AU2011213753B2

AU2011213753B2 - Implant sensor and control

Info

Publication number: AU2011213753B2
Application number: AU2011213753A
Authority: AU
Inventors: Erwin Hochmair; Ingeborg Hochmair; Martin Kerber; Werner Lindenthaler; Peter Nopp; Marcus Schmidt; Hansjorg Schoesser; Clemens Zierhofer; Martin Zimmerling
Original assignee: MED EL Elektromedizinische Geraete GmbH
Current assignee: MED EL Elektromedizinische Geraete GmbH
Priority date: 2007-02-20
Filing date: 2011-08-18
Publication date: 2012-12-20
Anticipated expiration: 2028-02-20
Also published as: AU2011213753A1; AU2013201684B2

Abstract

Abstract An implant includes a humidity sensor for generating a signal indicative of humidity within the implant. A controller within the implant receives the signal indicative of humidity, and controls the implant based on the signal indicative of humidity. 2776075_1 (GHMatters) P81661.AU.I Humidity Sensor Stimulator Controller

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant (s): MED-EL Elektromedizinische Geraete GmbH Invention Title: Implant sensor and control The following statement is a full description of this invention, including the best method for performing it known to me/us: 2 Implant Sensor and Control This application is a divisional application of Australian application no. 2008218695 the disclosure of which is incorporated herein by reference. Most of the disclosure of that application is also included herein, however, reference may be made to 5 the specification of application no. 2008218695 as filed or accepted to gain further understanding of the invention claimed herein. Technical Field The present invention relates to implants, and more particularly, to sensing and responding to humidity or another condition within an implant. 10 Background Art Often an implant is hermetically sealed to prevent build-up of moisture within the implant. The moisture buildup within the implant may adversely affect the electronic circuits within the implant. For example, moisture buildup in the implant may cause 15 incorrect stimulation, such as over-stimulation or stimulation including direct current and/or exceeding charge density per phase limits. Determination of moisture build-up within an implant can be problematic. Subjective feedback from the patient regarding implant stimulation behavior is often 20 difficult, particularly with younger patients. Another approach is to incorporate a humidity sensor/switch within the implant. An exemplary telemetry system for remotely monitoring sensed humidity within a pacemaker is disclosed in U.S. patent no. 4,332,256 (Brownlee et al.), which is incorporated herein by reference in its entirety. However, interpretation of telemetry data received from the implant is often difficult with corrective 25 measures performed in an untimely and/or inconvenient manner. Summary of the Invention In a first aspect of the present invention, there is provided a cochlear implant comprising: an electrode array; 30 a stimulator for stimulating the electrode array; 2778075_1 (GHMatters) P81661 AU.1 3 a sensor for generating a signal indicative of an environmental condition within the implant; and a controller within the implant for receiving the signal and controlling the implant, based on the signal, to stimulate the electrodes so as to produce a perceived audio alert. 5 In an embodiment, the signal is indicative of a temperature. In an embodiment, the signal is indicative of a concentration of one or more gases. 10 In an embodiment, the controller inhibits output of the stimulator based on the signal. In an embodiment, the alert is produced for a predetermined duration upon turning is on of the implant. In an embodiment, the controller provides an externally audible alert based on the signal indicative of humidity. 20 In an embodiment, the controller turns power off based on the signal. In an embodiment, the implant includes a battery, and wherein the controller discharges the battery based on the signal. 25 In an embodiment, the implant further comprising a hydrophilic agent positioned with the implant so as to direct moisture to a desired location within the implant, wherein the humidity sensor is positioned substantially adjacent the hydrophilic agent. In a second aspect of the present invention, there is provided a method of 30 controlling a cochlear implant, the implant including a stimulator for stimulating an array of electrodes, the method comprising: generating a signal indicative of an environmental condition within the implant; and controlling the implant based on the signal, wherein the generating and 2776075_1 (GHMatters) P81661.AU.1 controlling is performed within the implant, and wherein controlling includes controlling the stimulator to stimulate the electrodes so as to produce a perceived alert based on the signal indicative of an environmental condition. 5 In an embodiment, the signal is indicative of a temperature. In an embodiment, the signal is indicative of a concentration of one or more gases. 10 In an embodiment, controlling the implant includes inhibiting output of the stimulator based on the signal. In an embodiment, the alert is produced for a predetermined duration upon turning on of the implant. 15 In an embodiment, controlling the implant includes providing an externally audible alert based on the signal. In an embodiment, controlling the implant includes turning power off based on 20 the signal. In an embodiment, the implant includes a battery, and wherein controlling the implant includes discharging the battery based on the signal. Brief Description of the Drawings 25 The foregoing features of the invention will be more readily understood by reference to the following detailed description, taken with reference to the accompanying drawings, in which: Fig. I shows a conventional cochlear prosthesis; and 30 Fig. 2 is a block diagram showing a cochlear implant system that implements sensing and control, in accordance with one embodiment of the invention; 3870820_1 (GHMatters) P81641.AU).

5 Detailed Description of Specific Embodiments In illustrative embodiments, a sensor and/or self-test module is exploited by a controller within the implant for various control and switching functions. Thus, there is no need to rely on patient feedback, or interpretation of telemetry data, to monitor and 5 react to changes in implant humidity. The sensor may be, for example, a humidity sensor, a temperature sensor, and/or a concentration of one or more gases. Details are discussed below. Fig. 1 shows an exemplary cochlear implant. It is to be understood that the 10 present invention is not limited to a cochlear prosthesis, and that the present invention is applicable to other types of implants, as known in the art. The cochlear implant typically includes two parts, an external component including a microphone 27 and a speech processor 29, and an implanted component 22 15 that includes a stimulator element 22. The speech processor 29 includes the power supply (batteries) of the overall system and is used to perform signal processing of the acoustic signal received by the microphone 27 to extract the stimulation parameters. Attached to the speech processor 29 is a transmitter coil 24 that transmits power and data signals to the implanted unit 22 transcutaneously via a radio frequency (RF) link. The implanted 20 component 22 includes a receiver coil 24 that is capable of receiving the data and/or power from the transmitter coil 24 and a stimulator 28. Based on the received data, the stimulator 28 sends stimulation signals via a cable 21 to an electrode array 20 positioned in the cochlea 12, stimulating the auditory nerve 9. It is to be understood that in various embodiments of the invention, various parts or all of the cochlear may be implanted. An 25 exemplary fully implantable is described in U.S. Patent No. 6,272,382 (Faltys et al.), incorporated herein by reference in its entirety. Furthermore, in various embodiments both the external component and the internal component may include a processor, with various functionality split between the two processors. 30 Fig. 2 is a block diagram showing various elements of an implanted component 122 of a cochlear implant system, in accordance with one embodiment of the invention. The implanted component typically includes a hermetically sealed housing 128, which may be made of, without limitation, titanium, nonmagnetic stainless steel, or a ceramic. 2776075_1 (GHMatters) P81681.AU.1 6 The implanted component 122 includes a sensor 125, such as a humidity sensor 125 which generates a signal indicative of humidity within the implant. The humidity sensor 125 may be, without limitation, a capacitive or resistive humidity sensor, as 5 known in the art. It is to be understood that instead of, or in addition to, a humidity sensor, other types of sensors known in the art, such as a temperature sensor, motion sensor, and/or gas sensor, may be used in accordance with the invention described herein, that provide a signal indicative of one or more conditions, such as an environmental condition, within the implant. In various embodiments, the implant may include a self 10 test module. The self-test module may initiate various tests within the implant, and/or receive input from one or more sensors, and provide a signal indicative of the performed self-test or a sensed condition. The self-test module may initiate, without limitation, self test periodically or upon implant power-on. 15 A controller 130 is positioned within the implanted component 122. The controller 130 is operationally coupled to, and receives the signal from the sensor 125 and/or self-test module. In various embodiments, the controller 130 may be, for example, electrically coupled to the sensor 125 and/or self-test module. 20 In illustrative embodiments of the invention, the controller 130 controls the implant based on the signal received from the sensor 125 and/or self-test module. Since both the controller 130 and the sensor 125 is positioned within the implanted component 122, control of the implant based on sensed signal and/or self-test is advantageously performed without having to externally send or process telemetry data, and without 25 patient interaction. The controller 130 may include, without limitation, a processor (e.g., a microprocessor, microcontroller, digital signal processor, or general purpose computer), programmable logic for use with a programmable logic device (e.g., a Field 30 Programmable Gate Array (FPGA) or other PLD), discrete components, integrated circuitry (e.g., an Application Specific Integrated Circuit (ASIC)), memory, or any other means including any combination thereof.. Memory may include, for example, a diskette, a fixed disk, a Compact Disk (CD), Read Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), and/or Random Access Memory (RAM). 2776075_1 (GHMaers) P8181.AU.I 7 Computer program logic implementing all or part of the functionality previously described herein may be embodied in various forms, including, but in no way limited to, a source code form, a computer executable form, and various intermediate forms (e.g., forms generated by an assembler, compiler, linker, or locator.) Source code may include 5 a series of computer program instructions implemented in any of various programming languages (e.g., an object code, an assembly language, or a high-level language such as Fortran, C, C++, JAVA, or HTML) for use with various operating systems or operating environments. The source code may define and use various data structures and communication messages. The source code may be in a computer executable form (e.g., 10 via an interpreter), or the source code may be converted (e.g., via a translator, assembler, or compiler) into a computer executable form. The controller 130 may command various functionality based on the signal received from the sensor 125 and/or self-test module. Deviations from a desired 15 environmental condition may trigger the command and control. For example, in receiving signals from a humidity sensor, at the beginning ingress of humidity the controller 130 may cause stimulator 150 to stimulate electrode array 160 to produce a perceived alert to the person wearing the cochlear implant. Note that such an alert is perceived only by the person wearing the cochlear implant, who can then proceed, for 20 example, to see an audiologist for a telemetry check (which may include reading out relative humidity). In other embodiments, the controller 130 may cause an externally audible alert when, for example, the speech processor is attached. Instead of an audible alert, other types of alerts may be provided, such as a visual alert. 25 The alert provided may last for a predetermined duration upon turning on the implant. For example, when turning on the implant, three short beeps may be provided. Of course, other alerts may be provided upon further ingress, or at various levels, of humidity or other condition within the implant. 30 Upon further ingress of humidity (or other condition within the implant), or at, for example, a predetermined humidity level, the controller 130 may inhibit stimulation at the electrode array 160, thus avoiding any current flow at the electrodes. In various embodiments, the controller 130 may switch power off in the implant and/or discharge an implanted battery 165 in a controlled fashion. In still further embodiments, the resonance 2776075_1 (GHMatters) P81661.AU.1 8 frequency and /or the quality factor of the RF circuit on the implant side may be changed. In various embodiments, a hydrophilic agent 170, such as silica gel, may be positioned in the internal component 122 to concentrate moisture at a desired location. 5 For example, the hydrophilic agent 170 may be positioned in close proximity to the humidity sensor 125. Water vapor is thus concentrated at the hydrophilic agent 170, and consequently at the humidity sensor 125, increasing the implant's sensitivity to humidity. In various embodiments, the disclosed method may be implemented as a 10 computer program product for use with a computer system. Such implementation may include a series of computer instructions fixed either on a tangible medium, such as a computer readable media (e.g., a diskette, CD-ROM, ROM, or fixed disk) or transmittable to a computer system, via a modem or other interface device, such as a communications adapter connected to a network over a medium. Medium may be either 15 a tangible medium (e.g., optical or analog communications lines) or a medium implemented with wireless techniques ( e.g., microwave, infrared or other transmission techniques). The series of computer instructions embodies all or part of the functionality previously described herein with respect to the system. Those skilled in the art should appreciate that such computer instructions can be written in a number of programming 20 languages for use with many computer architectures or operating systems. Furthermore, such instructions may be stored in any memory device, such as semiconductor, magnetic, optical or other memory devices, and may be transmitted using any communications technology, such as optical, infrared, microwave, or other transmission technologies. It is expected that such a computer program product may be distributed as a removable media 25 with accompanying printed or electronic documentation (e.g., shrink wrapped software), preloaded with a computer system (e.g., on system ROM or fixed disk), or distributed from a server or electronic bulletin board over the network (e.g., the Internet or World Wide Web). 30 Although various exemplary embodiments of the invention have been disclosed, it should be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the true scope of the invention. 2776075_1 (GHMatters) P81661 AU-1 In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to 5 preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that such prior art forms a part of the common general 10 knowledge in the art, in Australia or any other country. 3870820 _l(GHMatters) P81881.AUAt

Claims

1. A cochlear implant comprising: an electrode array; 5 a stimulator for stimulating the electrode array; a sensor for generating a signal indicative of an environmental condition within the implant; and a controller within the implant for receiving the signal and controlling the implant, based on the signal, to stimulate the electrodes so as to produce a perceived audio alert. 10

2. The implant according to claim 1, wherein the signal is indicative of a temperature.

3. The implant according to either claim 1 or 2, wherein the signal is indicative of a concentration of one or more gases. 15

4. The implant according to any one of claims I to 3, wherein the controller inhibits output of the stimulator based on the signal.

5. The implant according to any one of claims I to 4, wherein the alert is produced for a 20 predetermined duration upon turning on of the implant.

6. The implant according to any one of claims 1 to 5, wherein the controller provides an externally audible alert based on the signal indicative of humidity. 25

7. The implant according to any one of claims 1 to 6, wherein the controller turns power off based on the signal.

8. The implant according to any one of claims 1 to 7, wherein the implant includes a battery, and wherein the controller discharges the battery based on the signal. 30

9. The implant according to any one of claims I to 8, further comprising a hydrophilic agent positioned with the implant so as to direct moisture to a desired location within the implant, wherein the humidity sensor is positioned substantially adjacent the hydrophilic agent. 3870820_1 (GHMatters) P8161.AU.1

10. A method of controlling a cochlear implant, the implant including a stimulator for stimulating an array of electrodes, the method comprising: generating a signal indicative of an environmental condition within the implant; 5 and controlling the implant based on the signal, wherein the generating and controlling is performed within the implant, and wherein controlling includes controlling the stimulator to stimulate the electrodes so as to produce a perceived alert based on the signal indicative of an environmental condition. 10

11. The method according to claim 10, wherein the signal is indicative of a temperature.

12. The method according to either claim 10 or 11, wherein the signal is indicative of a concentration of one or more gases. 15

13. The method of any one of claims 10 to 12, wherein controlling the implant includes inhibiting output of the stimulator based on the signal.

14. The method according to any one of claims 10 to 13, wherein the alert is produced for 20 a predetermined duration upon turning on of the implant.

15. The method according to any one of claims 10 to 14, wherein controlling the implant includes providing an externally audible alert based on the signal. 25

16. The method according to any one of claims 10 to 15, wherein controlling the implant includes turning power off based on the signal.

17. The method according to any one of claims 10 to 16, wherein the implant includes a battery, and wherein controlling the implant includes discharging the battery based on the 30 signal.

18. A cochlear implant substantially as herein described with reference to Figure 2 of the accompanying drawings. 3870820L1 (GHMatten) PO1561.AU.1

19. A method of controlling a cochlear implant substantially as herein described with reference to Figure 2 of the accompanying drawings. 3870820_1 (GHMatters) P$1661.AU.1