System and method for magnet detection and operational tuning

Abstract

An apparatus includes a housing configured to be placed over a tissue portion of a recipient, the tissue portion overlaying an implanted device. The housing includes a cavity configured to hold a magnet therein. The apparatus further includes at least one sensor on or within the housing. The at least one sensor is configured to detect the magnet within the cavity and to generate at least one signal indicative of at least one attribute of the magnet. The apparatus further includes control circuitry within the housing. The control circuitry is configured to receive the at least one signal and, in response to the at least one signal, adjust at least one operational parameter of the apparatus.

Description

SYSTEM AND METHOD FOR MAGNET DETECTION AND OPERATIONALTUNINGBACKGROUNDField

[0001] The present application relates generally to systems and methods for operating an external component held in place over a device implanted on or within a recipient’s body by a magnetic retention force.Description of the Related Art

[0002] Medical devices have provided a wide range of therapeutic benefits to recipients over recent decades. Medical devices can include internal or implantable components / de vices, external or wearable components / devices, or combinations thereof (e.g., a device having an external component communicating with an implantable component). Medical devices, such as traditional 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 in performing lifesaving and / or lifestyle enhancement functions and / or recipient monitoring for a number of years.

[0003] The types of medical devices and the ranges of functions performed thereby have increased over the years. For example, many medical devices, sometimes referred to as “implantable medical devices,” now often include one or more instruments, apparatus, sensors, processors, controllers or other functional mechanical or electrical components that are permanently or temporarily implanted in a recipient. These functional devices are typically used to diagnose, prevent, monitor, treat, or manage a disease / injury or symptom thereof, or to investigate, replace or modify the anatomy or a physiological process. Many of these functional devices utilize power and / or data received from external devices that are part of, or operate in conjunction with, implantable components.SUMMARY

[0004] In one aspect disclosed herein, an apparatus comprises a housing configured to be placed over a tissue portion of a recipient, the tissue portion overlaying an implanted device. The housing comprises a cavity configured to hold a magnet therein. The apparatusfurther comprises at least one sensor on or within the housing. The at least one sensor is configured to detect the magnet within the cavity and to generate at least one signal indicative of at least one attribute of the magnet. The apparatus further comprises control circuitry within the housing. The control circuitry is configured to receive the at least one signal and, in response to the at least one signal, adjust at least one operational parameter of the apparatus.

[0005] In another aspect disclosed herein, a method comprises generating information indicative of magnetic field strengths of magnets placed within an external device at different times and indicative of the different times at which the magnets are placed within the external device. The external device is configured to be held on a recipient’s body over an internal device within the recipient’s body by attractive magnetic forces generated by an interaction of a magnet within the external device with the internal device. The external device and the internal device have a wireless transcutaneous communication link therebetween. The method further comprises adjusting at least one operational parameter of the external device and / or the internal device in response to a real-time portion of the information.

[0006] In another aspect disclosed herein, an apparatus comprises a housing, a first sensor on or within the housing, a second sensor on or within the housing, and control circuitry within the housing. The first sensor is configured to generate a first signal indicative of at least one attribute of a magnet on or within the housing. The second sensor is configured to generate a second signal indicative of at least one attribute of ambient sound. The control circuitry is configured to receive the first signal and the second signal and, in response to the first signal, adjust an operational parameter for processing the second signal.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Implementations are described herein in conjunction with the accompanying drawings, in which:

[0008] FIG. 1A is a perspective view of an example cochlear implant auditory prosthesis implanted in a recipient in accordance with certain implementations described herein;

[0009] FIG. IB is a perspective view of an example fully implantable middle ear implant auditory prosthesis implanted in a recipient in accordance with certain implementations described herein;

[0010] FIG. 2A schematically illustrates a side cross-sectional view of an example apparatus in accordance with certain implementations described herein;

[0011] FIG. 2B schematically illustrates a side cross-sectional view of the example apparatus of FIG. 2A over a tissue portion of a recipient in accordance with certain implementations described herein;

[0012] FIGs. 3A-3G schematically illustrate various example types and combinations of a magnet of the apparatus and an internal magnetic element of the implanted device in accordance with certain implementations described herein;

[0013] FIGs. 4 A and 4B schematically illustrate two example sensors, example control circuitry, and example communication circuitry in accordance with certain implementations described herein; and

[0014] FIG. 5 is a flow diagram of an example method in accordance with certain implementations described herein.DETAILED DESCRIPTION

[0015] Certain implementations described herein provide an externally-worn apparatus that is usable with different magnets having different magnetic field strengths for holding the apparatus over an implanted device for different skin flap thicknesses (SFTs). The apparatus comprises at least one sensor configured to detect and to generate sensor signals indicative of the magnet and / or the magnetic field strength of the magnet. Different magnetic field strengths can have different effects on the power / data transfer circuit (e.g., different shifts or detuning of the resonant frequency of the circuit). Control circuitry of the apparatus is configured to receive the sensor signals and, in response, to automatically (e.g., in real time) to optimize the transfer efficiency by adjusting at least one operational parameter of the apparatus, examples of which can include: drive voltage and / or drive current applied to the power / data transfer circuit; electrical attributes of the power / data transfer circuit (e.g., capacitance; inductance; resonant frequency; quality (Q) factor); electrical permittivity of a housing of the apparatus; a distance and / or tilt of the magnet relative to the implanted device.

[0016] The teachings detailed herein are applicable, in at least some implementations, to any type of implantable or non-implantable stimulation or measurement system (e.g., implantable or non-implantable auditory prosthesis device or system). The system (e.g., implantable sensor prostheses; implantable stimulation system; implantablemedicament administration system) can be configured to provide a portion of the recipient’s body with stimulation signals and / or medicament dosages from an implanted portion of the system in response to received information and / or control signals from an external portion of the system. The system (e.g., implantable sensing system) can be configured to provide sensor signals from an implanted portion of the system to an external portion of the system. Implementations can include any type of medical device that can utilize the teachings detailed herein and / or variations thereof. Furthermore, while certain implementations are described herein in the context of auditory prosthesis devices, certain other implementations are compatible in the context of other types of devices or systems that provide a wide range of therapeutic benefits to recipients, patients, or other users.

[0017] Merely for ease of description, apparatus and methods disclosed herein are primarily described with reference to an illustrative medical device, namely an implantable transducer assembly including but not limited to: electro-acoustic electrical / acoustic 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; transcutaneous bone conduction devices), Direct Acoustic Cochlear Implant (DACI), middle ear transducer (MET), electro-acoustic implant devices, other types of auditory prosthesis devices, and / or combinations or variations thereof, or any other suitable hearing prosthesis system with or without one or more external components. Implementations can include any type of auditory prosthesis that can utilize the teachings detailed herein and / or variations thereof. Certain such implementations can be referred to as “partially implantable,” “semi-implantable,” “mostly implantable,” “fully implantable,” or “totally implantable” auditory prostheses. In some implementations, the teachings detailed herein and / or variations thereof can be utilized in other types of prostheses beyond auditory prostheses.

[0018] While systems and devices of certain implementations are described herein in the context of auditory prosthesis devices, certain other systems and devices in the context of other types of sensory prosthesis systems that are configured to evoke other types of neural or sensory (e.g., sight, tactile, smell, taste) percepts are also compatible with certain implementations described herein, including but are not limited to: vestibular devices (e.g., vestibular implants), tinnitus treatment devices, visual devices (e.g., bionic eyes), visualprostheses (e.g., retinal implants), brain implants, somatosensory implants, and chemosensory implants. Certain other implementations are compatible with other types of medical devices 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 (e.g., epilepsy monitoring or treatment systems; pain control systems; bladder control systems; sleep apnea control systems; neurostimulators; cardiac pacemakers; drug delivery systems; defibrillators; functional electrical stimulation devices; electroporation devices), to perform monitoring or measuring functionalities (e.g., sensors; electroencephalogram monitoring of brain function; electrocardiogram monitoring of heart function), or other medical implants beyond sensory prostheses. Certain other implementations are compatible with consumer products (e.g., wireless chargers; charging cases for earbuds or other electronic devices) or other devices that can be used with different magnets with different magnetic field strengths and that can affect an operational configuration of the device.

[0019] FIG. 1A is a perspective view of an example cochlear implant auditory prosthesis 100 implanted in a recipient in accordance with certain implementations described herein. The example auditory prosthesis 100 is shown in FIG. 1A as comprising an implanted stimulator unit 120 and a microphone assembly 124 that is external to the recipient (e.g., a partially implantable cochlear implant). An example auditory prosthesis 100 (e.g., a totally implantable cochlear implant; a mostly implantable cochlear implant) in accordance with certain implementations described herein can replace the external microphone assembly 124 shown in FIG. 1 A with a subcutaneously implantable microphone assembly, as described more fully herein. In certain implementations, the example cochlear implant auditory prosthesis 100 of FIG. 1 A can be in conjunction with a reservoir of liquid medicament as described herein.

[0020] As shown in FIG. 1A, 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 comprises an auricle 110 and an ear canal 102. An acoustic pressure or sound wave 103 is collected by the auricle 110 and is channeled into and through the ear canal 102. Disposed across the distal end of the ear canal 102 is a tympanic membrane 104 which vibrates in response to the sound wave 103. This vibration is coupled to oval window or fenestra ovalis 112 through three bones of middle ear 105, collectively referred to as the ossicles 106 and comprising the malleus 108, the incus 109, and the stapes 111. The bones 108, 109, and 111 of the middle ear 105 serve to filter andamplify the sound wave 103, causing the oval window 112 to articulate, or vibrate in response to vibration of the tympanic membrane 104. This vibration sets up waves of fluid motion of the perilymph within cochlea 140. Such fluid motion, in turn, activates tiny hair cells (not shown) inside the cochlea 140. Activation of the hair cells causes appropriate nerve impulses to be generated and transferred through the spiral ganglion cells (not shown) and auditory nerve 114 to the brain (also not shown) where they are perceived as sound.

[0021] As shown in FIG. 1A, the example auditory prosthesis 100 comprises one or more components which are temporarily or permanently implanted in the recipient. The example auditory prosthesis 100 is shown in FIG. 1A with an external component 142 which is directly or indirectly attached to the recipient’s body, and an internal component 144 which is temporarily or permanently implanted in the recipient (e.g., positioned in a recess of the temporal bone adjacent auricle 110 of the recipient). The external component 142 typically comprises one or more sound input elements (e.g., an external microphone 124) for detecting sound, a sound processing unit 126 (e.g., disposed in a Behind-The-Ear unit), a power source (not shown), and an external transmitter unit 128. In the illustrative implementations of FIG. 1A, the external transmitter unit 128 comprises an external coil 130 (e.g., a wire antenna coil comprising multiple turns of electrically insulated single-strand or multi-strand platinum or gold wire) and, preferably, a magnet (not shown) secured directly or indirectly 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 that is positioned externally to the recipient’s body, in the depicted implementation, by the recipient’s auricle 110. The sound processing unit 126 processes the output of the microphone 124 and generates encoded signals, sometimes referred to herein as encoded data signals, which are provided to the external transmitter unit 128 (e.g., via a cable). As will be appreciated, the sound processing unit 126 can utilize digital processing techniques to provide frequency shaping, amplification, compression, and other signal conditioning, including conditioning based on recipient-specific fitting parameters.

[0022] The power source of the external component 142 is configured to provide power to the auditory prosthesis 100, where the auditory prosthesis 100 includes a battery (e.g., located in the internal component 144, or disposed in a separate implanted location) that isrecharged by the power provided from the external component 142 (e.g., via a transcutaneous energy transfer link). The transcutaneous energy transfer link is used to transfer power and / or data to the internal component 144 of the auditory prosthesis 100. Various types of energy transfer, such as infrared (IR), electromagnetic, capacitive, and inductive transfer, may be used to transfer the power and / or data from the external component 142 to the internal component 144. During operation of the auditory prosthesis 100, the power stored by the rechargeable battery is distributed to the various other implanted components as needed.

[0023] The internal component 144 comprises an internal receiver unit 132, a stimulator unit 120, and an elongate electrode assembly 118. In some implementations, the internal receiver unit 132 and the stimulator unit 120 are hermetically sealed within a biocompatible housing. The internal receiver unit 132 comprises an internal coil 136 (e.g., a wire antenna coil comprising multiple turns of electrically insulated single-strand or multistrand platinum or gold wire), and preferably, a magnet (also not shown) fixed relative to the internal coil 136. The internal receiver unit 132 and the stimulator unit 120 are hermetically sealed within a biocompatible housing, sometimes collectively referred to as a stimulator / receiver unit. The internal coil 136 receives power and / or data signals from the external coil 130 via a transcutaneous energy transfer link (e.g., an inductive RF link). The stimulator unit 120 generates electrical stimulation signals based on the data signals, and the stimulation signals are delivered to the recipient via the elongate electrode assembly 118.

[0024] The elongate 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 to the cochlea 140 through the mastoid bone 119. In some implementations, the electrode assembly 118 may be implanted at least in the basal region 116, and sometimes further. For example, the electrode assembly 118 may extend towards apical end of cochlea 140, referred to as cochlea apex 134. In certain circumstances, the electrode assembly 118 may be inserted into the cochlea 140 via a cochleostomy 122. In other circumstances, a cochleostomy may be formed through the round window 121, the oval window 112, the promontory 123, or through an apical turn 147 of the cochlea 140.

[0025] The elongate electrode assembly 118 comprises a longitudinally aligned and distally extending array 146 of contacts or electrodes 148, sometimes referred to as electrode or contact array 146 herein, disposed along a length thereof. Although the electrodearray 146 can 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 in the electrode assembly 118). As noted, the stimulator unit 120 generates stimulation signals which are applied by the electrodes 148 to the cochlea 140, thereby stimulating the auditory nerve 114.

[0026] While FIG. 1 A schematically illustrates an auditory prosthesis 100 utilizing an external component 142 comprising an external microphone 124, an external sound processing unit 126, and an external power source, in certain other implementations, one or more of the microphone 124, sound processing unit 126, and power source are implantable on or within the recipient (e.g., within the internal component 144). For example, the auditory prosthesis 100 can have each of the microphone 124, sound processing unit 126, and power source implantable on or within the recipient (e.g., encapsulated within a biocompatible assembly located subcutaneously), and can be referred to as a totally implantable cochlear implant (“TICI”). For another example, the auditory prosthesis 100 can have most components of the cochlear implant (e.g., excluding the microphone, which can be an in-the-ear-canal microphone) implantable on or within the recipient, and can be referred to as a mostly implantable cochlear implant (“MICI”).

[0027] FIG. IB schematically illustrates a perspective view of an example fully implantable auditory prosthesis 200 (e.g., fully implantable middle ear implant or totally implantable acoustic system), implanted in a recipient, utilizing an acoustic actuator in accordance with certain implementations described herein. The example auditory prosthesis 200 of FIG. IB comprises a biocompatible implantable assembly 202 (e.g., comprising an implantable capsule) located subcutaneously (e.g., beneath the recipient’s skin and on a recipient's skull). While FIG. IB schematically illustrates an example implantable assembly 202 comprising a microphone, in other example auditory prostheses 200, a pendant microphone can be used (e.g., connected to the implantable assembly 202 by a cable). The implantable assembly 202 includes a signal receiver 204 (e.g., comprising a coil element) and an acoustic transducer 206 (e.g., a microphone comprising a diaphragm and an electret or piezoelectric transducer) that is positioned to receive acoustic signals through the recipient’s overlying tissue. The implantable assembly 202 may further be utilized to house a number of components of the fully implantable auditory prosthesis 200. For example, the implantableassembly 202 can include an energy storage device and a signal processor (e.g., a sound processing unit). Various additional processing logic and / or circuitry components can also be included in the implantable assembly 202 as a matter of design choice.

[0028] For the example auditory prosthesis 200 shown in FIG. IB, the signal processor of the implantable assembly 202 is in operative communication (e.g., electrically interconnected via a wire 208) with an actuator 210 (e.g., comprising a transducer configured to generate mechanical vibrations in response to electrical signals from the signal processor). In certain implementations, the example auditory prosthesis 100, 200 shown in FIGs. 1A and IB can comprise an implantable microphone assembly, such as the microphone assembly 206 shown in FIG. IB. For such an example auditory prosthesis 100, the signal processor of the implantable assembly 202 can be in operative communication (e.g., electrically interconnected via a wire) with the microphone assembly 206 and the stimulator unit 120 of the main implantable component. In certain implementations, 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.

[0029] The actuator 210 of the example auditory prosthesis 200 shown in FIG. IB is supportably connected to a positioning system 212, which in turn, is connected to a bone anchor 214 mounted in the recipient's mastoid bone (e.g., via a hole drilled through the skull). The actuator 210 includes a connection apparatus 216 for connecting the actuator 210 to the ossicles 106 of the recipient. In a connected state, the connection apparatus 216 provides a communication path for acoustic stimulation of the ossicles 106 (e.g., through transmission of vibrations from the actuator 210 to the incus 109).

[0030] During normal operation, ambient acoustic signals (e.g., ambient sound) impinge on the recipient’ s tissue and are received transcutaneously at the microphone assembly 206. Upon receipt of the transcutaneous signals, a signal processor within the implantable assembly 202 processes the signals to provide a processed audio drive signal via wire 208 to the actuator 210. As will be appreciated, the signal processor may 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 the actuator 210 to transmit vibrations at acoustic frequencies to theconnection apparatus 216 to affect the desired sound sensation via mechanical stimulation of the incus 109 of the recipient.

[0031] The subcutaneously implantable microphone assembly 202 is configured to respond to auditory signals (e.g., sound; pressure variations in an audible frequency range) by generating output signals (e.g., electrical signals; optical signals; electromagnetic signals) indicative of the auditory signals received by the microphone assembly 202, and these output signals are used by the auditory prosthesis 100, 200 to generate stimulation signals which are provided to the recipient’s auditory system. To compensate for the decreased acoustic signal strength reaching the microphone assembly 202 by virtue of being implanted, the diaphragm of an implantable microphone assembly 202 can be configured to provide higher sensitivity than are external non-implantable microphone assemblies. For example, the diaphragm of an implantable microphone assembly 202 can be configured to be more robust and / or larger than diaphragms for external non-implantable microphone assemblies.

[0032] The example auditory prostheses 100 shown in FIG. 1 A utilizes an external microphone 124 and the auditory prosthesis 200 shown in FIG. IB utilizes an implantable microphone assembly 206 comprising a subcutaneously implantable acoustic transducer. In certain implementations described herein, the auditory prosthesis 100 utilizes one or more implanted microphone assemblies on or within the recipient. In certain implementations described herein, the auditory prosthesis 200 utilizes one or more microphone assemblies that are positioned external to the recipient and / or that are implanted on or within the recipient, and utilizes one or more acoustic transducers (e.g., actuator 210) that are implanted on or within the recipient. In certain implementations, an external microphone assembly can be used to supplement an implantable microphone assembly of the auditory prosthesis 100, 200. Thus, the teachings detailed herein and / or variations thereof can be utilized with any type of external or implantable microphone arrangement, and the acoustic transducers shown in FIGs. 1A and IB are merely illustrative.

[0033] FIG. 2A schematically illustrates a side cross-sectional view of an example apparatus 300 in accordance with certain implementations described herein. FIG. 2B schematically illustrates a side cross-sectional view of the example apparatus 300 of FIG. 2A over a tissue portion 230 (e.g., skin) of a recipient in accordance with certain implementations described herein. The apparatus 300 comprises a housing 310 configured to be placed overthe tissue portion 230 of the recipient. The tissue portion 230 overlays an implanted device 250. The housing 310 comprising a cavity 312 configured to hold a magnet 314 therein. The apparatus 300 further comprises at least one sensor 320 on or within the housing 310. The at least one sensor 320 is configured to detect the magnet 314 within the cavity 312 and to generate at least one signal 322 indicative of at least one attribute of the magnet 314. The apparatus 300 further comprises control circuitry 330 within the housing 310. The control circuitry 330 is configured to receive the at least one signal 322 and, in response to the at least one signal 322, adjust at least one operational parameter of the apparatus 300.

[0034] For example, the implanted device 250 (e.g., internal component 144) and the apparatus 300 (e.g., external component 142) can be components of a transcutaneous system (e.g., an auditory prosthesis 100, 200). The apparatus 300 can further comprise external communication circuitry 340 (e.g., an external transmitter unit 128) comprising at least one external coil 342 (e.g., external coil 130) configured to form a wireless transcutaneous communication link (e.g., energy transfer via magnetic induction) with internal communication circuitry 240 (e.g., at least one internal coil 242) of the implanted device 250. Besides the elements shown in FIGs. 2A and 2B, the apparatus 300 can further comprise an external microphone 124, sound processing unit 126, and a power source (e.g., battery).

[0035] The implanted device 250 can comprise a biocompatible housing 252 (e.g., plastic; PEEK; silicone; ceramic; zirconium oxide; non-magnetic metals; titanium) configured to be positioned beneath the tissue portion 230 of the recipient’s body (e.g., beneath the skin, fat, and / or muscular layers) and above a bone (e.g., skull) in a portion of the recipient’s body (e.g., the head). Within the biocompatible housing 252, the implanted device 250 can further comprise at least one active element 254 (e.g., stimulator unit 120; assembly 202; vibrating actuator; medicament reservoir with a flow control element or valve), an internal magnetic element 256, and the internal communication circuitry 240 (e.g., at least one internal coil 242). The biocompatible housing 252 can comprise a first portion configured to contain the at least one active element 254 and a second portion configured to contain the internal magnetic element 256 and the internal communication circuitry 240, or the biocompatible housing 252 can comprise a single housing portion configured to contain the at least one active element 254, the internal magnetic element 256, and the internal communication circuitry 240.-l i

[0036] The at least one active element 254 can be configured to provide the recipient’s body with stimulation signals and / or medicament and / or to generate measurement signals indicative of an attribute (e.g., electrical activity; analyte concentration) of the recipient’s body. The internal magnetic element 256 can comprise a disk or plate of a ferromagnetic or ferrimagnetic material or a permanent magnet, and can be configured to establish, with the magnet 314 of the apparatus 300, a magnetic attractive force 257 configured to hold the housing 310 on an outer surface of the tissue portion 230 (e.g., skin surface) with the external communication circuitry 340 (e.g., at least one external coil 342) in wireless communication with the internal communication circuitry 240 (e.g., at least one internal coil 242) during operation of the implanted device 250 with the apparatus 300.

[0037] The coupling coefficient between the external communication circuitry 340 of the apparatus 300 and the internal communication circuitry 240 of the implanted device 250 is inversely dependent on the distance between the at least one internal coil 242 and the at least one external coil 342. In addition, the strength of the magnetic attraction between the magnet 314 of the apparatus 300 and the internal magnetic element 256 is inversely dependent on the distance between the magnet 314 and the internal magnetic element 256. These distances are dependent on the thickness of the tissue portion 230 between the apparatus 300 and the implanted device 250, which can be referred to as the skin flap thickness (SFT), as denoted in FIG. 2B. Depending on the recipient, the SFT for auditory prosthesis systems can be, for example, in a range of 2 millimeters to 12 millimeters, and the SFT for other types of systems can have a larger maximum value. Besides differences of SFT among different recipients, the SFT can also change under various physiological situations (e.g., weight loss or gain by recipient; growth of the recipient).

[0038] In certain implementations, the housing 310 comprises at least one biocompatible material (e.g., compatible to be worn on the recipient’s skin) that is substantially transparent to electric, magnetic, and / or electromagnetic fields such that the housing 310 does not substantially interfere with the wireless transcutaneous communication link and / or the attractive magnetic force 257 between the apparatus 300 and the implanted device 250. For example, the material of the housing 310 can comprise at least one of: plastic; PEEK; silicone; ceramic; zirconium oxide; non-magnetic metals; titanium. The housing 310 can have a width along a lateral direction substantially parallel to the surface of the recipient’s tissue portion 230(e.g., skin) less than or equal to 40 millimeters (e.g., in a range of 15 millimeters to 35 millimeters; in a range of 25 millimeters to 35 millimeters; in a range of less than 30 millimeters; in a range of 15 millimeters to 30 millimeters) or larger. In certain implementations, the housing 310 comprises a removable or hinged cover (not shown) configured to be opened to provide access to the cavity 312 (e.g., to remove a magnet 314 from the cavity 312; to place a magnet 314 into the cavity 312).

[0039] In certain implementations, the cavity 312 has a cylindrical shape with a cross-section (e.g., circular; elliptical; square; rectangular; polygonal; geometric; irregular; symmetric; non-symmetric) with straight, curved, or irregular sides in a plane perpendicular to a longitudinal axis 313 of the cavity 312 and having a perimeter in the plane perpendicular to the longitudinal axis 313. For example, the cavity 312 can have a right circular cylindrical shape having a first diameter and a first circumference in the plane perpendicular to the longitudinal axis 313 (e.g., an axis of symmetry of the cavity 312) and a first height along the longitudinal axis 313. The first diameter can be in a range of 6 millimeters to 14 millimeters, and the first height can be in a range of 2 millimeters to 12 millimeters. Other shapes (e.g., rectangular prism; hexagonal prism) and / or sizes of the cavity 312 are also compatible with certain implementations described herein.

[0040] In certain implementations, the magnet 314 comprises a permanent magnet comprising at least one of: iron, nickel, cobalt, and steel. The magnet 314 can comprise a single, integral magnet 314 or a plurality of magnets 314 coupled to one another. The magnet 314 can generate an external static magnetic field 315 (e.g., magnetic flux) , as schematically illustrated in FIG. 2A. In certain implementations, the magnet 314 is configured to be contained within the cavity 312. In certain implementations, the magnet 314 has a cylindrical shape with a cross-section (e.g., circular; elliptical; square; rectangular; polygonal; geometric; irregular; symmetric; non-symmetric) with straight, curved, or irregular sides in a plane perpendicular to a longitudinal axis of the magnet 314 and having a perimeter in the plane perpendicular to the longitudinal axis. For example, the magnet 314 can have a right circular cylindrical shape having a second diameter and a second circumference in the plane perpendicular to the longitudinal axis of the magnet 314 (e.g., an axis of symmetry of the shape of the magnet 314) and a second height along the longitudinal axis. The second diameter can be smaller than or equal to the first diameter, the second circumference can be smaller than orequal to the first circumference, and the second height can be smaller than or equal to the first height, such that the magnet 314 is configured to fit within the cavity 312. The second diameter can be in a range of 6 millimeters to 14 millimeters, and the second height can be in a range of 2 millimeters to 12 millimeters. Other shapes (e.g., rectangular prism; hexagonal prism) and / or sizes of the magnet 314 are also compatible with certain implementations described herein. For example, the cavity 312 and the magnet 314 can both have a non-symmetric shape such that the magnet 314 is configured to be contained within the cavity 312 in only one orientation.

[0041] In view of the different possible SFT values that a recipient can have, the apparatus 300 can be configured to be operated with a magnet 314 within the cavity 312, the magnet 314 selected from among a set of different magnets 314 having different magnetic attraction strengths. The selected magnet 314 can be placed within the cavity 312 for operation of the apparatus 300 with the implanted device 250 spaced from the apparatus 300 by the SFT of the recipient, the magnet 314 selected to provide a sufficiently strong magnetic attractive force 257 to hold the apparatus 300 in place (e.g., against the outer surface of the tissue portion 230 with the external communication circuitry 340 in wireless communication with the internal communication circuitry 240 through the SFT).

[0042] FIGs. 3A-3G schematically illustrate various example types and combinations of the magnet 314 and the implanted magnetic element 256 in accordance with certain implementations described herein. As shown in FIGs. 3A-3G, each of the magnet 314 and the implanted magnetic element 256 can comprise a magnet type selected from the group consisting of: axially magnetized (axial) magnet; diametrically magnetized (dimetric) magnet; angled four pole magnet. The magnet 314 can have a permanent first magnetization comprising a first dipole magnetic moment 318 (e.g., dipole magnet; axial magnet; diametric magnet) or multiple first dipole magnetic moments 318 (e.g., a multipole magnetic moment; having two or more portions with different dipole magnetic moments or magnetizations; an angled four pole magnet). The implanted magnetic element 256 can have a permanent second magnetization comprising a second dipole magnetic moment 258 (e.g., a dipole magnet; an axial magnet, a diametric magnet) or multiple second dipole magnetic moments 258 (e.g., a multiple magnetic moment; having two or more portions with different dipole magnetic moments or magnetizations; an angled four pole magnet). The first magnetization isconfigured to interact with the second magnetization to generate the attractive magnetic force 257.

[0043] In certain implementations (see, e.g., FIGs. 3A-3G), the magnet 314 and the implanted magnetic element 256 are of substantially equal size and shape with one another, while in certain other implementations, the magnet 314 and the implanted magnetic element 256 have substantially different sizes and / or shapes. In addition, the magnet 314 and / or the implanted magnetic element 256 can include multiple magnetic elements or other types of magnets. In certain implementations, the magnet 314 at least partially overlies the implanted magnetic element 256.

[0044] In FIG. 3 A, each of the magnet 314 and the implanted magnetic element 256 comprises an axial magnet having corresponding first and second dipole magnetic moments 318, 258, respectively, that are substantially parallel to one another. In FIG. 3B, each of the magnet 314 and the implanted magnetic element 256 comprises a diametric magnet having corresponding first and second dipole magnetic moments 318, 258, respectively, that are substantially anti-parallel to one another (e.g., substantially parallel and pointing in substantially opposite directions). In FIG. 3C, each of the magnet 314 and the implanted magnetic element 256 comprises an angled four pole magnet having corresponding first and second dipole magnetic moments 318, 258, respectively. In FIG. 3D, the magnet 314 comprises a diametric magnet and the implanted magnetic element 256 comprises an angled four pole magnet, and in FIG. 3E, the magnet 314 comprises an angled four pole magnet and the implanted magnetic element 356 comprises a diametric magnet. In FIG. 3F, the magnet 314 comprises an axial magnet and the implanted magnetic element 256 comprises a diametric magnet, and in FIG. 3G, the magnet 314 comprises an axial magnet and the implanted magnetic element 256 comprises an angled four pole magnet.

[0045] While FIGs. 3C and 3E show each of the two first dipole magnetic moments 318 having a non-zero angle relative to the longitudinal axis of the magnet 314, the two first dipole magnetic moments 318 of the angled four pole magnet can be substantially parallel to the longitudinal axis of the magnet 314 (e.g., one of the first dipole magnetic moments 318 pointing upwards and the other of the first dipole magnetic moments 318 pointing downward). Similarly, while FIGs. 3C, 3D, and 3G show each of the two second dipole magnetic moments 258 having a non-zero angle relative to the longitudinal axis of the implanted magnetic element256, the two second dipole magnetic moments 258 of the angled four pole magnet can be substantially parallel to the longitudinal axis of the implanted magnetic element 256 (e.g., one of the second dipole magnetic moments 258 pointing upwards and the other of the second dipole magnetic moments 258 pointing downward).

[0046] In certain implementations (e.g., in which the magnet 314 comprises a diametric magnet or an angled four pole magnet), the magnet 314 is configured to freely rotate about the longitudinal axis of the magnet 314 while within the cavity 312 (e.g., in response to resultant magnetic forces) to substantially align the first dipole magnetic moment 318 with the second dipole magnetic moment 258. As a result of the rotation of the diametric magnet 314, the vector sum of the first dipole magnetic moments 318 can be substantially anti -parallel to the second dipole magnetic moment 258 (see, e.g., FIGs. 3B, 3E) or substantially anti-parallel to the vector sum of the second dipole magnetic moments 258 (see, e.g., FIGs. 3C, 3D). In certain implementations, in response to the attractive magnetic force 257, the magnet 314 can self-position (e.g., self-center) relative to the implanted magnetic element 256 of the implanted device 250, thereby moving the apparatus 300 relative to the implanted device 250.

[0047] In certain implementations, the attractive magnetic force 257 generated by the magnet 314 and the implanted magnetic element 256 is dependent upon the magnet types and the relative positions of the magnet 314 and the implanted magnetic element 256. For example, the attractive magnetic force 257 can be strongest (e.g., maximum magnitude) with the magnet 314 substantially overlying the implanted magnetic element 256 (see, e.g., FIGs. 3A-3E which have zero lateral displacement between the centers of the magnet 314 and the implanted magnetic element 256). For another example, a maximum magnitude of the attractive magnetic force 257 can correspond to a non-zero lateral displacement between the centers of the magnet 314 and the implanted magnetic element 256 (e.g., for comparable widths of the magnet 314 and the implanted magnetic element 256, the lateral displacement can be substantially equal to one -half the width; see, e.g., FIGs. 3F-3G).

[0048] In certain implementations, the at least one sensor 320 comprises at least one magnetic field sensor configured to generate at least one signal 322 (e.g., analog or digital electrical signals) indicative of a magnetic field strength generated by the magnet 314. The at least one magnetic field sensor can be positioned on or within the housing 310 and sufficiently close to the magnet 314 within the cavity 312 so as to receive a portion of the magnetic field315 (e.g., magnetic flux) from the magnet 314. While FIGs. 2A-2B show a sensor 320 located at a side of the cavity 312, other positions are also compatible with certain implementations described herein. Examples of magnetic field sensors compatible with certain implementations described herein include but are not limited to: Hall sensor; magnetoresistive sensor; semiconductor magnetoresistive (SMR) sensor; anisotropic magnetoresistive (AMR) sensor; giant magnetoresistive (GMR) sensor; tunnel magnetoresistive (TMR) sensor; reed switch; magnetic proximity sensor. Other types of magnetic field sensors (e.g., load cell responsive to tension or strain caused by a magnetic force resulting from the magnet 314; piezoelectric element responsive to displacement caused by a magnetic force resulting from the magnet 314) are also compatible with certain implementations described herein.

[0049] FIGs. 4A and 4B schematically illustrate two example sensors 320 in accordance with certain implementations described herein. The example sensor 320 of FIG. 4A comprises a three-axis Hall sensor 324 configured to generate digital signals 322 indicative of a measured magnetic field strength in three substantially orthogonal directions and to transmit the digital signals 322 to the control circuitry 330 via a communication bus (e.g., interintegrated circuity or I2C bus). The example sensor 320 of FIG. 4B comprises a magnetoresistive sensor 326 configured to adjust analog voltages indicative of a measured magnetic field strength in at least one direction and an analog-to-digital converter (ADC) 328 configured to receive the analog voltages, generate digital signals 322 in response, and to transmit the digital signals 322 to the control circuitry 330. While FIGs. 4A and 4B each show a single example sensor 320, the at least one sensor 320 of certain implementations comprises multiple sensors 320 with different positions on or within the housing 310 (e.g., three sensors 320 arranged in a triangular configuration).

[0050] In certain implementations, the at least one sensor 320 comprises at least one optical sensor and / or at least one switch configured to generate at least one signal 322 (e.g., analog or digital electrical signals) indicative of an identification of the magnet 314, the identification indicative of a magnetic field strength of the magnet 314. The at least one optical sensor can be positioned on or within the housing 310 such that the at least one optical sensor detects symbols, letters, numerals, or other optical indicia on the surface of the magnet 314 (e.g., via light reflected from a surface of the magnet 314). The at least one switch can be positioned at a boundary of the cavity 312 such that the at least one switch is opened or closeddepending on the existence of protrusions, recesses, or other tactile indicia at the surface of the magnet 314. In certain implementations, the at least one sensor 320 comprises circuitry which converts the detected optical or tactile indicia into a detected magnetic field strength of the magnet 314 (e.g., utilizing a look-up table and / or conversion algorithm in data storage circuitry of the at least one optical sensor) which is communicated to the control circuitry 330 by the at least one signal 322. In certain other implementations, the at least one signal 322 is indicative of the detected optical or tactile indicia and the control circuitry 330 is configured to convert the at least one signal 322 into a detected magnetic field strength of the magnet 314 (e.g., utilizing a look-up table and / or conversion algorithm in data storage circuitry of the control circuitry 330).

[0051] FIGs. 4A and 4B schematically illustrate example control circuitry 330 and external communication circuitry 340 in accordance with certain implementations described herein. In certain implementations, the control circuitry 330 comprises a processor 332 (e.g., microprocessor, application-specific integrated circuit, generalized integrated circuit programmed by software with computer executable instructions, microelectronic circuitry, microcontroller). The processor 332 can be in operative communication with 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) of the control circuitry 330 or separate from the apparatus 300 and in operative communication with the control circuitry 330. The at least one storage device can be configured to store information (e.g., data and / or commands) accessible by the processor 332 during operation. The at least one storage device can be encoded with software (e.g., a computer program downloaded as an application) comprising computer executable instructions for instructing the processor 332 (e.g., executable data access logic, evaluation logic, and / or information outputting logic). In certain implementations, the processor 332 executes the instructions of the software to provide functionality as described herein.

[0052] In certain implementations, the control circuitry 330 comprises at least one coil driver 334 (e.g., amplifier) configured to, in response to drive control signals 335 from the processor 332, generate and adjust a time-varying (e.g., oscillating) drive voltage and / or drive current applied to the external communication circuitry 340 (e.g., the at least one external coil 342) to wirelessly transmit power and / or data to the internal communication circuitry 240 (e.g.,the at least one internal coil 242) of the implanted device 250. For example, in response to the drive control signals 335, the at least one coil driver 334 can turn on the drive current, turn off the drive current, and / or adjust the drive current to have a selected magnitude, phase, and / or frequency.

[0053] In certain implementations, the external communication circuitry 340 comprises the at least one external coil 342 and adjustment circuitry 344 configured to, in response to adjustment control signals 337 from the processor 332, modify at least one electrical attribute of the external communication circuitry 340. For example, as schematically shown in FIGs. 4A and 4B, the at least one external coil 342 has a capacitance and an inductance and the adjustment circuitry 344 is in series electrical communication with the at least one external coil 342 such that the time-varying drive current generated by the at least one coil driver 334 flows in series through the adjustment circuitry 344 and the at least one external coil 342. While FIGs. 4A and 4B show the adjustment circuitry 344 as a component of the external communication circuitry 340, in certain other implementations, the adjustment circuitry 344 is a component of the control circuitry 330.

[0054] The adjustment circuitry 344 can comprise at least one switch 346 and at least one passive electrical element 348 (e.g., capacitor; inductor). The at least one switch 346 can have a first state in which the at least one passive electrical element 348 is in the circuit through which the time-varying drive current flows and a second state in which the at least one passive electrical element 348 is not in the circuit through which the time-varying drive current flows. The at least one switch 346 can respond to the adjustment control signals 337 from the processor 332 to switch from the first state to the second state or vice versa. In this way, the control circuitry 330 can adjust a capacitance, an inductance, a resonant frequency, and / or a Q factor of the external communication circuitry 340.

[0055] The control circuitry 330 can further comprise at least one input interface in operative communication with the processor 332. The at least one input interface can be configured to receive input signals (e.g., from the recipient; from the medical practitioner) comprising information (e.g., data and / or commands). For example, the information can include the size, strength, and / or magnet type of the implanted magnetic element 256 (e.g., identifying the implanted magnetic element 256 as an axial magnet, a diametric magnet, or an angled four pole magnet). For another example, the information can include the modelnumber, serial number, and / or other identifying indicia of the implanted device 250, and the control circuitry 330 can be configured to convert the received information into the information regarding the implanted magnetic element 256. Examples of the at least one input interface include but are not limited to: rotatable knobs (e.g., connected to potentiometers); buttons; switches; touchscreen; microphone and voice-responsive circuitry. As another example, the at least one input interface can comprise an antenna configured to receive wireless input signals (e.g., Bluetooth signals; WiFi signals) from a device separate from the apparatus 300 (e.g., smart phone, smart tablet, smart watch; computing device).

[0056] The control circuitry 330 can further comprise at least one output interface in operative communication with the processor 332. The at least one output interface can be configured to provide output signals (e.g., an alert signal) to a user (e.g., recipient; clinician; medical practitioner) or to a data storage device (e.g., at least one storage device in operative communication with the processor 332) to be later accessed by a user (e.g., as part of a data log of events). The output signals can comprise information relevant to at least one characteristic of the interaction between the apparatus 300 and the implanted device 250 (e.g., indicative of the at least one attribute of the magnet 314). Examples of the at least one output interface include but are not limited to: a speaker configured to generate audio signals; an LED or LCD display configured to generate visual signals (e.g., colored lights, images, or alphanumeric characters); a haptic motor configured to generate vibrations or other tactile signals. As another example, the at least one output interface can comprise an antenna on or within the housing 310, the antenna configured to transmit wireless output signals (e.g., Bluetooth signals; WiFi signals) to a communication device separate from the apparatus 300 (e.g., smart phone, smart tablet, smart watch; computing device) to display the indication. The communication device can be configured to generate, in response to the output signals, an audio, visual, or haptic signal indicative of the at least one attribute of the magnet 314 that is detected by the at least one sensor 320. In certain implementations, the control circuitry 330 comprises a user interface (e.g., touchscreen; transceiver antenna) configured to operate as both the at least one input interface and the at least one output interface.

[0057] In certain implementations, the cavity 312 is positioned within a region in proximity to (e.g., encircled by) the at least one external coil 342 of the external communication circuitry 340. In certain such positions, the magnet 314 within the cavity 312 can affect theoperational characteristics of the external communication circuitry 340 (e.g., by acting as a magnetic core of the at least one external coil 342). For example, the magnet 314 can produce a detuning contribution to the resonant frequency of the external communication circuitry 340, the detuning contribution in a range of ± 25 kHz, ± 50 kHz, ± 500 kHz, or higher (e.g., a magnet 314 with a stronger magnetic field 315 can produce a larger shift of a resonant frequency of the at least one external coil 342 than does a magnet 314 with a weaker magnetic field 315).

[0058] At various times, the magnet 314 within the cavity 312 can be removed and replaced with another magnet 314 with a different strength of magnetic field 315. For example, during a fitting procedure conducted by a clinician, the clinician can place different magnets 314 in the cavity 312 to determine which magnet 314 provides an adequate magnetic field strength to affix the apparatus 300 to the recipient’s body without causing discomfort to the recipient (e.g., skin compression due to an excessively strong magnet 314). For another example, during normal operation, the recipient can swap magnets 314 out of and into the apparatus 300 to find a magnet 314 with an optimal magnetic field strength for an expected activity level (e.g., a stronger magnet 314 for athletic activity; a weaker magnet 314 for sedentary activity). However, due to the differing magnetic field strengths of the magnets 314 having different detuning contributions, the resonant frequency of the external communication circuitry 340 can be dependent on the magnet 314 used, with the resulting resonant frequency of the external communication circuitry 340 potentially resulting in power and / or data transmission that is less than optimal.

[0059] In certain implementations, removing and replacing the magnet 314 comprises removing the apparatus 300 from the recipient’s body (e.g., detaching the apparatus 300 from the recipient’s skin). In certain implementations, the control circuitry 330 is configured to detect whether the apparatus 300 has been removed from and replaced onto the recipient’s body (e.g., by detecting the loss and reestablishment of the wireless transcutaneous communication link between the apparatus 300 and the implanted device 250). The control circuitry 330 can be further configured to receive the at least one signal 322 and / or to respond to the at least one signal 322 in response to detecting that the apparatus 300 has been removed from and replaced onto the recipient’s body (e.g., a process during which the magnet 314 may have been removed and replaced with another magnet 314).

[0060] In certain other implementations in which the housing 310 includes a removable or hinged cover configured to be opened to provide access to the cavity 312 (e.g., to remove a magnet 314 from the cavity 312; to place a magnet 314 into the cavity 312), the apparatus 300 can comprise a cover sensor (e.g., switch; optical sensor) configured to generate cover sensor signals indicative of whether the cover has been opened and closed. The control circuitry 330 can be further configured to receive the at least one signal 322 and / or to respond to the at least one signal 322 in response to detecting that the cover has been opened and closed (e.g., a process during which the magnet 314 may have been removed and replaced with another magnet 314).

[0061] In certain implementations, the control circuitry 330 is configured to receive the at least one signal 322 from the at least one sensor 320 while the apparatus 300 is removed from the recipient’s body (e.g., so that the at least one sensor 320 is not influenced by the magnetic field contribution from the implanted magnetic element 256). In certain other implementations, the control circuitry 330 is configured to receive the at least one signal 322 from the at least one sensor 320 while the apparatus 300 is on the recipient’s body and is configured to account for the magnetic field contribution from the implanted magnetic element 256 (e.g., using stored information regarding the implanted magnetic element 256).

[0062] In certain implementations, the control circuitry 330 is configured to receive the at least one signal 322 indicative of the at least one attribute of the magnet 314 from the at least one sensor 320 and to adjust at least one operational parameter of the apparatus 300 in response to the at least one signal 322. The at least one attribute of the magnet 314 can comprise a magnetic field strength (e.g., in a direction substantially parallel to the longitudinal axis 313) that is directly measured by the at least one sensor 320 (e.g., magnetic field sensor) and / or an identification of a magnet type that is detected by the at least one sensor 320 (e.g., optical and / or tactile sensor), the magnet type indicative of a magnetic field strength, magnetic field spatial distribution, or other magnetic characteristic of the magnet 314. For example, the control circuitry 330 can access a lookup table (e.g., stored by the at least one storage device) or a conversion algorithm configured to convert the detected identification into the magnet type of the magnet 314.

[0063] In certain implementations, the at least one operational parameter can comprise a drive voltage and / or drive current applied to the external communication circuitry340. For example, in response to the at least one signal 322 from the at least one sensor 320, the processor 332 can transmit drive control signals 335 to the at least one coil driver 334 to adjust a magnitude, phase, and / or frequency of a drive voltage and / or drive current applied to the external communication circuitry 340.

[0064] In certain implementations, the at least one operational parameter can be indicative of an electrical attribute of the external communication circuitry 340 (e.g., the at least one external coil 342) of the apparatus 300. The electrical attribute can be selected from the group consisting of: capacitance; inductance; resonant frequency; quality (Q) factor. For example, in response to the at least one signal 322 from the at least one sensor 320, the processor 332 can transmit adjustment control signals 337 to the adjustment circuitry 344 to change the state of the at least one switch 346 such that either the at least one passive element 348 receives the time-varying (e.g., oscillating) drive current generated by the at least one coil driver 334 or the at least one passive element 348 does not receive the time- varying drive current. As schematically shown in FIGs. 4A and 4B, the at least one passive element 348 can comprise a capacitor and, in response to the at least one signal 322 from the at least one sensor 320, the control circuitry 330 can compensate for detuning of the external communication circuitry 340 caused by the magnet 314 by including or excluding the passive element 348 (e.g., capacitor) from receiving the drive current, thereby changing the capacitance and the resonant frequency of the external communication circuitry 340. In certain other implementations, the at least one passive element 348 comprises an inductor and the control circuitry 330 can change the inductance of the external communication circuitry 340.

[0065] In certain implementations, the at least one operational parameter comprises a distance between the magnet 314 and the implanted device 250 and / or a tilt of the magnet 314 relative to the implanted device 250. For example, the apparatus 300 can comprise an adjustable element in mechanical communication with the magnet 314 and the housing 310. The adjustable element can comprise a piezoelectric or electroactive polymer material configured to respond to an applied electric voltage (e.g., generated in response to a control signal generated by the control circuitry 330) by controllably moving the magnet 314 and / or a portion of the housing 310 to adjust the distance (e.g., artificially adjusting the SFT) and / or the tilt. In certain other implementations, the at least one operational parameter comprises adistance between the housing 310 and the implanted device 250 or another component of the apparatus 300 within the housing 310.

[0066] In certain implementations, the at least one operational parameter comprises an electrical permittivity of a portion of the housing 310 between the communication circuitry 340 and the implanted device 250. For example, the portion of the housing 310 can comprise a ferroelectric material (e.g., zirconate; titanate) configured to change electrical permittivity in response to an applied electric voltage (e.g., generated in response to a control signal generated by the control circuitry 330).

[0067] In certain implementations, the apparatus 300 comprises at least one second sensor configured to generate electrical signals indicative of sensory stimulation signals received by the at least one second sensor, and the at least one operational parameter comprises an operational parameter of the at least one second sensor that is dependent on the strength of the magnet 314. For example, the at least one second sensor can comprise at least one microphone configured to generate electrical signals indicative of sounds received by the at least one microphone. The at least one microphone can be in proximity to the magnet 314 such that the performance of the at least one microphone is dependent on the magnetic field strength of the magnet 314 (e.g., due to eddy current damping from the interaction of a movable portion of the microphone with the magnetic field; due to an amplified noise contribution due to the magnetic field). In certain implementations, the at least one operational parameter is a physical operational parameter of the microphone (e.g., spring constant of the movable portion).

[0068] In certain other implementations, the at least one operational parameter is stored in firmware of the apparatus 300 and can be adjusted to improve data integrity performance. For example, the apparatus 300 can comprise signal processing circuity (e.g., a portion of the control circuitry 330) configured to receive sensory signals (e.g., from at least one second sensor) indicative of sensor information (e.g., sounds) and, in response to the sensory signals, to generate processed sensory signals using a signal processing algorithm. The processed sensory signals can be configured to be transmitted to (e.g., via the wireless transcutaneous link) and received by the implanted device 250 to generate stimulation signals to be applied to tissue of the recipient (e.g., by the at least one active element 254) to evoke a sensory (e.g., hearing) percept by the recipient. Example operational parameters can comprise a noise cancellation circuit (e.g., notch filter) of the signal processing circuitry and / or a notchdepth of the noise cancellation circuit, the noise cancellation circuit configured to operate on a portion of the sensory signals received from the at least one second sensor (e.g., a microphone) or on a signal derived from a portion of the sensor signals. For example, in response to the at least one signal 322 (e.g., from the at least one sensor 320), the control circuitry 330 can enable or disable the noise cancellation circuit (e.g., enabled if the magnetic field strength is sufficiently high to cause noise amplification) and / or can adjust the notch depth (e.g., to increase the notch depth for stronger magnetic field strengths). Another example operational parameter can comprise a stimulation map which is used by the control circuitry 330 or the at least one active element 254 to convert the processed sensory signals into stimulation signals, the stimulation map having stimulation levels as a function of stimulation frequency. For example, a first stimulation map can be used for stronger magnetic field strengths (e.g., for a magnet 314 selected for outdoor activities) and a second stimulation map can be used for weaker magnetic field strengths (e.g., for a magnet 314 selected for indoor activities).

[0069] FIG. 5 is a flow diagram of an example method 500 in accordance with certain implementations described herein. While the method 500 is described by referring to some of the structures of the example apparatus 300 of FIGs. 2A-2B, 3A-3G, and 4A-4B, other apparatus and systems with other configurations of components can also be used to perform the method 500 in accordance with certain implementations described herein.

[0070] In an operational block 510, the method 500 comprises generating information indicative of magnetic field strengths of magnets (e.g., magnets 314) placed within an external device (e.g., apparatus 300) at different times and indicative of the different times at which the magnets are placed within the external device. In an operational block 520, the method 500 further comprises adjusting, in response to a real-time portion of the information (e.g., automatically), at least one operational parameter of the external device and / or of an internal device (e.g., implanted device 250) in wireless communication with the external device.

[0071] The external device can be configured to be held on a recipient’s body over the internal device within the recipient’s body by attractive magnetic forces (e.g., magnetic attractive force 257) generated by an interaction of a magnet (e.g., magnet 314) within the external device (e.g., within the cavity 312) with the internal device (e.g., with the internal magnetic element 256). The external device and the internal device can have a wirelesstranscutaneous communication link therebetween. For example, the external device can comprise at least one first communication coil (e.g., at least one external coil 342) and the internal device can comprise at least one second communication coil (e.g., at least one internal coil 242), and the at least one first communication coil and the at least one second communication coil can be configured to be in magnetic inductive communication with one another to form the wireless transcutaneous communication link.

[0072] In certain implementations, generating the information is performed while the external device is off the recipient’s body (e.g., such that the internal device does not affect the generated information). In certain implementations, adjusting the at least one operational parameter comprises modifying at least one electrical property of the at least one first communication coil, the at least one electrical property selected from the group consisting of: drive voltage or current; capacitance; inductance; resonant frequency; quality (Q) factor. In certain other implementations, adjusting the at least one operational parameter comprises modifying a distance between the magnet and the internal device, modifying a tilt of the magnet relative to the internal device, and / or modifying an electrical permittivity of a portion of the external device between the magnet and the internal device.

[0073] In certain implementations, the method 500 further comprises using a signal processing algorithm (e.g., noise cancellation algorithm; stimulation mapping algorithm) to process sensory signals (e.g., microphone signals) received by the external device and transmitting processed sensory signals to the internal device (e.g., to be used in generating stimulation signals to be provided to the recipient’s tissue). In certain such implementations, adjusting the at least one operational parameter comprises modifying the signal processing algorithm.

[0074] In certain implementations, the method 500 further comprises, in response to the real-time portion of the information, detecting whether the external device and the internal device are misaligned with one another such that the wireless transcutaneous communication link is degraded. Adjusting the at least one operational parameter can be performed to counteract the degradation of the wireless transcutaneous communication link (e.g., by adjusting the at least one electrical property of the at least one first communication coil).

[0075] In certain implementations, the method 500 further comprises transmitting at least some of the information to data storage circuitry (e.g., non-volatile memory) to be stored as at least one data log accessible by a user. For example, the at least one data log can include magnetic field strengths or data derived from the measured magnetic field strengths as a function of time. The data storage circuitry can be a part of the external device (e.g., a component of the apparatus 300; a portion of the control circuitry 330). For another example, the data storage circuitry can be a component of a device (e.g., smart phone; smart tablet; smart watch; computing device) separate from the external device and the internal device, the device in wireless communication with a network (e.g., via the internet). The at least one data log can be configured to track usage of different magnets 314 with the apparatus 300 (e.g., times at which the magnet is swapped, the usage time duration for each magnet). Such a data log can be used by a clinician to assess magnet selections over time or wound healing (e.g., reductions of SFT due to reduced swelling over time after the implantation procedure).

[0076] Although commonly used terms are used to describe the systems and methods of certain implementations for ease of understanding, these terms are used herein to have their broadest reasonable interpretations. Although various aspects of the disclosure are described with regard to illustrative examples and implementations, the disclosed examples and implementations should not be construed as limiting. Conditional language, such as, among others, "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations include, while other implementations do not include, certain features, elements and / or steps. Thus, such conditional language is not generally intended to imply that features, elements and / or steps are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and / or steps are included or are to be performed in any particular implementation. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a nonexclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

[0077] It is to be appreciated that the implementations disclosed herein are not mutually exclusive and may be combined with one another in various arrangements. In addition, although the disclosed methods and apparatuses have largely been described in the context of various devices, various implementations described herein can be incorporated in a variety of other suitable devices, methods, and contexts. More generally, as can be appreciated, certain implementations described herein can be used in a variety of implantable medical device contexts that can benefit from certain attributes described herein.

[0078] Language of degree, as used herein, such as the terms “approximately,” “about,” “generally,” and “substantially,” represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within ± 10% of, within ± 5% of, within ± 2% of, within ± 1 % of, or within ± 0.1% of the stated amount. As another example, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by ± 10 degrees, by ± 5 degrees, by ± 2 degrees, by ± 1 degree, or by ± 0.1 degree, and the terms “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly perpendicular by ± 10 degrees, by ± 5 degrees, by ± 2 degrees, by ± 1 degree, or by ± 0.1 degree. The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” less than,” “between,” and the like includes the number recited. As used herein, the meaning of “a,” “an,” and “said” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “into” and “on,” unless the context clearly dictates otherwise.

[0079] While the methods and systems are discussed herein in terms of elements labeled by ordinal adjectives (e.g., first, second, etc.), the ordinal adjective are used merely as labels to distinguish one element from another (e.g., one signal from another or one circuit from one another), and the ordinal adjective is not used to denote an order of these elements or of their use.

[0080] The invention described and claimed herein is not to be limited in scope by the specific example implementations herein disclosed, since these implementations areintended as illustrations, and not limitations, of several aspects of the invention. Any equivalent implementations are intended to be within the scope of this invention. Indeed, various modifications of the invention in form and detail, in addition to those shown and described herein, will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the claims. The breadth and scope of the invention should not be limited by any of the example implementations disclosed herein but should be defined only in accordance with the claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. An apparatus comprising: a housing configured to be placed over a tissue portion of a recipient, the tissue portion overlaying an implanted device, the housing comprising a cavity configured to hold a magnet therein; at least one sensor on or within the housing, the at least one sensor configured to detect the magnet within the cavity and to generate at least one signal indicative of at least one attribute of the magnet; and control circuitry within the housing, the control circuitry configured to receive the at least one signal and, in response to the at least one signal, adjust at least one operational parameter of the apparatus.

2. The apparatus of claim 1 , wherein the at least one sensor comprises at least one magnetic field sensor, the at least one signal indicative of a magnetic field strength generated by the magnet.

3. The apparatus of claim 2, wherein the at least one magnetic field sensor is selected from the group consisting of: Hall sensor; magnetoresistive sensor; semiconductor magnetoresistive (SMR) sensor; anisotropic magnetoresistive (AMR) sensor; giant magnetoresistive (GMR) sensor; tunnel magnetoresistive (TMR) sensor; reed switch; magnetic proximity sensor.

4. The apparatus of claim 1 , wherein the at least one sensor comprises at least one optical sensor and / or at least one switch, the at least one signal indicative of an identification of the magnet, the identification indicative of a magnetic field strength of the magnet.

5. The apparatus of any preceding claim, further comprising communication circuitry configured to form a wireless magnetic induction link with the implanted device, wherein the magnet is configured to generate an attractive magnetic force with the implanted device, the attractive magnetic force configured to hold the housing on the tissue portion with the communication circuitry in wireless communication with the implanted device.

6. The apparatus of claim 5, wherein the at least one operational parameter comprises an electrical attribute of the communication circuitry, the electrical attribute selected from the group consisting of: capacitance; inductance; resonant frequency; quality (Q) factor.

7. The apparatus of claim 5, wherein the at least one operational parameter comprises a drive voltage and / or drive current applied to the communication circuitry.

8. The apparatus of claim 5, wherein the at least one operational parameter comprises an electrical permittivity of a portion of the housing between the communication circuitry and the implanted device.

9. The apparatus of any preceding claim, wherein the at least one operational parameter comprises a distance between the magnet and the implanted device and / or a tilt of the magnet relative to the implanted device.

10. The apparatus of claim 9, further comprising a piezoelectric element in mechanical communication with the magnet and the housing and configured to controllably adjust the distance and / or the tilt.

11. The apparatus of any preceding claim, further comprising at least one microphone, wherein the at least one operational parameter comprises an operational parameter of the at least one microphone.

12. The apparatus of any preceding claim, further comprising signal processing circuitry configured to receive sensory signals indicative of sensory information and, in response to the sensory signals, to generate processed sensory signals using a signal processing algorithm, the processed sensory signals configured to be received by the implanted device to generate stimulation signals to be applied to the recipient to evoke a sensory percept by the recipient, wherein the at least one operational parameter comprises the signal processing algorithm.

13. The apparatus of any preceding claim, wherein the control circuitry comprises at least one output interface configured to provide output signals to a user or to a data storage device, wherein the output signals are indicative of the at least one attribute.

14. The apparatus of claim 13, wherein the at least one output interface comprises at least one antenna on or with the housing, the at least one antenna configured to wirelessly transmit the output signals to a communication device separate from the apparatus and the implanted device, the communication device configured to generate, in response to the output signals, an audio, visual, or haptic signal indicative of the at least one attribute.

15. The apparatus of any preceding claim, wherein the apparatus comprises an external portion of an auditory prosthesis system and the implanted device comprises an internal portion of the auditory prosthesis system.

16. A method comprising: generating information indicative of magnetic field strengths of magnets placed within an external device at different times and indicative of the different times at which the magnets are placed within the external device, the external device configured to be held on a recipient’s body over an internal device within the recipient’s body by attractive magnetic forces generated by an interaction of a magnet within the external device with the internal device, the external device and the internal device having a wireless transcutaneous communication link therebetween; and adjusting at least one operational parameter of the external device and / or the internal device in response to a real-time portion of the information.

17. The method of claim 16, wherein said generating the information is performed while the external device is off the recipient’s body.

18. The method of claim 16 or claim 17, wherein the external device comprises at least one first communication coil and the internal device comprises at least one second communication coil, the at least one first communication coil and the at least one second communication coil configured to be in magnetic inductive communication with one another to form the wireless transcutaneous communication link.

19. The method of claim 18, wherein said adjusting the at least one operational parameter comprises modifying at least one electrical property of the at least one first communication coil, the at least one electrical property selected from the group consisting of: drive voltage or current; capacitance; inductance; resonant frequency; quality (Q) factor.

20. The method of claim 18, wherein said adjusting the at least one operational parameter comprises modifying a distance between the magnet and the internal device, modifying a tilt of the magnet relative to the internal device, and / or modifying an electrical permittivity of a portion of the external device between the magnet and the internal device.

21. The method of any of claims 16 to 20, further comprising using a signal processing algorithm to process sensory signals received by the external device andtransmitting processed sensory signals to the internal device, said adjusting the at least one operational parameter comprises modifying the signal processing algorithm.

22. The method of any of claims 16 to 21, further comprising, in response to the real-time portion of the information, detecting whether the external device and the internal device are misaligned with one another such that the wireless transcutaneous communication link is degraded.

23. The method of any of claims 16 to 22, further comprising transmitting at least some of the information to data storage circuitry be stored as at least one data log accessible by a user.

24. The method of claim 23, wherein the data storage circuitry is part of the external device.

25. The method of claim 23, wherein the data storage circuitry is part of a device separate from the external device and the internal device.

26. The method of claim 25, wherein the device comprises a smart phone, smart tablet, smart watch, or computing device in wireless communication with a network.

27. A non-transitory computer readable storage medium having stored thereon a computer program that instructs a computer system to perform the method of any of claims 16 to 26.

28. An apparatus comprising: a housing; a first sensor on or within the housing, the first sensor configured to generate a first signal indicative of at least one attribute of a magnet on or within the housing; a second sensor on or within the housing, the second sensor configured to generate a second signal indicative of at least one attribute of ambient sound; and control circuitry within the housing, the control circuitry configured to receive the first signal and the second signal and, in response to the first signal, adjust an operational parameter for processing the second signal.

29. The apparatus of claim 28, further comprising a notch filter configured to filter a third signal comprising a portion of the second signal or that is otherwise derived from the second signal, wherein the operational parameter affects operation of the notch filter.

30. The apparatus of claim 28 or claim 29, wherein the housing is configured to be placed over a portion of skin of a recipient, the portion of skin overlaying an implanted device, and the housing comprises a cavity configured to hold the magnet therein.

31. The apparatus of claim 30, wherein the apparatus comprises an external portion of an auditory prosthesis system and the implanted device comprises an internal portion of the auditory prosthesis system.

Images