of axis 181. Edges 182 and 183 have been illustratively separated from each other to show the structure depicted as Fig. 9A The inner surface 51 of the antenna window 40 is a flat surface facing in an outward direction as viewed in FIG.

[0182] like Fig. 9A As shown in FIG. 1 , a first receiving coil 184, a second receiving coil 185, a third receiving coil 186, and a fourth receiving coil 187 are attached to the inner surface 51 of the antenna window 40. Each of the receiving coils 184, 185, 186, and 187 includes a receiving coil formed with a plurality of electrodes for coupling the coil to the device ( Fig. 9A The receiving coils 184, 185, 186 and 187 may be reference coils. Figures 4A-4B Examples of receiver coils 70 are shown and described. For example, Fig. 9A , the receive coils 184, 185, 186, and 187 may be formed using an electrical conductor such as multiple strands of Litz wire. The receive coils 184, 185, 186, and 187 may be formed to have a generally rectangular shape, "bent" to form a curvature corresponding to the curvature of the inner surface 51 of the antenna window 40. The receive coils 184, 185, 186, and 187 may be formed using any of the materials, winding configurations, and techniques described for the flat or spirally wound planar coils and any equivalents thereof as described throughout this disclosure, or any combination thereof.

[0183] Reference again Fig. 9A, the curvature of the shape of the receiving coils 184, 185, 186, and 187 (as represented by the curved axis 189) allows the receiving coils to be attached to the inner surface 51 of the antenna window 40 and take on the shape of the curvature of the inner surface. As previously described, the curvature of the inner surface 51 can surround an inner cavity with a cylindrical shape having a circular cross-section. In some examples, the receiving coils 184, 185, 186, and 187 can be directly attached to the inner surface 51 of the antenna window 40. In some examples, the receiving coils 184, 185, 186, and 187 can be attached to one or more ferrite sheets ( Fig. 9A It is not shown in the figure, but for example, they are respectively as follows Fig. 9B , wherein the one or more ferrite sheets are then attached to the inner surface 51 such that the one or more ferrite sheets are respectively positioned between the receiving coil and the inner surface 51.

[0184] like Fig. 9A As shown in , the portion of the loop contained in each individual winding that forms the receiving coils 184, 185, 186 and 187 can extend into the antenna window 40 to a height dimension that is close to the height dimension 47 of the antenna window itself. In addition, the lateral dimension of the receiving coil extends in a direction that is oriented along an axis 189 that extends along the inner surface 51 between the first edge 182 and the second edge 183. In some examples, the height dimension and width dimension over which the individual windings of the receiving coils extend can be substantially the same for each of the receiving coils. The receiving coils 184, 185, 186 and 187 can be positioned relative to each other along the axis 189 so that only small gaps or no gaps are provided between the individual receiving coils. Therefore, a majority of the inner surface 51 around the entire periphery of the inner surface 51 falls within the area over which at least one of the receiving coils 184, 185, 186 and 187 extends. When the receiving coils 184, 185, 186 and 187 are arranged as shown in FIG. Fig. 9A When positioned within the antenna window of an implantable medical device as shown in FIG. , the receiving coil provides a wide range of relative angular orientations between the magnetic field applied to the device and the device itself, which can enable a high level of inductive coupling efficiency to be achieved between the applied magnetic field and the receiving coil, as described below with reference to FIG. Fig. 9B Further described.

[0185] Fig. 9B is included Fig. 9A 180A is a cross-sectional view of an implantable medical device having a receiving antenna configuration. View 180A shows the device 30 as viewed from a plane cut through the device 30 at the midpoint of the antenna window 40 along the longitudinal axis 46 of the device 30, wherein the longitudinal axis is perpendicular to the plane cut through the device. Fig. 9B In view 180A shown in FIG. 1 , the device 30 is shown viewed in the same direction as the orientation of the Y axis, with the X axis extending in a left-right (horizontal) orientation and the Z axis oriented in an up-down (vertical) orientation.

[0186] like Fig. 9B The example of the device 30 shown in FIG. 1 includes a device 30 as shown in FIG. Fig. 9A 180A and 180B illustrate receiving coils 184, 185, 186, and 187 arranged along a portion of the inner surface 51 of the antenna window 40 in the same or similar manner as shown and described in view 180 of FIG. As shown in view 180A, the first receiving coil 184 is positioned along the inner surface 51 of the antenna window 40 so that the windings forming the first receiving coil extend to both sides of the X axis along the side of the antenna window pointed by arrow 63. The second receiving coil 185 is positioned along the inner surface 51 of the antenna window 40 so that the windings forming the second receiving coil extend to both sides of the Z axis along the side of the antenna window pointed by arrow 64. The third receiving coil 186 is positioned along the inner surface 51 of the antenna window 40 so that the windings forming the third receiving coil extend to both sides of the Z axis along the side of the antenna window pointed by arrow 63A. The fourth receiving coil 187 is positioned along the inner surface 51 of the antenna window 40 so that the windings forming the fourth receiving coil extend to both sides of the Z axis along the side of the antenna window pointed by arrow 64A.

[0187] In some examples, the receiving coils 184, 185, 186, and 187 are directly attached to the inner surface 51 of the antenna window 40. In some alternative examples, the receiving coils 184, 185, 186, and 187 can be attached to one or more ferrite sheets, which are then attached to the inner surface 51 so that the one or more ferrites are interposed between the inner surface 51 and the receiving coils. Fig. 9B 180A, the first receiving coil 184 is attached to the ferrite sheet 190, the second receiving coil 185 is attached to the ferrite sheet 191, the third receiving coil 186 is attached to the ferrite sheet 192, and the fourth receiving coil 187 is attached to the ferrite sheet 193. Then, as shown in view 180A, the ferrite sheets 190, 191, 192 and 193 are attached to the inner surface 51 on the antenna window. Regardless of whether the ferrite sheets 190, 191, 192 and 193 are included in the given example as shown in view 180A or whether the receiving coils 184, 185, 186 and 187 are directly attached to the inner surface 51, the outer extensions of the loops forming each receiving coil are located in close proximity to each other so that at least some portion of the windings forming the receiving coils are arranged around the Y axis (the longitudinal axis of the device 30) to be around the inner surface 51 for almost a full 360 degrees.

[0188] For example, as shown in view 180A, gap 194A is provided between the first receiving coil 184 and the fourth receiving coil 187, gap 194B is provided between the first receiving coil 184 and the second receiving coil 185, gap 194C is provided between the second receiving coil 185 and the third receiving coil 186, and gap 194D is provided between the third receiving coil 186 and the fourth receiving coil 187. The arrangement of the receiving coils may leave only small gaps between the receiving coils at radial locations, indicated as gaps 194A-194D along the inner surface 51. In addition to these gaps, the inner surface 51 also contains some portion of the winding forming one of the receiving coils 184, 185, 186, and 187 around the Y axis of the device 30.

[0189] Using an arrangement of four receive coils configured as illustrated in views 180 and 180A provides a wide range of relative orientations between the device 30 and one or more magnetic fields applied to the device 30, which can result in a high level of inductive coupling efficiency between the one or more magnetic fields and one or more of the receive coils 184, 185, 186, and 187. For example, any magnetic field having a magnetic field direction that lies in a plane containing both the X-axis and the Z-axis (e.g., as illustrated by arrows 63, 63A, 64, 64A) can provide a high level of inductive coupling efficiency with one or more of the receive coils 184, 185, 186, and 187. Additionally, variations in the angle of incidence of the magnetic field, including a magnetic field having a magnetic field direction that intersects the plane containing the X-axis and the Z-axis of the device 30 at some non-zero angle (e.g., not perpendicular to the Y-axis), can also provide a high level of inductive coupling efficiency between the one or more magnetic fields and one or more of the receive coils 184, 185, 186, and 187.

[0190] In the form of reference Figure 2A-9BIn the example of coil windings of one or more receiving coils in the receiving coil of the receiving antenna configuration shown and described, each of the coil windings is shown and described as being positioned within the housing of the device and surrounded by the housing. However, the examples of coil windings (such as flat wound multi-loop coils, infinitely shaped multi-loop coils, and other multi-loop coils described herein) are not limited to coil windings positioned within the housing. In some examples, the coil windings or a portion of the coil windings can be formed on the outer surface of the housing, such as formed on the outer surface of the first housing portion 31, the second housing portion 36, and / or the antenna window 40 of the implantable medical device (such as the device 30). The external coil windings can include one or more flat spirally wound coils, one or more infinitely shaped coils and / or multi-loop coils (such as three-loop coils) or any combination thereof. In some examples, the coil windings formed on the outer surface of the device can be overmolded with a protective material (such as polysulfone) layer to encapsulate or embed the coil in a material (such as a polymer material) used to form the housing. In some instances, a portion of the housing in which the external coil winding is formed may be recessed relative to other exterior surfaces of the housing of the device, for example to form a groove or channel, such that the coil winding may be formed within the groove or channel to provide additional physical protection for the coil winding.

[0191] Fig.10 1 is a functional block diagram showing an example configuration of an intracardiac pacing device 15 according to various examples described in the present disclosure. The IMD 15 may correspond to reference Figure 1 Any of the IMDs 15A and 15B described and illustrated and / or as referenced Figure 2A-2BThe described and illustrated device 30 / 30A or another IMD configured to be rechargeable using the devices, systems, and methods described in the present disclosure. The IMD 15 includes a power source 204 that can be coupled to the electronic circuitry disposed in the IMD 15 and is configured to provide power to these circuits. The IMD 15 can be inductively rechargeable by applying one or more magnetic fields to the IMD 15, wherein energy from the one or more applied magnetic fields can induce electrical energy into an antenna 209 coupled to the communication circuitry 205 and the device recharging circuitry 206 or into an antenna 211 that can be provided in addition to the antenna 209 and coupled to the recharging circuitry 206 when provided. When configured for recharging the IMD 15, the antenna 209 and / or the antenna 211 can be a receiving antenna configuration according to any of the examples described in the present disclosure or any equivalent thereof. IMD 15 can be an example of a deeply implantable device, such as a device implanted within a chamber of a patient's heart and including a receiving antenna as described in the present disclosure that allows a power source (e.g., power source 204) positioned within the IMD to be efficiently recharged using a magnetic field applied to the IMD to recharge the power source.

[0192] like Fig.10 , device recharging circuitry 206 is coupled to power source 204 and may be coupled via switching device 210 to receive electrical energy induced in antenna 209 (or antenna 211, when configured) by one or more electromagnetic fields applied to the antenna, and to condition the energy to provide an energy level that is provided to power source 204 for the purpose of recharging power source 204 and / or powering other circuitry included as part of IMD 15. Device recharging circuitry 206 may perform various energy conditioning functions on energy induced in antenna 209 (or antenna 211, when configured) to generate “recharging energy” that is provided to power source 204, for example, by providing rectification, voltage level conditioning, current level conditioning, and / or other signal processing functions. Antenna 209 (and / or antenna 211, when configured) may be a multi-directional antenna that is not directionally specific with respect to coupling efficiency for inductive charging of power source 204 based on the orientation of the antenna relative to the orientation of one or more coils that provide one or more magnetic fields intended to recharge power source 204.

[0193] Thus, IMD 15 may be configured to couple magnetic energy captured by a receiving antenna (including but not necessarily a telemetry antenna) and directed into a suitable rectifying circuit for delivering electrical energy to an energy storage device (e.g., a rechargeable battery). Switching device 210 (which may be a transistor) may be included in IMD 15 and may be controlled, for example, by processing circuitry 200 to select whether the telemetry system or the power recharging system is active, and therefore whether antenna 209 is coupled to communication circuitry 205 or device recharging circuitry 206. In other examples, second antenna 211 is directly coupled to device recharging circuitry 206 and is configured to receive inductively coupled energy provided to antenna 211 and provide inductively coupled energy to device recharging circuitry 206 to recharge power source 204.

[0194] In the illustrated example, the IMD 15 includes a processing circuit system 200 and associated memory 201, a sensing circuit system 202, a therapy delivery circuit system 203, one or more sensors 207, and a communication circuit system 205 coupled to an antenna 209 as described above. However, the IMD 15 need not include all of these components, or may include additional components. For example, in some examples of the device, the IMD 15 may include the therapy delivery circuit system 203. The memory 201 includes computer-readable instructions that, when executed by the processing circuit system 200, cause the IMD 15 and the processing circuit system 200 to perform various functions attributed to the IMD 15 and the processing circuit system 200 as described herein (e.g., preparing information for transmission from the IMD 15 regarding the charge level present in the power source, such as battery management system information (BMS)). For example, the processing circuit system 200 can be configured to: provide information including a state of charge and / or temperature information regarding a battery (e.g., a battery positioned in the IMD 15), thereby determining an inductive coupling level (e.g., a level of energy generated in an antenna positioned in the IMD 15 due to one or more electromagnetic fields applied to the IMD 15); and generate information related to this inductively received energy for transmission via a communications antenna or a separate antenna and associated power regulation circuit system of the IMD 15.

[0195] The memory 201 may include any volatile, nonvolatile, magnetic, optical, or electrical media, such as random access memory (RAM), read-only memory (ROM), nonvolatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital or analog media. The memory 201 may store one or more thresholds for time of day, posture, heart rate, activity level, respiratory rate, and other parameters. The memory 201 may also store data indicating cardiovascular pressure measurements, and store other data associated with cardiac and / or other physiological events associated with the patient.

[0196] Processing circuit system 200 may include fixed function circuit systems and / or programmable processing circuit systems. Processing circuit system 200 may include any one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or an equivalent discrete or analog logic circuit system. In some examples, processing circuit system 200 may include multiple components (such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs) and other discrete or integrated logic circuit systems. The functions attributed to processing circuit system 200 herein may be embodied as software, firmware, hardware, or any combination thereof.

[0197] As shown, sensing circuitry 202 and therapy delivery circuitry 203 are coupled to electrode 212. Fig.10 The electrodes 212 shown in FIG. 1 may correspond to, for example, electrodes positioned at IMD 15A ( Figure 1 ) of the leads 21 and 22 and / or the electrodes or devices 30 on the housing 23 ( Figure 2A ) or device 30A( Figure 2B ) electrodes 32 and 33. Fig.10 The sensing circuit system 202 in the IMD 15 shown in FIG. 1 can monitor signals from selected two or more electrodes of the electrodes 212 to monitor the electrical activity, impedance, or some other electrical phenomenon of the heart. The sensing of the cardiac electrical signals can be performed to determine the heart rate or heart rate variability or to detect arrhythmias (e.g., tachyarrhythmias or bradycardias) or other electrical signals. In some examples, the sensing circuit system 202 can include one or more filters and amplifiers for filtering and amplifying the signals received from the electrodes 212.

[0198] In some examples, sensing circuitry 202 can sense or detect physiological parameters, such as heart rate, blood pressure, respiration, and other physiological parameters associated with a patient. The generated electrical signal can be transmitted to a cardiac event detection circuitry that detects a cardiac event, for example, when the cardiac electrical signal exceeds a sensing threshold. The cardiac event detection circuitry can include a rectifier, a filter and / or an amplifier, a sense amplifier, a comparator, and / or an analog-to-digital converter. Sensing circuitry 202 can output an indication to processing circuitry 200 in response to sensing of a cardiac event (e.g., a detected P wave or R wave).

[0199] In this manner, the processing circuit system 200 can receive detected cardiac event signals corresponding to the occurrence of detected R waves and P waves in the corresponding chambers of the heart. Indications of detected R waves and P waves can be used to detect ventricular and / or atrial tachyarrhythmia episodes, such as ventricular or atrial fibrillation episodes. Some detection channels can be configured to detect cardiac events (such as P waves or R waves) and provide an indication of the occurrence of such events to the processing circuit system 200, such as described in U.S. Patent No. 5,117,824, entitled "APPARATUS FOR MONITORING ELECTRICAL PHYSIOLOGIC SIGNALS", issued on June 2, 1992 to Keimel et al., which is incorporated herein by reference in its entirety.

[0200] The sensing circuitry 202 may also include switching circuitry to select which electrode (or electrode polarity) of the available electrodes 212 is used to sense cardiac activity. In examples with several electrodes 212, the processing circuitry 200 may select the electrodes that serve as sensing electrodes (i.e., select a sensing configuration) through switching circuitry within the sensing circuitry 202. The sensing circuitry 202 may also pass one or more digitized EGM signals to the processing circuitry 200 for analysis, such as for rhythm differentiation.

[0201] exist Fig.10 In the example of , IMD 15 includes one or more sensors 207 coupled to sensing circuit system 202. Although Fig.1015, but one or more of sensors 207 may be external to IMD 15 (e.g., coupled to IMD 15 via one or more leads) or configured to communicate wirelessly with IMD 15. In some examples, sensor 207 converts a signal indicative of a patient parameter, which may be amplified, filtered, or otherwise processed by sensing circuit system 202. In such examples, processing circuit system 200 determines a value of the patient parameter based on the signal. In some examples, sensor 207 determines the value of the patient parameter and transmits it to processing circuit system 200, for example, via a wired or wireless connection.

[0202] In some instances, the sensor 207 includes one or more accelerometers 208, such as one or more three-axis accelerometers. The signals generated by the one or more accelerometers 208 may indicate, for example, large body movements of the patient (e.g., activity), patient posture, heart sounds or other vibrations or movements associated with the beating of the heart, or coughing, rales, or other breathing abnormalities. The accelerometer 208 may generate a signal and transmit the signal to the processing circuit system 200 to make a determination about the patient's posture. In various instances, the signal from the accelerometer 208 is processed to determine activity, such as when the patient is taking one or more steps or, for example, when the patient is running, and the signal is used to provide an activity count associated with the patient's physical activity initiated by the patient. In some instances, the sensor 207 may include a sensor configured to convert a signal indicating blood flow, oxygen saturation of the blood, or patient temperature, and the processing circuit system 200 may determine a patient parameter value based on these signals. In various instances, the sensor 207 may include a sensor circuit 18 ( Figure 1 ) or a combination thereof.

[0203] In some examples, the processing circuit system 200 determines one or more patient parameter values ​​based on the pressure signal. The patient parameter values ​​determined based on the pressure may include, for example, systolic or diastolic pressure values, such as pulmonary artery diastolic pressure values. In some examples, such as the sensor circuit 18 ( Figure 1 ) includes one or more sensors and a sensing circuit system configured to generate a pressure signal, and the processing circuit system 200 determines a patient parameter value related to blood pressure based on the information received from the IMD 15.

[0204] The therapy delivery circuit system 203, when configured as part of the IMD 15, can be configured to generate and deliver electrical therapy to the heart. The therapy delivery circuit system 203 can include one or more pulse generators, capacitors, and / or other components capable of generating and / or storing energy for delivery as pacing therapy, defibrillation therapy, cardioversion therapy, other therapies, or a combination of therapies. In some cases, the therapy delivery circuit system 203 can include a first group of components configured to provide pacing therapy and a second group of components configured to provide anti-tachyarrhythmia shock therapy. In other cases, the therapy delivery circuit system 203 can utilize the same group of components to provide both pacing therapy and anti-tachyarrhythmia shock therapy. In still other cases, the therapy delivery circuit system 203 can share some of the pacing and shock therapy components, while using other components only for pacing or shock delivery.

[0205] The therapy delivery circuit system 203 may include charging circuitry, one or more charge storage devices (such as one or more capacitors), and switching circuitry that controls when to discharge the one or more capacitors to the electrodes 212 and the pulse width. Charging the capacitors to the programmed pulse amplitude and discharging the capacitors for the programmed pulse width may be performed by the therapy delivery circuit system 203 according to control signals received from the processing circuit system 200, which are provided by the processing circuit system 200 according to parameters stored in the memory 201. The processing circuit system 200 controls the therapy delivery circuit system 203 to deliver the generated therapy to the heart through a combination of one or more electrodes 212, for example, according to the parameters stored in the memory 201. The therapy delivery circuit system 203 may include switching circuitry to select which of the available electrodes 212 to use to deliver the therapy, for example, when controlled by the processing circuit system 200.

[0206] The communication circuit system 205 includes a Figure 1 and Figure 2A-2B Any suitable hardware, firmware, software, or any combination thereof, for communicating with the external device 11, transceiver 16, or another IMD or sensor (such as sensor circuit 18) shown in FIG. Fig.10 , under the control of processing circuit system 200, communication circuit system 205 can receive downlink telemetry from external device 11 or another device and send uplink telemetry to the external device or the other device by means of an antenna such as antenna 209 (which can be internal and / or external). In some examples, communication circuit system 205 can communicate with a local external device, for example, through transceiver 16, and processing circuit system 200 can communicate through the local external device and a computer network (such as developed by Medtronic, Inc. of Dublin, Ireland). Network) to communicate with networked computing devices.

[0207] As described above, in some examples (i.e., where a single receive / communication antenna is used), the antenna signal may be switched from the telemetry communication circuitry 205 to the recharging circuitry 206. In other examples, one or more recharging antennas / coils are separate from the communication / telemetry antenna. For example, the antenna 209 may be switched between coupling to the communication circuitry 205 and coupling to the device recharging circuitry 206 by a switching device 210, wherein the switching device 210 may be controlled by the processing circuitry 200 to determine when the antenna 209 is coupled to the communication circuitry 205 and when the antenna 209 is coupled to the device recharging circuitry 206.

[0208] In various examples, processing circuitry 200 is coupled to device recharging circuitry 206 and receives information (e.g., current level) induced in antenna 209 or antenna 211 due to electrical energy received by the antenna via magnetic energy applied to IMD 15 for the purpose of recharging power source 204. Processing circuitry 200 may provide this information and other information (e.g., charging rate and temperature information associated with power source 204) in the form of output signals to communication circuitry 205 for transmission from IMD 15 to one or more external devices (e.g., transceiver 16). This transmitted information may be used by the external device to control one or more aspects of the recharging process.

[0209] For example, the positioning of a recharging coil or pair of coils positioned external to IMD 15 and / or the power levels applied thereto and the generation of one or more magnetic fields applied to IMD 15 may be controlled using this information transmitted from IMD 15. The settings of electrical parameters used to energize a coil in a pair of coils that generates one or more magnetic fields applied to IMD 15 for the purpose of recharging power source 204 may be controlled using this information transmitted from IMD 15. Additionally, other information transmitted from IMD 15, such as temperature and field strength information, may be used to control the recharging process, for example, by adjusting the field strength generated by one or more external coils, or, for example, shutting down one or more external coils to stop the recharging process.

[0210] A clinician or other user may retrieve data from IMD 15 using external device 11 or another local or networked computing device configured to communicate with processing circuitry 200 via communication circuitry 205 (e.g., via a transceiver such as transceiver 16). A clinician may also use external device 11 or another local or networked computing device to program parameters of IMD 15. In some examples, a clinician may select patient parameters for determining time of day and target activity level to determine when to trigger a measurement using sensor 207, accelerometer 208, and / or by sensing circuitry 202.

[0211] In various instances, the processing circuit system 200 is configured to receive signals from the sensing circuit system 202, the sensor 207 including the accelerometer 208, and / or sensor signals provided by sensors external to the IMD 15 to process the sensor signals to generate one or more input parameters directly based on the sensor signals or to derive one or more input parameters from the sensor signals. The input parameters are associated with one or more values ​​of one or more physiological parameters associated with a patient (such as the patient 12 in which the IMD 15 may be implanted). The physiological parameters associated with the input parameters may include activity counts, respiration rate / breathing rate, movement, posture, and posture changes associated with the patient. The values ​​associated with the input parameters may be values ​​measured directly from the input parameters or derived for the input parameters.

[0212] For example, a value of a heart rate, such as measured in beats per minute or cardiac cycle length, may be determined as a current value (e.g., most recent value) of an input parameter associated with a patient's heart rate measured over some predetermined period of time. Similarly, a value of a respiratory rate, such as measured in breaths per minute or respiratory cycle length, may be determined as a current value (e.g., most recent value) of an input parameter associated with a patient's respiratory rate measured over some predetermined period of time.

[0213] Similarly, values ​​of other input parameters may be determined, such as activity counts (e.g., based on the patient's movement as measured, for example, in steps taken per minute by the patient), body temperature, and current values ​​of, for example, the patient's posture (e.g., lying down, standing, sitting). In some instances, the current value of a physiological parameter may be an average or median of measurements over a period of time. These parameters may be used to monitor the patient's physical condition and / or determine the effectiveness of a therapy administered to the patient and / or the need to administer a new or different therapy (e.g., a new or different electrical stimulation therapy) to the patient based on analysis of sensed parameters and / or instructions received by IMD 15 from one or more external devices.

[0214] Fig.11A schematic diagram 215 is shown including one or more receiving coils 223 that can be coupled to an implantable medical device according to various examples described in the present disclosure. Fig.11 One or more receiving antennas and / or additional circuitry shown in the figure may represent an implantable medical device (e.g. Figure 1 The IMD 15A or IMD 15B shown in FIG. Figure 2A-2B Schematic 215 includes one or more receiving coils 216, 218 that can be coupled to a rechargeable power source 223 via a switching device 222 controlled by a recharging circuit system 206. In some examples, the rechargeable power source 223 is the power source 204, and the recharging circuit system 206 is a reference Fig.10 The circuit system shown and described in the IMD 15 in FIG. 1 , and the rechargeable power source 223 is configured to provide power to the circuit system of the implantable medical device (such as IMD 15) to allow the device to operate. One or more receiving coils 218, 218 can be as shown in reference Fig.10 Examples of configurations of antenna 209 or antenna 211 are shown and described.

[0215] refer to Fig.11 , the receiving coil 216 may be formed of an electrical conductor configured as a receiving coil according to any of the receiving coils described throughout this disclosure or any equivalent thereof. For example, the receiving coil 216 may be configured as or similar to the receiving coils described in reference Figures 4A-4B The flat spirally wound coil of the receiver coil 70 shown and described. In some examples, the receiver coil 216 can be configured as or similar to the one described in reference Figures 5A-5C The receiving coil 90 shown and described, as reference Figure 5D The dual winding coil configuration 102 shown and described or as referenced Figures 7A-7C A multi-loop infinity shaped coil is shown and described as an infinity shaped coil. Fig.11 The schematic representation of the receiving coil 216 in FIG. 1 illustrates any type of receiving coil and its equivalent described in the present disclosure. For example, in a configuration where the receiving coil 216 is arranged as an infinitely large shaped coil, for example Fig.11 The depiction of the windings of the receive coil 216 shown in is intended to represent the multiple loops and one or more crossover regions that may be included in the configuration of the receive coil.

[0216] In some instances, such as Fig.11 The receiving coil 216 shown in FIG. 1 may be attached to the ferrite sheet 216A. Whether the receiving coil 216 is also attached to the ferrite sheet 216A (e.g., see FIG. 1 ) Figure 3A-3B In the examples shown and described with reference to the receive coil 55 shown and described, the receive coil 216 can be positioned along the curvature of the inner surface of the antenna window of the device. The receive coil 216 can be configured as a flat spirally wound coil positioned within the lumen of the implantable medical device, for example, with reference to Figure 3A The device 30 or Figure 3B 0A as shown and described in detail with reference to the accompanying drawings. Fig.11 The configuration of the receive coil 216 as a flat spirally wound coil may or may not include the receive coil being attached to a ferrite sheet such as ferrite sheet 216A.

[0217] like Fig.11 As shown in , capacitor 216B is coupled in parallel with receive coil 216. Capacitor 216B can be sized with respect to capacitance value so as to form, in combination with receive coil 216, a tank circuit having a resonant frequency that matches a frequency that may be applied by one or more externally generated magnetic fields applied to receive coil 216 for the purpose of inducing current into receive coil 216. Tuning the tank circuit including receive coil 216 and capacitor 216A to have a resonant frequency that matches the frequency of one or more magnetic fields expected to be applied to receive coil 216 allows a higher level of coupling efficiency to be achieved between the one or more applied magnetic fields and receive coil 216 when compared to other frequencies that do not match the resonant frequency of the tank circuit. Diode 216C is coupled in series with a first end of receive coil 216 and a terminal of capacitor 216B. A second end of receive coil 216 is coupled to common voltage node 220. In some examples, diode 216C is a Schottky diode. Diode 216C is configured to rectify any current induced into receive coil 216, illustratively represented by the arrow labeled “I(COIL_1)”, such that all current generated in receive coil 216 due to one or more externally applied magnetic fields will flow through diode 216C in the direction indicated as “I(COIL_1)” and toward node 219. In some examples, a minimum voltage level is required to forward bias diode 216C, and thus no current will be set to current “I(COIL_1)” until the minimum voltage level required to forward bias diode 216C exists, resulting in a minimum initial current level provided by the current induced into receive coil 216.

[0218] In instances where the receive coil 216 is the only receive coil included in the system depicted in schematic 215, the induced current provided by applying one or more externally generated magnetic fields to the receive coil 216 is provided to node 219 as the total amount of recharging current that can be used to perform recharging of the rechargeable power source 223. In other instances, additional receive coils can be included in the system depicted in schematic 215. The summing receive coil can provide one or more summing induced currents that can also be summed with the current from the receive coil 216 and provided to node 219.

[0219] As shown in schematic 215, the system illustrated in schematic 215 may include a second receiving coil 218. The second receiving coil 218 may be configured using any of the configurations described above with reference to receiving coil 216. The second receiving coil 218 may be configured as a flat spiral wound coil or an infinitely shaped coil having, for example, two or three loops. The second receiving coil 218 may or may not be attached to a ferrite sheet 218A. The second receiving coil 218 may be positioned along the inner surface 51 of the antenna window 40 of the device, or may be positioned within the inner cavity of the device as described above with reference to receiving coil 216. As described above with reference to receiving coil 216, in a similar manner and to provide similar functionality, the second receiving coil 218 may be coupled to a capacitor 218B and a diode 218C. For example, capacitor 218B may be sized with respect to a capacitance value so as to form, in combination with receiving coil 218, a tank circuit having a resonant frequency that matches a frequency that may be applied by one or more externally generated magnetic fields applied to receiving coil 218 for the purpose of inducing current into receiving coil 218. In various examples, the resonant frequency of the tank circuit formed by the second receiving coil 218 and the capacitor 218B is the same as the resonant frequency of the tank circuit formed by the first receiving coil 216 and the capacitor 216B. Thus, each of the receiving coils 216, 218 (and similarly, any additional coils represented by dots 217) is configured to provide a maximum level of coupling efficiency for a given level of magnetic field strength provided at the resonant frequency (compared to magnetic fields at other non-resonant frequencies). The second receiving coil 218 can be configured to provide a current illustratively represented by arrow "I(coil_N)" to the node 219 when one or more magnetic fields having sufficient magnetic field strength are applied to the receiving coil 218.

[0220] In various examples, the system shown in schematic 215 may include more than two receive coils. Additional coils are illustratively represented by "dots" generally indicated by brackets 217. In such examples, one or more separate additional receive coils may be arranged using any of the coil configurations and positioning configurations described above with reference to receive coils 216 and 218, and may include additional devices such as capacitors and diodes coupled to each of these additional coils in the same or similar manner as described above with reference to the capacitors and diodes associated with receive coils 216 and 218, respectively.

[0221] The configuration of the system with two or more coils shown in schematic 215 can have coils where each of the coils is configured in the same coil configuration (e.g., two or more flat spirally wound coils or two or more infinity-shaped coils). The configuration of the system with two or more receiving coils shown in schematic 215 is not limited to configuring the receiving coils uniquely or entirely for each coil in the same coil configuration (e.g., the same flat spirally wound coil configuration or the same infinity-shaped coil configuration). In some examples, at least one of the receiving coils can be configured in a first configuration (e.g., a flat spirally wound configuration) where at least one of the receiving coils is configured in an infinity-shaped coil (e.g., respectively, as shown in FIG. 214 ). Figure 3B For a system including two or more receiving coils, any current generated in a given coil providing current to node 219 in an amount in the coil may be summed together to provide a total recharging current indicated as "I (Total)".

[0222] like Fig.11As shown in , a smoothing capacitor 221 can be coupled between node 219 and the common voltage node 220 to smooth any rapid changes in the current provided to node 220. A power source 223 to be recharged using an "I(total)" current is coupled to node 219 via a switching device 222. The switching device 222 is not limited to any particular type of device, and in some instances, can be a semiconductor device (such as a transistor) controlled by the recharging circuit system 206. When the switching device 222 is operated to couple node 219 to the power source 223, the current provided to node 219 by one or more receiving coils can be provided to a first terminal of the power source 223 via the switching device 222. A second terminal of the power source 223 is coupled to the common voltage node 220. When coupled to node 219, the flow of current to the first terminal of the power source 223 provides a source of electrical energy to recharge the power source 223. In various examples, the recharging circuitry 206 is configured to control the coupling of the node 219 to the power source 223 by controlling the switching device 222 , and thereby regulate and control the rate and interval at which the power source 223 receives current from the node 219 .

[0223] Recharging circuit system 206 may include sensing circuit system 225. Sensing circuit system 225 may include circuits configured to sense, for example, Fig.11 The sensor and sensor processing circuit system of one or more parameters associated with the operation of the device shown in Fig.11 206). For example, the sensing circuit system 225 may include one or more sensors configured to sense the current level provided by one or more of the receiving coils 216, 218, and 217 (if provided). The sensing circuit system 225 may include one or more sensors configured to sense the current level provided to the power source 223 as the current "I (total)". The sensing circuit system 225 may also include one or more sensors configured to sense other parameters (such as the temperature of the power source 223 and / or the temperature within the receiving coils, the recharging circuit system 206, and the device in which the power source 223 is located). The recharging circuit system 206 may be configured to receive electrical signals sensed using the sensing circuit system 225 and / or data derived from the electrical signals, and control the recharging of the power source 223 based at least in part on these sensed signals and / or information derived from these sensed signals.

[0224] Sensing circuitry 225 may include one or more sensors configured to measure the voltage level and / or recharge level present at power source 223. Electrical signals sensed from sensing circuitry 225 and / or information derived from the electrical signals that indicate the voltage level and / or recharge level that has been contended with respect to power source 223 may also be used by recharging circuitry 206 as a basis for controlling recharging of power source 223. For example, the recharging circuitry may use these signals and / or information derived from these signals as a basis for regulating the current provided to power source 223 from node 219 by controlling the coupling provided between node 219 and power source 223 via switching device 222.

[0225] In some examples, a shunt device 224, which may include a resistive load, may be coupled to the switching device 222 such that the switching device 222 may couple the shunt device 224 to the node 219. At various times, when the recharging circuitry 206 determines that a recharging current is not being applied to the power source 223 but where a recharging current is being induced into one or more of the coils, the coupling of the shunt device 224 to the node 219 may be used to dissipate the current and, therefore, dissipate the energy applied to the coils 216, 218, and 217 (when set). In some examples, when it is determined that recharging of the power source 223 should be temporarily or permanently terminated, the recharging circuitry 206 may disconnect the coupling between the node 219 and the power source 223. When the node 219 is not coupled to the power source 223, the recharging circuitry 206 and the switching device 222 may be configured to optionally couple or not couple the shunt device 224 to the node 219.

[0226] Fig.12is a functional block diagram illustrating an example configuration of a system 230 for inductively recharging an implantable medical device 15 according to various examples described in the present disclosure. The system 230 includes: an external recharging circuit system 231 electrically coupled to a single recharging coil 232; in some examples, or a pair of recharging coils including a first coil 232 and a second coil 233; in some examples, one or more recharging coils positioned outside the body of a patient 12 having an implanted IMD 15 according to various examples described in the present disclosure. In some examples, the single coil 232 can be a flat planar coil arranged to be placed proximate to the patient 12 in an area adjacent to the IMD 15 and in some examples in direct contact with the patient. The single coil 232 can be electrically excited and configured to provide a time-varying magnetic field that can be applied to an implantable medical device (such as illustratively represented as an IMD 15 implanted in the body of the patient 12) for the purpose of recharging a power source within the IMD. In some examples, coil 232 can be arranged as a first coil of a pair of coils including a second coil 233, the pair of coils 232, 233 being physically arranged so that a time-varying magnetic field that can be applied to an implantable medical device (such as IMD 15) for the purpose of recharging a power source within the IMD is generated between the coils when the coils are electrically excited. In some examples, coils 232 and 233 can be physically arranged and electrically configured as Helmholtz coils. Fig.12 The arrangement of coil 232 and / or coils 232 and 233 shown relative to patient 12 and IMD 15 is not necessarily intended to illustrate an actual arrangement, for example, regarding the positioning and / or proportions of coil 232 or a pair of coils 232 and 233 and patient 12 / IMD 15 during a time period during which recharging of the IMD 15 is occurring, and is intended to illustrate various features of the example system 230.

[0227] like Fig.12, coil 232 (and coil 233 when provided) are coupled to recharging circuitry 231. Recharging circuitry 231 includes various electrical devices arranged to provide and control electrical excitation of coil 232 and / or coil pair 232 / 233 so as to generate one or more time-varying magnetic fields that can be applied to IMD 15 when the IMD is positioned proximate coil 232 or between coil pair 232 / 233. In various examples, IMD 15 includes a receive antenna positioned within or coupled to the IMD, a receive antenna configuration arranged as an example of any of the receive antenna configurations described in the present disclosure, or any equivalent thereof. The receive antenna arrangement can be configured to generate at least a minimum level of induced current in one or more of the receive coils of the receive antenna configuration regardless of the direction of the orientation of the magnetic field generated by coil 232 and / or coil 232 / 233 applied to the IMD 15 and for a given magnetic field strength applied to the IMD by one or more applied magnetic fields. Thus, an elaborate alignment equipment system and / or additional and more complex coil alignment procedures may not be required to achieve an acceptable level of inductive coupling efficiency between a magnetic field applied to IMD 15 and a receive antenna configuration of the IMD regardless of the orientation of IMD 15 relative to the direction of the applied magnetic field.

[0228] For example, a single coil 232 may be placed in a position proximate to the IMD 15 and external to the patient 12, such as covering and / or contacting an area of ​​the patient 12 adjacent to the location where the IMD 15 has been implanted, such as the patient's chest, when recharging a power source positioned within the IMD 15 while the IMD 15 is implanted within the patient 12. In some instances, the IMD 15 may be considered a deeply implantable device, such as a device implanted within a chamber of the heart of the patient 12. When positioned as described above, the coil 232 may be energized to generate a time-varying magnetic field that extends away from the coil 232 and is applied to the IMD 15 and a multi-axis antenna positioned within the IMD 15. Because the receive antenna configuration of the IMD 15 is at least somewhat non-directional, precise alignment of the direction of the applied magnetic field relative to the orientation of the IMD 15 and the receive antenna configuration is not critical or required and may be a random relative orientation.

[0229] Despite this random relative orientation, at least a minimum level of recharging current can be induced into the receive antenna configuration of IMD 15 for a given level of magnetic field strength provided by coil 232. The lack of a need for precise or specific alignment between the magnetic field and the orientation of IMD 15 can allow for efficient and rapid recharging of the power supply of the IMD without the need to perform complex alignment procedures and / or without the need to provide and operate complex alignment equipment to align coil 232 and IMD 15. In some instances, simply positioning coil 232 as a single coil proximate to an area of ​​IMD 15 (e.g., an area across the chest of patient 12 in the implant area of ​​IMD 15) is sufficient to allow for efficient levels of inductive coupling between the magnetic field generated by coil 232 and the receive antenna configuration of the IMD.

[0230] In a similar manner, when the power source of the IMD 15 is recharged using a pair of coils 232 and 233, the relative alignment of the direction of the magnetic field generated in the region between the coils 232 and 233 and the orientation of the IMD 15 may not be critical with respect to achieving an efficient level of inductive coupling between the magnetic field and a receive antenna configuration of the IMD. When the IMD 15 is positioned in the region between the coil pair 232, 233, the coil pair may be energized to generate a time-varying magnetic field that extends between the pair of coils and may be applied to the IMD 15 and the receive antenna configuration positioned within the IMD 15. The use of the coil pair 232, 233 may provide a more uniform magnetic field throughout the region between the coils and thus further reduce or eliminate the need to determine a particular positioning of the IMD 15 relative to the positioning of the coils 232, 233 while still providing an efficient level of inductive coupling for inducing a recharging current into the receive antenna configuration of the IMD. Further, because the receive antenna configuration of these example IMDs is somewhat non-directional, alignment of the direction of the applied magnetic field generated between coil 232 and coil 233 relative to the orientation of IMD 15 and the receive antenna configuration is not critical or required and can be a random relative orientation. Despite this random relative orientation, at least a minimum level of recharging current can be induced into the receive antenna configuration of IMD 15 for a given level of power provided by a pair of coils 232 and 233.

[0231] The lack of a need for precise or specific alignment between the magnetic field generated by the coil pair 232, 233 and the orientation of the IMD 15 may allow for efficient and rapid recharging of the IMD's power source without the need to perform complex alignment procedures and / or without the need to provide and operate complex alignment equipment to align the coil pair 232, 233 and the IMD 15. In some instances, simply positioning the IMD 15 within the region between the coils 232 and 233 (e.g., by positioning the coils 232 and 233 on opposite sides of the patient 12 such that a longitudinal axis common to the two coils is aligned with the IMD 15) is sufficient to allow for efficient levels of inductive coupling between the magnetic field generated by the pair of coils 232, 233 and the receive antenna configuration of the IMD. The use of a pair of coils 232, 233 can further simplify the need for positioning the IMD 15 relative to the coil pair, and the relatively uniform level of magnetic field provided between coils 232 and coils 233 can allow the IMD to be simply positioned somewhere in the area between the coils and thereby energize the coil pair to achieve an efficient level of inductive coupling between the magnetic field and the receiving antenna configuration of the IMD.

[0232] The recharging circuit system 231 can be coupled to a computing device 236 that includes a display 236A and one or more input devices 236B (e.g., a keyboard and / or a computer mouse) that allow a user to interact with the recharging circuit system 231 through the computing device 236. The computing device 236 can be communicatively linked to the recharging circuit system 231 via a wired connection 236C and / or via a wireless connection 236D. In various examples, the computing device 236 is configured to allow a user (e.g., a physician or technician) to Fig.12 2) operates and controls recharging circuitry 231 during a recharging session performed on IMD 15. Further, feedback received from IMD 15 (e.g., by computing device 236) may be used to control and adjust various aspects of recharging circuitry 231, including adjusting the field strength of the magnetic field applied to IMD 15 and controlling the duration of the recharging process.

[0233] In some examples, feedback from IMD 15 includes a value of a current level induced in a receiving coil of IMD 15 by inductive coupling of energy provided by coil 232 or by coil pair 232 and 233. Other information provided by IMD 15, such as temperature, charging rate, and percentage of charge information generated by IMD 15, may be transmitted from IMD 15 to computing device 236 or other external device and used by recharging circuitry 231 to control energization of coils 232 and 233 and / or determine when to terminate and / or adjust the power level applied to a recharging process performed by recharging circuitry 231 on IMD 15.

[0234] System 230 further includes external computing devices, such as server 238 and one or more other computing devices 241A-241N, that may be communicatively coupled to IMD 15, computing device 236, and / or external device 234 via network 237. In this example, IMD 15 may use its communication circuitry at different times and / or in different locations or settings to communicate with external device 234 via a first wireless connection and / or with access point 235 via a second wireless connection. Fig.12 In the example of , computing device 236 , access point 235 , external device 234 , server 238 , and computing devices 241A- 241N are interconnected and able to communicate with each other via network 237 .

[0235] Access point 235 may include a device connected to network 237 through any of a variety of connections, such as telephone dial-up, digital subscriber line (DSL), or cable modem connection. In other examples, access point 235 may be coupled to network 237 through different forms of connection, including wired or wireless connections. In some examples, access point 235 may be co-located with the patient. Access point 235 may interrogate IMD 15, for example, periodically or in response to a command from the patient or from network 237, to retrieve physiological measurements and / or other operational or patient data from IMD 15. Access point 235 may provide the retrieved data to server 238 through network 237. In various examples, access point 235 may be any example of transceiver 16 described above.

[0236] In some cases, server 238 may be configured to provide a secure storage location for data that has been collected from IMD 15, from recharging circuitry 231, and / or from external device 234. In some cases, server 238 may compile the data in a web page or other document via computing devices 241A-241N for viewing by a trained professional (e.g., a clinician). In some aspects, Fig.12 The illustrated system 230 may be used similar to that developed by Medtronic in Dublin, Ireland. The network is implemented using the general network technologies and functions provided by the network.

[0237] In some examples, computing device 236, access point 235, server 238, or one or more of computing devices 241A-241N may be configured to perform (e.g., may include processing circuitry configured to perform) some or all of the techniques described herein, for example, with reference to IMD 15 and the processing circuitry of external device 234, related to recharging a power source located within IMD 15. Fig.12In the example of system 230 shown in , server 238 includes memory 239 that may be configured to store physiological data and other data received from IMD 15 and / or external device 234 and processing circuitry 240 that may be configured to provide some or all of the functionality attributed to the processing circuitry of IMD 15 as described herein. For example, processing circuitry 240 may provide programming and / or parameters used by recharging circuitry 231 that may be used in providing inductive recharging of a power source located within IMD 15.

[0238] Fig.13 Graphs 250, 260 show representative waveforms 251, 261 that may be generated by a signal generator and applied to one or more recharging coils of a recharging system according to various examples described in the present disclosure. According to various examples described in the present disclosure, the representative waveforms 251, 261 may be generated by a signal generator (e.g., as described in reference to FIG. Fig.12 The signal generator included in the recharging circuit system 231 shown and described above generates and applies to a coil (e.g., Fig.12 Coil 232 or a pair of coils 232 and 233). Fig.13 , graph 250 illustrates an example waveform 251 of a square wave having amplitude values ​​plotted relative to a vertical axis 252 over time (time represented by a horizontal axis 253). Waveform 251 includes a peak-to-peak amplitude 254 and a cycle period 255. In various examples, the peak-to-peak amplitude 254 of waveform 251 can include a voltage range of 10 mV to 100 volts, and in some examples 5 volts. In some examples, the peak-to-peak amplitude depends on the selected power amplifier to which waveform 251 is being provided in order to generate an output for energizing a coil or a pair of electrical coils arranged as a recharging coil in a recharging system.

[0239] In some instances, the power amplifier driven by waveform 251 is a fixed gain power amplifier capable of providing a 400 watt output signal based on a variable input signal having a peak-to-peak amplitude of 10-200 mV. In some instances, reference voltage level 256 may include a zero volt reference voltage, wherein a portion of waveform 251 is set at a voltage level that is a higher voltage than reference voltage level 256, and a portion of waveform 251 is set at a voltage level that is less than reference voltage level 256. In various instances, the duty cycle of waveform 251 within period 255 provides a fifty percent duty cycle. In various instances, the duty cycle of waveform 251 within period 255 provides a duty cycle other than a fifty percent duty cycle. In various instances, the time period 255 of waveform 251 ranges from 100 microseconds to 100 nanoseconds, indicating that the frequency range of waveform 251 is 10 kHz to 10 MHz.

[0240] In some examples, a voltage having a waveform corresponding to waveform 251 can be applied to a single recharging coil to generate a magnetic field that can be applied to a receive antenna configuration of an implantable medical device to induce a recharging current into the receive antenna configuration for the purpose of recharging a power source of the implantable medical device. The receive antenna configuration can be any of the examples of receive antenna configurations described throughout the present disclosure that are configured to provide at least a minimum level of recharging current for a given energy level associated with the applied magnetic field regardless of the orientation of the magnetic field generated by the single recharging coil relative to the orientation of the implantable medical device.

[0241] In some examples, a voltage having a waveform corresponding to waveform 251 can be applied to a pair of coils to generate a generally uniform magnetic field between the pair of coils that can be applied to a receive antenna configuration of an implantable medical device positioned in a region between the pair of coils. For the purpose of recharging a power source of the implantable medical device, a uniform magnetic field can be used to induce a recharging current into the receive antenna configuration. The receive antenna configuration can be any of the examples of receive antenna configurations described throughout the present disclosure that are configured to provide at least a minimum level of recharging current for a given energy level associated with the applied magnetic field regardless of the orientation of the magnetic field generated by the pair of coils relative to the orientation of the implantable medical device.

[0242] In some examples, electrical energy having the same electrical parameters, such as the amplitude, duty cycle, and phase of waveform 251, is applied to each coil of a pair of coils used as recharging coils. Other and / or different combinations of differences between the electrical parameters of waveform 251 applied to a first electrical coil and simultaneously applied to a second electrical coil are not limited to changes in the amplitude 254 of the waveform, and may include other changes, such as a difference in the duty cycle of the waveform applied to, for example, the first coil compared to the duty cycle of the waveform applied to the second electrical coil.

[0243] Graph 260 shows an example waveform 261 of a sinusoidal waveform with different amplitude values ​​plotted relative to vertical axis 262 over time (time is represented by horizontal axis 263). Waveform 261 includes a peak-to-peak amplitude 264 and has a period 265. In various examples, the peak-to-peak amplitude 264 of waveform 261 can include a voltage range of 10mV to 100 volts, and in some examples, 5 volts. In some examples, the peak-to-peak amplitude depends on the desired peak magnetic field strength and the capacity of the power amplifier used. In some examples, the power amplifier driven by waveform 261 is a fixed 400 watt power amplifier, and in other examples, the power amplifier includes a variable output between 2 watts and 1 kW. In some examples, the reference voltage level 266 can include a zero volt reference voltage, wherein a portion of waveform 261 provides a voltage level higher than the reference voltage level 266, and another portion of each cycle of waveform 261 includes a voltage value lower than the reference voltage level 266. In various examples, the duty cycle of waveform 261 over period 265 provides a fifty percent duty cycle of voltage levels above reference voltage level 266. In various examples, time period 265 of waveform 261 ranges from 100 microseconds to 100 nanoseconds, representing a frequency range of waveform 261 of 10 kHz to 10 MHz.

[0244] In some examples, a voltage having a waveform corresponding to waveform 261 can be applied to a single recharging coil to generate a magnetic field that can be applied to a receive antenna configuration of an implantable medical device to induce a recharging current into the receive antenna configuration for the purpose of recharging a power source of the implantable medical device. The receive antenna configuration can be any of the examples of receive antenna configurations described throughout the present disclosure that are configured to provide at least a minimum level of recharging current for a given energy level associated with the applied magnetic field regardless of the orientation of the magnetic field generated by the single recharging coil relative to the orientation of the implantable medical device.

[0245] In some examples, a voltage having a waveform corresponding to waveform 261 can be applied to a pair of coils to generate a generally uniform magnetic field between the pair of coils that can be applied to a receive antenna configuration of an implantable medical device positioned in a region between the pair of coils. For the purpose of recharging a power source of the implantable medical device, a uniform magnetic field can be used to induce a recharging current into the receive antenna configuration. The receive antenna configuration can be any of the examples of receive antenna configurations described throughout the present disclosure that are configured to provide at least a minimum level of recharging current for a given energy level associated with the applied magnetic field regardless of the orientation of the magnetic field generated by the pair of coils relative to the orientation of the implantable medical device.

[0246] In some examples, electrical energy having the same electrical parameters, such as the amplitude, duty cycle, and phase of waveform 261, is applied to each coil of a pair of coils used as recharging coils. Other and / or different combinations of differences between the electrical parameters of waveform 261 applied to a first electrical coil and simultaneously applied to a second electrical coil are not limited to changes in the amplitude 264 of the waveform, and may include other changes, such as a difference in the phase of the waveform applied to, for example, the first coil compared to the phase of the waveform applied to the second coil.

[0247] Fig.14 is a flow chart illustrating a method 300 according to various examples described in the present disclosure. The method 300 includes recharging a power source in an implantable medical device 30 positioned within a patient's body. The method 300 also contemplates providing power to power and operate the implantable medical device by inductively coupling power from a magnetic field generated externally from the implantable device to a receiving antenna configuration within the implantable device. The method 300 is described as being performed by referring to Fig.12 The system 230 shown and described is used to perform the Figure 2A-9B The method 300 is not limited to the instance of executing the recharging process of the implantable medical device 30 having the receiving antenna configuration positioned within the device as shown and described in any one of the foregoing. However, the method 300 is not limited to executing the instance of the system 230 performing the recharging process on the implantable medical device, and the method 300 is not limited to the recharging process performed on the instance of the device 30. The process of the method 300 contemplates other devices having the instance of the receiving antenna configuration configured to induce a recharging current into the antenna for the purpose of recharging the power supply of the implantable medical device as described throughout this disclosure and any equivalents thereof.

[0248] Method 300 includes external recharging circuitry 231 of system 230 energizing at least one recharging coil (e.g., coil 232 or a pair of coils 232, 233) to generate a magnetic field (block 302). In the case where the recharging coil of the external recharging circuitry is a single recharging coil (such as coil 232), the recharging coil may be a flat spirally wound planar coil according to any of the examples described throughout this disclosure. In the case where the recharging coil includes a pair of coils (such as coils 232 and 233), the pair of coils may be physically arranged and electrically energized according to any of several pairs of coils described throughout this disclosure (including coils 232 and 233 arranged to form a Helmholtz coil).

[0249] Method 300 includes receiving one or more generated magnetic fields at a receiving antenna configuration of implantable medical device 30 (block 304). In some examples, the implantable medical device includes a rechargeable power source (e.g., battery 39 ( )) that is recharged using electrical energy induced into the receiving antenna configuration of the implantable medical device by the applied magnetic field. Figure 2A-2B )). In some instances, the implantable medical device is configured to use electrical energy induced into the device's receiving antenna configuration to power the implantable medical device's circuit system in order to operate the implantable medical device. In some instances where a single recharging coil is used to generate a magnetic field, applying the magnetic field to the receiving antenna configuration of the implantable medical device 30 includes placing the recharging coil in proximity to and in some instances in contact with an external area or surface of a patient having an implantable medical device to be recharged that is adjacent to the location of the implantable device. In some instances where a pair of coils are used to generate a magnetic field, applying the magnetic field to the multi-axis antenna can include positioning the patient, and therefore the implantable medical device 30, within an area positioned between the pair of coils 232, 233.

[0250] The receive antenna configuration may include any of the instances of receive coils as described throughout the present disclosure, and may include a combination of two or more receive coils as described in the present disclosure that are configured to generate one or more induced currents in one or more receive coils when a magnetic field is applied to the one or more receive coils and to provide the generated currents to additional circuitry of the implantable medical device.

[0251] In some examples of method 300, the receive antenna configuration includes at least one receive coil including an electrical conductor forming a coil winding, the coil winding being positioned within an inner cavity surrounded by a housing of the implantable medical device, the coil winding being formed into a curved shape conforming to the curvature of at least a portion of an inner surface of the housing at least partially surrounding the inner cavity, the coil winding being positioned adjacent to the curvature of the inner surface such that the coil winding bends along the curvature of the inner surface and is positioned adjacent to the curvature of the inner surface. The electrical conductor may include any form of electrical conductor described throughout the present disclosure, including a wire or a stranded conductor (such as Litz wire) formed of a conductive metal (such as copper).

[0252] The coil winding positioned adjacent to the inner surface of the housing may comprise a helically wound planar coil, as shown in reference Figures 4A-4B The receiver coil 70 shown and described. The coil winding positioned adjacent to the inner surface of the housing may include an infinitely shaped coil winding, as shown in reference Figure 5B-5C The receiving coil 90 shown and described or referenced Figure 5DThe illustrated and described dual winding coil configuration 102. The coil winding positioned adjacent to the inner surface of the housing may include an infinitely shaped coil winding including three loops, wherein a first loop and a second loop of the coil winding are attached to or positioned adjacent to the inner surface of the housing, and include a configuration consistent with Figure 7B The curvature of the inner surface shown and described in the figure is the curvature along the longitudinal axis of the first and second loops. The third loop of the coil winding is oriented so that the central axis of the coil winding of the third loop corresponds to the longitudinal axis of the implantable medical device and is located as shown in the figure. Figure 7B In some examples, a portion of the housing including the inner surface includes an antenna window, such as antenna window 40 described by the present disclosure. In some examples, the portion of the housing is not formed by a separate antenna window and is included in a portion of the housing, such as Figure 2B The second housing portion 36 is shown in FIG.

[0253] The receive antenna configuration of method 300 may include a plurality of receive coils that may be individually coupled to the recharging circuitry 206 of the implantable medical device, each receive coil being configured to provide an individual current to the recharging circuitry when current is induced into the receive coil. The receive antenna configuration and / or the recharging circuitry is configured to sum the individual currents provided by one or more receive coils of the receive antenna configuration to generate a recharging current. The recharging current may be applied to a recharging power source (battery 39- Figure 2A-2B ) to recharge a rechargeable power source, or to power and operate the circuit system of an implantable medical device.

[0254] In some examples of receive antenna configurations having multiple receive coils, the first receive coil 55 can be positioned adjacent to and include a curved shape that conforms to the curvature of a portion of the inner surface of the housing (which can include the antenna window 40), while the second receive coil 65 is positioned as a flat planar coil positioned within the inner cavity 53 of the antenna window, as shown in reference Figure 3A The first receiving coil may be a spirally wound planar coil (as shown and described in reference Figure 4A The receiving coil 70 shown and received, or may be an infinitely large shaped coil (as shown in reference Figure 5B-5C The receiving coil 90 shown and described or referenced Figure 5D The illustrated and described dual winding coil configuration 102. The first receiving coil 55 and / or the second receiving coil 65 may each be attached to a separate ferrite sheet.

[0255] In some examples of a receive antenna configuration having multiple receive coils, the first receive coil 55 can be positioned adjacent to and have a curved shape that conforms to the curvature of a first portion of an inner surface of the housing (which can include the antenna window 40), and the second receive coil 112 can be positioned adjacent to and have a curved shape that conforms to the curvature of a second portion of the inner surface of the antenna window, as described with reference to FIG. Figure 6 In this example, one or both of the first receiving coil 55 and the second receiving coil 112 may include a spirally wound planar coil or an infinitely shaped coil winding. The first receiving coil 55 and / or the second receiving coil 65 may be attached to separate ferrite sheets, respectively. In this example, the receiving antenna configuration may further include the Figure 6 The third receive coil 65 is shown and described as being positioned within the interior cavity 53 of the antenna window. The third receive coil 65 may include a flat spirally wound coil winding that may or may not be attached to a ferrite sheet 66.

[0256] In some examples of a receive antenna configuration having multiple receive coils, the receive antenna configuration may include an infinity-shaped receive coil having a first loop, a second loop coupled to the first loop via a first crossover region, and a third loop coupled to the second loop via a second crossover region, the three-loop receive coil being positioned within antenna window 40 of implantable medical device 30, as described with reference to Figure 7B As shown and described.

[0257] In some examples of a receive antenna configuration having multiple receive coils, the receive antenna configuration includes a first receive coil 164 having an infinity-shaped coil winding and a second receive coil 174 having an infinity-shaped coil winding, the first receive coil 164 having a curved shape and positioned adjacent to a first portion of the curved shape of an inner surface of a housing (which may include an antenna window 40), and the second receive coil 174 having a curved shape and positioned adjacent to a second portion of the curved shape of an inner surface of the antenna window, as described with reference to FIG. Figures 8A-8B As shown and described.

[0258] In some examples of a receive antenna configuration having multiple receive coils, the receive antenna configuration includes multiple receive coils (e.g., a first receive coil 184, a second receive coil 185, a third receive coil 186, and a fourth receive coil 187), each of the multiple receive coils including a spirally wound planar coil having a curved shape that conforms to the curvature of the inner surface of the antenna window 40, wherein the multiple receive coils are positioned around and adjacent to the curved inner surface of the antenna window 40 and adjacent to each other along the longitudinal axis 189, as shown. Figures 9A-9BThe multiple receive coils may or may not be attached to one or more ferrite sheets positioned between the inner surface 51 and the individual receive coils.

[0259] Reference again Fig.14 , method 300 includes summing, by the recharging circuit system, one or more currents induced into at least one receiving coil of the receiving antenna configuration to generate a recharging current (block 306). Summing the induced currents may include coupling each of the plurality of receiving coils of the receiving antenna configuration to a separate diode, as described with reference to schematics 215 and Fig.11 The diodes 216C, 218D are shown and described. In various examples, summing the sensed currents may include using capacitors (such as those shown in the reference schematics 215 and Fig.11 The capacitors 216B, 218B and / or capacitor 221) are shown and described to filter one or more currents generated in one or more of the receive coils of the receive antenna configuration.

[0260] Reference again Fig.14 , method 300 includes applying, by the recharging circuit system, the generated recharging current to the circuit system of the implantable medical device 30 (block 308). In some examples, applying the recharging current to the circuit system includes applying the recharging current to a rechargeable power source (e.g., battery 39) of the implantable medical device 30 (block 308). In various examples, applying the recharging current to the power source includes controlling the recharging current to the power source (e.g., power source 204 ( Fig.10 ) or power supply 223( Fig.11 )) is coupled, the switching device is composed of a recharging circuit system ((as referenced Fig.10 and / or schematic diagram 215 and Fig.11 In some examples, applying the recharging current to the circuit system includes applying the recharging current to the circuit system (as shown and described in reference to Fig.10 any of the circuit systems shown and described in the IMD 15 in the embodiment of the present invention) to power and operate the implantable medical device.

[0261] Fig.15 320 is a flow chart illustrating another method 320 according to various examples described in the present disclosure. The method 320 includes a method for manufacturing a receiving antenna configuration of an implantable medical device for implantation in a patient according to the devices, systems, and techniques described herein. The method 320 is described as manufacturing an implantable medical device 30 (designed to be implanted in a chamber of a patient's heart and including a receiving antenna configuration configured to generate a recharging current when a magnetic field is applied to the antenna. Figure 2A-2B ), the recharging current is used to recharge the power source (e.g., battery 39) of the device 30. However, the method 320 is not limited to manufacturing a device having, for example, a reference Figure 2A-9B The illustrated and described implantable medical device 30 of the receive antenna configuration may be applied to the manufacturing process of various implantable medical devices having receive antenna configurations according to the examples as described throughout this disclosure and any equivalents thereof.

[0262] Method 320 includes forming a receive antenna configuration for an implantable medical device 30 including at least one receive coil (block 322). The at least one receive coil may include a planar coil wound as a spiral (eg, as shown in FIG. Figures 4A-4B The at least one receiving coil may include a coil winding formed of an electrical conductor of the receiving coil 70 shown and described. The at least one receiving coil may include a coil winding formed into an infinite shape including two loops coupled at a crossover region (as shown in reference Figures 5A-5C The at least one receiving coil may include a coil winding formed by an electrical conductor of the receiving coil 90) shown and described. Figure 5D The dual winding coil configuration 102 is shown and described. The at least one receiving coil may include a coil winding formed into an infinite shape including three loops (as shown in reference Figure 7A-7B A coil winding formed by an electrical conductor (as shown and described).

[0263] The electrical conductor used to form the coil winding of the receive coil is not limited to any particular type of electrical conductor, and can be any type of electrical conductor that can be used to form a receive coil as described throughout this disclosure, including a wire or a plurality of strands of electrical conductors (such as Litz wire) composed of a conductive metal (such as copper). The coil winding can be formed using any technique that can be used to form a receive coil, including any of the techniques described throughout this disclosure, including twisting the loops of the coil winding of the electrical conductor to form an infinitely shaped coil winding as described herein.

[0264] Reference again Fig.15, method 320 includes attaching at least one receiving coil of the antenna configuration to an inner surface of a portion of a housing of the implantable medical device (block 326). In some instances, the portion of the housing that includes the inner surface is a separate antenna window portion. In some instances, the portion of the housing that includes the inner surface is not a separate antenna window portion, wherein the inner surface is included in a portion of the device that is attached to an end cap at one end and to another portion of the housing at an opposite end. Attaching the at least one receiving coil to the inner surface of the housing may include attaching the at least one receiving coil directly to the inner surface such that a coil winding forming the at least one receiving coil is in contact with at least some portion of the inner surface. Attaching the at least one receiving coil to the inner surface of the housing may include: attaching the at least one receiving coil to a first surface of a flexible ferrite sheet (block 324); and then attaching a second surface of the ferrite sheet opposite the first surface to the inner surface of the housing such that the ferrite sheet is positioned between the inner surface and the coil winding of the at least one receiving coil (block 326).

[0265] Attaching the at least one receive coil to the inner surface of the shell may include: bending the coil winding of the at least one receive antenna so that the at least one receive coil has a curved shape corresponding to the curved shape on the inner surface of the shell; and attaching the at least one receive antenna so that the coil winding of the at least one receive antenna is positioned adjacent to the inner surface and so that the curved shape of the at least one receive antenna corresponds to at least a portion of the curved inner surface. In some examples, attaching the at least one receive coil to the inner surface of the shell includes attaching a first loop and a second loop of a three-loop infinity-shaped coil to the inner surface of the shell and positioning a third loop of the three-loop infinity-shaped coil within an inner cavity at least partially surrounded by the inner surface.

[0266] Attaching at least one receive coil to the inner surface of the housing can include attaching a plurality of receive coil windings directly to the inner surface of the housing (e.g., without an intervening ferrite sheet). In some instances, the plurality of receive coils include two separate infinity-shaped receive coils. In some instances, the plurality of receive coils include a plurality of spirally wound planar coils. Attaching at least one receive coil to the inner surface of the antenna window can include positioning a second receive coil within an inner cavity at least partially surrounded by the inner surface.

[0267] The method 320 includes electrically coupling one or more receive coils of the receive antenna configuration to recharging circuitry of the device 30 (block 328). Coupling the receive antenna configuration may include coupling a first lead of each receive coil to a separate diode and coupling a second lead of each receive coil to a common voltage conductor. In the example of a receive antenna configuration including multiple receive coils, coupling the receive antenna configuration to the recharging circuitry may include coupling each receive coil to circuitry including an electrical diode so that any currents generated in any of the receive coils may be summed together to generate a recharging current that includes all of the one or more currents generated by any and all of the receive coils at any given time.

[0268] Method 320 includes coupling a portion of the housing including a receiving antenna configuration to one or more additional portions of the housing of the implantable medical device (block 330). Coupling the portion of the housing including the receiving antenna configuration to the additional portions of the housing may include coupling an antenna window (e.g., antenna window 40) to the first housing portion 31 and the second housing portion 36, as described with reference to FIG. Figure 2A In some examples, a portion of the housing may include or form part of the housing (e.g. Figure 2B ), and coupling the portion of the housing to the other portion of the housing may include coupling the portion of the housing including the receiving antenna configuration to another portion of the housing (such as the first housing portion 31).

[0269] The method 320 includes sealing the portion of the housing to another portion of the housing to create a sealed interior cavity containing the receiving antenna configuration (block 332). Sealing the antenna window may include forming a first sealing seam 41 between a top side of the antenna window and the first housing portion 31 and forming a second sealing seam 42 between a bottom side of the antenna window and the second housing portion 36 of the implantable medical device, as described with reference to FIG. Figure 2A Sealing the portion of the housing containing the receiving antenna arrangement may include forming a first sealed seam 42 between the portion of the housing containing the receiving antenna arrangement and another portion of the housing, as shown and described in reference Figure 2B Sealing portions of the housing and / or the antenna window may include using any material (e.g., adhesive) and / or any type of welding or bonding process that may be used to provide a hermetic seal between the type of material used to form the portion of the housing that appears to be joined or between the antenna window and other portions of the housing and one or more material types used to form another portion of the housing to which the antenna window is coupled.

[0270] The use of the devices, systems and techniques described in the present disclosure is not limited to use in the device only during the recharging session applied to the device. The examples of the receiving antenna configuration as described throughout the present disclosure or any equivalent thereof may be included as part of a passive device. In some examples, the passive device may not include an internal power source capable of storing electrical energy during an extended period of time during which the device may be required to operate, wherein the device may receive power from the external device, for example, through inductive coupling power provided by an external device, and only operate during the time and period or time period when the device is excited from the external power source. When operating the passive device, an external device may include a transmission coil that is arranged to be electrically excited to generate a magnetic field applied to the receiving antenna configuration incorporated in the passive device or coupled to the passive device. The applied magnetic field generates one or more currents in the receiving antenna configuration of the passive device, and the other circuit system of the passive device is arranged to receive these induced currents to power and operate the passive device. Because these currents induced in the receiving antenna configuration are used to power and operate the passive implantable medical device, they can be referred to as "operating currents".

[0271] Once powered by the induced current, the implantable medical device can perform various functions, including sensing physiological parameters associated with the patient, so as to monitor and / or diagnose the patient's condition and / or provide therapy (such as electrical stimulation therapy) to the patient when the passive device is powered by the applied magnetic field. In some cases, the need to operate the passive device may only require powering the device within a short time interval (e.g., a period of thirty minutes) and only periodically (e.g., once a day or once a week or once a month in other instances). By eliminating the need to locate the power supply within the passive device or as part of the passive device, the overall size and / or dimensions of the passive device can be reduced relative to similar devices that include a power supply as part of the device. The smaller size of the passive device can allow for less invasive implantation to implant the passive device at the implantation site, and can help to make the patient comfortable after the implantation of the device due to the smaller size of the implantable device.

[0272] The technology of the present disclosure can be implemented in a variety of computing devices, medical devices, or any combination thereof. Any of the described units, modules, or components may also be implemented together or individually as discrete but interoperable logic devices. Depicting different features as modules or units is intended to highlight different functional aspects, and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. On the contrary, the functions associated with one or more modules or units may be performed by separate hardware or software components, or integrated in shared or separate hardware or software components.

[0273] The techniques described in the present disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of the techniques may be implemented in one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuit systems, and any combination of these components, embodied in a programmer (such as a physician or patient programmer), a stimulator, or other device. The terms "processor," "processor circuitry," "processing circuitry," "controller," or "control module" may generally refer to any of the aforementioned logic circuitry, either alone or in combination with other logic circuitry, or any other equivalent circuitry, either alone or in combination with other digital or analog circuitry.

[0274] For various aspects implemented in software, at least some of the functions attributed to the systems and devices described in the present disclosure may be embodied as instructions on a tangible computer-readable storage medium (e.g., random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic media, optical media, etc.). Computer-readable storage media may be referred to as non-transitory. A server, client computing device, or any other computing device may also contain a more portable type of removable memory to enable easy data transfer or offline data analysis. Instructions may be executed to support one or more aspects of the functionality described in the present disclosure.

[0275] In some instances, computer-readable storage media include non-transitory media. The term "non-transitory" may indicate that the storage media is not embodied in a carrier wave or propagated signal. In some instances, non-transitory storage media may store data that may change over time (e.g., in RAM or cache).

[0276] Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

1. An implantable medical device comprising: a rechargeable power source coupled to one or more circuits positioned within a housing of the implantable medical device, the rechargeable power source configured to provide power to the one or more circuits; a receiving antenna configuration, the receiving antenna configuration comprising at least one receiving coil, the at least one receiving coil comprising an electrical conductor forming a coil winding, the coil winding being positioned within an inner cavity surrounded by the housing of the implantable medical device and being attached to an inner surface of an antenna window portion of the housing, the coil winding being formed into a curved shape conforming to a curvature of at least a portion of the inner surface of the housing that at least partially surrounds the inner cavity, the coil winding being positioned adjacent to the curvature of the inner surface such that the coil winding bends along and is positioned adjacent to the curvature of the at least a portion of the inner surface, the receiving coil being configured to generate a current induced into the at least one receiving coil when an externally generated magnetic field is applied to the at least one receiving coil; as well as a recharging circuit system coupled to the at least one receiving coil and to the rechargeable power source, the recharging circuit system being configured to receive the current induced into the at least one receiving coil and to provide a recharging current to the rechargeable power source, wherein the coil winding of the at least one receiving coil includes a half twist such that the at least one receiving coil and the recharging circuit system are configured to provide at least a minimum level of recharging current for a given level of magnetic field strength provided by the magnetic field applied to the at least one receiving coil for a plurality of orientations of the magnetic field direction relative to the orientation of the implantable medical device.

2. The implantable medical device of claim 1, wherein the electrical conductor is formed as an infinity-shaped coil winding.

3. An implantable medical device according to claim 2, wherein the infinity-shaped coil winding includes a first loop, a second loop, and an intersection area coupling the first loop and the second loop, the first loop and the second loop extending in opposite directions away from the intersection area along the longitudinal axis of the coil winding, and the longitudinal axis has a curved shape corresponding to the curvature of the inner surface of the portion of the shell positioned adjacent to the infinity-shaped coil winding.

4. The implantable medical device of claim 2, wherein the infinity-shaped coil winding comprises a first loop, a second loop, a third loop, a first crossover region coupling the first loop and the second loop, and a second crossover region coupling the second loop to the third loop, wherein the first loop and the second loop extend in opposite directions away from the first intersection region along a first longitudinal coil axis having a curved shape corresponding to a curvature of an inner surface of a portion of the housing adjacent to the first loop and the second loop, and wherein the third loop of the coil winding is oriented such that a central axis of the coil winding of the third loop corresponds to a longitudinal axis of the implantable medical device and lies in a plane or a set of coplanar planes that are perpendicular to the longitudinal axis of the implantable medical device.

5. The implantable medical device of claim 2, wherein the at least one receiving coil comprises a second receiving coil formed as a flat, spirally wound planar coil, the second receiving coil being positioned away from the inner surface of the housing and within the inner cavity of the housing.

6. The implantable medical device of claim 1, wherein the coil winding of the at least one receive coil attached to the inner surface of the housing comprises a helically wound planar coil.

7. The implantable medical device of claim 1 , wherein the at least one receiving coil comprises: a first infinity-shaped receive coil positioned adjacent to the interior surface and comprising a curved shape conforming to a curvature of a first portion of the interior surface of the housing; as well as A second infinity shaped receive coil is positioned adjacent to the interior surface and includes a curved shape that conforms to the curvature of a second portion of the interior surface of the housing.

8. The implantable medical device of claim 1, wherein the portion of the housing surrounding the inner cavity comprises a cylindrically shaped exterior extending along a longitudinal axis of the implantable medical device, the cylindrically shaped exterior having a circular shape in cross-section relative to the longitudinal axis.

9. An implantable medical device according to any one of claims 1-8, wherein the implantable medical device comprises one or more fixing members, and the one or more fixing members are configured to fix the implantable medical device at an implantation site, and the implantation site is positioned within an internal portion of a chamber of the patient's heart.

10. An implantable medical device according to claim 1, wherein the receiving antenna configuration is positioned adjacent to and surrounded by an antenna window forming the portion of the shell of the implantable medical device, the antenna window being sealingly coupled to a first portion of the shell at a first seam and to a second portion of the shell at a second seam, the second portion of the shell being sealingly coupled to an end cap of the implantable medical device to form the shell into an airtightly sealed housing.

11. The implantable medical device of claim 10, wherein the antenna window is formed of a material comprising sapphire.

12. An implantable medical device according to any one of claims 1-8, wherein at least a portion of the housing at least partially surrounding the receiving antenna arrangement is formed from a material comprising a biocompatible ceramic.

13. An implantable medical device according to any one of claims 1-8, wherein at least a portion of the housing at least partially surrounding the receiving antenna arrangement is formed from a cermet material made using a metal injection molding process.

14. A method for forming a receive antenna configuration for an implantable medical device according to claim 1, the method comprising: forming an electrical conductor into at least one receive coil, the at least one receive coil comprising a first set of coil windings forming a first loop, a second set of coil windings forming a second loop, and coupling the coil windings of the first loop with the coil windings of the second loop to form the at least one receive coil into an infinity shape with a crossover region comprising a half twist; attaching the at least one receiving coil comprising the infinity shape to an inner surface of an antenna window portion of a housing of the implantable medical device such that a curvature of a longitudinal axis of the at least one receiving coil conforms to a curvature of the inner surface; electrically coupling the at least one receiving coil to recharging circuitry of the implantable medical device; as well as The antenna window is coupled to one or more additional portions of the housing to enclose the at least one receive coil and the recharging circuitry within the housing of the implantable medical device.

15. The method according to claim 14, further comprising: The antenna window is sealed to the one or more additional portions of the housing to form a hermetically sealed interior cavity, wherein the at least one receive coil is positioned within the interior cavity.

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