Implantable hearing aid transducer interface
An implantable hearing aid transducer interface disposable between an implantable transducer and a mounting apparatus and having at least a portion that is displaceable in response to a predeterminable range of transducer movement. According to one aspect of the invention, the predeterminable range of transducer movement includes movement in response to a physiological movement of an auditory component that results in pressure on the implantable transducer. In this case, the compliant interface permits adaptive movement of the implantable transducer in response to the pressure to maintain a desired interface between the implantable transducer and an auditory component. According to another aspect, the predeterminable range of transducer movement may be transducer vibration resulting from an acoustic stimulation of an auditory component by the implantable transducer. In this case, the compliant interface reduces the transmission of transducer vibration over a feedback path to a microphone of a hearing aid.
1 . An implantable transducer system comprising:
an implantable transducer including a distal actuator to form a first contact relationship with an auditory component of a patient;
a mounting apparatus for attaching the implantable transducer to a skull of the patient;
a compliant interface disposed between the mounting apparatus and the implantable transducer.
2 . The system of claim 1 wherein at least a portion of the compliant interface is displaceable in response to a predeterminable type of transducer movement.
3 . The system of claim 2 wherein the predeterminable type of transducer movement includes transducer vibrations during stimulation of the auditory component.
4 . The system of claim 2 wherein the predeterminable type of transducer movement includes movement in response to a physiological movement of the auditory component.
5 . The system of claim 4 wherein the at least a portion of the compliant interface is displaceable in response to the physiological movement to maintain a desired interface between the implantable transducer and the auditory component.
6 . The system of claim 4 wherein the compliant interface comprises:
a fluid filled housing; and
a compliant member in a second contact relationship with the implantable transducer and defining at least a portion of a wall of the housing, wherein the fluid is displaceable within the housing in response to pressure on the implantable transducer from the physiological movement of the auditory component.
7 . The system of claim 6 wherein the housing comprises:
a first chamber and second chamber; and
a passage between the first and second chambers for fluid communication therebetween.
8 . The system of claim 7 wherein the passage includes a cross sectional area smaller than the first and second chambers.
9 . The system of claim 7 wherein the compliant interface comprises:
a second compliant member defining at least a portion of a distal wall of the second chamber.
10 . The system of claim 7 wherein the first chamber and the second chamber are axially aligned.
11 . The system of claim 9 wherein the housing comprises:
a third chamber in axial alignment with the second chamber; and
a resilient member disposed in the third chamber between the second compliant member and a distal wall of the third chamber.
12 . The system of claim 9 wherein the first and second compliant members comprise:
a first and second bellows each including a plurality of undulations to control a compliance of the first and second bellows.
13 . The system of claim 9 wherein the resilient member comprises:
a spring.
14 . The system of claim 3 wherein the compliant interface lessons transmission of the transducer vibrations over a feedback path to a microphone of a hearing aid.
15 . The system of claim 3 wherein the compliant interface comprises:
a compliant member including a predetermined spring rate to reduce the relative transmissibility of vibrations through the compliant member.
16 . The system of claim 15 wherein the compliant member reduces a resonant frequency below a predetermined frequency range of concern for a given transducer system.
17 . The system of claim 16 wherein the compliant member reduces the resonant frequency to less than one half a lowest frequency in said predetermined feedback frequency range of concern.
18 . The system of claim 16 wherein the compliant member reduces the resonant frequency to substantially less than one fifth a lowest frequency in said predetermined feedback frequency range of concern.
19 . The system of claim 3 wherein the compliant interface comprises:
a damping member including a predetermined damping coefficient to reduce the relative transmissibility of vibrations through the compliant interface.
20 . The system of claim 15 wherein the compliant member includes a spring rate such that the natural frequency of the system comprising transducer and compliant member is substantially less than the lowest frequency to be isolated.
21 . The system of claim 3 wherein the compliant member comprises:
a resilient member.
22 . The system of claim 21 wherein the resilient member comprises:
an elastomeric material.
23 . The system of claim 21 wherein the resilient member comprises:
a spring.
24 . The system of claim 22 wherein the compliant interface comprises:
at least one anchor member to secure the elastomeric material between the mounting apparatus and the implantable transducer.
25 . The system of claim 24 wherein the compliant interface comprises:
a plurality of anchor members to secure the elastomeric material between the mounting apparatus and the implantable transducer.
26 . The system of claim 23 wherein the spring comprises:
a coil spring.
27 . The system of claim 1 wherein the compliant interface is directly connected to the mounting apparatus and to the implantable transducer.
28 . A compliant interface for an implantable hearing aid transducer comprising:
a housing;
a compliant member in a first contact relationship with the implantable transducer and defining at least a portion of a wall of the housing; and
fluid displaceable within the housing, wherein the fluid is displaceable within the housing in response to pressure on the implantable transducer from a physiological movement of an auditory component in a second contact relationship with the implantable transducer.
29 . The compliant interface of claim 28 wherein the housing comprises:
a first chamber and second chamber; and
a passage between the first and second chambers for fluid communication therebetween.
30 . The compliant interface of claim 29 comprising:
a second compliant member defining at least a portion of a distal wall of the second chamber.
31 . The compliant interface of claim 29 wherein the passage includes a cross sectional area smaller than the first and second chambers.
32 . The compliant interface of claim 30 wherein the housing comprises:
a third chamber; and
a resilient member disposed in the third chamber between the second compliant member and a distal wall of the third chamber.
33 . The compliant interface of claim 30 wherein the first and second compliant members comprise:
a first and second bellows each including a plurality of undulations to control a compliance of the first and second bellows.
34 . The compliant interface of claim 32 wherein the resilient member comprises:
a spring.
35 . A method for operating an implantable hearing aid transducer, the method comprising:
implanting, in a patient, a hearing aid transducer system including a compliant interface disposed between an implantable transducer and a mounting apparatus;
establishing a desired contact relationship between the implantable transducer and an auditory component of the patient;
acoustically stimulating the auditory component using the transducer; and
displacing at least a portion of the compliant interface in response to a predeterminable range of transducer movement.
36 . The method of claim 35 wherein the predeterminable range of transducer movement includes movement in response to a physiological movement of the auditory component and the displacing step includes:
displacing at least a portion of the compliant interface to maintain the desired contact relationship between the implantable transducer and the auditory component.
37 . The method of claim 35 wherein the predeterminable range of transducer movement includes transducer vibrations and the displacing step includes:
displacing at least a portion of the compliant interface to lesson transmission of the transducer vibrations over a feedback path to a microphone of the hearing aid system.
38 . The method of claim 37 wherein the displacing step includes:
displacing at least a portion of the compliant interface to substantially eliminate transmission of the transducer vibrations over the feedback path to the microphone.
39 . The method of claim 37 wherein lessoning transmission of the transducer vibrations over the feedback path to the microphone includes lowering a frequency range over a conduction path between the mounting apparatus and the implantable transducer.
40 . The method of claim 37 wherein the displacing step includes:
displacing at least a portion of the compliant interface to substantially isolate the output of the implantable transducer in response to transducer drive signals from a hearing aid processor.
41 . The method of claim 36 wherein the displacing step includes:
communicating pressure applied on the implantable transducer during the physiological movement of the auditory component to displace at least a portion of the compliant interface.
42 . The method of claim 36 wherein the compliant interface includes a fluid filled housing defining first and second chambers and including a compliant member in a contact relationship with the implantable transducer, and the displacing step includes:
displacing the fluid between the first and second chambers to accommodate pressure on the transducer resulting from the physiological movement.
43 . The method of claim 42 the method comprising:
varying at least one parameter of at least one of a passage between the first and second chamber, a viscosity of the fluid, and the compliant member, to control the fluid displacement.