Floating intermediate coil array for medical implants

Abstract

An apparatus includes a first magnetic induction (MI) antenna and circuitry in electrical communication with the first MI antenna. The apparatus also includes an MI antenna array galvanically isolated from the first MI antenna and the circuitry. The array includes a second MI antenna and a third MI antenna. The second MI antenna has a non-zero first coupling coefficient with the first MI antenna, and the third MI antenna has a non-zero second coupling coefficient with the first MI antenna, and a third coupling coefficient with the second MI antenna that is substantially equal to zero.

Description

background Technical Field

[0001] This application generally relates to systems and methods for wirelessly transmitting data to or from a device implanted on or within the body of a recipient. Background Technology

[0002] Over the past few decades, medical devices have provided a wide range of therapeutic benefits to recipients. Medical devices can include internal or implantable components / devices, external or wearable components / devices, or combinations thereof (e.g., devices having an external component that communicates with the implantable component). Medical devices, such as conventional hearing aids, partially or fully implantable hearing prostheses (e.g., bone conduction devices, mechanical stimulators, cochlear implants, etc.), pacemakers, defibrillators, functional electrical stimulation devices, and other medical devices, have been successful for many years in performing life-saving and / or lifestyle improvement functions and / or recipient monitoring.

[0003] Over the years, the types of medical devices and the range of functions they perform have increased. For example, many medical devices, sometimes referred to as “implantable medical devices,” now typically include one or more instruments, devices, sensors, processors, controllers, or other functional mechanical or electrical components permanently or temporarily implanted in a recipient. These functional devices are typically used to diagnose, prevent, monitor, treat, or manage diseases / injuries or their symptoms, or to study, replace, or modify anatomical structures or physiological processes. Many of these functional devices utilize power and / or data received from an external device that is part of or operates in conjunction with the implantable component. Summary of the Invention

[0004] In one aspect disclosed herein, an apparatus includes a first magnetic induction (MI) antenna, the first MI antenna including a conductive first coil extending around and substantially orthogonal to a first antenna axis. The apparatus also includes a circuitry in electrical communication with the first MI antenna. The circuitry is configured to supply current to and / or receive current from the first MI antenna. The apparatus further includes an MI antenna array that is current-isolated from the first MI antenna and the circuitry. The array includes at least a second MI antenna and a third MI antenna. The second MI antenna includes a conductive second coil extending around and substantially orthogonal to a second antenna axis, the second antenna axis being substantially parallel to the first antenna axis, and the second MI antenna having a non-zero first coupling coefficient with the first MI antenna. The third MI antenna includes a conductive third coil extending around and substantially orthogonal to a third antenna axis, the third antenna axis being substantially parallel to the first antenna axis, and the third MI antenna having a non-zero second coupling coefficient with the first MI antenna and a substantially zero third coupling coefficient with the second MI antenna.

[0005] In another aspect disclosed herein, a method includes providing a first MI antenna within a housing. The method further includes attaching a second MI antenna to the housing. The second MI antenna is electrically floating relative to the first MI antenna and has a non-zero mutual inductance with the first MI antenna. The method further includes attaching a third MI antenna to the housing. The third MI antenna is electrically floating relative to the first MI antenna and has a non-zero mutual inductance with the first MI antenna. The third MI antenna has substantially zero mutual inductance with the second MI antenna.

[0006] In another aspect disclosed herein, a device includes a first coil that is conductive and substantially planar. The device also includes a circuit system in electrical communication with the first coil. The device further includes a plurality of second coils that are conductive and substantially planar, the plurality of second coils being electrically isolated from the circuit system and the first coil. The plurality of second coils are substantially parallel to each other and substantially parallel to the first coil. The plurality of second coils have substantially zero magnetic inductive coupling to each other. Attached Figure Description

[0007] The embodiments are described in this article with reference to the accompanying drawings, in which: Figure 1A This is a perspective view of an example cochlear implant auditory prosthesis implanted in a recipient according to some of the embodiments described herein; Figure 1B This is a perspective view of all example implantable middle ear implants and auditory prostheses implanted in a recipient according to some embodiments described herein; Figure 2A A schematic cross-sectional view of an example device according to certain embodiments described herein and a device outside the body of a recipient is shown. Figure 2B This illustration schematically shows some embodiments according to those described herein. Figure 2A A top view of an example device; Figure 3A This illustration schematically shows another example first MI antenna and an example MI antenna array according to certain embodiments described herein; Figure 3B This illustration schematically shows another example first MI antenna and an example MI antenna array according to certain embodiments described herein; Figure 4 A schematic top view of an example MI antenna array with three coils according to some embodiments described herein is shown. Figure 5 It refers to the mutual coupling coefficients for, for example, the second and third coils, according to certain embodiments described herein. k normalized displacement d / R A schematic drawing illustrating the changes; Figure 6 An example sensing link between devices and apparatuses according to certain embodiments described herein is illustrated schematically. Figure 7 The schematic illustration shows an example of inductive coupling between an external coil and an example first coil, second coil, and third coil, according to certain embodiments described herein; Figure 8 This schematically illustrates another example of a sensing link between a device and apparatus according to certain embodiments described herein; Figure 9 An example Q-control circuit system according to some embodiments described herein is illustrated schematically; Figure 10A and 10B The schematic diagram shows a top view of two example devices according to certain embodiments described herein; Figure 10C This is a flowchart of an example method for manufacturing an apparatus according to some embodiments described herein; Figure 11 The illustration schematically depicts an example inductive link between a device and an apparatus according to certain embodiments described herein, wherein the device includes a floating MI antenna coil; and the apparatus includes a floating MI antenna coil; and Figure 12An example inductive link between a device and an apparatus according to certain embodiments described herein is illustrated, wherein the device includes a second coil and a third coil, and the apparatus includes a second coil and a third coil. Detailed Implementation

[0008] Some embodiments described herein provide stimulation or measurement systems (e.g., sensory prosthetic systems) with improved wireless (e.g., transdermal) communication between an implantable portion and an external portion. Each portion includes a corresponding first magnetic induction (MI) antenna coil in electrical communication with the corresponding circuitry. At least one of the implantable portion and the external portion also includes an array of MI antenna coils, which is current-isolated from the first MI antenna coil and from the circuitry of both the implantable portion and the external portion. The MI antenna coil array is tuned to the resonant frequency of the first MI antenna coil to withstand significant coil current without large power dissipation. In this way, the MI antenna coil array can be configured to provide intermediate (e.g., indirect) coupling between the first MI antenna coils (e.g., acting as relay coils) to facilitate wireless communication between the implantable portion and the external portion. Despite significant movement and / or misalignment between the implantable portion and the external portion (e.g., in a magnetless link), the MI antenna coil array is able to maintain the wireless communication link.

[0009] The teachings detailed herein are applicable in at least some embodiments to any type of implantable or non-implantable stimulation or measurement system (e.g., implantable or non-implantable auditory prosthesis device or system). Embodiments may include any type of medical device that can utilize the teachings detailed herein and / or variations thereof. Furthermore, while some embodiments are described herein in the context of auditory prosthesis devices, certain other embodiments are compatible in the context of other types of devices or systems.

[0010] For ease of description only, the devices and methods disclosed herein are described primarily with reference to exemplary medical devices (i.e., implantable transducer assemblies), including but not limited to: electroacoustic / electrical systems, cochlear implant devices, implantable hearing aid devices, middle ear implant devices, bone conduction devices (e.g., active bone conduction devices; passive bone conduction devices; percutaneous bone conduction devices; transdermal bone conduction devices), direct acoustic cochlear implants (DACI), middle ear transducers (MET), electroacoustic implant devices, other types of auditory prostheses and / or combinations or variations thereof, or any other suitable hearing prosthesis system with or without one or more external components. Embodiments may include any type of auditory prosthesis capable of utilizing the teachings detailed herein and / or variations thereof. Some such embodiments may be referred to as “partially implantable,” “semi-implantable,” “largely implantable,” “fully implantable,” or “completely implantable” auditory prostheses. In some embodiments, the teachings detailed herein and / or variations thereof may be utilized in other types of prostheses besides auditory prostheses.

[0011] While certain embodiments are described herein in the context of auditory prosthetic devices, certain other embodiments compatible with other types of sensory prosthetic systems configured to evoke other types of neural or sensory perception (e.g., vision, touch, smell, taste) are also compatible with some of the embodiments described herein. These other types of sensory prosthetic systems include, but are not limited to, vestibular devices (e.g., vestibular implants), visual devices (e.g., bionic eyes), visual prostheses (e.g., retinal implants), somatosensory implants, and chemosensory implants. Certain other embodiments are compatible with other types of medical devices (e.g., epilepsy monitoring systems; pain control systems; bladder control systems; neurostimulators; pacemakers; other medical implants including implantable power sources) that can utilize the teachings detailed herein and / or variations thereof to provide a wide range of therapeutic benefits to recipients, patients, or other users.

[0012] Figure 1A This is a perspective view of an example cochlear implant auditory prosthesis 100 in an implant recipient according to certain embodiments described herein. The example auditory prosthesis 100 is... Figure 1A The image is shown to include an implantable stimulator unit 120 and a microphone assembly 124 (e.g., a partially implantable cochlear implant) external to the recipient. Example auditory prostheses 100 according to certain embodiments described herein (e.g., fully implantable cochlear implants; partially implantable cochlear implants) can be replaced with subcutaneously implantable microphone assemblies as described more fully herein. Figure 1A The external microphone assembly 124 is shown. In some embodiments, Figure 1AThe example cochlear implant auditory prosthesis 100 can be combined with a liquid drug reservoir as described herein.

[0013] like Figure 1A As shown, the recipient has an outer ear 101, a middle ear 105, and an inner ear 107. In a fully functional ear, the outer ear 101 includes an auricle 110 and an ear canal 102. Sound pressure, or sound wave 103, is collected by the auricle 110 and guided into and through the ear canal 102. A tympanic membrane 104, which vibrates in response to the sound wave 103, is located at the distal end of the ear canal 102. This vibration is connected to an elliptical or oval window 112 by three bones in the middle ear 105, collectively referred to as ossicles 106, and including the malleus 108, incus 109, and stapes 111. The bones 108, 109, and 111 of the middle ear 105 filter and amplify the sound wave 103, thereby causing the elliptical window 112 to hinge or vibrate in response to the vibration of the tympanic membrane 104. This vibration establishes a fluid motion wave of perilymph within the cochlea 140. This fluid motion then activates tiny hair cells (not shown) inside the cochlea 140. The activation of the hair cells causes appropriate neural impulses to be generated and transmitted to the brain (also not shown) via spiral ganglion cells (not shown) and the auditory nerve 114, where they are perceived as sound.

[0014] like Figure 1A As shown, the example hearing prosthesis 100 includes one or more components that are temporarily or permanently implanted in a recipient. The example hearing prosthesis 100 in... Figure 1A The device is shown to have: an external component 142 that is directly or indirectly attached to the recipient's body; and an internal component 144 that is temporarily or permanently implanted in the recipient's body (e.g., located in a recess of the temporal bone adjacent to the recipient's auricle 110). The external component 142 typically includes one or more sound input elements for detecting sound (e.g., an external microphone 124), a sound processing unit 126 (e.g., disposed in a behind-the-ear unit), a power supply (not shown), and an external transmitter unit 128. Figure 1AIn an exemplary embodiment, the external transmitter unit 128 includes an external coil 130 (e.g., a linear antenna coil comprising a single or multiple strands of electrically insulated platinum or gold wire), and preferably includes a magnet (not shown) directly or indirectly attached to the external coil 130. The external coil 130 of the external transmitter unit 128 is part of an inductive radio frequency (RF) communication link with the internal component 144. The sound processing unit 126 processes the output of the microphone 124, which in the depicted embodiment is positioned outside the receiver's body by the receiver's auricle 110. The sound processing unit 126 processes the output of the microphone 124 and generates an encoded signal, sometimes referred to herein as an encoded data signal, which is provided to the external transmitter unit 128 (e.g., via a cable). It will be appreciated that the sound processing unit 126 may utilize digital processing techniques to provide frequency shaping, amplification, compression, and other signal conditioning, including conditioning based on receiver-specific fitting parameters.

[0015] The power source of the external component 142 is configured to supply power to the hearing prosthesis 100, which includes a battery (e.g., located in the internal component 144 or disposed at a separate implantation site) that is recharged by power supplied from the external component 142 (e.g., via a transdermal power delivery link). The transdermal power delivery link is used to transfer power and / or data to the internal component 144 of the hearing prosthesis 100. Various types of power delivery (e.g., infrared (IR), electromagnetic, capacitive, and inductive) can be used to transfer power and / or data from the external component 142 to the internal component 144. During operation of the hearing prosthesis 100, the power stored by the rechargeable battery is distributed as needed to various other implanted components.

[0016] Internal component 144 includes an internal receiver unit 132, a stimulator unit 120, and an elongated electrode assembly 118. In some embodiments, the internal receiver unit 132 and the stimulator unit 120 are hermetically sealed within a biocompatible housing. The internal receiver unit 132 includes an internal coil 136 (e.g., a linear antenna coil comprising a single or multiple strands of electrically insulated platinum or gold wire), and preferably includes a magnet (also not shown) fixed relative to the internal coil 136. The internal receiver unit 132 and the stimulator unit 120, hermetically sealed within a biocompatible housing, are sometimes collectively referred to as the stimulator / receiver unit. The internal coil 136 receives electrical and / or data signals from the external coil 130 via a transdermal power delivery link (e.g., an inductive RF link). The stimulator unit 120 generates an electrical stimulation signal based on the data signal, and the stimulation signal is delivered to the recipient via the elongated electrode assembly 118.

[0017] An elongated electrode assembly 118 has a proximal end connected to the stimulator unit 120 and a distal end implanted in the cochlea 140. The electrode assembly 118 extends from the stimulator unit 120 through the mastoid bone 119 to reach the cochlea 140. In some embodiments, the electrode assembly 118 may be implanted at least in the basal region 116, and sometimes deeper. For example, the electrode assembly 118 may extend toward the apex of the cochlea 140 (referred to as the cochlear apex 134). In some cases, the electrode assembly 118 may be inserted into the cochlea 140 via a cochlear fenestration 122. In other cases, the cochlear fenestration may be formed via a round window 121, an elliptical window 112, a promontory 123, or through the apical gyrus 147 of the cochlea 140.

[0018] The elongated electrode assembly 118 includes a longitudinally aligned and distally extending array 146 of electrodes or contacts 148 disposed along its length, sometimes referred to herein as an electrode or contact array 146. Although the electrode array 146 may be disposed on the electrode assembly 118, in most practical applications, the electrode array 146 is integrated into the electrode assembly 118 (e.g., the electrode array 146 is disposed within the electrode assembly 118). As noted, the stimulator unit 120 generates a stimulation signal, which is applied by the electrodes 148 to the cochlea 140, thereby stimulating the auditory nerve 114.

[0019] Although Figure 1A The illustration schematically depicts an auditory prosthesis 100 utilizing an external component 142 comprising an external microphone 124, an external sound processing unit 126, and an external power supply. However, in some other embodiments, one or more of the microphone 124, sound processing unit 126, and power supply may be implanted on or within the recipient (e.g., within the internal component 144). For example, the auditory prosthesis 100 may have each of the microphone 124, sound processing unit 126, and power supply implantable on or within the recipient (e.g., enclosed within a subcutaneous biocompatible component) and may be referred to as a fully implantable cochlear implant (“TICI”). For another example, the auditory prosthesis 100 may have most of the components of a cochlear implantable on or within the recipient (e.g., excluding the microphone, which may be an in-ear canal microphone) and may be referred to as a largely implantable cochlear implant (“MICI”).

[0020] Figure 1B The illustration schematically shows a perspective view of an example fully implantable auditory prosthesis 200 (e.g., a fully implantable middle ear implant or a fully implantable acoustic system) in an implant recipient utilizing an acoustic actuator according to certain embodiments described herein. Figure 1B Example hearing prosthesis 200 includes a biocompatible implantable component 202 (e.g., including an implantable capsule) located subcutaneously (e.g., under the recipient's skin and on the recipient's skull). Although Figure 1B An example implantable component 202 including a microphone is illustrated schematically, but in other example hearing prostheses 200, a pendant microphone (e.g., connected to the implantable component 202 via a cable) may be used. The implantable component 202 includes a signal receiver 204 (e.g., including a coil element) and an acoustic transducer 206 (e.g., a microphone including a diaphragm and an electret or piezoelectric transducer), the acoustic transducer being positioned to receive acoustic signals through the recipient's covering tissue. The implantable component 202 may also be used to accommodate multiple components of the entire implantable hearing prosthesis 200. For example, the implantable component 202 may include an energy storage device and a signal processor (e.g., a sound processing unit). Various additional processing logic and / or circuitry components may also be included in the implantable component 202 as a design option.

[0021] for Figure 1B The example hearing prosthesis 200 shown includes an implantable component 202 whose signal processor and actuator 210 (e.g., including a transducer configured to generate mechanical vibrations in response to an electrical signal from the signal processor) operate in communication (e.g., via electrical interconnection through wire 208). In some embodiments, Figure 1A and 1B The example auditory prostheses 100, 200 shown may include implantable microphone components, such as Figure 1B The microphone assembly 206 is shown. For such an example auditory prosthesis 100, the signal processor of the implantable component 202 can operatively communicate (e.g., via electrical interconnection via wires) with the microphone assembly 206 and the stimulator unit of the main implantable component 120. In some embodiments, at least one of the microphone assembly 206 and the signal processor (e.g., a sound processing unit) is implanted on or within the recipient.

[0022] Figure 1B The actuator 210 of the example auditory prosthesis 200 shown is supportably connected to a positioning system 212, which is then (e.g., via a hole drilled through the skull) connected to a bone anchor 214 installed within the recipient's mastoid process. The actuator 210 includes a connection device 216 for connecting the actuator 210 to the recipient's ossicles 106. In the connected state, the connection device 216 provides a communication path for acoustic stimulation of the ossicles 106 (e.g., by transmitting vibrations from the actuator 210 to the incus 109).

[0023] During normal operation, ambient acoustic signals (e.g., ambient sounds) impact the recipient's tissue and are received transdermally at microphone assembly 206. Upon receiving the transdermal signal, a signal processor implantable within assembly 202 processes the signal to provide a processed audio drive signal to actuator 210 via wire 208. It will be appreciated that the signal processor can utilize digital processing techniques to provide frequency shaping, amplification, compression, and other signal conditioning, including conditioning based on recipient-specific fitting parameters. The audio drive signal causes actuator 210 to transmit acoustic vibrations to connection device 216 to influence the desired sound sensation via mechanical stimulation of the recipient's incus 109.

[0024] The subcutaneously implantable microphone assembly 202 is configured to respond to auditory signals (e.g., sound; pressure changes within the audible frequency range) by generating output signals (e.g., electrical signals; optical signals; electromagnetic signals), the output signals indicating auditory signals received by the microphone assembly 202, and these output signals are used by auditory prostheses 100, 200 to generate stimulus signals that are provided to the auditory system of a recipient. To compensate for the reduced acoustic signal intensity reaching the microphone assembly 202 due to implantation, the septum of the implantable microphone assembly 202 may be configured to provide higher sensitivity than that of externally non-implantable microphone assemblies. For example, the septum of the implantable microphone assembly 202 may be configured to be more robust and / or larger than that of externally non-implantable microphone assemblies.

[0025] Figure 1A The example hearing prosthesis 100 shown utilizes an external microphone 124, and Figure 1B The auditory prosthesis 200 shown utilizes an implantable microphone assembly 206 including a subcutaneously implantable acoustic transducer. In some embodiments described herein, the auditory prosthesis 100 utilizes one or more implantable microphone assemblies located on or within the recipient. In some embodiments described herein, the auditory prosthesis 200 utilizes one or more microphone assemblies positioned externally to the recipient and / or implanted on or within the recipient, and utilizes one or more acoustic transducers (e.g., actuator 210) implanted on or within the recipient. In some embodiments, an external microphone assembly may be used to supplement the implantable microphone assembly of the auditory prosthesis 100, 200. Therefore, the teachings detailed herein and / or variations thereof can be used with any type of external or implantable microphone arrangement, and Figure 1A and 1B The acoustic transducer shown is merely illustrative.

[0026] A magnetic link between the implanted portion of a medical system (e.g., a sensory prosthetic system) and its external portion can be used to generate an attractive magnetic force that holds the external portion in place relative to the implanted portion, facilitating a sufficiently strong and consistent magnetic induction (MI) communication channel between the two across the maximum skin-flap separation. In contrast, a non-magnetic link can have highly variable misalignment between the external and implanted portions, resulting in highly variable coil coupling coefficients (e.g., ranging from...). k =0.1 to 0.02 or less). Therefore, given the significant misalignment of the coil in the external portion relative to the implanted portion, it may be difficult to achieve sufficiently strong and consistent power delivery efficiency. Furthermore, for auditory prosthesis systems, the anatomy of the concha can be a source of additional variability, resulting in a wide range of postauricular placement, subsequent daily variations, and variability due to recipient activity (e.g., running). Some embodiments described herein are configured to provide sufficiently strong and consistent MI communication between the implanted and external portions despite the positional variability of the magnetless link.

[0027] Figure 2A A schematic cross-sectional view is shown of an example device 300 having two MI antenna arrays 330a, b and a device 400 outside the body of a receiver, according to certain embodiments described herein. Figure 2B This illustration schematically shows some embodiments according to those described herein. Figure 2A A top view of example device 300.

[0028] Device 300 includes a first magnetic induction (MI) antenna 310, which includes a conductive first coil 312 extending around and substantially orthogonal to a first antenna axis 314. Device 300 also includes a circuit system 320 electrically communicating with the first MI antenna 310, configured to supply current to and / or receive current from the first MI antenna 310. Device 300 also includes an MI antenna array 330 that is currently isolated from the first MI antenna 310 and the circuit system 320. MI antenna array 330 includes at least a second MI antenna 330a and a third MI antenna 330b. The second MI antenna 330a includes a conductive second coil 332a extending around and substantially orthogonal to a second antenna axis 334a, the second antenna axis being substantially parallel to the first antenna axis 314, and the second MI antenna 330a having a non-zero first coupling coefficient with the first MI antenna 310. k 1The third MI antenna 330b includes a conductive third coil 332b extending around and substantially orthogonal to a third antenna axis 334b, which is substantially parallel to the first antenna axis 314, and the third MI antenna 330b has a non-zero second coupling coefficient with the first MI antenna 310. k 2 And has a third coupling coefficient that is essentially zero with the second MI antenna 330a. k 3 .

[0029] In some implementations, such as by Figure 2A As schematically illustrated, device 300 is part of a transdermal system (e.g., an auditory prosthesis system) that includes device 300 (e.g., the implantable portion of an acoustic prosthesis system) and device 400 (e.g., the external portion of an acoustic prosthesis system). For example, device 300 may be configured to be implanted onto and substantially parallel to a bone surface 510 within the recipient's body (e.g., the surface of a portion of the skull 520 behind the recipient's auricle 110; the surface of the mastoid bone 119), and external device 400 may be configured to be worn on the recipient's skin 530 above device 300 (e.g., on and / or behind the recipient's auricle). In some embodiments, device 300 is configured to be implanted onto a substantially flat region of the skull, the region being configured to accommodate an increased lateral extent of device 300 due to the second and third MI antennas 330a, b (e.g., compared to embodiments without the second and third MI antennas 330a, b). In some embodiments, the first, second, and third coils 312, 332a, b are substantially planar, while in other embodiments, at least one of the first, second, and third coils 312, 332a, b is substantially non-planar. For example, a brain stimulator implant may include an MI antenna array 330 configured to be implanted under the scalp or skull and conform to its curvature. This MI antenna array 330 may be configured to provide a wireless and transdermal inductive communication link with an external coil 412 of a device 400 worn on the recipient's head (e.g., in a cap).

[0030] In some embodiments, device 300 includes a housing 305 (e.g., a shell) configured to be implanted on or within a recipient's body and to house a first MI antenna 310, a circuit system 320, and an MI antenna array 330. Housing 305 may comprise electrically insulating and biocompatible materials (e.g., silicone rubber; polymers; polyetheretherketone (PEEK); ceramics; titanium dioxide; glass; glycerin) and may be configured to be fixed to a bone surface 510 within the recipient's body (e.g., where the first antenna axis 314 is substantially perpendicular to the bone surface 510). For example, housing 305 may be configured to be positioned below skin 530 and other tissues (e.g., adipose tissue and / or muscle tissue 408) and above and over a bone surface 510 in a part of the recipient's body (e.g., the head). Housing 305 may be substantially parallel to the bone surface 510 (e.g., in…) Figure 2A (Illustrated schematically). In some embodiments, the housing 305 may be bent to conform to the curvature of the bone surface 510 (e.g., fit; conform), while in other embodiments, the bone surface 510 may be modified (e.g., machined) to provide a portion compatible with the housing 305. In some embodiments, the housing 305 may be configured to be secured to the bone surface 510 using at least one biocompatible anchor, screw, or adhesive. In some embodiments, the housing 305 is configured to hermetically seal the first MI antenna 310, circuitry 320, and MI antenna array 330 from the environment surrounding the housing 305. The housing 305 may also be substantially permeable to electromagnetic or magnetic fields between the device 300 and the apparatus 400 (e.g., such that the housing 305 substantially does not interfere with power transmission from the apparatus 400 to the device 300 and / or data transmission to and / or from the device 300).

[0031] Device 400 may include a housing 405 (e.g., biocompatible; skin-friendly) and at least one external MI antenna 410, said at least one external MI antenna including at least one conductive coil 412, said at least one conductive coil being configured to provide power and / or data to and / or receive data from device 300 via magnetic induction. For example, a first MI antenna 310 and MI antenna array 330 may be configured to wirelessly transmit signals to and / or receive signals from said at least one external MI antenna 410 of device 400 located outside the recipient's skin 530 and above device 300 (e.g., to inductively receive power, data, and / or control signals transmitted transdermally from device 400, and / or transmit data and / or control signals transdermally to device 400).

[0032] The circuit system 320 can be configured to receive power from the first MI antenna 310 and the MI antenna array 330, and to receive and / or transmit data signals via the first MI antenna 310 and the MI antenna array 330. For example, the circuit system 320 may include one or more active elements (e.g., stimulator unit 120; assembly 202; vibration actuator) configured to deliver stimulation (e.g., stimulation signal) to a portion of the recipient's body and / or detect attributes or conditions of the recipient's body. The circuit system 320 may be in electrical communication with a portion of the recipient's body via an electrical conduit 322 (e.g., electrode assembly 118; return electrode), the electrical conduit being in electrical communication with the circuit system 320 and extending from the housing 305 to a region of the recipient's body. In some embodiments, the first MI antenna 310, the circuit system 320, and the MI antenna array 330 are housed within the same housing 305 (see, for example...). Figure 2A-2B In some other embodiments, the circuit system 320 is located within the first housing, and the first MI antenna 310 and the MI antenna array 330 are located in a second housing attached to the first housing (e.g., electrically connected by at least one electrical conductor).

[0033] Circuit system 320 may include one or more microprocessors (e.g., application-specific integrated circuits; general-purpose integrated circuits programmed with software having computer-executable instructions; microelectronic circuit systems; microcontrollers) and at least one storage device (e.g., at least one tangible or non-transitory computer-readable storage medium; read-only memory; random access memory; flash memory), said at least one storage device being configured to store information (e.g., data; commands) accessed by the one or more microprocessors during operation. The at least one storage device may be encoded with software (e.g., a computer program downloaded as an application) including computer-executable instructions (e.g., executable data access logic, evaluation logic, and / or information output logic) for instructing the one or more microprocessors. In some embodiments, the one or more microprocessors execute the instructions of the software to provide the functionality described herein. Circuit system 320 may be configured to receive power signals, data signals, and / or control signals wirelessly transmitted from device 400 via at least one external coil 412, MI antenna array 330, and a first MI antenna 310.

[0034] In some embodiments, the first coil 312 includes a first conductive wire wound around and substantially orthogonal to the first antenna axis 314, the second coil 332a includes a second conductive wire wound around and substantially orthogonal to the second antenna axis 334a, and the third coil 332b includes a third conductive wire wound around and substantially orthogonal to the third antenna axis 334b. The second coil 332a may be current-isolated from the third coil 332b (e.g., floating), or the second and third coils 332a and 332b may be connected in series with each other. The first coil 312, the second coil 332a, and the third coil 332b may each include a planar conductive wire portion having multiple windings (e.g., platinum, gold, copper, or other metals; electrically insulated single or multiple strands), and may each have a substantially circular, rectangular, spiral, elliptical, oblong, bean-shaped, kidney-shaped, or other shape. In another example, the first coil 312, the second coil 332a, and the third coil 332b may each include a metal trace on a printed circuit board traveling (e.g., wound) around a corresponding antenna axis. The first coil 312, the second coil 332a, and the third coil 332b may each have a diameter, length, and / or width (e.g., along a lateral direction substantially parallel to the bone surface 510) of less than or equal to 100 mm (e.g., in the range of 15 mm to 40 mm; in the range of 25 mm to 50 mm; in the range of less than 30 mm; in the range of 20 mm to 60 mm; in the range of greater than 60 mm). The first coil 312, the second coil 332a, and the third coil 332b may be substantially coplanar with each other or substantially parallel to each other. The first coil 312, the second coil 332a, and the third coil 332b may be configured to inductively receive electrical, data, and / or control signals from a device 400 outside the recipient's body, and / or inductively transmit data and / or control signals to the device 400.

[0035] In some embodiments, at least one of the first coil 312, the second coil 332a, and the third coil 332b has a fixed Q value, while in other embodiments, at least one of the first coil 312, the second coil 332a, and the third coil 332b has an adjustable Q value (e.g., adjusted by a corresponding Q-control circuitry system). At least two of the first coil 312, the second coil 332a, and the third coil 332b may have the same size, shape, and / or number of turns, and / or at least two of the first coil 312, the second coil 332a, and the third coil 332b may have substantially different sizes, shapes, and / or numbers of turns.

[0036] In the Figure 2A and 2BIn the example device 300 shown, the first coil 312 includes a plurality of first loops (e.g., two, three, four or more) having substantially equal widths. Figure 2B As shown, the second coil 332a may include a plurality of second loops (e.g., 2, 3, 4 or more) having substantially equal widths, and the third coil 332b may include a plurality of third loops (e.g., 2, 3, 4 or more) having substantially equal widths. For example, the width of the first loop may be substantially equal to the width of the second and / or third loops (see example). Figure 2B In another example, the width of the first ring may be substantially different from the width of the second ring and / or the width of the third ring. In yet another example, the widths of the second and third rings may be substantially equal to each other or substantially different from each other.

[0037] although Figure 2A and 2B A first MI antenna 310 comprising a generally circular coil 312 and an MI antenna array 330 comprising two generally circular coils 332 are shown, but coils of other shapes are also compatible with some embodiments described herein. Figure 3A This schematically illustrates another example of a first MI antenna 310 and an example MI antenna array 330 according to certain embodiments described herein. Figure 3A As shown, the first coil 312 may have a first helical shape, the second coil 332a may have a second helical shape, and the third coil 322b may have a third helical shape. The number of turns of at least two of the first coil 312, the second coil 322a, and the third coil 322b may be substantially equal to each other, and / or the number of turns of at least two of the first coil 312, the second coil 322a, and the third coil 322b may be substantially different from each other. The width of at least two of the first helical shape, the second helical shape, and the third helical shape may be substantially equal to each other, and / or the width of at least two of the first helical shape, the second helical shape, and the third helical shape may be substantially different from each other.

[0038] Figure 3B This schematically illustrates another example of a first MI antenna 310 and an example MI antenna array 330 according to certain embodiments described herein. Figure 3BIn this embodiment, the first coil 312 has a first kidney-shaped (e.g., kidney-shaped) shape, the second coil 332a has a second kidney-shaped shape, and the third coil 332b has a third kidney-shaped shape. The kidney-shaped shapes can be configured to account for anticipated misalignment (e.g., radial and angular misalignment) of at least one outer coil 422 relative to the first MI antenna 310. The dimensions of the first, second, and third kidney-shaped shapes can be substantially the same or substantially different from each other. Certain embodiments of the kidney-shaped coils 312, 332a, and 332b are particularly suitable for use in magnetless inductive links between device 300 and apparatus 400 because the kidney-shaped coils substantially match the curvature of apparatus 400 when positioned behind the concha of the ear (e.g., auricle 110). Other shapes (e.g., rectangular; square; elongated elliptical; elliptical; oblong; bean-shaped; pea-shaped) are also compatible with certain embodiments described herein.

[0039] In some embodiments, a first coil 312 defines a first region 316, a second coil 332a defines a second region 336a, and a third coil 332b defines a third region 336b, wherein the first region 316 partially overlaps with the second region 336a and the third region 336b, and the second region 336a partially overlaps with the third region 336b. For example, as Figure 2B As shown, the outer boundary of the first loop of the first coil 312 defines a substantially circular first region 316, the outer boundary of the second loop of the second coil 332b defines a substantially circular second region 336a, and the outer boundary of the third loop of the third coil 332b defines a substantially circular third region 336b. For another example, as... Figure 3A As shown, the outer boundary of the first coil 312 of the first spiral shape defines a substantially circular first region 316, the outer boundary of the second coil 332a of the second spiral shape defines a substantially circular second region 336a, and the outer boundary of the third coil 332b of the third spiral shape defines a substantially circular third region 336b. In these examples, the first region 316 partially (e.g., not completely) overlaps with the second and third regions 336a, b, and the second and third regions 336a, b partially (e.g., not completely) overlap with each other.

[0040] In some implementations (see, for example) Figure 2A , 2B In 3A and 3B, the MI antenna array 330 includes two coils 332, while in some other embodiments, the MI antenna array 330 includes three coils 332 in various configurations. Figure 4The diagram schematically shows a top view of an example MI antenna array 330 with three coils 332 according to certain embodiments described herein. In addition to the second MI antenna 330a and the third MI antenna 330b, Figure 4 The MI antenna array 330 includes a fourth MI antenna 330c, which includes a conductive and substantially planar fourth coil 332c extending around and substantially orthogonal to a fourth antenna axis 334c substantially parallel to a first antenna axis 314. The fourth coil 332c may be current-isolated (e.g., floating) from the second coil 332a and / or the third coil 332b, or the fourth coil 332c may be connected in series with at least one of the second and third coils 332a, b. The fourth coil 332c may have a fourth helical shape (e.g., the same as or different from the first, second, and / or third helical shapes), or may include a plurality of fourth loops having substantially equal widths (e.g., the same as or different from the loop widths of the first, second, and / or third coils 312, 332a, 332b). The fourth MI antenna 330c may have a non-zero fourth coupling coefficient with the first MI antenna 310. k 4 It has a fifth coupling coefficient that is essentially zero with the second MI antenna 330a. k 5 And it has a sixth coupling coefficient that is essentially zero with the third MI antenna 330b. k 6 .although Figure 4 Each of the coils 312, 332a-c has a substantially circular shape, but other shapes (e.g., spirals) and other numbers of loops or turns are also compatible with some of the embodiments described herein.

[0041] like Figure 4 As shown, the first coil 312 defines a first region 316, the second coil 332a defines a second region 336a, the third coil 332b defines a third region 336b, and the fourth coil 332c defines a fourth region 336c. Figure 4 As shown, the first region 316 may partially (e.g., incompletely) overlap with each of the second, third, and fourth regions 336a-c; the second region 336a may partially (e.g., incompletely) overlap with each of the third and fourth regions 336b, c; and the third region 336b may partially (e.g., incompletely) overlap with the fourth region 336c. Other configurations of the first, second, and third coils 312a, b, c are also compatible with certain embodiments described herein.

[0042] In some embodiments, the second coil 332a and the third coil 332b partially overlap each other, such that the second MI antenna and the third MI antenna 330a,b have a mutual coupling coefficient that is substantially zero. k Essentially zero coupling corresponds to essentially no magnetic flux coupling from one of the second and third coils 332a and 332b to the other. Figure 5 It refers to the mutual coupling coefficients for, for example, the second and third coils 332a and b, according to certain embodiments described herein. k normalized displacement d / R A schematic drawing illustrating the changes. Figure 5 Example: The second and third coils 332a and b each include coils with outer boundary radii. R Multiple essentially circular rings, offset from each other by a distance. d The centers 331a, b (e.g., at the second antenna axis and the third antenna axis 334a, b).

[0043] Figure 5 The mutual coupling coefficients shown k It has the following characteristics: • When the second and third coils 332a and b are exactly stacked on top of each other (e.g., d / R When =0), the mutual coupling coefficient k It is at its maximum value.

[0044] • When the second and third coils 332a and b are laterally offset from each other (e.g., 0 < d / R When <2), the mutual coupling coefficient k It monotonically decreases from zero to a small and negative value. Specifically, when the second and third coils 332a and b do not overlap (e.g., d / R When ~2), the mutual coupling coefficient k It is small, and as the second and third coils 332a, b shift further (e.g., d / R >2) It becomes smaller.

[0045] • When the second coil and the third coil 332a, b are relatively far apart (e.g., d / R When >>1), the mutual coupling coefficient k It is negative because when the coils are relatively close together (e.g., d / R When <<1), the magnetic flux directions are opposite. Furthermore, when the second and third coils 332a and b are laterally offset from each other further (e.g., d / R When →∞), the mutual coupling coefficient k It asymptotically approaches zero from the negative side.

[0046] • Due to the mutual coupling coefficient k exist d / R The value is positive relative to the hour, and... d / R When the value is relatively large, it is negative, and there can be no discontinuity in magnetic flux coupling. Therefore, for the second and third coils 332a and b, which are approximately half-overlapping, d / R The value of the cross-coupling coefficient k It is essentially equal to zero.

[0047] although Figure 5 The mutual coupling coefficients for two example circular toroidal second and third coils 332a and b are shown. k Follow d / R The variation, but the mutual coupling coefficients of other types of coils (e.g., spirals) and other shapes (e.g., kidney-shaped) k Having the above description and in Figure 5 The same general characteristics are shown in the figure, although with d / R Changing cross-coupling coefficients k Specific values ​​and mutual coupling coefficients k When it is basically equal to zero d / R The value can be different Figure 5 Those values ​​in the table. For any pair of substantially coplanar or substantially parallel coils 332 having any shape (e.g., identical to each other; different from each other), coils 332 can be configured to have substantially zero mutual coupling, which is without magnetic monopoles ( The result of ).

[0048] Figure 6 An example inductive link between device 300 and apparatus 400 according to certain embodiments described herein is illustrated schematically. Device 300 has a first coil 312 currently coupled (e.g., wired) to circuit system 320, and second and third coils 332a, b are currently isolated (e.g., floated) from the first coil 312 and circuit system 320, and are currently isolated from each other. Apparatus 400 has a coil 412 currently coupled to circuit system 420 of apparatus 400. Figure 6 The dashed vertical line represents the skin surface (e.g., device 300 is implanted below the skin surface, and device 400 is worn on the skin surface). The first coil 312 is inductively coupled to each of the second and third coils 332a, b, and also inductively coupled to coil 412 of device 400. Coil 412 of device 400 is also inductively coupled to each of the second and third coils 332a, b. The second and third coils 332a, b are positioned such that their mutual inductance is substantially zero.

[0049] In some embodiments, the first coil, second coil, and third coils 312, 332a, b are substantially coplanar with each other, while in other embodiments, the first coil 312 is substantially parallel to both the second and third coils 332a, b, and offset from the second and third coils 332a, b in a direction substantially perpendicular to the first coil 312 (e.g., the first coil 312 is farther or closer to the skin surface than the second and third coils 332a, b). In some embodiments, the second coil and third coils 332a, b are substantially coplanar with each other, while in other embodiments, the second coil and third coils 332a, b are substantially parallel to each other and offset from each other in a direction substantially perpendicular to the second and third coils 332a, b (e.g., the second coil 332a is farther or closer to the skin surface than the third coil 332b).

[0050] The first coil 312 has a first inductance. L w1 and the first capacitor C w1 The second coil 332a has a second inductance. L f1 Second capacitor C f1 Furthermore, the third coil 332b has a third inductance. L f2 and the third capacitor C f2 For simplicity and ease of tuning, each of the first, second, and third coils 312, 332a, and b may have the same inductance value (e.g., L w1 = L f1 = L f2 = L 1 However, in other embodiments, at least two of these inductance values ​​may be different from each other. The first coil 312 of device 300 and the coil 412 of device 400 may have a coupling coefficient. k 0 Furthermore, the first coil 312 can have a coupling coefficient with the second coil 332a. k 1 And it has a coupling coefficient with the third coil 332b k 2 Furthermore, coil 412 can have a coupling coefficient with the second coil 332a. k a And it has a coupling coefficient with the third coil 332b k bFor simplicity, the coupling coefficients of the first coil 312 with each of the second and third coils 332a and b can be substantially equal to each other (e.g., k 1 = k 2 ), and the coupling coefficients of coil 412 with each of the second and third coils 332a, b can be substantially equal to each other (e.g., k a = k b However, in other implementations, the coupling coefficient... k 1 and k 2 They are different from each other, and / or their coupling coefficients are different. k a and k b They are different from each other.

[0051] In some embodiments, the first coil, the second coil, and the third coils 312, 332a, and b are each tuned to a common resonant frequency. For example, in L w1 = L f1 = L f2 = L , C w1 = C f1 = C f2 = C , k 1 = k 2 When the coupling between the second coil and the third coils 332a and b is essentially zero, the tuning capacitor (e.g., resonant capacitor) of the first coil 312 is used. And the tuning capacitors of each of the second and third coils 332a and b resonant frequency It can be equal to Typically, for current isolation from the first coil 312... N A substantially similar coil 332, the tuning capacitor of the first coil 312 can be In some embodiments having coils 332 that are substantially equal in size and substantially circular, N Equals one, two, or three. For example (see Examples) Figure 4Three substantially equal-sized, substantially circular coils 332a-c can be positioned in a zero-coupling arrangement (e.g., the mutual inductance of each pair of coils in coils 332a-c is substantially zero), wherein the antenna axes 334a-c of coils 332a-c are arranged in an equilateral triangle, and each of coils 332a-c has a non-zero coupling coefficient with the first coil 312 (e.g., such that the antenna axis 314 is at the center of the equilateral triangle). For more than three coils 332, some pairs of coils 332 will have substantially non-zero coupling to each other, or some coils 332 will be substantially uncoupled to the first coil 312.

[0052] Figure 7 The illustration schematically shows the inductive coupling between an example first coil, a second coil, and third coils 312, 332a, b and coil 412 according to certain embodiments described herein. Figure 7 In the top portion, the first coil 312, the second coil 332a, and the third coil 332b have substantially equal coil radii. R And are substantially circular coils that are essentially coplanar with each other. The second and third coils 332a and b are offset from the first coil 312 in a direction substantially parallel to the first coil 312 (e.g., offset ±). R / 2), and offset from each other by the coil radius R Due to the offset between the second and third coils 332a and b, their mutual coupling coefficients are essentially zero (see example...). Figure 5 And due to the offset between the first coil 312 and each of the second and third coils 332a and b, the coupling coefficient between the first coil 312 and each of the second and third coils 332a and b k 1 and k 2 Each is approximately 0.5 (see example). Figure 5 ).

[0053] Figure 7 The bottom portion schematically shows the coupling coefficients of coil 412 of device 400 with each of the first, second, and third coils 312, 332a, b at their respective positions relative to the first, second, and third coils 312, 332a, b. The coupling coefficients of coil 412 with the first coil 312 are shown in the case of only the first coil 312. k 0 In coil 412 at ±3 R The offset of / 2 decreases significantly when it is misaligned with the first coil 312, and the offset is ± RThe time can be essentially equal to zero. However, in the case of having a second coil and a third coil 332a, b, due to the indirect coupling provided by the second coil and the third coil 332a, b between coil 412 and the first coil 312, coil 412 experiences these large offsets (e.g., ±). R ±3 R / 2) The coil 412 can have a stronger coupling with the first coil 312. For example, the coil 412 can have a non-zero coupling coefficient with the second coil 332a. k a Furthermore, the second coil 332a can have a coupling coefficient of 0.5 with the first coil 312, thereby generating a 0.5 coupling coefficient between coil 412 and the first coil 312. k a The coupling coefficient.

[0054] The current-isolated MI antenna array 330 can provide significantly improved convergent coupling between coil 412 and the first coil 312 over a wider misalignment range. For example, with the second and third coils 332a,b not floating, the power transfer efficiency across the link between the first coil 312 and coil 412 improves through the ± R The offset of / 2 is halved, and through ± R The offset is reduced to near zero (e.g., rendering the link useless). However, with the second and third coils 332a, b floating, the power transfer efficiency is essentially not affected by the ± distance between the first coil 312 and coil 412. R The offset changes by / 2, and even if the offset is ± R It still maintains significant intensity. For another example, it is arranged in a substantially equilateral triangular configuration (see, for example...). Figure 4 The three floating coils (e.g., second, third, and fourth coils 332a-c) in the coil 412 can improve power transfer efficiency to address the two-dimensional misalignment between the first coil 312 and coil 412. The second and third coils 332a and 332b can both be substantially coplanar with the first coil 312, or the second and third coils 332a and 332b can be substantially coplanar with each other and offset from the first coil 312 in a direction substantially perpendicular to the first coil 312, while maintaining the coupling coefficient with the first coil 312 (e.g., ...). k 1 ≤0.5; k 2 ≤0.5).

[0055] Figure 8This schematically illustrates another example inductive link between device 300 and apparatus 400 according to certain embodiments described herein. Device 300 has a first coil 312 currently coupled (e.g., wired) to circuit system 320, and second and third coils 332a, b are currently isolated (e.g., floated) from the first coil 312 and circuit system 320. The second and third coils 332a, b are currently coupled to each other (e.g., in series) such that the voltages induced in the second and third coils 332a, b are added to each other. Figure 6 In the example inductive link, the current of coil 412 is coupled to the circuit system 420 of device 400, and the first coil 312 is inductively coupled to each of the second and third coils 332a, b (e.g., having a coupling coefficient). k 1 , k 2 And it is inductively coupled to coil 412 (e.g., having a coupling coefficient). k 0 Coil 412 is inductively coupled to each of the second and third coils 332a and b (e.g., having a coupling coefficient). k a , k b Furthermore, the second and third coils 332a and b are positioned such that their mutual inductance is essentially zero. Common tuning capacitor. It can be used (e.g., having equal to) Figure 6 Approximately 0.5 C f1 Or 0.5 C f2 capacitor C Furthermore, a common Q-control circuit system (not shown) can be used to adjust the Q values ​​of both the second and third coils 332a and b.

[0056] The device 300 may also include a Q-control circuitry system 340 (e.g., a switch; a digital control) configured to control (e.g., adjust) the Q value of the MI antenna array 330. Figure 9 An example Q-control circuit system 340 according to certain embodiments described herein is illustrated schematically. The Q-control circuit system 340 can be configured to adjust the capacitance of the tuning capacitors of the second and third coils 332a, b (e.g., C f1 ; C f2 ; C f ) and / or the resistance of the tuning resistor (e.g., R f1 ; Rf2 ; R f The Q-control circuit system 340 can (e.g., via an isolation capacitor) C iso1 , C iso2 The optocoupler is current-isolated from the circuit system 320, ensuring that the Q-control circuit system, tuning capacitor, and tuning resistor do not represent additional DC or AC current paths into the implanted electronics (e.g., when the external lead portion is in the fluid contact feedthrough region). For a power-only link, the Q-control circuit system 340 can maximize a Q value, which can depend on the winding resistance of the coils (e.g., largely set by geometry and the choice of lead metal). For a power / data link, the Q-control circuit system 340 can (e.g., by using calculated resistances for each of the second and third coils 332a, b) set a Q value that provides a satisfactory trade-off between power delivery and data delivery. Q-adjustment can be performed dynamically (e.g., to switch between power delivery optimization and data delivery optimization).

[0057] In some implementations, such as by Figure 2A , 2B As schematically shown in 4, 6, and 8, the device 300, including an MI antenna array 330 (e.g., both the second and third coils 332a, b) that is electrically isolated from the first MI antenna 310 and the circuitry 320, is an implanted portion of a stimulation or measurement system (e.g., a transdermal system; an auditory prosthesis system) configured to wirelessly communicate with a portion of the stimulation or measurement system (e.g., device 400) outside the recipient's body. In some other embodiments, the external device 400 (e.g., configured to be worn on the recipient's skin 530 over the implanted portion) includes an MI antenna array 430 that is electrically isolated from the first MI antenna 410 and the circuitry 420 of the device 400. The MI antenna array 430 may be configured as described herein with respect to an implanted MI antenna array 330 and may facilitate wireless and transdermal electrical and / or data transfer with the device 300, and / or receive data from the device 300 via magnetic induction with the first MI antenna 310 of the device 300.

[0058] Figure 10A and 10BThe diagram schematically illustrates a top view of two example devices 400 according to certain embodiments described herein. Device 400 includes a first MI antenna 410 comprising a conductive and substantially planar first coil 412 extending around and substantially orthogonal to a first antenna axis (not shown). Device 400 also includes a circuitry 420 electrically communicating with the first MI antenna 410, the circuitry 420 being configured to supply current to and / or receive current from the first MI antenna 410. Device 400 further includes an MI antenna array 430 currently isolated from the first MI antenna 410 and the circuitry 420. MI antenna array 430 includes at least a second MI antenna 430a and a third MI antenna 430b. The second MI antenna 430a includes a conductive and substantially planar second coil 432a extending around and substantially orthogonal to a second antenna axis (not shown), the second antenna axis being substantially parallel to the first antenna axis, and the second MI antenna 430a having a non-zero first coupling coefficient with the first MI antenna 410. k 1 The third MI antenna 430b includes a conductive and substantially planar third coil 432b extending around and substantially orthogonal to a third antenna axis (not shown), the third antenna axis being substantially parallel to the first antenna axis, and the third MI antenna 430b having a non-zero second coupling coefficient with the first MI antenna 410. k 2 And it has a third coupling coefficient that is essentially zero with the second MI antenna 430a. k 3 .

[0059] In some embodiments, the first MI antenna 410, circuitry 420, and MI antenna array 430 are located within the housing 405 (e.g., in an area defined by the inner surface of the housing 405), while in other embodiments, at least one MI antenna 430 of the MI antenna array 430 is located outside the housing 405 (e.g., on the outer surface of the housing 405). For example, at least one MI antenna 430 located outside the housing 405 may be secured to the housing 405 by an adhesive layer (e.g., glue). At least one MI antenna 430 located outside the housing 405 may be configured to be removed from a first location on the exterior of the housing 405 and repositioned to a second location on the exterior of the housing 405, where at least one MI antenna 430 better facilitates improved coupling between the first MI antenna 410 and the implanted portion (e.g., device 300).

[0060] Figure 10C This is a flowchart of an example method 600 for manufacturing an apparatus 400 according to certain embodiments described herein. Although by reference... Figures 10A-10BThe example apparatus 400 describes some of the structures of method 600, but other devices and systems with other configurations of components may also be used to perform method 600 according to some of the embodiments described herein.

[0061] In operation block 610, method 600 includes providing a first MI antenna 410 within housing 405. In operation block 620, method 600 further includes attaching a second MI antenna 430a to housing 405. The second MI antenna 430a is electrically floating relative to the first MI antenna 410 and has a non-zero mutual inductance with the first MI antenna 410. In operation block 630, method 600 further includes attaching a third MI antenna 430b to housing 405. The third MI antenna 430b is electrically floating relative to the first MI antenna 410 and has a non-zero mutual inductance with the first MI antenna 410. The third MI antenna 430b has substantially zero mutual inductance with the second MI antenna 430a.

[0062] In some embodiments, the first MI antenna 410 includes a substantially planar first coil 412 (e.g., having a first size and shape and including a first number of turns), the second MI antenna 430a includes a substantially planar second coil 432a (e.g., having a second size and shape and including a second number of turns), and the third MI antenna 430b includes a substantially planar third coil 432b (e.g., having a third size and shape and including a third number of turns). Attaching the second MI antenna 430a may include placing the second MI antenna 430a substantially parallel to the first MI antenna 410, and attaching the third MI antenna 430b may include placing the third MI antenna 430b substantially parallel to the first MI antenna 410. At least two of the first number of turns, the second number of turns, and the third number of turns may be substantially equal to each other. At least two of the first size and shape, the second size and shape, and the third size and shape may be substantially equal to each other.

[0063] For example, attaching a second MI antenna 430a may include placing the second MI antenna 430a (e.g., a second coil 432a) on the outer surface of the housing 405, and attaching a third MI antenna 430b may include placing a third MI antenna 430b (e.g., a third coil 432b) on the outer surface of the housing 405. The second and third MI antennas 430a and 430b may each include an adhesive layer configured to hold the respective second and third coils 432a and 432b on the outer surface of the housing 405. The adhesive layer may also be configured to allow the respective second and third coils 432a and 432b to be repeatedly removed from the outer surface and reattached to the outer surface at different locations (e.g., locations providing improved coupling with the device 300 compared to the initial coupling location).

[0064] In some embodiments, method 600 further includes attaching a fourth MI antenna 430c to housing 405, the fourth MI antenna 430c being electrically buoyant relative to the first MI antenna 410 and having a non-zero mutual inductance with the first MI antenna 410 and a substantially zero mutual inductance with the second MI antenna 430a and the third MI antenna 430b. For example, attaching the fourth MI antenna 430c may include placing the fourth MI antenna 430c on an outer surface of housing 405. In some embodiments, the fourth MI antenna 430c includes a substantially planar fourth coil 432c (e.g., having a fourth size and shape and including a fourth number of turns), and attaching the fourth MI antenna 430c includes positioning the fourth MI antenna 430c substantially parallel to the first MI antenna 410.

[0065] In some embodiments, device 300 includes at least one of current-isolated MI antennas 330 and 430, and apparatus 400 includes at least another of current-isolated MI antennas 330 and 430. At least one MI antenna 330 may be current-isolated from the first MI antenna 310 and circuit system 320, and at least another MI antenna 430 may be current-isolated from the first MI antenna 410 and circuit system 420. Figure 11 An example inductive link between device 300 and apparatus 400 according to certain embodiments described herein is schematically illustrated, wherein device 300 includes a floating MI antenna coil 332, and apparatus 400 includes a floating MI antenna coil 432. The mutual inductive coupling between the two floating MI antenna coils 332, 432 can be substantially zero. The inductance of coil 332... L f1 It can be roughly equal to the inductance of coil 312. L w1 And the inductance of coil 432 L f2 It can be roughly equal to the inductance of coil 412. L w2 Tuning capacitor C f1 , C f2 The frequency can be adjusted (e.g., by a corresponding Q-control circuit system) to implement the tuned frequency for device 300 and apparatus 400 respectively.

[0066] Figure 12An example inductive link between device 300 and apparatus 400 according to certain embodiments described herein is schematically illustrated, wherein device 300 includes second and third coils 332a, b, and apparatus 400 includes second and third coils 432a, b. Two coupling coefficients ( ) are shown between the first coil 312 and the two floating coils 332a, b. k 1 ; k 2 ) can be substantially equal to each other, and the two coupling coefficients between the first coil 412 and the two floating coils 432a, b ( k 3 ; k 4 The coils 312, 332a, b of device 300 and the coils 412, 432a, b of device 400 have nine coupling coefficients ( ). k 0 ; k a ; k b ; k c ; k d ; k e ; k f ; k g ; k h Two floating coils 332a, b are positioned relative to each other such that their mutual coupling coefficient is substantially zero, and two floating coils 432a, b are positioned relative to each other such that their mutual coupling coefficient is substantially zero. In some embodiments, one or both of device 300 and apparatus 400 each include up to three MI antennas, which are currently isolated (e.g., floating) from their respective first MI antennas 310, 410 and circuit systems 320, 420.

[0067] In some implementations, such as in Figure 2A-2BAs shown, device 300 does not include magnetic elements (e.g., a non-magnetic link) within housing 305 that are configured to generate a magnetic force with respect to device 400 to hold device 400 on a recipient's body. In some other embodiments, device 300 includes magnetic elements (e.g., a magnetic element hermetically sealed within housing 305) within housing 305. For example, the magnetic element may include at least one magnetic material (e.g., ferromagnetic; ferrimagnetic; permanent magnet; diamagnetic magnet) and may have a substantially planar shape (e.g., a disk; a plate; substantially circular, elliptical, or rectangular). The magnetic element may be configured to generate a magnetic force of sufficient strength to hold device 400 on or above the skin 530 of a recipient above device 300, such that coil 412 is operatively wirelessly wirelessly connected to MI antenna array 330 to wirelessly and transdermally transfer energy from device 400 to device 300 (e.g., via magnetic induction; via radio frequency or RF link).

[0068] In some embodiments, the first coil, second coil, and third coils 312, 332a, b extend in one or both lateral directions across a two-dimensional region larger than the area covered by the first coil 312 alone. The MI antenna array 330, which is current-isolated from the first MI antenna 310, can provide sufficient coupling with at least one external coil 412 of the device 400 (e.g., a behind-the-ear unit) over a substantially larger location range than a single first coil 312 could provide, which can facilitate use in a magnetless link between the device 300 and the device 400. For example, the coils 332 of the MI antenna array 330 can be arranged to overlap each other and overlap with the first MI antenna 310, while covering a larger total region than the area covered by the first MI antenna 310 alone. The first MI antenna 310 and the MI antenna array 330 can define a substantially planar region through which magnetic flux from the device 400 extends in a direction not parallel to the region. Because the total area covered by the MI antenna array 330 is large, the device 300 can tolerate greater movement and / or misalignment of the coil 412 of the external device 400 than could be tolerated using only the first MI antenna 310 (e.g., movement / misalignment that may result from the lack of attractive magnetic force to hold the device 400 in place). At least one of the second and third coils 332a, b can provide sufficient coupling with the coil 412 of the external device 400 to establish an operable wireless transdermal communication link between the device 300 and the external device 400, taking into account movement and / or misalignment of the coil 412.

[0069] In some embodiments, the first MI antenna 310 and the MI antenna array 330 include coils having substantially the same shape or geometry, substantially the same number of turns, and substantially the same coil type (e.g., toroidal; spiral). While making the first coil, second coil, and third coils 312, 332a, b substantially identical to each other simplifies the overall design of the device 300 and makes it easier to model the performance of the device 300, in some other embodiments, the first MI antenna 310 and the MI antenna array 330 include coils that vary significantly from each other in shape or geometry, type, and / or number of turns. For example, size, shape, and / or number of turns may vary on the MI antenna array 330 (e.g., to improve convergent coupling at a predetermined location by having more turns in a nearby coil 332). For pole array distributions (e.g., for magnetless links), larger radius coils 332 may have larger lengths such that coils 332 cover the same arc angle. Some such embodiments can improve coil overlap while maintaining substantially zero magnetic inductive coupling between coils 332.

[0070] While common terminology is used to describe the systems and methods of certain embodiments for ease of understanding, these terms are intended to have the broadest reasonable interpretation herein. Although various aspects of this disclosure are described with respect to illustrative examples and embodiments, the disclosed examples and embodiments should not be construed as limiting. Unless otherwise specifically stated, or understood otherwise in the context used, conditional language such as “can,” “could,” “might,” or “may” is generally intended to convey that a particular embodiment includes a particular feature, element, and / or step, while other embodiments do not include a particular feature, element, and / or step. Therefore, such conditional language is generally not intended to imply that a feature, element, and / or step is required in any way for one or more embodiments, or to imply that one or more embodiments must include logic for determining whether such features, elements, and / or steps are included in or will be performed in any particular embodiment, with or without user input or prompting. Specifically, the terms “comprises” and “comprising” should be interpreted as referring to an element, component, or step in a non-exclusive manner, indicating that the referenced element, component, or step may exist, utilize, or be combined with other elements, components, or steps not expressly referenced.

[0071] It should be understood that the embodiments disclosed herein are not mutually exclusive and can be combined with each other in various arrangements. Furthermore, although the disclosed methods and apparatus are described largely in the context of various devices, the various embodiments described herein can be incorporated into a variety of other suitable devices, methods, and contexts. More generally, as will be understood, certain embodiments described herein can be used in the context of various implantable medical devices that can benefit from certain properties described herein.

[0072] As used herein, degree terms such as “approximately,” “about,” “substantially,” and “basically” indicate a value, quantity, or characteristic that is close to the stated value, quantity, or characteristic while still performing the desired function or achieving the desired result. For example, the terms “approximately,” “about,” “substantially,” and “basically” can refer to a quantity within ±10%, ±5%, ±2%, ±1%, or ±0.1% of the stated quantity. As another example, the terms “substantially parallel” and “basically parallel” refer to a value, quantity, or characteristic that deviates from exact parallelism by ±10, ±5, ±2, ±1, or ±0.1 degrees, and the terms “substantially perpendicular” and “basically perpendicular” refer to a value, quantity, or characteristic that deviates from exact perpendicularity by ±10, ±5, ±2, ±1, or ±0.1 degrees. The scope of this disclosure also covers any and all overlapping, subscopes, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” etc., includes the listed numbers. As used herein, unless the context clearly indicates otherwise, “a / an” and “the” include the plural. Additionally, as used in the description herein, unless the context clearly indicates otherwise, “in” includes “towards” and “on”.

[0073] Although the methods and systems are discussed in this paper based on elements marked with ordinal adjectives (e.g., first, second, etc.), ordinal adjectives are used only as markers to distinguish one element from another (e.g., one signal from another signal, or one circuit from another circuit), and ordinal adjectives are not used to indicate the order of these elements or their order of use.

[0074] The invention described and claimed herein is not limited in scope to the specific exemplary embodiments disclosed herein, as these embodiments are intended to be illustrative of several aspects of the invention and not to limit those aspects. Any equivalent embodiments are intended to be within the scope of the invention. In fact, various modifications in form and detail of the invention will become apparent to those skilled in the art based on the foregoing description, in addition to those shown and described herein. Such modifications are also intended to fall within the scope of the claims. The breadth and scope of the invention should not be limited to any of the exemplary embodiments disclosed herein, but should be defined only by the claims and their equivalents.

Claims

1. An apparatus comprising: A first magnetic induction (MI) antenna, the first MI antenna including a conductive first coil that surrounds and extends substantially orthogonally to the axis of the first antenna; A circuit system that is in electrical communication with the first MI antenna, the circuit system being configured to supply current to the first MI antenna and / or receive current from the first MI antenna; as well as An MI antenna array that is current-isolated from the first MI antenna and the circuit system, the array comprising at least: The second MI antenna includes a conductive second coil extending around and substantially orthogonal to the second antenna axis, the second antenna axis being substantially parallel to the first antenna axis, and the second MI antenna having a non-zero first coupling coefficient with the first MI antenna. as well as The third MI antenna includes a conductive third coil extending around and substantially orthogonal to a third antenna axis that is substantially parallel to the first antenna axis. The third MI antenna has a non-zero second coupling coefficient with the first MI antenna and a substantially zero third coupling coefficient with the second MI antenna.

2. The device of claim 1, wherein the first coil includes a first conductor wound around and substantially orthogonal to the axis of the first antenna, the second coil includes a second conductor wound around and substantially orthogonal to the axis of the second antenna, and the third coil includes a third conductor wound around and substantially orthogonal to the axis of the third antenna.

3. The device according to claim 1 or claim 2, wherein the first coil has a first helical shape, the second coil has a second helical shape, and the third coil has a third helical shape.

4. The device according to any of the preceding claims, wherein the first coil includes a plurality of first loops having substantially equal widths, the second coil includes a plurality of second loops having substantially equal widths, and the third coil includes a plurality of third loops having substantially equal widths.

5. The device according to any of the preceding claims, wherein the first coil defines a first region, the second coil defines a second region, and the third coil defines a third region, the first region partially overlapping the second region and the third region, and the second region partially overlapping the third region.

6. The device according to any of the preceding claims, wherein the second coil is current-isolated from the third coil.

7. The device according to any of the preceding claims, wherein the MI antenna array further comprises a fourth MI antenna, the fourth MI antenna comprising a conductive fourth coil extending around and substantially orthogonal to a fourth antenna axis substantially parallel to the first antenna axis, wherein the fourth MI antenna has a non-zero fourth coupling coefficient with the first MI antenna, a substantially zero fifth coupling coefficient with the second MI antenna, and a substantially zero sixth coupling coefficient with the third MI antenna.

8. The device of claim 7, wherein the first coil defines a first region, the second coil defines a second region, the third coil defines a third region, and the fourth coil defines a fourth region, the first region partially overlapping the second region, the third region, and the fourth region, the second region partially overlapping the third region and the fourth region, and the third region partially overlapping the fourth region.

9. The device according to claim 7 or claim 8, wherein the fourth coil has a fourth helical shape or comprises a plurality of fourth loops having substantially equal widths.

10. The device according to any one of claims 7 to 9, wherein the fourth coil is current-isolated from the second coil and / or the third coil.

11. The device according to any of the preceding claims further includes a housing housing the first MI antenna, the housing being configured as an implantable device fixed to a bone surface within the body of a recipient, wherein the first antenna axis, the second antenna axis, and the third antenna axis are substantially perpendicular to the bone surface.

12. The device of claim 11, wherein the first MI antenna and the MI antenna array are configured to wirelessly transmit signals to and / or wirelessly receive signals from a device outside the body of the receiver.

13. The device of claim 12, wherein the first MI antenna and the MI antenna array define a substantially planar region, and magnetic flux from the device extends through the region in a direction not parallel to the region.

14. The device of claim 13, wherein the device is an implantable portion of an acoustic prosthesis system configured to be positioned behind the auricle of the recipient, and the bone surface includes the skull surface.

15. A method comprising: A first MI antenna is provided within the housing; The second MI antenna is attached to the housing, the second MI antenna is electrically floating relative to the first MI antenna, and has a non-zero mutual inductance with the first MI antenna; as well as A third MI antenna is attached to the housing, the third MI antenna being electrically floating relative to the first MI antenna and having a non-zero mutual inductance with the first MI antenna, and the third MI antenna having a substantially zero mutual inductance with the second MI antenna.

16. The method of claim 15, wherein attaching the second MI antenna includes placing the second MI antenna on the outer surface of the housing, and attaching the third MI antenna includes placing the third MI antenna on the outer surface of the housing.

17. The method of claim 15 or claim 16, wherein the first MI antenna includes a substantially planar first coil, the second MI antenna includes a substantially planar second coil, and the third MI antenna includes a substantially planar third coil, the attachment of the second MI antenna includes placing the second MI antenna substantially parallel to the first MI antenna, and the attachment of the third MI antenna includes placing the third MI antenna substantially parallel to the first MI antenna.

18. The method according to any one of claims 15 to 17, wherein the first MI antenna comprises a first number of turns, the second MI antenna comprises a second number of turns, and the third MI antenna comprises a third number of turns, wherein at least two of the first number, the second number, and the third number are equal to each other.

19. The method according to any one of claims 15 to 18, wherein the first MI antenna includes a first coil having a first size and shape, the second MI antenna includes a second coil having a second size and shape, and the third MI antenna includes a third coil having a third size and shape, wherein at least two of the first size and shape, the second size and shape, and the third size and shape are substantially the same as each other.

20. The method according to any one of claims 15 to 19, further comprising attaching a fourth MI antenna to the housing, the fourth MI antenna being electrically buoyant relative to the first MI antenna and having a non-zero mutual inductance with the first MI antenna, the fourth MI antenna having substantially zero mutual inductance with the second MI antenna and the third MI antenna.

21. The method of claim 20, wherein attaching the fourth MI antenna comprises placing the fourth MI antenna on the outer surface of the housing.

22. The method of claim 20 or claim 21, wherein the first MI antenna includes a substantially planar first coil, and the fourth MI antenna includes a substantially planar fourth coil, and attaching the fourth MI antenna includes placing the fourth MI antenna substantially parallel to the first MI antenna.

23. An apparatus comprising: A first coil that is conductive and substantially planar; A circuit system that communicates electrically with the first coil; as well as A plurality of conductive and substantially planar second coils, electrically isolated from the circuit system and the first coil, the plurality of second coils being substantially parallel to each other and substantially parallel to the first coil, and having substantially zero magnetic induction coupling to each other.

24. The device of claim 23, wherein the first coil comprises a plurality of substantially coplanar coil loops, and the second coil is substantially coplanar with each other.

25. The device of claim 23 or claim 24, wherein the first coil overlaps with the plurality of second coils.

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