Evoked biological response proximity analysis

Abstract

Presented herein are techniques for determining the relative proximity of an electrode to a target structure in a recipient using an evoked biological response (evoked response). For example, in certain embodiments, techniques presented herein use evoked biological responses to determine the relative proximity of an electrode to the cochlear axis of the cochlea.

Description

background Technical Field

[0001] The present invention generally relates to techniques for analyzing an induced biological response to determine the relative proximity of an electrode to a target structure. Background Art

[0002] Medical devices have provided a wide range of therapeutic benefits to recipients over the last several decades. Medical devices may include internal or implantable components / devices, external or wearable components / devices, or combinations thereof (e.g., devices having external components that communicate with implantable components). 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 over the years in performing life-saving and / or lifestyle-improving functions and / or recipient monitoring.

[0003] Over the years, the types of medical devices and the range of functions performed by them 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 that are permanently or temporarily implanted in a recipient's body. These functional devices are typically used to diagnose, prevent, monitor, treat, or manage disease / injury or its 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, a method is provided. The method includes capturing a plurality of electrically evoked compound action potentials (ECAPs) via electrodes configured to be inserted into an inner ear, and estimating a proximity of at least one of the electrodes to a modiolus based on the plurality of ECAPs.

[0005] In another aspect, one or more non-transitory computer-readable storage media comprising instructions are provided. The instructions, when executed by one or more processors, cause the one or more processors to: perform neural response telemetry measurements using one or more of a plurality of electrodes configured to be inserted into an inner ear of a recipient to obtain a plurality of evoked bio-responses; and estimate a relative proximity of the electrodes to a wall of the inner ear using the plurality of evoked bio-responses.

[0006] In another aspect, a method is provided. The method includes obtaining a plurality of induced biological responses using one or more electrodes of a plurality of electrodes configured to be inserted into a body of a recipient, and analyzing the plurality of induced biological responses relative to each other to determine a relative proximity of at least one of the electrodes to a target structure in the body of the recipient.

[0007] In another aspect, a system is provided. The system includes: one or more electrodes configured to record a plurality of evoked biological responses from a cochlea of ​​a recipient; and one or more processors configured to analyze the plurality of evoked biological responses relative to each other to determine relative modiolar proximity of the electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments of the present invention are described herein with reference to the accompanying drawings, in which:

[0009] Figure 1A is a schematic diagram illustrating a cochlear implant system with which aspects of the technology presented herein may be implemented;

[0010] Figure 1B Yes Wear Figure 1A A side view of a recipient of a sound processing unit of a cochlear implant system;

[0011] Figure 1C yes Figure 1A A schematic diagram of components of a cochlear implant system;

[0012] Figure 1D yes Figure 1A Block diagram of a cochlear implant system;

[0013] Figure 1E is a schematic diagram illustrating a computing system with which aspects of the techniques presented herein may be implemented;

[0014] Figure 2A and 2B is a schematic diagram showing the effect that the relative positioning of the electrode to the modiolus may have on the excitation distribution;

[0015] Figure 3 is a graph showing a nominal / typical ECAP response obtained from a recipient's inner ear in response to a biphasic stimulation signal, displayed in the time domain;

[0016] Figure 4 is a graph showing an exemplary distribution of excitation (SOE) function determined from an ECAP response obtained from the inner ear of a recipient;

[0017] Figure 5A and 5Bis a graph showing an exemplary SOE function according to various aspects presented herein, wherein the peak is shifted from the detection electrode toward the apex and / or toward the base of the cochlea;

[0018] Fig. 6A , 6B , 6C and 6D are diagrams further illustrating the concept of shifting or "off-detection peaks" (assuming spiral ganglia and order homogeneity) according to various aspects presented herein;

[0019] Figure 7 is a diagram showing that ECAP threshold distributions may vary across an electrode array in accordance with various aspects presented herein;

[0020] Fig. 8A , 8B and 8C schematically illustrates the effects of over-insertion and retraction of a stimulation component that may be caused using the techniques presented herein;

[0021] Fig. 9 is a representation of a computed tomography (CT) image of an over-inserted so-called slim modiolar stimulation component according to various aspects presented herein;

[0022] Fig.10 shows expected SOE curves according to various aspects presented herein;

[0023] Fig.11 is a graph showing ECAP amplitude induced by a probe pulse following a previous masking pulse at the same electrode according to various aspects presented herein;

[0024] Fig. 12A , 12B and 12C are images showing optimal positioning of the sheath during insertion of the electrode array into a plastic model of the cochlea;

[0025] Fig.13 is an annotated image showing suboptimal positioning of the sheath during insertion of the electrode array into a plastic model of the cochlea;

[0026] Fig.14A and 14B is a schematic diagram illustrating a sheath having electrodes disposed thereon according to certain embodiments presented herein;

[0027] Fig.15 is a schematic diagram showing a sheath having electrodes disposed thereon, wherein the sheath is in a suboptimal position for insertion into an electrode array;

[0028] Fig.16A is a schematic diagram showing a sheath having electrodes disposed thereon during round window insertion, wherein the sheath is at an improper angle for insertion of the electrode array;

[0029] Fig. 16Bis a schematic diagram showing a sheath with electrodes disposed thereon during round window insertion, wherein the sheath is at a correct angle for insertion of an electrode array;

[0030] Fig. 16C is another schematic diagram showing a sheath having electrodes disposed thereon during round window insertion, wherein the sheath is at an improper angle for insertion of the electrode array;

[0031] Fig.16D It shows that for Fig.16A , 16B and a graph of the distance of insertion from the modiolus versus the angle of the sheath shown in 16C ;

[0032] Fig.17A is a schematic diagram showing a sheath having electrodes disposed thereon during cochlear fenestration insertion, wherein the sheath is at an improper angle for insertion of the electrode array;

[0033] Fig. 17B is a schematic diagram showing a sheath with electrodes disposed thereon during cochlear fenestration insertion, wherein the sheath is at a correct angle for insertion of an electrode array;

[0034] Fig. 17C is another schematic diagram showing a sheath having electrodes disposed thereon during cochlear fenestration insertion, wherein the sheath is at an improper angle for insertion of the electrode array;

[0035] Fig.17D It shows that for Fig.17A , 17B and a graph of the distance of insertion from the modiolus versus the angle of the sheath shown in 17C ;

[0036] Fig.18 is a functional block diagram illustrating an exemplary induced biological response analysis system configured to implement aspects of the technology presented herein;

[0037] Fig.19 A schematic diagram illustrating a vestibular system with which aspects of the technology presented herein may be implemented;

[0038] Fig. 20 is a flow chart of another exemplary method according to certain embodiments presented herein;

[0039] Fig.21 is a flow chart of another exemplary method according to certain embodiments presented herein; and

[0040] Fig. 22 is a flow chart of another exemplary method according to certain embodiments presented herein. DETAILED DESCRIPTION

[0041] Presented herein are techniques for determining the relative proximity of an electrode to a target structure in a recipient using an induced biological response (induced response). For example, in certain embodiments, the techniques presented herein use an induced biological response to determine the relative proximity of an electrode to the modiolus of the cochlea. The proximity of an electrode to the modiolus of the cochlea is referred to herein as the "modiolus proximity" of the electrode.

[0042] For ease of description only, the technology presented herein is mainly described with reference to a specific medical device system, i.e., a cochlear implant system. However, it should be understood that the technology presented herein can also be partially or completely implemented by other types of medical device systems. For example, the technology presented herein can be implemented by a hearing aid system and / or an auditory prosthesis system including one or more other types of auditory prostheses, middle ear auditory prostheses, bone conduction devices, direct acoustic stimulators, electroacoustic prostheses, auditory brain stimulators, combinations or variations thereof. The technology presented herein can also be implemented by a dedicated tinnitus treatment device and a tinnitus treatment device system. In other embodiments, the technology presented herein can also be implemented by a vestibular device (e.g., a vestibular implant), a visual device (i.e., a bionic eye), a sensor, a pacemaker, a drug delivery system, a defibrillator, a functional electrical stimulation device, a catheter, an epileptic seizure device (e.g., a device for monitoring and / or treating epileptic events), a sleep apnea device, an electroporation device, etc., or used in combination with them.

[0043] Figures 1A-1E An exemplary cochlear implant system 102 is shown with which aspects of the technology presented herein may be implemented. Cochlear implant system 102 includes an external component 104 and an implantable component 112. Figures 1A-1E In the example of a cochlear implant, the implantable component is sometimes referred to as a "cochlear implant." Figure 1A A cochlear implant 112 is shown implanted in a user's head 154, and Figure 1B is a schematic diagram of the external component 104 worn on the head 154 of the user. Figure 1C is another schematic diagram of a cochlear implant system 102, and Figure 1D Further details of cochlear implant system 102 are shown. For ease of description, the Figures 1A-1E .

[0044] Cochlear implant system 102 includes an external component 104 configured to be attached directly or indirectly to a user's body, and an implantable component 112 configured to be implanted in the user's body. Figures 1A-1E In the example of FIG. 1 , external component 104 includes a sound processing unit 106 and cochlear implant 112 includes an implantable coil 114, an implant body 134, and an elongated stimulation assembly 116 configured to be implanted in the cochlea of ​​a user.

[0045] exist Figures 1A-1E In the example of the present invention, the sound processing unit 106 is an outside-the-ear (OTE) sound processing unit (sometimes referred to herein as an OTE component) that is configured to send data and power to the implantable component 112. Generally speaking, the OTE sound processing unit is a component having a generally cylindrical housing 111 and configured to be magnetically coupled to the user's head (e.g., including an integrated external magnet 150 configured to be magnetically coupled to an implantable magnet 152 in the implantable component 112). The OTE sound processing unit 106 also includes an integrated external (head component) coil 108 configured to be inductively coupled to the implantable coil 114.

[0046] It should be understood that the OTE sound processing unit 106 is merely illustrative of an external device that can operate with the implantable component 112. For example, in alternative examples, the external component can include a behind-the-ear (BTE) sound processing unit or a micro-BTE sound processing unit and a separate external component. Generally speaking, the BTE sound processing unit includes a housing that is shaped to be worn on the outer ear of the user and is connected to a separate external coil assembly via a cable, wherein the external coil assembly is configured to be magnetically coupled and inductively coupled to the implantable coil 114. It should also be understood that alternative external components can be located in the ear canal of the user, worn on the body, etc.

[0047] As described above, cochlear implant system 102 includes sound processing unit 106 and cochlear implant 112. However, as further described below, cochlear implant 112 can operate independently of sound processing unit 106 for at least a period of time to stimulate a user. For example, cochlear implant 112 can operate in a first general mode, sometimes referred to as an "external hearing mode", in which sound processing unit 106 captures sound signals, which are then used as a basis for delivering stimulation signals to the user. Cochlear implant 112 can also operate in a second general mode (sometimes referred to as an "invisible hearing" mode), in which sound processing unit 106 cannot provide sound signals to cochlear implant 112 (e.g., sound processing unit 106 is not present, sound processing unit 106 is powered off, sound processing unit 106 is malfunctioning, etc.). Therefore, in the invisible hearing mode, cochlear implant 112 captures the sound signals itself via an implantable sound sensor, and then uses these sound signals as a basis for delivering stimulation signals to the user. Further details regarding the operation of cochlear implant 112 in the external hearing mode are provided below, followed by details regarding the operation of cochlear implant 112 in the invisible hearing mode. It should be understood that the reference to the external hearing mode and the invisible hearing mode is merely illustrative, and cochlear implant 112 may also operate in alternative modes.

[0048] exist Figure 1A and 1CIn FIG. 1 , a cochlear implant system 102 is shown having an external computing device 110 that is configured to implement various aspects of the presented technology. Figure 1E 10 is a computer system (shown in more detail in ), such as a personal computer, a server computer, a handheld device, a laptop device, a multiprocessor system, a microprocessor-based system, a programmable consumer electronic product (e.g., a smart phone), a network PC, a minicomputer, a mainframe computer, a tablet computer, a remote control unit, a distributed computing environment including any of the above systems or devices, etc. The computing device 110 can be a single virtual or physical device operating in a networked environment through a communication link to one or more remote devices, such as an implantable medical device or an implantable medical device system.

[0049] In its most basic configuration, computing device 110 includes at least one processing unit 183 and memory 184. Processing unit 183 includes one or more hardware or software processors (e.g., central processing units) that can obtain and execute instructions. Processing unit 183 can communicate with other components of computing system 110 and control the execution of the other components.

[0050] Memory 184 is one or more software or hardware-based computer-readable storage media that can be operated to store information that can be accessed by processing unit 183. Memory 184 can store instructions and other data, among other things, which can be executed by processing unit 183 to implement applications or enable operations described herein to be performed. Memory 184 can be volatile memory (e.g., RAM), non-volatile memory (e.g., ROM), or a combination thereof. Memory 884 can include temporary memory or non-temporary memory. Memory 184 can also include one or more removable or non-removable storage devices. In an example, memory 184 can include RAM, ROM, EEPROM (electrically erasable programmable read-only memory), flash memory, optical disk storage, magnetic storage, solid-state storage, or any other storage medium that can be used to store information for later access. In an example, memory 184 contains a modulated data signal (e.g., a signal whose one or more characteristics are set or changed in a manner to encode information in the signal), such as a carrier or other transmission mechanism, and includes any information delivery medium. By way of example and not limitation, memory 184 may include wired media (e.g., a wired network or direct wired connection), as well as wireless media (e.g., acoustic, RF, infrared, and other wireless media), or a combination thereof. In some embodiments, memory 184 includes ambient sound training logic 185, which, when executed, enables processing unit 183 to perform aspects of the presented techniques.

[0051] In the example shown, system 110 also includes a network adapter 186, one or more input devices 187, and one or more output devices 188. System 110 may include other components such as a system bus, component interfaces, a graphics system, a power source (eg, a battery), and other components.

[0052] The network adapter 186 is a component of the computing system 110 that provides network access (e.g., access to at least one network 189). The network adapter 186 can provide wired or wireless network access and can support one or more of a variety of communication technologies and protocols, such as Ethernet, cellular, Bluetooth, near field communication, and RF (radio frequency), etc. The network adapter 186 may include one or more antennas and associated components configured to communicate wirelessly according to one or more wireless communication technologies and protocols.

[0053] One or more input devices 187 are devices through which the computing system 110 receives input from a user. One or more input devices 187 may include physically actuatable user interface elements (e.g., buttons, switches, or dials), touch screens, keyboards, mice, pens, and voice input devices, among other input devices.

[0054] One or more output devices 188 are devices through which computing system 810 can provide output to a user. Output devices 188 may include a display 190 and one or more speakers 191, among other output devices.

[0055] It should be recognized that Figure 1E The arrangement of the computing system 110 shown in is merely illustrative, and aspects of the technology presented herein can be implemented on many different types of systems / devices. For example, the computing system 110 can be a laptop, a tablet computer, a mobile phone, a surgical system, etc.

[0056] The OTE sound processing unit 106 includes one or more input devices configured to receive input signals (e.g., sound or data signals). The one or more input devices include one or more sound input devices 118 (e.g., one or more external microphones, audio input ports, telecoils, etc.), one or more auxiliary input devices 128 (e.g., audio ports, such as direct audio input (DAI), data ports, such as universal serial bus (USB) ports, cable ports, etc.), and wireless transmitter / receiver (transceiver) 120 (e.g., for communicating with external devices 110). However, it should be understood that the one or more input devices may include additional types of input devices and / or fewer input devices (e.g., the wireless short-range radio transceiver 120 and / or one or more auxiliary input devices 128 may be omitted).

[0057] The OTE sound processing unit 106 also includes an external coil 108, a charging coil 121, a tightly coupled transmitter / receiver (RF transceiver) 122 (sometimes referred to as a radio frequency (RF) transceiver 122), at least one rechargeable battery 132, and an external sound processing module 124. The external sound processing module 124 may include, for example, one or more processors and a memory device (memory) including sound processing logic. The memory device may include any one or more of the following: non-volatile memory (NVM), ferroelectric random access memory (FRAM), read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical or other physical / tangible memory storage devices. The one or more processors are, for example, microprocessors or microcontrollers that execute instructions of the sound processing logic stored in the memory device.

[0058] The implantable component 112 includes an implant body (main module) 134, a lead region 136, and an intracochlear stimulation assembly 116, all configured to be implanted beneath the user's skin / tissue (tissue) 115. The implant body 134 generally includes a hermetically sealed housing 138 in which at least one battery 125, RF interface circuitry 140, and a stimulator unit 142 are disposed. The implant body 134 also includes an internal / implantable coil 114, which is generally external to the housing 138 but is connected to the stimulator unit 142 via a hermetic feedthrough ( Figure 1D ) is connected to the RF interface circuit system 140.

[0059] As mentioned, the stimulation assembly 116 is configured to be at least partially implanted in the cochlea of ​​the user. The stimulation assembly 116 includes a plurality of longitudinally spaced intracochlear electrical stimulation contacts (electrodes) 144 that collectively form a contact or electrode array 146 for delivering electrical stimulation (electrical current) to the cochlea of ​​the user.

[0060] The stimulation assembly 116 extends through an opening in the user's cochlea (e.g., a cochlear fenestration, a round window, etc.) and has a lead region 136 and an airtight feedthrough ( Figure 1D The implantable component 112 also includes an electrode 144 (not shown) connected to the proximal end of the stimulator unit 142. The lead region 136 includes a plurality of conductors (wires) that electrically couple the electrode 144 to the stimulator unit 142. The implantable component 112 also includes an electrode outside the cochlea, sometimes referred to as an extracochlear electrode (ECE) 139.

[0061] As described, the cochlear implant system 102 includes an external coil 108 and an implantable coil 114. An external magnet 152 is fixed relative to the external coil 108, and the implantable magnet 152 is fixed relative to the implantable coil 114. The magnets fixed relative to the external coil 108 and the implantable coil 114 facilitate operational alignment of the external coil 108 with the implantable coil 114. This operational alignment of the coils enables the external component 104 to transmit data and power to the implantable component 112 via a closely coupled wireless link 148 formed between the external coil 108 and the implantable coil 114. In some examples, the closely coupled wireless link 148 is a radio frequency (RF) link. However, various other types of energy transfer (e.g., infrared (IR), electromagnetic, capacitive, and inductive transfer) may be used to transfer power and / or data from the external component to the implantable component, and thus, Figure 1D Only one exemplary arrangement is shown.

[0062] As described above, the sound processing unit 106 includes an external sound processing module 124. The external sound processing module 124 is configured to convert received input signals (received at one or more of the input devices) into output signals for stimulating the first ear of the user (i.e., the external sound processing module 124 is configured to perform sound processing on the input signals received at the sound processing unit 106). In other words, the one or more processors in the external sound processing module 124 are configured to execute the sound processing logic in the memory to convert the received input signals into output signals representing electrical stimulation for delivery to the user.

[0063] As mentioned above, Figure 1D An embodiment is shown in which an external sound processing module 124 in the sound processing unit 106 generates an output signal. In an alternative embodiment, the sound processing unit 106 can send less processed information (e.g., audio data) to the implantable component 112, and the sound processing operations (e.g., conversion of sound to output signals) can be performed by a processor within the implantable component 112.

[0064] Return to Figure 1DIn a specific example, the output signal is provided to the RF transceiver 122, which transmits the output signal (e.g., in an encoded manner) transcutaneously to the implantable component 112 via the external coil 108 and the implantable coil 114. That is, the output signal is received at the RF interface circuit system 140 via the implantable coil 114 and provided to the stimulator unit 142. The stimulator unit 142 is configured to use the output signal to generate an electrical stimulation signal (e.g., a current signal) for delivery to the cochlea of ​​the user. In this way, the cochlear implant system 102 electrically stimulates the auditory nerve cells of the user, thereby bypassing the missing or defective hair cells that normally convert acoustic vibrations into neural activity in a manner that causes the user to perceive one or more components of the received sound signal.

[0065] As described above, in the external hearing mode, the cochlear implant 112 receives processed sound signals from the sound processing unit 106. However, in the invisible hearing mode, the cochlear implant 112 is configured to capture and process the sound signals for electrical stimulation of the user's auditory nerve cells. Figure 1D As shown in , the cochlear implant 112 includes a plurality of implantable sound sensors 160 and an implantable sound processing module 158. Similar to the external sound processing module 124, the implantable sound processing module 158 may include, for example, one or more processors and a memory device (memory) including sound processing logic. The memory device may include any one or more of the following: non-volatile memory (NVM), ferroelectric random access memory (FRAM), read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical or other physical / tangible memory storage devices. The one or more processors are, for example, microprocessors or microcontrollers that execute instructions of the sound processing logic stored in the memory device.

[0066] In the invisible hearing mode, the implantable sound sensor 160 is configured to detect / capture a signal (e.g., an acoustic sound signal, a vibration, etc.), which is provided to the implantable sound processing module 158. The implantable sound processing module 158 is configured to convert the received input signal (received at one or more of the implantable sound sensors 160) into an output signal for stimulating the first ear of the user (i.e., the processing module 158 is configured to perform a sound processing operation). In other words, the one or more processors in the implantable sound processing module 158 are configured to execute the sound processing logic in the memory to convert the received input signal into an output signal 156 provided to the stimulator unit 142. The stimulator unit 142 is configured to generate an electrical stimulation signal (e.g., an electric current signal) for delivery to the cochlea of ​​the user using the output signal 156, thereby bypassing the missing or defective hair cells that normally convert the acoustic vibrations into neural activity.

[0067] It should be appreciated that the above description of the so-called external hearing mode and the so-called invisible hearing mode is merely illustrative, and that cochlear implant system 102 may operate differently in different embodiments. For example, in an alternative embodiment of the external hearing mode, cochlear implant 112 may use signals captured by sound input device 118 and implantable sound sensor 160 to generate stimulation signals for delivery to the user.

[0068] Implantable medical devices, such as cochlear implant system 102, typically rely on various induced biological responses (evoked responses) to determine settings / parameters for the operation of the implantable medical device, where the term "induced" is used herein in a synonymous manner with stimulation, i.e., an additional response (e.g., a response superimposed on the basal response of the nerve) produced as a result of the input stimulation (stimulation) / stimulus. Therefore, there are prior arts for determining / identifying the presence of induced biological responses. For example, there are certain prior arts for identifying evoked compound action potential (ECAP) responses, where the ECAP response can be measured as the collective response of all neurons within a nerve or nerve portion to various stimuli. Neural response telemetry (NRT) is another term used in the field for measuring the response of nerve cells to evoked potentials. Therefore, recording ECAPs using a cochlear implant provides an objective measurement of the response of the auditory nerve to electrical stimulation (such as delivered by the implant electrodes).

[0069] Typically, the intracochlear location of a stimulation assembly electrode (such as electrode 144 of stimulation assembly 116) relative to the modiolus is an important outcome of cochlear implant surgery. Figure 2A and 2B As shown in , the positioning of the electrodes relative to the modiolus can have an impact on the amount of excitation distribution. More specifically, Figure 2A A perimodiolar stimulation assembly 216A is shown having electrodes 244A, and Figure 2B A lateral wall stimulation assembly 216B having an electrode 244B is shown. Electrode 244A is shown positioned relatively closer to the modiolus (e.g., a target neuron) than electrode 244B. Due to this closer positioning, when both electrodes stimulate at the same level (including a threshold level or a comfort level) within the dynamic range for activating the neural array, the excitation distribution from the electrical stimulation signal (current) delivered via electrode 244A is narrower relative to the electrical stimulation signal (current) delivered via electrode 244B. A narrower excitation distribution can be advantageous and can enable improved hearing performance.

[0070] For ease of description, various aspects of the presented technology will be described with reference to the analysis of a particular type of evoked biological response, namely, an evoked compound action potential (ECAP) response. As described elsewhere herein, it will be appreciated that the technology may also be implemented to detect other types of evoked biological responses and may be implemented by various implantable medical devices alone and / or in combination with one or more external devices.

[0071] Figure 3 is a graph showing a nominal / typical ECAP response 392 captured from a recipient's cochlea in response to a biphasic stimulation signal 394, displayed in the time domain. That is, Figure 3 ECAP measurements are schematically shown, including stimulation amplitude, ECAP amplitude, and ECAP duration. Figure 4 is a graph showing an exemplary spread of excitation (SOE) function determined for electrode number nine (9) (the detection electrode) in a twenty-two (22) electrode array, wherein the SOE function is normalized to unity at the peak (1) of the curve. Additional details regarding the spread of excitation (SOE) function and measurements can be found, for example, in Cohen et al., "Spatial Spread of Neural Excitation in Cochlear Implant Recipients: Comparison of Improved ECAP Method and Psychophysical Forward Masking," Hearing Research 179 (2003) 72-87, the contents of which are hereby incorporated herein by reference.

[0072] Presented herein are techniques for determining the proximity of one or more electrodes to a target structure using induced bioresponses, possibly in combination with other information (e.g., electrical measurements, such as impedance, voltage, or current measurements). According to certain aspects, the techniques presented herein analyze the relative proximity of multiple (e.g., two or more) electrodes to a target structure (such as the modiolus of the cochlea). That is, certain embodiments determine / estimate the relative modiolus proximity of electrodes of an intracochlear stimulation assembly. The determined relative modiolus proximity can be used to optimize results for the recipient (e.g., instructing a surgeon or robot to act based on the determined modiolus proximity). In certain aspects, the techniques presented herein use an ECAP threshold distribution and / or a distribution of excitation (SOE) function to determine the relative modiolus proximity.

[0073] In certain embodiments presented herein, the system obtains multiple measurements, analyzes the multiple measurements at different electrodes relative to each other to infer the modiolar position (e.g., analyzes the measurements relative to each other, and infers proximity using the relative analysis). As further described below, the techniques presented herein can, for example, detect that the middle electrode has moved away from the modiolus due to over-insertion, and notify the surgeon (or robotic system) to take corrective action (e.g., pull back) to optimize the modiolar position.

[0074] As described above, certain aspects presented herein use a distribution of excitation (SOE) function to determine / estimate for use in assessing the relative proximity of multiple electrodes to a target structure in a recipient (e.g., assessing the relative modiolus proximity of multiple electrodes). The SOE function is obtained by capturing the ECAP response amplitude and plotting the ECAP response amplitude at multiple different points, wherein stimulation is delivered via a "detection" electrode and a "masking" electrode. For example, in a so-called forward masking method, measurements are performed using only detection stimulation (e.g., stimulation only at the detection electrode), measurements are performed using only masking stimulation (e.g., no detection stimulation), and then measurements are performed using both masking stimulation and detection stimulation. The measurements performed during these three measurement windows are then used to determine the "SOE function," wherein the entire process is referred to herein as "SOE" measurement (e.g., SOE measurement is used to generate the SOE function).

[0075] like Figure 4 As shown in , the idealized SOE has an excitation peak at the detection electrode. However, the inventors of the present invention have found that in some cases, the peak can be shifted to the apex or base of the cochlea relative to the detection electrode. In rare cases, there may be a double peak, where the peak is at both the base side and the apex side of the cochlea relative to the detection piece. Figure 5A and 5B is an exemplary graph showing an exemplary SOE function in which the peak is shifted toward the apex and / or toward the base of the cochlea.

[0076] More specifically, in Figure 5A and 5B In the graph, the probe electrode is in the middle (0), and the X-axis numbers show where the excitation peak is relative to the probe. Negative numbers indicate locations closer to the cochlear base, while positive numbers indicate locations closer to the cochlear apex. These graphs correspond to the average SOE curves obtained when the probe current level is equal to the masking current level. The following Table 1 is the corresponding Figure 5A and 5B A summary of the tests indicates the percentage of each SOE peak located at an electrode different from the probe electrode (e.g., how often the probe detected a peak at the apex versus the base of the cochlea). In Table 1, "n" is the number of SOE curves used for averaging.

[0077] Table 1:

[0078] EL % relative to the peak value of the probe at the top of the snail % relative to the probe peak at the snail bottom 17(n:191) 37 5 11(n:203) 48 5 5(n:192) 27 6

[0079] As can be seen from Table 1, if there is a shift in the excitation peak, the peak is most often shifted in the direction of the apex of the cochlea. The inventors of the present invention have recognized that this apex shift is most likely the result of a change in distance from the spiral ganglion (modiolus). Therefore, the peak shift can be used to estimate modiolus proximity, which is then used to establish a sequence of SOE peak measurements to provide an indication of where the electrode is closest to the modiolus and where the electrode is further away from the modiolus.

[0080] Fig. 6A , 6B , 6C and 6D are diagrams further illustrating the concept of shifting or "departing from the detection peak" (assuming the spiral ganglion and order are homogeneous). Specifically, Figure 6B A portion of an electrode array 646A is shown that includes a plurality of electrodes 644A, wherein the electrodes 644 are all located at substantially the same distance from the spiral ganglion (modiolus) 662. Fig. 6A is a graph of a SOE function / curve generated from SOE measurements performed via electrode array 646A. Similarly, Fig.6D A portion of an electrode array 646B is shown that includes a plurality of electrodes 644B, wherein the electrodes 644B are located at different distances from the spiral ganglion (modiolus) 662 . Figure 6C is a graph of a SOE function / curve generated from SOE measurements performed via electrode array 646B.

[0081] When stimulated at the same current level, a masking electrode that is closer to the modiolus (and therefore the spiral ganglion) than the probing electrode will be more effective in masking the activated probing field, thus producing a larger ECAP amplitude. Fig. 6A While showing the standard SOE function / curve where the excitation peak is at the detection electrode, Figure 6C An SOE function / curve is shown where the peak is shifted toward the apex (e.g., toward electrodes positioned relatively closer to the modiolus). Thus, according to certain embodiments presented herein, a SOE function obtained from multiple electrodes can be used to determine the relative modiolus proximity of one or more electrodes.

[0082] In certain embodiments presented herein, the ECAP threshold distribution can be used to further optimize the estimate of modiolar proximity of one or more electrodes. Figure 7 Graphs showing ECAP threshold distributions for different stimulation assemblies having different properties such that electrodes of corresponding electrode arrays will each have at least slightly different relative modiolar proximity (eg, different final positions within the cochlea). Figure 7It is shown that the ECAP threshold distribution can vary across an electrode array, and generally the lower the ECAP threshold, the closer the electrode is to the modiolus. Thus, the ECAP distribution provides insight into the relative proximity to the modiolus (eg, the ECAP threshold can be used to estimate relative modiolus proximity).

[0083] exist Figure 7 In the 3D images, it was noted that the thresholds increased at the base (lower electrode numbers) and this increase may be due to the electrode distance as the straight portion of the stimulation assembly enters the cochlea and the electrodes for approximately electrode numbers 4-6 are closer to the modiolus. The electrodes tend to move away from the modiolus, especially the electrodes of the "straight" stimulation assembly and the electrodes of the stimulation assembly that are over-inserted. At the apex (highest electrode number) the electrodes are closer to the modiolus.

[0084] In some examples, the ECAP threshold distribution can be used as a first indication of modiolar proximity, and / or can be used in addition to determine / limit the most informative SOE measurement(s) at the location where the circummodiolar electrode is moved away from the modiolar axis. In some examples, the ECAP threshold distribution can be used as a weighting factor to correct the SOE curve, or can be used to set / adjust masking current levels to ensure that they all produce similar amounts of neural activation.

[0085] In one specific implementation use case, when the electrode is over-inserted, the middle electrode (e.g., the electrode approximately between the apex-most electrode and the base-most electrode) moves away from the modiolus, which can be corrected by pulling back the electrode (e.g., by hand or by a robot when the surgeon is using a robot). Thus, using the techniques described herein, the surgical system can assess the relative modiolus proximity of the electrodes within the electrode array and determine when the stimulation assembly has been inserted (e.g., detecting that the middle electrode is relatively further away from the modiolus than the apex and / or base electrodes). As a result, the surgical system can notify the surgeon, or instruct the robot to directly manipulate the stimulation assembly.

[0086] Fig. 8A , 8B 8C schematically illustrates the effects of over-insertion and retraction of the stimulation component that may be caused using the techniques presented herein. Fig. 8A , 8B and 8C , the length of the arrow generally represents the distance between the electrode and the modiolus.

[0087] Fig. 8A A conventional / standard insertion of the stimulation assembly 816A is shown, while Figure 8B"Over-insertion" of stimulation assembly 816B is shown. As described above in the case of over-inserted stimulation assembly 816B, the middle electrode (e.g., an electrode roughly between the most apical electrode and the most basal electrode) moves away from the modiolus. The positioning of the middle electrode further away from the modiolus relative to the positioning of the apical electrode and / or the basal electrode can be determined using evoked biological responses captured and analyzed using the techniques presented herein. For example, the SOE distribution can show that the peak of the SOE function is moving toward the apex (e.g., the SOE peak is deviating from a known or expected position determined based on previous data), which indicates that certain electrodes (e.g., the apical electrode) are closer to the modiolus than the middle electrode.

[0088] Figure 8C shows that after the so-called "pull back" operation Figure 8B As shown, after the pullback operation, the middle electrode is larger than before. Figure 8B The over-insertion position is positioned closer to the modiolus.

[0089] Fig. 9 is a representation of a computed tomography (CT) image of an over-insertion of a so-called slim modiolar stimulation assembly 916. As shown, the apex electrode is approximately in the modiolar position, while the middle electrode is moving away from the modiolar. In this example, electrode 16 is where the electrode (moving from the apex direction to the base direction) begins to move away from the modiolar. That is, the deep insertion of certain stimulation assemblies pushes the electrode in the middle of the electrode array away from the modiolar. The SOE measurement can be used to focus on this phenomenon (e.g., performing a measurement when the electrode is expected to move away from the modiolar), and to inform the surgeon about further manipulation of the electrode to obtain the optimal modiolar electrode position.

[0090] In About Fig. 9 In one example of a stimulation component 916 of the invention, overinsertion can be determined based on an ECAP threshold distribution and one or more SOE measurements. For example, an ECAP can be recorded from the stimulation component 916, and an ECAP threshold distribution can be generated and used to provide a first indication of overinsertion. To this end, a set of data can be used in which imaging data (e.g., CT imaging data) is correlated with a target ECAP threshold distribution. Based on this correlation, an indicator can be set regarding the likelihood of overinsertion. In some embodiments, artificial intelligence (AI) can be used to identify the most prominent factors that predict overinsertion, and which can then be used in the algorithm.

[0091] When looking at the ECAP threshold distribution for the slim modiolar stimulation assembly 916, it may be expected that the focus will be on the middle electrode that is moved away from the modiolar axis, and there will be a peak somewhere in the middle in the threshold distribution. The speed at which the excitation distribution drops / rises near the peak (e.g., the slope of the ECAP threshold distribution curve near the peak, or the degree of excitation distribution) can also be an indicator. In addition, the location of the drop in the ECAP threshold distribution (e.g., approximately electrodes 4-6) can also be an indicator. Moreover, it is expected that this drop can vary with the insertion technique utilizing a round window or cochlear fenestration and / or the size / dimension of the cochlea.

[0092] Based on the ECAP threshold distribution, a SOE measurement may be established where (with respect to the slim modiolar stimulation assembly 916 and starting at electrode 22 at the top) electrode 16 is the position where the electrode begins to move away from the modiolus in the direction of the cochlear base. Fig.10 The expected SOE curve with the probe at electrode 16 is shown, with a shallow flank at the top end with a possible offset peak, and a deep flank at the bottom end.

[0093] A given ratio of deviation from the peak and the flank steepness may be an indication that the stimulation assembly 916 is over-inserted. Electrical measurements during stimulation, such as impedance measurements, current measurements, voltage measurements (e.g., EVT measurements, transimpedance matrix (TIM) measurements, etc.) may be used to examine the extent to which the voltage distribution is asymmetric, as this may be the cause of an asymmetric SOE curve. In certain embodiments, the voltage distribution may be used to normalize (weight) the SOE curve to increase sensitivity, thereby detecting the extent to which the shape of the SOE curve is a predictor of modiolar distance.

[0094] In addition, the techniques presented herein can take into account the recording electrodes, which may be the reason for the observed SOE curves and / or can utilize the amplitude growth function (AGF) of the ECAP with respect to the current level of stimulation. For example, the ECAP amplitude growth function can be used to check the health of the nerve, which in turn can be used to normalize the ECAP threshold and SOE curve to derive the modiolar distance therefrom (e.g., the ECAP AGF function is steeper when the nerve is well alive).

[0095] In certain embodiments, the techniques presented herein can control neural factors by any set of measures of neural health (e.g., electrocochlear gram (ECochG), ECAP threshold, IPG effect, polarity effect, focal threshold minus unipolar threshold). This control can be accomplished, for example, by normalizing ECAP measurements (threshold distribution, SOE, AGF, etc.) against neural health measures.

[0096] Furthermore, it may be the case that the AGF obtained with an electrode close to the modiolus is steeper than the AGF obtained with an electrode further away from the modiolus. This can be used to detect whether manipulation of the electrodes results in a closer modiolus proximity.

[0097] As described, the techniques presented herein can use a combination of evoked biological responses (ECAPs) and data derived therefrom (e.g., SOE functions, ECAP threshold distributions, etc.) with additional information. In certain embodiments, the additional information may include electrical measurements obtained via electrodes positioned within the recipient, such as impedance measurements, current measurements, voltage measurements, and the like. For example, as described above, it is assumed that the SOE peak shift is due to relative modiolar proximity. However, there may be other reasons for the shift (e.g., neural survival). In certain aspects, additional data (e.g., EVT measurements and / or some neural survival measurements) can be used to confirm that the shift is actually due to modiolar proximity, rather than some other root cause (e.g., other measurements are used to eliminate other possible causes).

[0098] In further aspects, additional information used with the evoked bioresponses (ECAPs) and / or data derived therefrom (e.g., SOE functions, ECAP threshold distributions, etc.) can include standard population data (e.g., multiple ECAPs are analyzed relative to standard population data to estimate modiolar proximity). Standard population data include, for example, imaging data (possibly in conjunction with modeling) for assessing modiolar periposition. In addition, there can be several standard sets, such as one standard set for modiolar periposition electrodes having optimal proximal modiolar periposition and one standard set for lateral wall electrodes distal to the modiolar periposition. In some such examples, the evoked bioresponses are analyzed relative to standard data (e.g., data indicating proximal modiolar proximity), and greater deviations from a "good" mean (a prior population data set) can be used to infer modiolar proximity.

[0099] In some embodiments, the ECAP response to a stimulation pulse may be facilitated by a preceding pulse. Fig.11 Shown is the ECAP amplitude induced by a probe pulse at the same electrode after a previous masking pulse. This facilitatory effect occurs at short inter-pulse intervals.

[0100] The inventors of the present invention have envisioned that this facilitation effect is greater when the electrode is closer to the modiolus, and therefore this facilitation effect can be used, for example, to detect whether operation of the stimulation assembly results in increased modiolus proximity. Previously, masking pulses can also be positioned at electrodes close to the detection electrode, and it is expected that this effect is greater when the masking electrode is closer to the modiolus. This effect can be used to detect whether operation of the electrode results in a closer proximity of the detection electrode.

[0101] All of the above or other metrics, either individually or together (e.g., based on the results of an artificial intelligence-based algorithm), can be used to instruct the surgeon to manipulate the stimulation assembly to obtain the best possible modiolus proximity, e.g., pulling back an over-inserted stimulation assembly to bring the middle electrode closer to the modiolus, inserting the stimulation assembly deeper to ensure that the modiolus base electrode is closer to the modiolus, twisting the stimulation assembly to ensure that a pre-bent stimulation assembly places itself in the "most convenient / least mechanically stressful" position, etc.

[0102] The stimulation assembly can be inserted manually by the surgeon or through a partially or fully automated process using a robotic system (e.g., a partially or fully automated robotic system). According to certain embodiments, the robotic system can operate the stimulation assembly (as indicated above) based on the above metrics to achieve the most likely perimodiolar position of the stimulation assembly.

[0103] The above embodiments have been generally described with reference to evoked potentials (such as electrically evoked compound action potentials (ECAPs)) captured by electrodes of a stimulation assembly at least partially inserted into the cochlea of ​​a recipient. However, in certain embodiments, evoked potentials may also or alternatively be captured by electrodes positioned into an auxiliary / supplementary component used during the insertion process. Such auxiliary components may include, for example, an insertion tool, an insertion sheath, a detection assembly, etc.

[0104] For example, pre-curved stimulation assemblies are often inserted using a reinforcing sheath that holds the electrode array in a straight arrangement prior to insertion and is then removed during insertion. The position of the sheath in the cochlea can be important to ensure a smooth insertion. Ideally, the tip of the sheath is positioned close to the modiolus so that the electrode array extends smoothly onto the modiolus wall when exiting the sheath. Figures 12A-12C 12 shows the correct positioning of the sheath 1201 during insertion of the electrode array 1216. However, Fig.13 As shown in , if the sheath 1201 is held with the tip toward the outer side wall, then in the case of a wide lumen, the stimulation component 1216 can bend immediately upon exiting the sheath 1201 and be captured on the modiolus near the sheath tip.

[0105] The solution to this problem is to include electrodes on the sheath and apply the same measurement techniques as described above to determine the distance of the sheath from the modiolus and / or lateral wall. That is, by including electrodes on the sheath, the position of the sheath in the cochlea relative to the modiolus can be estimated. If the tip is not close enough to the modiolus, this can indicate that the sheath is at a suboptimal angle or depth, thus risking complications during insertion. The system can monitor the position of the sheath relative to the modiolus and lateral wall (and therefore the position in the cochlear duct) and indicate to the surgeon whether the sheath is maintained at the optimal angle and depth. Note that during the deployment of the electrode array, the sheath is intended to remain in a static position, however, it is known that sometimes surgeons inadvertently change the angle or depth of the sheath during the deployment of the electrode. The system can continuously monitor the position of the sheath and alert the surgeon to unexpected changes. These feedback signals can be provided to the surgeon or a robot that performs the robotic insertion of the electrode array. In the case of a robot, a closed-loop feedback system can be implemented to manage the optimal positioning of the sheath and the insertion of the electrodes.

[0106] In some examples, the measurement is performed using an electrode positioned at the tip of the sheath and / or the most apical electrode of the electrode array. When this (multiple) electrode contacts the modiolus, it is expected that a large ECAP response will be detected, and the amplitude of the ECAP response will decrease as the (multiple) electrode is removed. This can be a single signal (e.g., insertion angle, insertion depth) that can be focused on and provide direct feedback to the surgeon during insertion and operation of the sheath.

[0107] In some embodiments, transimpedance matrix measurements may also or alternatively be used.In addition, multipolar stimulation is used to provide "virtual" sheath contact.

[0108] Fig.14A and 14B A sheath 1401 is shown having an electrode 1405 disposed therein. Fig.14A The sheath 1401 is shown in an optimal / preferred position, while Fig. 14B The sheath 1401 is shown not fully inserted. Fig. 14B The placement of the electrode array 1405(A) can be detected and signal the surgeon (or robot) to adjust the angle and depth of the sheath prior to or as the electrode array is advanced forward out of the sheath to optimize insertion. In one example, electrode 1405(A) can be used to capture an induced biological response, which, as described above, can be used to determine whether the tip of the sheath 1401 is in an optimal position proximal to the modiolus. In some such examples, the impedance of electrode 1405(B) can be used to confirm that the sheath 1401 is fully inserted with the stop resting on the cochlea. If the sheath 1401 is accidentally retained outside the cochlea, such as Fig. 14BAs shown in , electrode 1405 (B) will lose connection with the cochlear fluid and become high impedance.

[0109] Note that sheath positioning can be measured when the electrodes are on one side of the sheath. Fig.14A and 14B It is also advantageous to include electrodes on either side of the sheath (inside and outside) as shown in to improve the accuracy of the estimate of relative position within the cochlea, because the algorithm detects the volume of the space immediately adjacent to the electrodes and can therefore determine the relative distance to the nearest wall with greater accuracy.

[0110] In some instances, holding the sheath against the modiolus too firmly may cause the sheath to bend or kink. This may squeeze the stimulation component in the sheath, thereby preventing insertion, such as Fig.15 . Sheath bending can also cause the electrode array to twist and leave the sheath in a trajectory toward the lateral wall and possibly impact the lateral wall. Using the techniques presented herein, measurements of the distance from the modiolus and lateral wall can be used to detect that the electrode array is not in the expected position when deployed from the sheath.

[0111] To determine whether the sheath is in the optimal position, the Figures 16A-16D The model described in the application algorithm. Fig.16A , 16B 16C show three positions of the sheath as it is inserted into the cochlea through the round window. In operation, the surgeon can move the angle of the sheath from low to high and back again to traverse the space. The measurement system can then record the spacing of the tip electrode and the midpoint electrode to the modiolus and estimate the optimal angle when the tip electrode is just in close proximity to the modiolus and the midpoint electrode is spaced a reasonable distance apart. Fig.16D The algorithm for the curve shown in can be used to determine whether the angle of the sheath has been optimized.

[0112] Figures 16A-16D The model of the curves shown in can also be applied to electrodes inserted through a cochlear fenestration. If inserted through a cochlear fenestration, then according to Figures 17A-17D The exact location of the cochlear fenestration shown in the figure will modify the angle of the three cases by an amount. Fig.17A , 17B The absolute angle of each of the three positions shown in 17C will be further counterclockwise relative to the orientation of the cochlea, however, Fig.17A , 17B The difference in angle between the 17C and the cochlear fenestration will be similar to the round window insertion. Again, based on Fig.17D The algorithm for the curve shown in can be used to determine whether the angle of the sheath has been optimized.

[0113] As stated, Figures 12A-17DThe concept of using electrodes attached to a sheath is shown. It will be appreciated that many embodiments are possible with respect to this arrangement. For example, in some embodiments, the electrodes on the sheath may be connected back to a measurement system via wires, or the electrodes may be connected to a small wireless transmitter included in the sheath to transmit information back without the inconvenience of a wired connection. In some embodiments, the electrodes on the sheath may be connected to electrodes of an intracochlear electrode array by means of brushes on the interior of the sheath to connect to the contacts of the electrode array. Moreover, instead of including electrodes on the sheath, the contacts of the electrode array may be utilized simply by creating openings in the sheath over a plurality of contacts. Yet another refinement of the above is to add a strain gauge to the sheath to detect whether deformation has occurred. The signal from the strain gauge may be included in the analysis of the position of the electrode array to further improve the likelihood of detecting a suboptimal sheath position.

[0114] It will be appreciated that straight (e.g., non-pre-bent) electrode array insertion can be monitored in a similar manner as described for perimodiolar stimulation insertion. The characteristic trajectory of a straight electrode array is known. By applying detailed knowledge of the optimal insertion trajectory and known suboptimal trajectories, it can be determined when stimulation deviates from the optimal insertion trajectory.

[0115] It should be understood that measurements using the sheath and electrodes through the stimulation assembly are not mutually exclusive, and the various embodiments described above may be combined in different arrangements. For example, a sheath without electrodes thereon may be used with a stimulation assembly to obtain an induced bio-response (e.g., the sheath should include a conductive portion or hole at the tip to ensure that an induced bio-response measurement is feasible). Other embodiments may utilize electrodes on both the sheath and the stimulation assembly to obtain an induced bio-response.

[0116] As described above, aspects of the technology presented herein capture / record evoked bioresponses (e.g., ECAPs) from a recipient for use in assessing the relative proximity of multiple electrodes to target structures within the recipient (e.g., assessing relative modiolar proximity of multiple electrodes). Fig.18 1 is a functional block diagram illustrating an exemplary induced bio-response analysis system 1865 configured to implement aspects of the techniques presented herein. Evoked bio-response analysis system 1865 may be implemented, for example, by an implantable medical device (e.g., cochlear implant 102), a combination of an implantable medical device and an external device (e.g., cochlear implant 102 and external device 110), multiple implantable medical devices, multiple implantable medical devices and multiple external devices, and the like.

[0117] As shown, the induced biological response analysis system 1865 includes a control module 1866, a stimulator unit 1868, a plurality of electrodes 1844, a recording module 1872, and an induced biological response analysis module 1876. Again, for ease of illustration, the description will be made with reference to the analysis of ECAP responses. Fig.18As described elsewhere herein, it will be appreciated that the induced bioresponse analysis system 1865 or similar systems may be used to detect other types of induced bioresponses and may be implemented by various implantable medical devices alone and / or in combination with one or more external devices. In addition, the induced bioresponse analysis system 1865 may also be used to capture / record, for example, impedance or voltage measurements for use in assessing, for example, modiolar proximity of an electrode.

[0118] exist Fig.18 In a specific illustrative ECAP example, system 1865 is configured to capture / record multiple sets of electrophysiological signals from tissue of a recipient. In some examples, a medical professional (e.g., a clinician, an audiologist, etc.) selects one or more electrodes of a plurality of electrodes 1844 disposed within the cochlea of ​​the recipient for evaluation. Control module 1866 provides control signal 1867 to stimulator unit 1868, which causes stimulator unit 1868 to deliver electrical stimulation signal 1869 to the recipient via, for example, the selected one or more electrodes 1844 or another electrode in close proximity to the selected one or more electrodes 1844 to perform one or more ECAP measurements.

[0119] After delivering the electrical stimulation signal 1869, the recording module 1872 records an electrophysiological trace 1871 (i.e., a set of electrophysiological signals representing electrical activity from the stimulated tissue) from the tissue. The recording module 1872 can be configured to amplify the electrophysiological trace 1871, among other operations. The electrophysiological trace 1871, when captured via the recording module 1872, is provided to the induced biological response analysis module 1876.

[0120] As described above, the stimulation signals used to perform ECAP measurements can be complex. Therefore, the above process of delivering the stimulation signal to the recipient and recording the resulting electrophysiological trace 1871 can be repeated many times (e.g., using different stimulation and / or recording electrodes), and each electrophysiological trace 1871 can be associated with a separate time window (referred to as an epoch). It is recognized that the stimulation signal can use a variety of different pulse shapes, such as rectangular pulses, ramp pulses, rhombic pulses, curved pulses (e.g., sine waves), etc.

[0121] The induced bio-response analysis module 1876 is configured to use multiple electrophysiological traces 1871 that form an ECAP response (as described elsewhere herein) to evaluate the induced bio-response (as described elsewhere herein) of one or more electrodes 1844. The induced bio-response analysis module 1876 can generate one or more outputs 1877 representing the final classification / determination of electrode proximity (e.g., modiolus proximity). In some embodiments, one or more outputs can be audible or visual outputs, represented by arrows 1877 (A). In other embodiments, as further described below, one or more outputs can be control outputs (represented by arrows 1877 (B)), which are sent to, for example, a control module 1866 for use as part of a closed-loop control system.

[0122] As previously stated, the technology disclosed herein can be applied to any of a variety of situations and used with a variety of different devices. Fig.19 An exemplary device that may benefit from the techniques disclosed herein is described in more detail in FIG. Fig.19 An exemplary vestibular stimulator system 1902 is shown, which can be used to implement the embodiments presented herein. As shown, the vestibular stimulator system 1902 includes an implantable component (vestibular stimulator) 1912 and an external device / component 1904 (e.g., an external processing device, a battery charger, a remote control, etc.). The external device 1904 includes a transceiver unit 1960. Thus, the external device 1904 is configured to transmit data (and possibly power) to the vestibular stimulator 1912.

[0123] The vestibular stimulator 1912 includes an implant body (main module) 1934, a lead region 1936, and a stimulation assembly 1916, all configured to be implanted beneath the skin / tissue (tissue) 1915 of a recipient. The implant body 1934 generally includes an airtight sealed housing 1938 in which an RF interface circuit system, one or more rechargeable batteries, one or more processors, and a stimulator unit are disposed. The implant body 1914 also includes an internal / implantable coil 1914, which is generally external to the housing 1938 but connected to a transceiver via an airtight feedthrough (not shown).

[0124] The stimulation assembly 1916 includes a plurality of electrodes 1944 disposed in a carrier member (e.g., a flexible silicone body). In this particular example, the stimulation assembly 1916 includes three (3) stimulation electrodes, referred to as stimulation electrodes 1944(1), 1944(2), and 1944(3). The stimulation electrodes 1944(1), 1944(2), and 1944(3) serve as an electrical interface for delivering electrical stimulation signals to the vestibular system of a recipient.

[0125] The stimulation assembly 1916 is configured so that a surgeon can implant the stimulation assembly near the recipient's otolith organ via, for example, the recipient's oval window. It should be appreciated that this particular embodiment with three stimulation electrodes is merely illustrative, and the techniques presented herein can be used with stimulation assemblies with different numbers of stimulation electrodes, stimulation assemblies with different lengths, etc.

[0126] In operation, the vestibular stimulator 1912, the external device 1904, and / or another external device may be configured to implement the techniques presented herein. That is, the vestibular stimulator 1912, possibly in combination with the external device 1904 and / or another external device, may include an induced bio-response analysis system as described elsewhere herein.

[0127] Fig. 20 2 is a flow chart of an exemplary method 2000 according to some embodiments presented herein. The method 2000 begins at 2002, where a plurality of electrically evoked compound action potentials (ECAPs) are captured via an electrode configured to be inserted into the inner ear. At 2004, the system estimates a modiolar proximity of at least one of the electrodes based on the plurality of ECAPs.

[0128] Fig.21 21 is a flow chart of another exemplary method 2100 according to certain embodiments presented herein. The method 2100 begins at 2102, where the system performs neural response telemetry measurements using one or more of a plurality of electrodes configured to be inserted into an inner ear of a recipient to obtain a plurality of evoked bio-responses. At 2104, the proximity of at least one of the electrodes to a wall of the inner ear is estimated using the plurality of evoked bio-responses.

[0129] Fig. 22 2200. The method 2200 begins at 2202, where the system obtains a plurality of induced biological responses using one or more electrodes of a plurality of electrodes configured to be inserted into a body of a recipient. At 2204, the system analyzes the plurality of induced biological responses relative to each other to determine a relative proximity of at least one of the electrodes to a target structure in the body of the recipient.

[0130] It should be understood that although specific uses of the present technology have been illustrated and discussed above, the disclosed technology can be used with various devices according to many examples of the present technology. The above discussion is not intended to indicate that the disclosed technology is only suitable for implementation in systems similar to those shown in the accompanying drawings. In general, additional configurations can be used to practice the processes and systems herein, and / or some aspects described can be excluded without departing from the processes and systems disclosed herein.

[0131] The present disclosure describes some aspects of the present invention technology with reference to the accompanying drawings, in which only some possible aspects are shown. However, other aspects may be embodied in many different forms and should not be construed as being limited to the aspects set forth herein. Instead, these aspects are provided to make the present disclosure detailed and complete and to fully convey the scope of possible aspects to those skilled in the art.

[0132] It should be understood that the various aspects (e.g., parts, components, etc.) described herein with respect to the figures are not intended to limit the systems and processes to the specific aspects described. Therefore, additional configurations can be used to practice the methods and systems herein, and / or some aspects described can be excluded without departing from the methods and systems disclosed herein.

[0133] According to certain aspects, a system and a non-transitory computer-readable storage medium are provided. The system is configured with hardware, and the hardware is configured to perform operations similar to the method of the present disclosure. One or more non-transitory computer-readable storage media include instructions, and the instructions, when executed by one or more processors, cause the one or more processors to perform operations similar to the method of the present disclosure.

[0134] Similarly, where steps of a process are disclosed, these steps are described for the purpose of illustrating the present methods and systems, and are not intended to limit the present disclosure to a particular sequence of steps. For example, the steps may be performed in a different order, two or more steps may be performed simultaneously, additional steps may be performed, and disclosed steps may be eliminated without departing from the present disclosure. Furthermore, the disclosed processes may be repeated.

[0135] Although specific aspects are described herein, the scope of the present technology is not limited to these specific aspects. Those skilled in the art will recognize other aspects or improvements within the scope of the present technology. Therefore, specific structures, actions or media are disclosed only as illustrative aspects. The scope of the present technology is limited by the following claims and any equivalents therein.

[0136] It should also be understood that the embodiments presented herein are not mutually exclusive and that various embodiments can be combined with another embodiment in any of a variety of different ways.

Claims

1. A method comprising: capturing a plurality of electrically evoked compound action potentials (ECAPs) via an electrode configured to be inserted into the inner ear; as well as A modiolar proximity of at least one of the electrodes is estimated based on the plurality of ECAPs.

2. The method of claim 1 , wherein estimating the modiolar proximity of at least one of the electrodes comprises: A relative modiolar proximity of at least a first one of the electrodes and at least a second one of the electrodes is determined.

3. The method of claim 1 , wherein estimating the modiolar proximity of at least one of the electrodes comprises: The modiolar proximity is estimated based on one or more ECAP threshold distributions determined from the plurality of ECAPs.

4. The method according to claim 1, 2 or 3, further comprising: determining at least one distribution of excitation (SOE) function from the plurality of ECAPs, and The modiolar proximity of at least one of the electrodes is estimated based on the at least one SOE function.

5. The method of claim 4, wherein estimating the modiolar proximity of at least one of the electrodes based on the at least one SOE function comprises: The location of the excitation peak associated with the at least one SOE function is analyzed relative to the location where the probing stimulus is delivered to obtain the at least one SOE function.

6. The method of claim 4, wherein estimating the modiolar proximity of at least one of the electrodes based on the at least one SOE function comprises: An excitation distribution level associated with at least one SOE function is analyzed.

7. The method according to claim 1, 2 or 3, further comprising: A modiolar proximity of at least one of the electrodes is estimated based on the plurality of ECAPs and one or more electrical measurements. The method of claim 7 , wherein the one or more electrical measurements include impedance measurements.

9. The method of claim 7, wherein the one or more electrical measurements include voltage or current measurements.

10. The method according to claim 1, 2 or 3, further comprising: A modiolar proximity of at least one of the electrodes is estimated based on one or more ECAP magnitude growth functions determined from the plurality of ECAPs.

11. The method of claim 1 , 2 or 3, wherein estimating the modiolar proximity of at least one of the electrodes comprises: The plurality of ECAPs are analyzed relative to each other to estimate the modiolar proximity.

12. The method of claim 1 , 2 or 3, wherein estimating the modiolar proximity of at least one of the electrodes comprises: The multiple ECAPs are analyzed relative to standard population data to estimate the modiolar proximity.

13. One or more non-transitory computer-readable storage media comprising instructions that, when executed by one or more processors, cause the one or more processors to: performing neural response telemetry measurements using one or more of a plurality of electrodes configured to be inserted into an inner ear of a recipient to obtain a plurality of evoked bio-responses; and The relative proximity of the electrode to a wall of the inner ear is estimated using the plurality of evoked biological responses.

14. The one or more non-transitory computer-readable storage media of claim 13, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear using the plurality of evoked biological responses comprise instructions executable to: The modiolar proximity of at least a first electrode of the plurality of electrodes is determined relative to the modiolar proximity of at least a second electrode of the plurality of electrodes.

15. The one or more non-transitory computer-readable storage media of claim 13, wherein the instructions executable to perform neural response telemetry measurements to obtain a plurality of evoked biological responses include instructions executable to: Neural response telemetry measurements were performed to obtain multiple electrically evoked compound action potentials (ECAPs).

16. The one or more non-transitory computer-readable storage media of claim 13, 14, or 15, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear using the plurality of evoked biological responses comprise instructions executable to: The relative proximity of the electrode to the wall of the inner ear is estimated based on one or more ECAP threshold distributions determined from the plurality of ECAPs.

17. The one or more non-transitory computer-readable storage media of claim 15, further comprising instructions executable to: determining at least one distribution of excitation (SOE) function from the plurality of ECAPs, and The relative proximity of the electrode to the wall of the inner ear is estimated based on the at least one SOE function.

18. The one or more non-transitory computer-readable storage media of claim 17, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear based on the at least one SOE function comprise instructions executable to: The location of the excitation peak associated with the at least one SOE function is analyzed relative to the location where the probing stimulus is delivered to obtain the at least one SOE function.

19. The one or more non-transitory computer-readable storage media of claim 17, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear based on the at least one SOE function comprise instructions executable to: An excitation distribution level associated with at least one SOE measurement is analyzed.

20. The one or more non-transitory computer-readable storage media of claim 15, further comprising instructions executable to: The relative proximity of the electrode to the wall of the inner ear is estimated based on one or more ECAP magnitude growth functions determined from the plurality of ECAPs.

21. The one or more non-transitory computer-readable storage media of claim 13, 14, or 15, further comprising instructions executable to: The relative proximity of the electrode to the wall of the inner ear is estimated based on the plurality of evoked biological responses and one or more electrical measurements.

22. The one or more non-transitory computer-readable storage media of claim 13, 14, or 15, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear using the plurality of evoked biological responses comprise instructions executable to: The plurality of evoked biological responses are analyzed relative to each other to estimate the relative proximity of the electrode to a wall of the inner ear.

23. The one or more non-transitory computer-readable storage media of claim 13, 14, or 15, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear using the plurality of evoked bio-responses comprise instructions executable to: The plurality of evoked biological responses are analyzed relative to standard population data to estimate the relative proximity of the electrode to the wall of the inner ear.

24. The one or more non-transitory computer-readable storage media of claim 13, 14, or 15, wherein the instructions executable to estimate the relative proximity of the electrode to the wall of the inner ear using the plurality of evoked biological responses comprise instructions executable to: The plurality of evoked biological responses are analyzed to estimate a relative proximity of the electrode to the modiolar wall of the inner ear.

25. A method comprising: obtaining a plurality of induced biological responses using one or more electrodes of a plurality of electrodes configured to be inserted into a body of a recipient; as well as The plurality of induced biological responses are analyzed relative to one another to determine a relative proximity of at least one of the electrodes to a target structure within the recipient.

26. The method of claim 25, wherein analyzing the induced biological responses relative to each other to determine the relative proximity of at least one of the electrodes to a target structure in the recipient comprises: The evoked biological responses are analyzed relative to each other to estimate the relative proximity of the at least one of the electrodes to the modiolus of the cochlea.

27. The method of claim 25 or 26, wherein the plurality of evoked biological responses comprises electrically evoked compound action potentials (ECAPs).

28. The method according to claim 27, further comprising: determining at least one distribution of excitation (SOE) function from the plurality of ECAPs, and The SOE function is analyzed to determine the relative proximity of at least one of the electrodes to a target structure within the recipient.

29. The method of claim 28, wherein analyzing the SOE function to determine the relative proximity of at least one of the electrodes to a target structure in the recipient comprises: The location of the excitation peak associated with the at least one SOE function is analyzed relative to the location where the probing stimulus is delivered to obtain the at least one SOE function.

30. The method of claim 28, wherein analyzing the SOE function to determine the relative proximity of at least one of the electrodes to a target structure in the recipient comprises: An excitation distribution level associated with at least one SOE function is analyzed.

31. A system comprising: one or more electrodes configured to record a plurality of evoked biological responses from a cochlea of ​​a recipient; as well as One or more processors configured to analyze the plurality of evoked biological responses relative to each other to determine a relative modiolar proximity of the electrodes.

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