Intraoperative vibration feedback evaluation

Abstract

This document presents a technique for generating information that characterizes the amount of vibration isolation between an implantable vibration sensor and an implantable mechanical actuator (actuator) when each is implanted in a recipient. Specifically, the implantable mechanical actuator is configured to generate a mechanical stimulation signal based on one or more actuator control signals and deliver it to the recipient. The vibration sensor is configured to capture vibrations caused by delivering the mechanical stimulation signal to the recipient. Next, a vibration transfer function is generated that relates the positioning of the vibration sensor to the actuator based on the captured vibrations and properties of the actuator control signal. The vibration transfer function provides an indication of the vibration isolation that exists between the vibration sensor and the actuator at their respective locations within the recipient's body.

Description

background Technical Field

[0002] The present invention generally relates to evaluating intraoperative vibro-feedback at an implantable sound input module. Background Art

[0004] In recent decades, medical devices have provided a wide range of therapeutic benefits to recipients. Medical devices can include internal or implantable components / devices, external or wearable components / devices, or a combination thereof (e.g., a device having an external component that communicates 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 for many years in performing life-saving and / or lifestyle-improving functions and / or recipient monitoring.

[0005] 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. 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

[0006] In one aspect, a method is provided. The method includes delivering one or more sets of mechanical stimulation signals to a recipient via an actuator of an implantable hearing prosthesis; capturing vibrations caused by each of the one or more sets of mechanical stimulation signals at a vibration sensor located at a first location in the recipient; determining a vibration transfer function between the actuator and the vibration sensor at the first location; and providing an indication of the vibration transfer function between the actuator and the vibration sensor at the first location to a user.

[0007] In another aspect, a method is provided. The method includes positioning a sound input module at a first location in a recipient, the sound input module including a sound sensor and a vibration sensor; driving an actuator implanted in the recipient with one or more sets of actuator control signals, wherein each of the one or more sets of actuator control signals causes the actuator to deliver one or more mechanical stimulation signals to the recipient; capturing vibrations caused by each of the one or more sets of mechanical stimulation signals at the vibration sensor; and analyzing properties of the one or more sets of control signals relative to properties of the vibrations caused by each of the one or more sets of mechanical stimulation signals to assess the suitability of the first location for implanting the sound input module at the first location.

[0008] In another aspect, one or more non-transitory computer-readable storage media are provided. The non-transitory computer-readable storage media include instructions that, when executed by a processor, cause the processor to: generate one or more sets of actuator control signals at an implantable hearing prosthesis, wherein the implantable hearing prosthesis includes an actuator and a sound input module, each configured to be implanted in a recipient, wherein the sound input module includes a sound sensor and a vibration sensor; provide the one or more sets of actuator control signals to the actuator to deliver one or more sets of mechanical stimulation signals to the recipient using the actuator, wherein each of the one or more sets of mechanical stimulation signals is generated based on at least one of the one or more sets of actuator control signals; receive one or more sets of output signals from the vibration sensor in response to each of the one or more sets of mechanical stimulation signals indicating that a vibration is detected at the vibration sensor; and generate an indication of relative vibration isolation between the acceleration sensor and the actuator based on the one or more sets of actuator control signals and the one or more sets of output signals from the acceleration sensor indicating that an acceleration is detected.

[0009] In another aspect, a system is provided that includes an actuator configured to be implanted in a recipient and to generate one or more sets of mechanical stimulation signals for delivery to the recipient; a vibration sensor configured to be implanted at a first location in the recipient and configured to capture vibrations induced by each of the one or more sets of mechanical stimulation signals; and one or more processors configured to generate a vibration transfer function between the actuator and the vibration sensor at the first location based on at least the vibrations induced by each of the one or more sets of mechanical stimulation signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the present invention are described herein with reference to the accompanying drawings, in which:

[0011] Figure 1A is a top view of a fully implantable middle ear hearing prosthesis according to certain embodiments presented herein;

[0012] Figure 1B is a diagram showing some embodiments according to the present invention Figure 1A Schematic diagram of a fully implantable middle ear hearing prosthesis being implanted in a recipient's head;

[0013] Figure 1C According to certain embodiments of the present invention Figure 1A Functional block diagram of a fully implantable middle ear hearing prosthesis;

[0014] Figure 1D According to certain embodiments of the present invention Figure 1A A perspective view of the actuator and fixation system of the fully implantable middle ear hearing prosthesis;

[0015] Figure 1E According to certain embodiments of the present invention Figure 1D Another perspective view of the actuator and fixing system;

[0016] Figure 2 is a schematic block diagram illustrating an open-loop vibration feedback measurement technique according to certain embodiments presented herein;

[0017] Figure 3 is a schematic block diagram illustrating a closed-loop vibration feedback measurement technique according to certain embodiments presented herein;

[0018] Figure 4 is a graph showing results of two example vibration feedback measurements according to certain embodiments presented herein;

[0019] Figure 5 is a schematic diagram illustrating an example information display that may be generated based on vibration feedback measurements according to certain embodiments presented herein;

[0020] Figure 6 is a block diagram of an adaptation system configured to perform techniques according to embodiments of the present invention;

[0021] Figure 7 is a high-level flow chart of a method according to certain embodiments presented herein; and

[0022] Figure 8 is a high-level flow chart of another method according to certain embodiments presented herein. DETAILED DESCRIPTION

[0023] This document presents a technique for generating information that characterizes the amount of vibration isolation between an implantable vibration sensor and an implantable mechanical actuator (actuator) when each is implanted in a recipient. Specifically, the implantable mechanical actuator is configured to generate a mechanical stimulation signal based on one or more actuator control signals and deliver it to the recipient. The vibration sensor is configured to capture vibrations caused by delivering the mechanical stimulation signal to the recipient. Next, a vibration transfer function is generated that relates the positioning of the vibration sensor to the actuator based on the captured vibrations and properties of the actuator control signal. The vibration transfer function provides an indication of the vibration isolation that exists between the vibration sensor and the actuator at their respective locations within the recipient's body.

[0024] For ease of description only, the technology presented herein is described primarily with reference to fully implantable middle ear hearing prostheses (middle ear implants). However, it should be understood that the technology presented herein can also be incorporated into or performed by a variety of other implantable medical devices. For example, the technology presented herein can be used with other hearing prostheses, including cochlear implants, bone conduction devices, direct acoustic stimulators, auditory brain stimulators, and the like. The technology presented herein can also be used with vestibular devices (e.g., vestibular implants), visual devices (i.e., bionic eyes), sensors, pacemakers, drug delivery systems, defibrillators, functional electrical stimulation devices, catheters, epileptic seizure devices (e.g., devices for monitoring and / or treating epileptic events), sleep apnea devices, electroporation devices, and the like.

[0025] Figure 1A is a top view of a fully implantable middle ear hearing prosthesis 100 according to certain embodiments presented herein. Figure 1B It shows Figure 1A Schematic diagram of a middle ear hearing prosthesis 100 implanted in a recipient 10, and Figure 1C is a schematic block diagram of the middle ear hearing prosthesis 100. For ease of description, Figures 1A-1C .

[0026] Figures 1A-1CThe middle ear hearing prosthesis 100 includes a sound input unit 102, an implant body 104, an actuator 106, and a coil 108, all of which are implanted beneath the skin / tissue of a recipient 101. The sound input unit 102 includes a substantially rigid shell 110 in which at least two implantable sensors 112 and 114 are disposed / positioned. The implantable sensor 112 is configured / designed to pick up (capture) external acoustic sounds, while the implantable sensor 114 is configured / designed to pick up (capture) vibrations, such as those caused by body noise. That is, the implantable sensor 112 is a "sound" sensor / transducer, such as an implantable microphone, that is primarily configured to detect / receive external acoustic sounds, while the implantable sensor 114 is a "vibration" sensor that is primarily configured to detect / receive internal body noise and vibrations (e.g., vibrations caused by the action of the implantable actuator). The sound sensor 112 and the vibration sensor 114 are sometimes collectively referred to herein as "implantable sensors" 144.

[0027] Generally speaking, the vibration sensor 114 is mechanically attached to the housing 110 so that body noise (vibration) transmitted to the housing can be detected / captured by the vibration sensor (e.g., sensing vibration of the housing). The housing 110 is airtight and includes a diaphragm 116 proximate to the sound sensor 112. The diaphragm 116 can be integral with the housing 116 and / or can be a separate element attached (e.g., welded) to the housing 112. The sound input unit 102 is configured to be implanted within the recipient 101. Figure 1B In one example shown, the sound input unit 102 is configured to be implanted within the skin / tissue adjacent to the recipient's outer ear 103. In this position, the diaphragm 116 is beneath the recipient's skin near the recipient's ear canal 105. In operation, a sound signal incident on the skin adjacent to the diaphragm 116 (i.e., on top of the diaphragm) causes the skin adjacent to the diaphragm 116, and therefore the diaphragm 116 itself, to displace (vibrate) in response to the sound signal. The displacement of the diaphragm 116 is detected by the sound sensor 112. In this way, the sound sensor 112 is able to detect external acoustic sound signals (external acoustic sounds) despite being implanted within the recipient's body.

[0028] The implantable sound sensor 112 and the vibration sensor 114 can each be electrically connected to the implant body 104. In operation, the sound sensor 112 and the vibration sensor 114 detect input signals (e.g., external acoustic sounds and / or vibrations) and convert the detected input signals into electrical signals that are provided to the processing unit 118 (e.g., via the leads 120). Figure 1C In FIG. 1 , arrow 117 represents the electrical output of the acoustic sensor 112, sometimes referred to herein as the "acoustic sensor output signal." Figure 1CArrow 119 in FIG. 1 represents the electrical output of vibration sensor 114, sometimes referred to herein as a "vibration sensor output signal." In other words, sound sensor 112 provides sound sensor output signal 117 to processing unit 118, while vibration sensor 114 provides vibration sensor output signal 119 to processing unit 118. Processing unit 118 is configured to generate stimulus control signal 121 ( FIG. 12 ) based at least on the external acoustic sound and / or vibration detected by sound sensor 112 and / or vibration sensor 114, respectively. Figure 1C ).

[0029] exist Figure 1B In the example of FIG. 1 , the processing unit 118 includes at least one processor 122 and a memory 124. The memory 124 includes sound processing logic 126 and signal acquisition logic 125. When the sound processing logic 126 is executed by the at least one processor 122, the sound processing logic 126 causes the at least one processor 122 to perform the sound processing operations described herein (e.g., converting external acoustic sounds and / or body noises detected by the sound sensor 112 and / or the vibration sensor 114 into the stimulus control signal 121). When the signal acquisition logic 125 is executed by the at least one processor 122, the signal acquisition logic 125 causes the at least one processor 122 to perform the signal acquisition operations described herein. For example, in some embodiments, the signal acquisition operations include performing open-loop or closed-loop measurements as described elsewhere herein to capture vibration feedback data for use in generating a position-dependent transfer function of the vibration sensor 114. In some embodiments, in addition to performing open-loop or closed-loop measurements, the signal acquisition operations also include determining a position-dependent vibration transfer function. The signal acquisition operations also include transmitting the vibration feedback data and / or the position-dependent vibration transfer function to an external device. Further details regarding signal acquisition operations are provided below.

[0030] The memory 124 may include any suitable volatile or non-volatile computer-readable storage medium, including, for example, random access memory (RAM), cache memory, persistent storage (e.g., semiconductor memory, read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, etc.), or any other computer-readable storage medium capable of storing program instructions or digital information. The processing unit 118 may be implemented, for example, on one or more printed circuit boards (PCBs).

[0031] It should be understood that Figure 1CThe arrangement of the processing unit 118 in FIG. 1 is merely illustrative, and the techniques presented herein may be implemented with many different processing arrangements. For example, the sound processing unit 118 may be implemented with a processing unit formed by any one or a combination of the following: one or more processors (e.g., one or more digital signal processors (DSPs), one or more uC cores, etc.), firmware, software, etc., arranged to perform operations such as those described herein.

[0032] As shown, the implant body 114 includes a hermetically sealed housing 128 in which the processing unit 118 is disposed. Also disposed within the housing 128 is a power source (e.g., a rechargeable battery) 130 and a radio frequency (RF) interface circuit 132. The implantable coil 108, disposed externally to the housing 128, is electrically connected to the RF interface circuit 132. Generally, the implantable coil 108 and the RF interface circuit 132 enable the processing unit 118 to be received from an external device (e.g., a power source). Figures 1A-1C However, it should be understood that various types of energy transmission can be used to transmit power and / or data from an external device, and therefore, Figure 1B Only one example arrangement is shown.

[0033] As described above, the RF interface circuit 132 and the implantable coil 108 enable the middle ear hearing prosthesis 100 to receive data / power from an external device and / or transmit data to an external device. In other words, the modulated signals transmitted bidirectionally via the inductive link (RF coil 108 and external) are used to support battery charging, device programming, status querying, and user remote control.

[0034] In some examples, the external device may include an over-the-ear (OTE) unit. In other examples, the external device may include a behind-the-ear (BTE) unit or a miniature BTE unit that is configured to be worn adjacent to the recipient's outer ear. Alternative external devices may include a device worn in the recipient's ear canal, a body-worn processor, an adaptation system, a computing device, a consumer electronic device (e.g., a mobile phone communication), etc. For example, as further described below, during surgery, the middle ear prosthesis 100 is configured to communicate with a computing device to display an indication of the position-dependent transfer function to a user (e.g., a surgeon).

[0035] The present invention has been described with reference to using the RF interface circuit 132 and the implantable coil 108 to communicate with external devices. Figure 1C However, in some embodiments, the implant body 104 may also include a short-range wireless interface 133 for communicating with an external device. The short-range wireless interface 133 may be, for example, interface, Low Energy (BLE) interface, or other interface utilizing any number of standard or proprietary protocols. is Registered trademark owned by SIG.

[0036] As described above, the processing unit 118 generates the stimulation control signal 121. The stimulation control signal 121 is provided to the actuator 106 (eg, via the lead 134) for delivering the mechanical stimulation signal to the recipient. Figure 1C , the mechanical stimulation signal (vibration signal or vibration) delivered to the recipient is represented by arrow 123.

[0037] exist Figure 1B In the example of FIG, the actuator 106 delivers the vibrations 123 to the recipient via the ossicular chain (ossicles) 136 (i.e., the bones of the middle ear, which include the malleus, incus, and stapes). The ossicles 136 are located in the middle ear cavity 113 and are mechanically coupled between the tympanic membrane 113 and the oval window (not shown) of the cochlea 138. In natural hearing, the ossicles 136 serve to filter and amplify sound waves received via the recipient's ear canal 111.

[0038] like Figure 1B As shown in , the actuator 106 is configured to be implanted in a recipient to impart motion (e.g., vibration) directly to the ossicles 136 or cochlear fluid via, for example, the oval window, round window, cochlear fenestration, etc. Figure 1B In the embodiment, the actuator 106 is attached to the recipient's bone 115 (also in Figure 1D and 1E ). Additionally, the actuator 106 is mechanically coupled to the ossicle 136 (e.g., the incus) via a coupling member 140, which may be part of the actuator 106 and / or a separate element attached to the actuator. The actuator 106 and fixation system 142 are sometimes collectively referred to herein as an "actuator device" 145.

[0039] In operation, the actuator 106 is configured to generate vibrations 123 based on the stimulation control signal 121 received from the processing unit 118. Because the ossicles 136 are coupled to the oval window (not shown) of the cochlea 138, as described above, the vibrations imparted by the actuator 106 to the ossicles 136 will, in turn, cause the oval window to articulate (vibrate) in response to the vibrations. Similar to normal hearing, this vibration of the oval window creates waves of fluid motion of the perilymph within the cochlea 138, which in turn activates the hair cells within the cochlea 138. The activation of the hair cells causes the generation of appropriate nerve impulses, which are transmitted to the brain (also not shown) via spiral ganglion cells (not shown) and the auditory nerve (not shown), where they are perceived as sound.

[0040] It should be understood that Figure 1BThe arrangement in which the actuator 106 is mechanically coupled to the ossicles 136 as shown in FIG is merely illustrative, and the techniques presented herein can be used with different mechanical stimulation arrangements. For example, in alternative embodiments, the actuator 106 can be coupled directly to the oval window, another opening in the cochlea 138 (e.g., a cochlear fenestration or a round window), an opening in the recipient's semicircular canals, a recipient's skull, etc.

[0041] Figures 1A-1E The middle ear hearing prosthesis 100 is sometimes referred to as a "fully implantable middle ear hearing prosthesis" because all components of the prosthesis are configured to be implanted beneath the skin / tissue of the recipient. Because all components of the middle ear hearing prosthesis 100 are implantable, the middle ear hearing prosthesis can function without the need for external devices, at least for a limited period of time. However, as mentioned, external devices can be used to support battery charging, device programming, status querying, user remote control, etc. of the middle ear hearing prosthesis 100.

[0042] For fully implantable middle ear hearing prostheses, such as prosthesis 100, there is a potential vibration feedback path for vibration to be transmitted from the implanted actuator 106 to the implantable sensor 144. This vibration feedback (i.e., the portion of the vibration delivered to the recipient) can limit the gain available for delivering the mechanical stimulation signal (vibration) to the recipient. In particular, the vibration feedback can interfere with the operation of the sound sensor 112 and can limit the gain available for generating the mechanical stimulation signal. However, the vibration feedback can be significantly reduced or substantially eliminated by appropriately placing the implantable sensor 144 relative to the actuator 106. In particular, the sound sensor 112 should be implanted in a position such that the vibration feedback captured / received by the sound sensor 112 is below a threshold level.

[0043] More specifically, as described above, the actuator 106 is configured to deliver a mechanical stimulation signal (vibration) 123 to the recipient. Although the actuator 106 is configured to deliver the mechanical stimulation signal 123 to the recipient via the ossicles, cochlea, etc., the mechanical stimulation signal may also be partially imparted to other internal structures, such as the recipient's skull, via the fixation system 142 (which is itself mechanically fixed to the skull). Depending on the implant location of the sound sensor 112, there may be a physical path (e.g., formed by bone, cartilage, implant components, or other internal structures) that enables a portion of the mechanical stimulation signal generated by the actuator 106 and imparted to the recipient's skull or other internal structure to reach the housing 110 of the sound input unit 102 and, in turn, to the sound sensor 112 within the housing 110. This portion of the mechanical stimulation signal that is delivered to the sound sensor 112 is sometimes referred to herein as "vibration feedback." The physical path that enables the vibration feedback to reach the sound sensor 112 is sometimes referred to herein as the "vibration feedback path."

[0044] A particularly problematic situation occurs after implantation when there is physical contact between the housing 110 of the sound input unit 102 and the actuator device 145, which establishes what is referred to herein as a "direct" vibration feedback path between the sound sensor 112 and the actuator 106. If such a direct vibration feedback path exists, then when the actuator 106 delivers mechanical stimulation signals to the recipient, a portion of these mechanical stimulation signals is directed directly to the housing 110 and the sound sensor 112.

[0045] The particular anatomy / condition of the recipient, surgical access, etc. may limit what the surgeon is able to see during surgical implantation. Thus, avoiding direct contact between the housing 110 and the actuator assembly 145 (i.e., the actuator 106 and / or the actuator securing system 142) may not be as simple as performing an in situ visual inspection during surgery. For example, a surgeon may perform a procedure and believe that there is a physical separation between the housing 110 and the actuator assembly 145 of the sound input unit 102 when, in fact, the housing 110 and the actuator assembly 145 are still in direct contact with each other, given his / her limited visibility.

[0046] In addition, each recipient has different physical characteristics (e.g., bone density at certain locations), which may affect the amount of vibration feedback reaching the sound sensor 112 at different locations in the recipient. That is, due to the physical characteristics of a particular recipient, the sound sensor 112 may be less sensitive to the vibration of the mechanical stimulation signal generated by the actuator 106 at certain locations than at other locations. Therefore, the sound sensor 112 may be affected differently by the vibration feedback at different implant locations.

[0047] As described above, the vibration feedback reaching the sound sensor 112 due to the operation of the implanted actuator 106 can limit the gain that can be used to deliver the mechanical stimulation signal to the recipient. Similarly, as described above, the vibration feedback reaching the sound sensor 112 due to the operation of the implanted actuator 106 is a function of the vibration feedback path and the properties of the mechanical stimulation delivered to the recipient. Therefore, it is ideal to determine intraoperatively (i.e., during surgical implantation of the prosthesis 100) the extent to which the sound sensor 112 will be affected by the vibration feedback from the actuator 106 at a given implant location in the recipient's body. That is, it would be beneficial to determine the vibration response of the sound sensor 112 to the vibration of the actuator 106 before closing the suture line during surgery.

[0048] However, it has been found that it is not possible to determine the vibration response of an implanted sound sensor to the vibration of an implanted actuator intraoperatively because the intraoperative vibration sensitivity of the sound sensor is very different from the postoperative vibration sensitivity of the sound sensor. The difference in the intraoperative and postoperative vibration sensitivity of the sound sensor is caused by many postoperative factors, such as flap thickness (i.e., the thickness of the skin layer to be positioned above the sound sensor), skin tension, the healing process, etc., which cannot be accurately accounted for in the surgical environment.

[0049] Thus, recognizing the difference in intraoperative and postoperative vibration sensitivity of a sound sensor, the inventors of the present application have proposed a technique for generating / determining an estimated vibration sensitivity of a sound sensor to an actuator during surgery based on data captured by a vibration sensor co-located with the sound sensor (e.g., both the sound sensor and the vibration sensor are located within a sound input module). In other words, the present invention proposes determining intraoperatively (i.e., during surgical implantation of a prosthesis) the extent to which a vibration sensor will be affected by vibration feedback from an actuator at a given implant location in a recipient. However, such a determination is made based on data obtained from the vibration sensor, rather than based on data obtained from the sound sensor. In particular, the vibration sensor co-located with the sound sensor and rigidly coupled to the skull has a vibration sensitivity that is independent of postoperative factors that affect / change the sensitivity of the sound sensor (i.e., the sensitivity of the vibration sensor is independent of flap thickness, skin tension, healing process, etc.). Therefore, the data captured from the vibration sensor is used to objectively assess the suitability of the location for implanting the sound input module.

[0050] Thus, in situ techniques for capturing / acquiring data are presented herein that objectively characterize the implant location of an implantable sound sensor relative to the implant location of an implantable actuator device, but based on indirect / inconsistent data related to a co-located vibration sensor. Specifically, according to the techniques presented herein, data (sometimes referred to herein as "vibration feedback data") is captured in situ by a processing unit of a hearing prosthesis (e.g., middle ear hearing prosthesis 100) to represent a vibration transfer function between the vibration sensor 114 and the actuator 106. Generally speaking, the vibration feedback data includes properties of vibrations detected by the vibration sensor 114 and / or actuator control signals that cause these vibrations. The vibration transfer function generated from the vibration feedback data represents the vibrations detected by the vibration sensor 114 relative to the properties of the actuator control signals that cause these vibrations (i.e., data representing the electrical output provided to the implanted actuator relative to the electrical output from the implanted vibration sensor).

[0051] exist Figures 1A-1CIn the example of FIG, the electrical output provided to the implanted actuator 106 is the stimulation control signal 121, and the electrical output from the implanted vibration sensor 114 is the vibration sensor output signal 119. Figures 1A-1C In the example of FIG. 1 , the vibration transfer function is determined based on analyzing the stimulus control signal 121 relative to the vibration sensor output signal 119 .

[0052] As further described below, the vibration transfer function can be provided to a user (e.g., a surgeon). If the vibration transfer function has a value outside of an acceptable range, this indicates incorrect placement of the entire sound input unit 102 and, therefore, incorrect placement of the sound sensor 112 relative to the actuator device 145. Thus, the techniques presented herein provide the ability to objectively assess the placement of the vibration sensor with respect to its effect on gain, providing guidance to surgeons, particularly less experienced surgeons.

[0053] As noted, the vibration transfer function from the input of the implanted actuator (e.g., stimulation control signal 121) to the output of the vibration sensor (e.g., vibration sensor output signal 119) is measured intraoperatively. However, this measurement can be performed in several different ways, including by open-loop measurement techniques or by closed-loop measurement techniques. Figure 2 Further details on an example open-loop measurement technique are provided below with reference to Figure 3 Further details on an example closed-loop measurement technique are provided. For ease of description, reference Figures 1A-1E Example open-loop measurement techniques and closed-loop measurement techniques are described for the elements of the middle ear hearing prosthesis 100 .

[0054] First reference Figure 2 , shows an example open-loop measurement technique for performing vibration feedback measurements by injecting a test signal into the actuator 106 and measuring the resulting output signal of the vibration sensor 114. More specifically, as Figure 2 As shown in FIG, the actuator 106 is driven with a test control signal 250 (e.g., a stimulus control signal having specific properties) to vibrate the actuator 106 and thereby deliver a mechanical test stimulus signal (test signal or test vibration) 223 to a predetermined structure in the recipient's head (e.g., the ossicular chain, the skull, the cochlea, etc.). The test signal 223 can be any of many different signals used to characterize the vibration transfer function. Example test signals include, but are not limited to, a white noise signal (i.e., a signal representing white noise), a maximum length sequence, a series of sinusoidal tones presented simultaneously or sequentially, a series of narrowband noise signals presented simultaneously or sequentially, a sinusoidal sweep, and the like.

[0055] Generally speaking, the feedback to the vibration sensor 114 depends on the frequency of the test signal 223. That is, the vibration transfer function will vary with frequency. Therefore, the test signal 223 (and therefore the test control signal 250) will include a plurality of different frequencies (e.g., different frequencies in the range of 250 Hertz (Hz) to 4,000 Hz) to enable objective evaluation of the feedback within a selected frequency range.

[0056] In some embodiments, the test control signal 250 is generated by the processing unit 118. However, in other embodiments, the test control signal 250 is generated by an external device (e.g., Figure 2 ) and downloaded to the processing unit 118 via an inductive link, a wireless link, etc. prior to implantation, before the start of a measurement, etc. In other embodiments, the test control signal 250 is calculated by the external device and streamed to the processing unit 118 in real time (e.g., during a measurement) via an inductive link, a wireless link, etc.

[0057] return Figure 2 , when the test control signal 250 is used to drive the actuator 106, a portion of the test signal 223 may be passed from the actuator 106 and / or the fixation system 142 to the vibration sensor 114 via a vibration feedback path. As mentioned, the portion of the test signal 223 that is passed from the actuator 106 and / or the fixation system 142 to the vibration sensor 114 is referred to herein as vibration feedback. As also mentioned, the vibration feedback path may be a direct path (i.e., where feedback is passed directly from the actuator device 145 to the housing 110 coupled to the vibration sensor 114) or an indirect path (e.g., where feedback is passed from the actuator device 145 to the housing 110 coupled to the vibration sensor 114 via bone, cartilage, etc.). Figure 2 , the vibration feedback path is represented by dashed line 252 , and the vibration feedback is represented by arrow 254 .

[0058] The vibration feedback 254 through the vibration feedback path 252 is captured / detected by the vibration sensor 114 as vibrations, which in turn causes the generation of a corresponding vibration sensor output signal 219 .

[0059] The vibration sensor 114 provides a vibration sensor output signal 219 to the processing unit 118. In certain embodiments, the processing unit 118 is configured to analyze one or more vibration sensor output signals 219 relative to the test signal 250 to determine the vibration transfer function of the vibration sensor 114 at a particular implant location. That is, the processing unit 118 is configured to determine the extent to which the vibration sensor 114 is affected by the vibration of the actuator 106 when the vibration sensor 114 is at a particular implant location based on the vibration sensor output signal 219 and the test signal 250. Thus, the transfer function of the vibration sensor 114 is position-dependent and is sometimes referred to herein as a "position-dependent vibration transfer function."

[0060] The processing unit 118 receives an input signal identified by the vibration sensor 114 (represented by the vibration sensor output signal 219), wherein the input signal is a combination of vibration feedback 254 (the signal of interest) and uncorrelated background noise that is unrelated but may be larger than the signal of interest and, therefore, may prevent the value of the signal of interest from being determined. Methods such as time-domain averaging or filtering can be used to increase the level of the relevant (feedback) signal relative to the level of the uncorrelated (background noise) signal to generate a "clean" input signal for determining the vibration transfer function. The vibration transfer function is the ratio of the input signal level identified by the vibration sensor 114 (represented by the vibration sensor output signal 219) to the output signal level generated by the actuator 106 on a per-frequency basis. These levels can be expressed as peak or RMS values.

[0061] As mentioned, the vibrations captured by the vibration sensor 114 are in-situ measurements. Therefore, in some examples, the processing unit 118 is configured to perform some pre-processing on the vibration sensor output signal 219. For example, the vibration sensor output signal 219 can be pre-processed to normalize background noise (e.g., the subject's breathing, etc.), the vibration sensor output signal 219 can be filtered to extract the actuator signal (e.g., the frequency of the sine wave used to drive the actuator), etc., and to isolate vibrations attributable to the mechanical stimulus signal.

[0062] Back to Figure 2 , data representing the position-dependent vibration transfer function can be sent to an external device for further analysis and / or for presentation to a surgeon. As further described below, the position-dependent vibration transfer function can be presented to a user (e.g., a surgeon) in a variety of different ways, such as by a visual display, an audible tone, etc. Figure 2 , data representing the position-dependent vibration transfer function is represented by arrow 262 , where the data is wirelessly transmitted from the processing unit 118 to the external device 260 .

[0063] The position-dependent vibration transfer function can be used to objectively assess the implantation position of the sound input module 102, which includes both the sound sensor 112 and the vibration sensor 114. For example, if the position-dependent vibration transfer function is outside of an acceptable range (e.g., above a certain threshold) at one or more frequencies, this indicates that the sound input module 102 is incorrectly positioned relative to the actuator device 145. If the position-dependent vibration transfer function is outside of the acceptable range, the surgeon can change the position of the sound input module 102 relative to the actuator device 145 (e.g., reposition one or more of the sound input module 102 and / or the fixation system 142).

[0064] Once the position of the sound input module 102 relative to the actuator device 145 has changed, an updated position-dependent vibration transfer function (e.g., substantially the same as described above) can be determined. The updated position-dependent vibration transfer function can again be used to objectively assess the implantation position of the sound input module 102. This process can continue until an acceptable position-dependent vibration transfer function is determined. At this point, the measurement can be terminated, and the surgeon can complete the remainder of the procedure (e.g., closing the surgical incision, etc.).

[0065] As stated, Figure 2 1. Embodiments in which the processing unit 118 is configured to determine a position-dependent vibration transfer function are shown. As described, in these embodiments, data 262 representing the position-dependent vibration transfer function is sent to an external device 260 for further analysis and / or for presentation to a user. That is, in some embodiments, the vibrations captured by the vibration sensor 114 are obtained by the processing unit 118, preprocessed, and correlated with the actuator control signals, and only the resulting position-dependent feedback is sent to the external device 260. However, in alternative embodiments, the processing unit 118 may be configured to obtain the vibrations captured by the vibration sensor 114, but the analysis is performed at the external device 260. In such embodiments, preprocessing may be performed at either the processing unit 118 or the external device 260, if desired.

[0066] For example, in alternative embodiments, processing unit 118 obtains vibration sensor output signal 219 and then streams vibration sensor output signal 219 in real time to external device 260. In these examples, external device 260 also knows the properties of test signal 250 (e.g., identifies one or more test signals, receives properties of one or more test signals from processing unit 118, etc.) and can therefore determine the position-dependent vibration transfer function.

[0067] As stated, Figure 2 An open-loop measurement technique for determining the position-dependent vibration transfer function is shown. Figure 3An alternative closed-loop measurement technique for determining the position-dependent vibration transfer function is shown. Figure 3 In the example, the position-dependent vibration transfer function is determined by sending an amplified vibration sensor signal to an actuator and then increasing the gain until feedback can be detected.

[0068] More specifically, in Figure 3 In the example of FIG, some initial signal 350 is used to drive the actuator 106 to deliver an initial mechanical test stimulus signal (initial vibration) 323 to a predetermined structure in the recipient's head (e.g., the ossicular chain, the skull, the cochlea, etc.). The initial signal 323 can be any of many different signals (e.g., ambient noise, a predetermined signal at a selected frequency, etc.).

[0069] When the initial signal 350 is used to drive the actuator 106, a portion of the initial vibration 323 may be transmitted from the actuator 106 and / or the fixation system 142 to the vibration sensor 114 via a vibration feedback path. The portion of the initial vibration 323 that is transmitted from the actuator 106 and / or the fixation system 142 to the vibration sensor 114 is referred to herein as the "initial" vibration feedback. As described above, the vibration feedback path may be a direct path (i.e., where feedback is transmitted directly from the actuator device 145 to the housing 110 coupled to the vibration sensor 114) or an indirect path (e.g., where feedback is transmitted from the actuator device 145 to the housing 110 coupled to the vibration sensor 114 via bone, cartilage, etc.). Figure 3 , the vibration feedback path is represented by dashed line 352 , and the initial vibration feedback is represented by arrow 354 .

[0070] The initial vibration feedback 354 through the vibration feedback path 352 is captured / detected as vibrations by the vibration sensor 114, which in turn causes the generation of a corresponding vibration sensor output signal 319. This output signal 319 is then provided to the processing unit 118 for amplification and stimulation of the recipient.

[0071] Thus, the following process is iteratively repeated: (1) delivering an amplified test control signal to the actuator 106 (represented by arrows 355(A)-355(N)), (2) delivering the amplified test signal to the receiver via the actuator (represented by arrows 357(A)-357(N)), (3) capturing amplified vibration feedback at the vibration sensor 114, and (4) providing a corresponding vibration sensor output signal to the processing unit 118 (represented by arrows 361(A)-361(N)), wherein the applied gain (and thus the vibration feedback) increases with each iteration. Iterations continue until the applied gain causes the processing unit 118 to detect a maximum stable gain (e.g., how much gain can be provided without feedback). In some examples, the maximum stable gain has been exceeded when a "whoosh" is detected. Generally speaking, a whoosh is the point at which the system detects that the output level has saturated, i.e., has reached the maximum value allowed by the amplifier's input-output curve. That is, once the applied gain reaches a certain level, the amount of vibration feedback detected by the vibration sensor 114 will become too high, which can be detected in the processing unit 118. Thus, the processing unit 118 is configured to determine the gain level at which a whine sound will be generated, indicating that the maximum stable gain of the system has been exceeded. The position-dependent vibration transfer function of the vibration sensor (i.e., the extent to which the vibration sensor 114 is affected by the vibration of the actuator 106 when the vibration sensor 114 is in a specific implant position) can in turn be inferred from the maximum stable gain.

[0072] For example, the system can perform measurements on a feedback path, which is called a "device under test" (DUT). The input to the DUT is the voltage output by the implant to the actuator. The output of the DUT is the voltage output by the vibration sensor. Therefore, a vibration transfer function of 0.1 means that if the actuator is driven with 500mV, the system will measure 50mV at the vibration sensor. Now suppose that sound produces an actuator input of 1mV, and the processing unit amplifies this input nine (9) times. The 1mV signal will be amplified to 1x9 or 9mV at the output, which will produce a feedback signal of 0.9mV in the next "cycle", and 0.9x9x0.1 in the next cycle, and lower and lower, and then the system stabilizes. However, if the processor amplifies eleven (11) times, the 1mV input signal will become 11mV at the output, which will produce a feedback signal of 1.1mV in the next cycle, and 1.1x11x0.1 in the next cycle, and higher and higher, until the system saturates, which produces audible feedback. Therefore, if the feedback gain is G, then the maximum stable forward gain will not produce this catastrophic behavior if it is just below 1 / G.

[0073] As mentioned, the feedback to vibration sensor 114 depends on the frequency of the signal. That is, the vibration transfer function will vary with frequency. Therefore, the closed-loop measurements described above can be performed at multiple different frequencies (e.g., different frequencies in the range of 250 Hertz (Hz) to 4,000 Hz) to enable objective evaluation of the feedback over a selected frequency range.

[0074] Similar to the above-described embodiments, data representing the position-dependent vibration transfer function can be sent to an external device for further analysis and / or for presentation to a surgeon. As further described below, the position-dependent vibration transfer function can be presented to a user (e.g., a surgeon) in a variety of different ways, such as by a visual display, an audible tone, etc. Figure 3 , data representing the position-dependent vibration transfer function is represented by arrow 362 , where the data is wirelessly transmitted from the processing unit 118 to the external device 360 ​​.

[0075] As in the above-described embodiments, the position-dependent vibration transfer function can be used to objectively assess the implantation position of the sound input module 102 (which includes the sound sensor 112 and the vibration sensor 114). For example, if the position-dependent vibration transfer function is outside the acceptable range (e.g., above a certain threshold) at one or more frequencies, this indicates that the sound input module 102 is incorrectly positioned relative to the actuator device 145. If the position-dependent vibration transfer function is outside the acceptable range, the surgeon can change the position of the sound input module 102 relative to the actuator device 145 (e.g., reposition one or more of the sound input module 102 and / or the fixation system 142).

[0076] Once the position of the sound input module 102 relative to the actuator device 145 has changed, an updated position-dependent vibration transfer function (e.g., substantially the same as described above) can be determined. The updated position-dependent vibration transfer function can again be used to objectively assess the implantation position of the sound input module 102. This process can continue until an acceptable position-dependent vibration transfer function is determined. At this point, the measurement can be terminated, and the surgeon can complete the remainder of the procedure (e.g., closing the surgical incision, etc.).

[0077] As stated, Figure 3Embodiments are shown in which processing unit 118 is configured to determine a position-dependent vibration transfer function. As described, in these embodiments, data 362 representing the position-dependent vibration transfer function is sent to external device 360 ​​for further analysis and / or for presentation to a user. That is, in some embodiments, vibrations captured by vibration sensor 114 are obtained, pre-processed, and correlated with actuator control signals by processing unit 118, and only the resulting position-dependent feedback is sent to external device 360. However, in alternative embodiments, processing unit 118 may be configured to obtain vibrations captured by vibration sensor 114, but the analysis is performed at external device 360. In such embodiments, pre-processing may be performed at either processing unit 118 or external device 360, if desired.

[0078] As described, the position-dependent vibration transfer function of the vibration sensor 114, determined as described herein, provides an objective indication of the vibration sensitivity of the sound sensor 112 (which is co-located with the vibration sensor in the sound input module 102) to the vibrations of the actuator 106 at their respective locations within the recipient's body. Also as described, positioning the actuator assembly 145 in direct contact with the housing 110 of the sound input module 102 is problematic. Furthermore, as also described above, different locations within each recipient will provide greater or lesser amounts of vibration sensitivity due to the recipient's specific physical characteristics. 106. Thus, in practice, the techniques presented herein can be implemented in several different ways.

[0079] For example, in some embodiments, the actuator 106 may be implanted in a recipient at a target location, and the vibration sensor 114 may be implanted at a first location. This first location may be selected based on, for example, normative data (e.g., research, previous recipient data, etc.). One of the techniques described above is used to determine a position-dependent vibration transfer function for the vibration sensor 114 at this first location. The position-dependent vibration transfer function determined for the vibration sensor 114 at this first location may then be compared to a predetermined position-dependent vibration transfer function to assess whether the first location is acceptable (e.g., if the vibration feedback between the vibration sensor 114 and the actuator 106 is less than a predetermined threshold at the first location). If unacceptable, the vibration sensor 114 may be moved to a second location, and the process repeated at this second location to determine the position-dependent feedback transfer of the vibration sensor 114 at the second location. This process may be repeated for several locations, with the results for each location compared to each other to select a preferred / optimal location. Alternatively, the process may be repeated until a location with an acceptable position-dependent vibration transfer function is identified.

[0080] As described above, the position-dependent vibration transfer function can be provided to a user (e.g., a surgeon) in a variety of different ways. In certain embodiments, the results of the position-dependent vibration transfer function can be analyzed relative to normative data (e.g., from previous surgeries, cadaver studies, etc.), and an indication can be provided to the user as to whether the evaluated position is acceptable. For example, the results of the comparison can be displayed as a pass / fail classification for a particular (tested) vibration sensor position (e.g., by representing the current result relative to a distribution of normative values, e.g., as a percentile, etc.). The pass / fail indication can be a visible indication, an audible indication, etc.

[0081] In some embodiments, the position-dependent vibration transfer function is presented to the user in digital form by an external device (e.g., external device 260 or 260) in communication with processing unit 118. In other embodiments, the results of the transfer function measurement are presented to the clinician in graphical form (e.g., a plot of feedback gain versus frequency) by the external device.

[0082] For example, Figure 4 An example graph 466 of vibration sensor input level versus frequency in full decibel scale (dB FS) is shown, which illustrates the input level (vibration) perceived by the vibration sensor due to a (constant level) stimulus from the actuator. Generally speaking, the higher the input level, the worse (larger) the vibration transfer function (the worse the vibration feedback).

[0083] exist Figure 4 In FIG, curve / line 468 is the input level without stimulation (i.e., only background noise in the room), called "Quiet". Figure 4 , curve 470 shows a "low feedback (low FB)" state where the actuator is well isolated from the vibration sensor, while curve 472 shows a "high feedback (high FB)" state where the actuator is in direct contact with the housing in which the vibration sensor is located. Figure 4 The vibration sensor input level is shown to be much higher under "high FB" conditions, particularly between approximately 500 Hz and 4000 Hz. This results in significant feedback and significant gain limitation for the receiver. In fact, at low FB, the vibration sensor signal is so small that it is indistinguishable from the background noise 468, except at approximately 1200 Hz.

[0084] exist Figure 4 In one example, curves 470 and 472 represent two different implantation positions of the vibration sensor relative to the implanted actuator. Thus, in some examples, curves 470 and 472 (as well as other curves) can be presented to a surgeon, and the surgeon can identify the position corresponding to curve 470 as the optimal placement of the vibration sensor in a particular recipient.

[0085] In one example, the graph 466 may be displayed to the user. However, in another example, the data represented in the graph 466 may be displayed to the user in one or more other formats. For example, Figure 5 Shows that it can be based on Figure 4 The example information generated by the data shown in 575 is displayed. Specifically, Figure 5 Feedback level is shown relative to frequency. In this example, the "target" value is a predetermined value that indicates what feedback level can / should be achieved at different frequencies. The target value can be generated, for example, based on a large amount of normative data from previous surgeries, clinical studies, etc. The "actual" value shows the feedback level measured by the surgeon and, accordingly, indicates how close he / she is to the target performance. The background noise floor serves as an indication of the maximum possible performance at a given frequency (e.g., if the noise floor is above the target, the noise level in the operating room is too high and measurements cannot be taken).

[0086] In other embodiments, the results of the transfer function measurement can be presented to the user as an acoustic signal, wherein the relevant value is encoded in at least one of the loudness, pitch, and / or repetition rate of the acoustic signal. For example, a low-frequency beep can indicate a low transfer function (i.e., low feedback), while a high-frequency beep can indicate a high transfer function (i.e., high feedback), etc.

[0087] As described above, the technology presented herein enables objective evaluation / assessment of the placement of an implantable sound input module relative to an implantable actuator by determining the vibration transfer function between an implantable vibration sensor (located together with a sound sensor in the sound input module) and the implantable actuator. In certain embodiments, the suitability of the implantation location of the sound input module is determined by comparing two or more position-dependent vibration transfer functions, respectively associated with different locations, with each other. The location with the lowest position-dependent vibration transfer function (i.e., indicating the lowest feedback between the vibration sensor and the actuator) is selected as the optimal or preferred location.

[0088] In some embodiments, the suitability of the implant location of the sound input module is determined by comparing a position-dependent vibration transfer function determined for the implant location with one or more predetermined vibration transfer functions. That is, if the position-dependent vibration transfer function indicates that the vibration feedback is below a predetermined threshold level at a selected frequency, then the location corresponding to the position-dependent vibration transfer function may be a suitable location for the sound input module. In some such embodiments, the predetermined vibration transfer function may be a standard predetermined vibration transfer function for all patients. However, in other embodiments, the predetermined vibration feedback transfer function used for comparison may be different for different recipients.

[0089] For example, recipients may have varying degrees of hearing loss, which in turn affects the amount of gain that needs to be applied by the implantable middle ear hearing prosthesis. As described, the amount of vibration feedback can limit the amount of gain that can be applied. Therefore, as the recipient's hearing loss is greater (and therefore requires greater gain), it may be necessary to ensure that the sound sensor is less sensitive to the vibrations of the actuator. However, as the recipient's hearing loss is less (and therefore requires less gain), the need for the sound sensor to be less sensitive to the vibrations of the actuator may be less important. Therefore, the predetermined vibration transfer function used for comparison with the position-dependent vibration transfer function can be a function of the recipient's hearing loss, where lower vibration feedback is required for recipients with greater hearing loss.

[0090] In one example, the recipient's audio metric data (e.g., an audio chart) can be input or imported before the procedure, and the system calculates how much gain the recipient may need (plus some safety margin to account for possible inaccuracies in the measurement and calculation of the recipient's hearing loss and / or the foreseeable progression over a certain period of time in the future). This information can then be used to calculate a predetermined vibration transfer function for comparison with the position-dependent vibration transfer function. In other words, the total required gain (represented by the predetermined vibration transfer function determined based on the hearing loss) can be compared with the predicted achievable gain (represented by the position-dependent vibration transfer function). If the current achievable gain is significantly lower than the required gain, an indication is provided to the user that the tested position is unacceptable. If the achievable gain is acceptable, either because the achievable gain is very high (low feedback, good surgical outcome, etc.) or because the required gain is low (average feedback, but the patient's residual hearing is good), an indication is provided to the user that the tested position is acceptable.

[0091] As mentioned above, aspects of the technology presented herein can be implemented in external devices, such as Figure 2 and 3 The corresponding external devices 260 and 360 are executed. Figure 6 is a block diagram illustrating a computing device 671 configured to perform such aspects of the techniques presented herein, according to certain embodiments.

[0092] Computer 671 includes one or more interfaces / ports 673(1)-673(N), memory 676, processor 678, and user interface 679. Interfaces 673(1)-673(N) may include, for example, any combination of network ports (e.g., Ethernet ports), wireless network interfaces, Universal Serial Bus (USB) ports, Institute of Electrical and Electronics Engineers (IEEE) 1394 interfaces, PS / 2 ports, and the like. Figure 6In the example of , interface 673(1) is connected to coil 663, which communicates with coil 108 of middle ear hearing prosthesis 100 implanted in recipient 661. Alternatively, interface 673(1) may be configured to communicate with cochlear implant system 100 via a short-range wireless connection (e.g., Bluetooth, etc.).

[0093] The user interface 679 includes one or more output devices, such as a liquid crystal display (LCD) and a speaker, for presenting visual or auditory information to a clinician, audiologist, or other user. The user interface 679 may also include one or more input devices, such as a keypad, keyboard, mouse, touch screen, etc.

[0094] The memory 676 includes signal acquisition logic 677. Generally speaking, the signal acquisition logic 677, when executed by the processor 678, causes the computing device 671 to perform the operations described elsewhere herein. For example, in some embodiments, the signal acquisition logic 677 can be executed to provide an audible or visual indication of the vibration transfer function to the user. In some embodiments, the vibration transfer function feedback analysis logic 677 can also be executed to determine the vibration transfer function and / or control aspects of open-loop or closed-loop feedback measurements at the middle ear hearing prosthesis 100.

[0095] The memory 676 may include 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 processor 678 is, for example, a microprocessor or microcontroller that executes the instructions of the signal acquisition logic 677. Thus, in general, the memory 676 may include one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (by the processor 678), it is operable to perform the techniques described herein.

[0096] It should be understood that Figure 6 The arrangement of the computing device 671 shown in FIG is merely illustrative, and aspects of the technology presented herein can be implemented on many different types of external devices. For example, the computing device 671 can be a laptop, a tablet, a mobile phone, a surgical system, etc.

[0097] Figure 77 is a high-level flow chart of a method 780 according to an embodiment presented herein. Method 780 begins at 782, where one or more sets of mechanical stimulation signals are delivered to a recipient via an actuator of an implantable hearing prosthesis. At 784, a vibration sensor positioned at a first location in the recipient captures vibrations caused by each of the one or more sets of mechanical stimulation signals. At 786, a vibration transfer function is determined between the actuator and the vibration sensor at the first location. At 788, an indication of the vibration transfer function between the actuator and the vibration sensor at the first location is provided to a user.

[0098] Figure 8 is a high-level flow chart of method 890 according to an embodiment presented herein. Method 890 begins at 892 by positioning a sound input module comprising a sound sensor and a vibration sensor at a first location in a recipient. At 894, an actuator implanted in the recipient is driven with one or more sets of actuator control signals, wherein each of the one or more sets of actuator control signals causes the actuator to deliver one or more mechanical stimulation signals to the recipient. At 896, vibrations caused by the mechanical stimulation signals are captured at the vibration sensor. At 898, properties of the one or more sets of actuator control signals are analyzed relative to properties of the vibrations caused by each of the one or more sets of mechanical stimulation signals to assess the suitability of the first location for implanting the sound input module at the first location.

[0099] The above describes various embodiments primarily with reference to implantable actuators that deliver vibrations to, for example, the recipient's ossicular chain and / or the recipient's cochlea. However, as noted elsewhere herein, these embodiments are merely illustrative, and the technology presented herein can be implemented with any of a number of different implantable actuators. For example, the technology presented herein can be implemented with an implantable actuator that delivers vibrations directly to the recipient's skull (e.g., an active transcutaneous bone conduction device). In another example, the technology presented herein can be implemented with an implantable actuator that is part of a prosthesis (e.g., an electroacoustic hearing prosthesis) that delivers both mechanical stimulation and another type of stimulation (e.g., electrical stimulation) to the recipient. More generally, the technology presented herein is applicable to any implantable medical device having an implantable actuator and a sound input unit / module (having a vibration sensor and a sound sensor co-located).

[0100] It should 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.

[0101] The invention described and claimed herein is not limited in scope by the specific preferred embodiments disclosed herein, as these embodiments are intended to illustrate and not to limit several aspects of the invention. Any equivalent embodiments are intended to be within the scope of the invention. In fact, in addition to those modifications shown and described herein, various modifications of the present invention will become apparent to those skilled in the art based on the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.

Claims

1. An apparatus for generating information, wherein the apparatus comprises a processor and a memory, the memory being coupled to the processor and comprising instructions stored thereon, the instructions, when executed by the processor, causing the apparatus to perform operations comprising: capturing, at a vibration sensor located at a first location in a recipient, a vibration caused by each of the one or more sets of mechanical stimulation signals delivered to the recipient via an actuator of an implantable hearing prosthesis; determining a vibration transfer function between the actuator and the vibration sensor at the first location, the vibration transfer function providing an indication of relative vibration isolation between the vibration sensor and the actuator to assess suitability of the first location for implanting a sound sensor at the first location; as well as An indication of a vibration transfer function between the actuator and the vibration sensor at the first location is provided to a user.

2. The apparatus of claim 1, wherein the one or more sets of mechanical stimulation signals are delivered to the middle ear bones of the recipient.

3. The device of claim 1, wherein the one or more sets of mechanical stimulation signals are delivered to an opening in the recipient's cochlea.

4. The apparatus of claim 1, wherein the one or more sets of mechanical stimulation signals are delivered to the recipient's skull.

5. The apparatus of claim 1 , wherein capturing the vibration caused by each of the one or more sets of mechanical stimulation signals comprises: Vibrations caused by each of the one or more sets of mechanical stimulation signals are captured at a vibration sensor located in a housing configured to be implanted in the recipient, wherein the housing further includes a microphone located in the housing and the sound sensor includes the microphone.

6. The apparatus of claim 1 , wherein the actuator is configured to generate each of the one or more sets of mechanical stimulation signals from one or more sets of actuator control signals, and wherein determining a vibration transfer function between the actuator and the vibration sensor at the first location comprises: performing open-loop measurements of vibrations induced by each of the one or more sets of mechanical stimulation signals; as well as Vibrations determined by the open-loop measurements are analyzed relative to the one or more sets of actuator control signals to generate the vibration transfer function.

7. The apparatus of claim 1 , wherein the actuator is configured to generate each of the one or more sets of mechanical stimulation signals from one or more sets of actuator control signals, and wherein determining a vibration transfer function between the actuator and the vibration sensor at the first location comprises: Closed-loop measurements are performed to determine a maximum stable gain for generating the one or more sets of actuator control signals.

8. The apparatus of claim 1, 2, 3, or 4, wherein the operations further comprise: determining the vibration transfer function with one or more processors of the implantable hearing prosthesis; as well as Data representing the vibration transfer function is transmitted to an external device.

9. The apparatus of claim 1, 2, 3, or 4, wherein the operations further comprise: transmitting data representing the vibration caused by each of the one or more sets of mechanical stimulation signals to an external device; as well as The vibration transfer function is determined at the external device.

10. The apparatus of claim 1 , wherein the actuator is configured to generate each of the one or more sets of mechanical stimulation signals from one or more sets of actuator control signals, and wherein the operations further comprise: Data representing the one or more sets of actuator control signals is transmitted to an external device.

11. The apparatus of claim 1 , wherein providing an indication of the vibration transfer function to a user comprises: A visual representation of the vibration transfer function is displayed to the user.

12. The apparatus of claim 1 , wherein providing an indication of the vibration transfer function to a user comprises: An audible representation of the vibration transfer function to an external device is provided to the user.

13. The apparatus of claim 1, 2, 3, or 4, wherein the operations further comprise: capturing, at the vibration sensor located at a second location in the recipient, vibrations caused by each of the one or more sets of mechanical stimulation signals delivered by the actuator; determining a vibration transfer function between the actuator and the vibration sensor at the second location; as well as An indication of a vibration transfer function between the actuator and the vibration sensor at the second location is provided to a user.

14. An apparatus for generating information, wherein the apparatus comprises a processor and a memory, the memory being coupled to the processor and comprising instructions stored thereon, the instructions, when executed by the processor, causing the apparatus to perform operations comprising: driving an actuator implanted in a recipient with one or more sets of actuator control signals, wherein each of the one or more sets of actuator control signals causes the actuator to deliver one or more mechanical stimulation signals to the recipient, and wherein a sound input module including a sound sensor and a vibration sensor is positioned at a first location in the recipient; capturing, at the vibration sensor, a vibration caused by each of the one or more sets of mechanical stimulus signals; as well as Properties of one or more sets of control signals are analyzed relative to properties of vibrations induced by each of the one or more sets of mechanical stimulation signals to assess suitability of the first location for implanting the sound input module at the first location.

15. The apparatus of claim 14 , wherein analyzing properties of one or more sets of control signals relative to properties of vibrations induced by each of the one or more sets of mechanical stimulation signals to assess suitability of the first location for implanting the sound input module at the first location comprises: determining a vibration transfer function between the actuator and the vibration sensor at the first location; as well as An indication of a vibration transfer function between the actuator and the vibration sensor at the first location is provided to a user.

16. The apparatus of claim 15, wherein determining a vibration transfer function between the actuator and the vibration sensor at the first location comprises: performing open-loop measurements of vibrations induced by each of the one or more sets of mechanical stimulation signals; as well as Vibrations determined by the open-loop measurements are analyzed relative to the one or more sets of actuator control signals to generate the vibration transfer function.

17. The apparatus of claim 15, wherein determining a vibration transfer function between the actuator and the vibration sensor at the first location comprises: Closed-loop measurements are performed to determine a maximum stable gain for generating the one or more sets of actuator control signals.

18. The apparatus of claim 15 , wherein providing an indication of the vibration transfer function to a user comprises: A visual representation of the vibration transfer function is displayed to the user.

19. The apparatus of claim 15, wherein providing an indication of the vibration transfer function to a user comprises: An audible representation of the vibration transfer function to an external device is provided to the user.

20. One or more non-transitory computer-readable storage media comprising instructions that, when executed by a processor, cause the processor to: generating one or more sets of actuator control signals at an implantable hearing prosthesis, wherein the implantable hearing prosthesis includes an actuator and a sound input module, the actuator and the sound input module each configured to be implanted in a recipient, wherein the sound input module includes a sound sensor and a vibration sensor and is positioned at a first location in the recipient; providing the one or more sets of actuator control signals to the actuator to deliver one or more sets of mechanical stimulation signals to the recipient using the actuator, wherein each of the one or more sets of mechanical stimulation signals is generated based on at least one of the one or more sets of actuator control signals; receiving, in response to each of the one or more sets of mechanical stimulation signals, from the vibration sensor one or more sets of output signals indicative of vibrations detected at the vibration sensor; and An indication of relative vibration isolation between the vibration sensor and the actuator is generated based on the one or more sets of actuator control signals and the one or more sets of output signals indicative of vibrations detected at the vibration sensor to assess suitability of the first location for implanting the sound input module at the first location.

21. The non-transitory computer-readable storage medium of claim 20, wherein the instructions operable to generate the one or more sets of actuator control signals comprise instructions operable to: receiving control data from an external device; and The one or more sets of actuator control signals are generated from the control data.

22. The non-transitory computer-readable storage medium of claim 20 or 21, wherein the instructions operable to generate an indication of relative vibration isolation between the vibration sensor and the actuator comprise instructions operable to: determining a position-dependent transfer function relating the positioning of the vibration sensor at the first location to a position of the actuator; and The position-dependent transfer function is sent to an external device.

23. The non-transitory computer-readable storage medium of claim 20 or 21, wherein the instructions operable to generate an indication of relative vibration isolation between the vibration sensor and the actuator comprise instructions operable to: Data representing the output signal is transmitted to an external device, the output signal being indicative of vibrations detected at the vibration sensor.

24. The non-transitory computer-readable storage medium of claim 23, wherein the instructions operable to generate an indication of relative vibration isolation between the vibration sensor and the actuator comprise instructions operable to: Data representing the one or more sets of actuator control signals is sent to the external device.

25. A system for generating information, comprising: an actuator configured to be implanted in a recipient and to generate one or more sets of mechanical stimulation signals for delivery to the recipient; a vibration sensor configured to be implanted at a first location in the recipient and configured to capture vibrations caused by each of the one or more sets of mechanical stimulation signals; as well as One or more processors configured to: Based at least on the vibrations induced by each of the one or more sets of mechanical stimulation signals, a vibration transfer function is generated between the actuator and the vibration sensor at the first location, the vibration transfer function providing an indication of relative vibration isolation between the vibration sensor and the actuator to assess the suitability of the first location for implanting a sound sensor at the first location.

26. The system of claim 25, wherein the actuator is configured to deliver the one or more sets of mechanical stimulation signals to a middle ear bone of the recipient.

27. The system of claim 25, wherein the actuator is configured to deliver the one or more sets of mechanical stimulation signals to an opening in the cochlea of ​​the recipient.

28. The system of claim 25, wherein the actuator is configured to deliver the one or more sets of mechanical stimulation signals to a skull of the recipient.

29. The system of claim 25, 26, 27, or 28, wherein the vibration sensor is located in a housing configured to be implanted in the recipient, wherein the housing further comprises the sound sensor located in the housing.

30. The system of claim 25, 26, 27, or 28, wherein the actuator is configured to generate each of the one or more sets of mechanical stimulation signals from one or more sets of actuator control signals, and wherein the one or more processors are configured to: Open-loop measurements of vibrations induced by each of the one or more sets of mechanical stimulation signals are performed to generate data representative of the vibration transfer function.

31. The system of claim 25, 26, 27, or 28, wherein the actuator is configured to generate each of the one or more sets of mechanical stimulation signals from one or more sets of actuator control signals, and wherein the one or more processors are configured to: Closed-loop measurements are performed to determine a maximum stable gain for generating the one or more sets of actuator control signals.

32. The system of claim 25, 26, 27 or 28, further comprising: A display screen, wherein the one or more processors are configured to generate a visual representation of the vibration transfer function at the display screen.

33. The system of claim 25, 26, 27 or 28, further comprising: A receiver is configured to generate an audio signal, wherein the one or more processors are configured to generate an audible representation of the vibration transfer function via the receiver.

34. The system of claim 25, 26, 27 or 28, wherein the one or more processors, actuators, and vibration sensors are all components of an implantable hearing prosthesis.

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