WO2011095229A1

WO2011095229A1 - Fully implantable hearing aid

Info

Publication number: WO2011095229A1
Application number: PCT/EP2010/051503
Authority: WO
Inventors: Felix Buehlmann; Renzo Magnin
Original assignee: Advanced Bionics Ag
Priority date: 2010-02-08
Filing date: 2010-02-08
Publication date: 2011-08-11

Abstract

The invention relates to a fully implantable hearing aid, comprising at least one implantable input transducer (20, 26) for capturing audio signals from ambient sound, an audio signal processing unit (40) for processing the audio signals provided by at least one (20) of the input transducers, an output transducer (12) for stimulating a user's hearing according to the processed audio signals, and means (40, 66, 61) for manual control of the audio signal processing unit, wherein the control means is adapted to recognize control commands for the audio signal processing unit from user-generated non-speech sound events to be detected from audio signals captured by at least one (20, 26) of the input transducers.

Description

Fully implantable hearing aid

The invention relates to a fully implantable hearing aid comprising an input transducer for capturing audio signals from ambient sound, an audio signal processing unit for processing the captured audio signals and an output transducer for stimulating the user's hearing according to the processed audio signals.

Examples of fully implantable hearing aids can be found in US 5,814,095, US 6,394,947 Bl and US 6,629,923 B2.

Operation of a hearing aid requires, at least from time to time, some user interaction in order to adjust various settings of the device, such as adjustment of the volume, selection of a specific hearing aid program, switching the device on and off, etc. Usually such user interaction takes place by using a remote control device carried by the user all the time when utilizing the hearing aid.

WO 97/01314 Al relates to a cochlear implant device which may be fully or partially implantable and which comprises a microphone for receiving both ambient sounds and voice commands of the patient. The device comprises a speech recognition function in order to identify voice commands for controlling certain functions of the device, such as volume control processing, according to the recognized voice commands.

US 5,012,520 relates to a fully implantable hearing aid comprising a remote control device including a vibrator to be placed by the user at his head in order to achieve transmission of remote control commands to the implanted hearing aid via bone conduction.

US 6,137,889 and US 6,940,989 Bl relate to a hearing aid to be worn in the ear canal, which comprises a latching reed switch which responds to a magnetic field introduced into the vicinity of the hearing aid and which serves to switch the hearing aid on and off.

US 6,020,593 relates to a transcutaneous infrared remote control for an implanted pump for medical drug delivery.

US 6,358,281 Bl relates to a fully implantable hearing instrument including a cochlear electrode and a housing which is implanted against the patient's skull behind the ear and which comprises a piezoelectric sensor for enabling volume control and on/off switching of the hearing aid by transcutaneous interaction with the patient, namely by the patient pressing a finger onto the skin above the sensor.

It is an object of the invention to provide for a fully implantable hearing aid which can be used by the patient in a particularly simple manner. It is also an object of the invention to provide for a corresponding method of operating such hearing aid.

According to the invention, these objects are achieved by a hearing aid as defined in claims 1 and 10 and a method of operating such hearing aid as defined in claims 25 and 26, respectively. The invention is beneficial in that the need for a remote control is eliminated. The solution according to claims 1 and 25 is particularly beneficial in that, by providing a control means which is adapted to recognize control commands for the audio signal processing unit from user-generated non-speech sound events to be detected from audio signals captured by at least one of the input transducers, both the need for a sensor to be provided in addition to the hearing aid input transducer and the need for implementation of speech recognition capability, which would require relatively large signal processing capacities, are avoided. The solution according to claims 10 and 26 is particularly beneficial in that, by providing at least one implantable sensor capable of detecting a movement of a part of the user's body without being touched by that part of user's body, the need for an implanted pressure sensor is avoided.

Preferred embodiments of the invention are defined in the dependent claims.

Hereinafter, examples of the invention will be illustrated by reference to the attached drawings, wherein:

Fig. 1 is a cross-sectional view of an example of a fully implantable hearing aid according to the invention when having been implanted;

Fig. 2 is a schematic block diagram of the most relevant components of a fully implantable hearing aid according to the invention; Fig. 3 is a schematic cross-sectional view of an example of an implanted capacitive sensor according to the invention;

Fig. 4 is a schematic cross-sectional view of an example of an implanted optical sensor according to the invention;

Fig. 5 is a schematic cross-sectional view of an example of an implanted housing of a fully implantable hearing aid comprising an accelerometer sensor; and

Fig. 6 is a schematic cross-sectional view of an example of an implanted electrode-on- muscle sensor according to the invention.

In the example shown in Fig. 1, a fully implantable hearing aid comprises an implanted housing 10 containing an audio signal processing unit, an electric power supply and optionally components for wireless communication with a remote device, an output transducer 12 which is connected via an implanted line 14 to the housing 10 and which, in the example of Fig. 1, is designed as an electro-mechanical transducer for vibrating, via a mechanical coupling element 16, an ossicle 18, and an implanted microphone 20 connected via a line 22 to the housing 10. The housing 10 is accommodated in an artificial cavity 24 created in the mastoid area.

The hearing aid also may comprises at least one implanted sensor capable of detecting a movement of a part of the user's body, such as a sensor 26 which is implanted at the boundary between the mastoid bone 28 and the skin 30 and which is connected to the housing 10 via a line 32. However, according to other embodiments, such sensor may be integrated within the housing 10, as will be explained below.

According to the block diagram of Fig. 2, the housing 10 contains a power supply 34 including an induction coil 36 for receiving electro-magnetic power from a respective power transmission coil of an external charging device (not shown in Fig. 2) and a rechargeable battery 38. Typically, charging of the power supply 34 is carried out during night when the user is sleeping. The housing 10 also contains an audio signal processing unit 40, which is typically realized by a digital signal processor (DSP), and a driver unit 42 for driving the output transducer 12.

The audio signal processing unit 40 receives the audio signals captured by the microphone 20 and transforms them into processed audio signals by applying various filtering techniques known in the art, which processed audio signals are supplied to the driver unit 42 for transforming them into a respective vibrational output of the transducer 12. Rather than being implemented as an electro-mechanical output transducer, the output transducer 12 could be any other known type of transducer, such as a floating mass transducer coupled to an ossicle, a cochlear electrode for electrical stimulation of the cochlea or an electro-mechanical transducer acting directly on the cochlear wall.

The housing 10 also may contain a sensor 126 which is capable of detecting a movement of a part of the user's body.

The output signals produced by the sensors 26, 126 and also the audio signals captured to by the microphone 20 are supplied to a control unit 66 which is provided for control of the operation of the hearing aid according to the signals provided by the sensors 26, 126 and/or the microphone 20. Such control may include actions like adjusting the volume, selecting a desired audio signal processing scheme/program, switching the hearing aid on and off, etc. Alternatively, the DSP forming the audio signal processing unit 40 also may act as the controller of the hearing aid; in this case the output signals of the sensors 26, 126 would be supplied to the audio signal processing unit 40.

The control unit 66 comprises a command recognizing unit 67 for recognizing the respective control command from the input signals provided to the control unit 66 by analyzing the signal in the time domain and in the frequency domain.

The microphone 20 can be used by the user for controlling the hearing aid by generating non- speech, i.e. noise, sound events, such as click sounds generated by movement of the user's tongue or whistle sounds, or shocks acting on the user's body in the vicinity of the microphone 20, such as teeth shocks and/or shocks created by movement of an extremity of the user. The unit 67 is able to detect such pulse-like sound events in the audios signals captured by the microphone 20. In particular, the unit 67 is able to detect and distinguish different sequences of such pulse-like sound events (repetition of sound events, rhythm of sound events, etc), wherein each of the sequences is associated to a different control command. Optionally, the microphone 20 may be designed as a microphone array capable of detecting the direction where a shock signal comes from.

Preferably, the unit 67 is designed to detect the type of noise sound (for example, shock on the skin, teeth shock, whistle, etc.), the level of the noise sound (i.e. loudness) and the sequence of the noise sound (for example, repetition of the sound, rhythm of the sound, etc.). In general, by detecting the direction, the type, the level and/or the sequence of the sound events, various control commands can be discriminated from each other.

The sensors 26, 126 can be used by the user for controlling the hearing aid by moving a part of his body, typically towards the sensor, without the need to touch the sensor, i.e. the skin above the sensor. Thus the sensor remotely senses the user's body movement, without be touched or squeezed by the user, in contrast to, for example, the piezoelectric pressure sensor proposed in US 6,358,281 Bl .

In order to perform its control function, the control unit 66 may receive input signals from both the sensors 26, 126 and the microphone 20 (as shown in the example of Fig. 2), or it may receive input from the microphone 20 only (in the this case, the sensors 26, 126 would be obsolete), or it may receive input from the sensors 26, 126 only. In the example of Fig. 3, the sensor 26 is designed as a capacitive sensor which is capable of detecting when an extremity of the user approaches the sensor and which comprises two spaced-apart electrode plates 52 located in essentially the same plane. The sensor 26 rests against the bone 28 and is encapsulated within an elastic fluid-tight housing 46. The sensor 26 is capable to sense capacitance changes caused by a hand of the user approaching the electrode plates 52; i.e. the sensor is capable of detecting changes in the effective permittivity of the area around the sensor.

While the sensor of Fig 3 is shown as being directly implanted against the bone 28, such sensors alternatively may be implanted indirectly against the bone 28 in the sense that the sensor is designed to rest against a component of the hearing aid which is implanted directly against the bone 28. For example, the sensor may be integrated in the casing 10 which is implanted directly against the bone 28. A schematic example of such an integrated sensor is shown in Fig. 5, wherein a the electrode plates 52 are located in a recessed portion of the outside of the housing 10.

According to a further alternative, the sensor 26, rather than being implanted directly against the bone 28, may placed closer to the extrenal layer of the skin in order to enhance the sensitivity of the sensor 26. Also, the sensor 26 may be "floating" inside the skin.

According to a further embodiment, the sensor 26, 126 may be designed as an accelerometer which is capable of detecting shocks acting on the user's body in the vicinity of the accelerometer. For example, an accelerometer 56 may be integrated within an implanted casing which is fixed to a user's bone 28. Fig. 5 shows an example wherein an accelerometer 56 is integrated within the housing 10. Alternatively, the accelerometer 56 may be provided as a sensor which is directly implanted against a bone 28, as in the case of Fig. 3. Preferably, the accelerometer 56 is capable of detecting teeth shocks and/or shocks created by movement of an extremity of the user. In Fig. 4 an example is shown, wherein the sensor 26 is designed as an optical sensor comprising a light-sensitive element 58, such as a photo-diode, for sensing light passing through the user's skin 30. Rather than being implanted separately from the housing 10, as shown in Fig. 4, such sensor also could be integrated within a recess of the outer side of the housing 10 in the manner shown in Fig. 5. Such optical sensor could be actuated by temporarily preventing light from reaching the element 58, for example by temporarily covering the skin in this region by a hand. Alternatively, the sensor could be actuated by temporarily irradiating the skin in the region of the element 58 with a light source.

According to one embodiment, the sensor 26 also may be designed as a microphone arrangement which is provided in addition to the microphone 20 serving as the input transducer of the hearing aid. In such case, the audio signals captured by the microphone 20 usually would be used only for stimulation of the user's hearing, but would not be used for receognizing control commands and hence would not be supplied to unit 67. Rather, the microphone arrangement 26 would supply its audio signals to the unit 67 for recognizing control commands. In particular, the microphone arrangement 26 may be capable of detecting shocks acting on the user's body in the vicinity of the microphone arrangement 26, such as teeth shocks and/or shocks created by the movement of an extremity of the user. In case that the microphone arrangement 26 is designed as a microphone array comprising at least two microphones, the direction, from where a shock signal comes from can be detected. The audio signals from the microphone arrangement 26 also may be used to detect the type of noise sound (for example, shock on the skin, teeth shock, whistle, etc.), the level of the noise sound (i.e. loudness) and the sequence of the noise sound (for example, repetition of the sound, rhythm of the sound, etc.). The latter features also could be detected by a single microphone. In general, by detecting the direction of the sound and type, the level and/or the sequence of the sound by the unit 67, various control commands can be discriminated from each other. For example, sweeping the finger on the skin upwards (i.e. noise source location changing versus time) could stand for the command "volume up", while sweeping the finger downwards could stand for "volume down". As a further variant, click-sounds may be generated by movement of the user's tongue.

According to a further embodiment shown in Fig. 6, the sensor 26 may be designed to detect a movement of a muscle 60, comprising a first electrode 62 and a second electrode 64, wherein at least one of the electrodes 62, 64 is placed on the muscle 60, and wherein contraction of the muscle 60 creates a potential difference between the electrode 62 and the electrode 64, which signal can be used to detect movement of the muscle 60.

In all cases, the implantable sensor 26 preferably is to be implanted somewhere at the user's head, in particular close to the ear, such as somewhere behind the ear. In general, since the user of the hearing aid usually wants to hide the fact of having an implant, the position of the implantable sensor is selected such that the actions the user has to take for controlling the hearing aid (such as moving an extremity) look as natural as possible.

In all embodiments the sensor 26, 126 may be used to detect in the unit 67 sequences of user actions from the output signals of the sensor in order to distinguish various control commands from each other and to generate the appropriate control signal associated to the respective user action sequence.

Claims

1. A fully implantable hearing aid, comprising at least one implantable input transducer (20, 26) for capturing audio signals from ambient sound, an audio signal processing unit (40) for processing the audio signals provided by at least one (20) of the input transducers, an output transducer (12) for stimulating a user's hearing according to the processed audio signals, and means (40, 66, 67) for manual control of the audio signal processing unit, wherein the control means is adapted to recognize control commands for the audio signal processing unit from user-generated non-speech sound events to be detected from audio signals captured by at least one (20, 26) of the input transducers.

2. The hearing aid of claim 1, wherein the control means (67) is capable of detecting pulselike sound events.

3. The hearing aid of claim 2, wherein the control means (67) is capable of detecting and distinguishing different sequences of pulse-like sound events, wherein each of the sequences is associated to a different control command.

4. The hearing aid of one of claims 2 and 3, wherein the control means (67) is capable of detecting shocks acting on the user's body in the vicinity of the input transducer (20, 26).

5. The hearing aid of claim 4, wherein the control means (67) is capable of detecting teeth shocks and/or shocks created by movement of an extremity of the user.

6. The hearing aid of one of claims 2 to 5, wherein the control means (67) is capable of detecting click sounds generated by movement of the user's tongue.

7. The hearing aid of one of the preceding claims, wherein a microphone arrangement (20) is provided as the only input transducer.

8. The hearing aid of one of claims 1 to 6, wherein a first microphone arrangement (20) and a second microphone arrangement (26) are provided as the input transducer, wherein only the audio signals captured by the first microphone arrangement are to be used for stimulating the user's hearing, whereas the audio signals captured by the second microphone arrangement are to be used for recognizing the control commands.

9. The hearing aid of one of claims 7 and 8, wherein the microphone arrangement (20) or the second microphone arrangement (26), respectively, comprises a microphone array capable of detecting the direction where a shock signal or noise signal comes from.

10. A fully implantable hearing aid, comprising an input transducer (20) for capturing audio signals from ambient sound, an audio signal processing unit (40) for processing the captured audio signals, an output transducer (12) for stimulating a user's hearing according to the processed audio signals, and means (40, 66, 67) for manual control of the audio signal processing unit, wherein the control means comprise at least one implantable sensor (26, 126) capable of detecting a movement of a part of the user's body without being touched by that part of user's body.

11. The hearing aid of claim 10, wherein the implantable (26) sensor is a capacitive sensor (52, 54) which is capable of detecting when an extremity of the user moves towards the sensor.

12. The hearing aid of one of claims 10 and 11, wherein the sensor (26, 126) is to be implanted against a user's bone (28).

13. The hearing aid of one of claims 10 and 1 1, wherein the sensor (26, 126) is to rest against a component (10) of the hearing aid, which component is to be implanted against a user's bone.

14. The hearing aid of claim 13, wherein the sensor (126) is integrated in a casing (10) implanted against a user's bone (28).

15. The hearing aid of claim 11, wherein the capacitive sensor comprises two electrode plates (52) and is designed to sense capacitance changes caused by a user's hand approaching the electrodes.

16. The hearing aid of one of claims 10 to 15, wherein the implantable sensor (26, 126) is an accelerometer (56) capable of detecting shocks acting on the user's body in the vicinity of the accelerometer.

17. The hearing aid of claim 16, wherein the accelerometer (56) is integrated within an implant casing (10) which is to be fixed to a user's bone (28).

18. The hearing aid of one of claims 16 and 17, wherein the accelerometer (56) is capable of detecting teeth shocks and/or shocks created by movement of an extremity of the user.

19. The hearing aid of one of claims 10 to 18, wherein the implantable sensor is an optical sensor (58) which is adapted to sense light passing through the user's skin (30).

20. The hearing aid of one of claims 10 to 19, wherein the control means (40, 66, 67) is capable of processing the output signals of the sensor(s) (26, 126) in order to generate control signals supplied to the audio signal processing unit (40).

21. The hearing aid of one of claims 10 to 20, wherein the control means (40, 66, 67) is capable of detecting sequences of user actions, from the output signals of the sensor(s), in order to generate the appropriate control signal associated to the respective user action sequence.

22. The hearing aid of one of the preceding claims, wherein the implantable sensor (26, 126) is to be implanted at the user's head.

23. The hearing aid of one of the preceding claims, wherein the control means (40, 66, 67) is adapted to control at least one of the parameters selected from the group consisting of volume, power on/off, and type of audio program.

24. The hearing aid of one of the preceding claims, wherein the control means (40, 66) and the audio signal processing unit (40) comprise a DSP.

25. A method of operating a fully implantable hearing aid comprising at least one input transducer (20, 26) for capturing audio signals from ambient sound, an audio signal processing unit (40) for processing audio signals captured by at least one (20) of the input transducers and an output transducer (12) for stimulating a user's hearing according to the processed audio signals, the method comprising: manually controlling the audio signal processing unit by recognizing control commands for the audio signal processing unit from user-generated non-speech sound events detected from the audio signals captured by one (20, 26) of the input transducers.

26. A method of operating a fully implantable hearing aid comprising an input transducer (20) for capturing audio signals from ambient sound, an audio signal processing unit (40) for processing the captured audio signals and an output transducer (12) for stimulating a user's hearing according to the processed audio signals, the method comprising: manually controlling the audio signal processing unit by detecting, by at least one implantable sensor (26, 126) of the hearing aid, a movement of a part of the user¹ s body which does not touch the sensor.