EP1179969B1 - At least partially implantable hearing system - Google Patents

Abstract

The system has a switchable coupling arrangement that EPcouples a passive coupling element from a transducer output when the driving electronics is inactive so that the mechanical output impedance of the transducer has essentially no effect on the natural resonance of the bone chain in the middle ear and hence the natural residual hearing capacity for sound in air is substantially maintained. The system has at least one sound detection sensor for picking up sound signals and converting them to electrical form, an electronic signal processing unit, a power stage and at least one active electromechanical element (12,13) of an electromechanical transducer (10) for stimulating a small middle ear bone via a passive coupling element (21). A switchable coupling arrangement (22) decouples the passive element from the transducer output when the driving electronics is inactive so that the mechanical output impedance of the transducer has essentially no effect on the natural resonance of the bone chain in the middle ear and hence the natural residual hearing capacity of for sound in air is substantially maintained. Independent claims are also included for the following: an arrangement for implementing the method.

Description

The present invention relates to an at least partially implantable hearing system with at least one sound-absorbing sensor for receiving sound signals and their conversion into corresponding electrical signals, an electronic signal processing unit for audio signal processing and amplification, an electrical power supply unit that supplies power to individual components of the system, and at least an output-side electromechanical transducer having an active electromechanical element, driven by a driving electronic assembly of the signal processing unit, for stimulating any middle ear target ossicles via a passive coupling element.

At least partially implantable hearing systems are to be understood herein systems in which the sound signal with at least one sensor that converts a sound signal into an electrical signal (microphone function), recorded and electronically processed and amplified and its output signal stimulates the damaged hearing in an electro-mechanical manner ,

In the present case, the term "hearing impairment" should be understood as meaning all types of inner ear damage as well as intermittent or permanent ear noises (tinnitus).

Electronic measures for the rehabilitation of surgically irrecoverable inner ear damage have reached an important status today. In case of total failure of the inner ear, cochlear implants with direct electrical stimulation of the remaining auditory nerve are in routine clinical use. In the case of moderate to severe inner ear damage, fully digital hearing aids are being used for the first time, opening up a new world of electronic audio signal processing and offering extended options for the targeted audiological fine adjustment of the hearing aids to the individual inner ear damage. Despite this, achieved in recent years, considerable improvements in the apparatus hearing aid supply remain conventional hearing in principle disadvantages, which are due to the principle of acoustic amplification, that is, in particular by the reconversion of the electronic amplified signal in airborne sound. These disadvantages include aspects such as the visibility of the hearing aids, lack of sound quality due to the electromagnetic transducer (loudspeaker), closed outer ear canal and feedback effects with high acoustic amplification.

Because of these principal disadvantages has long been the desire to deviate from conventional hearing aids with acoustic stimulation of the damaged inner ear and replace them with partially or fully implantable hearing systems with a direct mechanical stimulation. Implantable hearing systems are different from conventional hearing aids: although the sound signal is converted into an electrical signal with an adequate microphone and amplified in an electronic signal processing stage; However, this amplified electrical signal is not supplied to an electroacoustic transducer (speaker), but an implanted electromechanical transducer whose output side mechanical vibrations directly, ie with direct mechanical contact, the middle or inner ear are fed or indirectly by a frictional connection via an air gap at Example of electromagnetic transducer systems. This principle applies regardless of a partial or complete implantation of all necessary system elements as well as regardless of whether a pure inner ear hearing loss in completely intact middle ear or a combined deafness (middle and inner ear damaged) to be rehabilitated. Therefore, in the recent scientific literature and in numerous patents implantable electromechanical transducers and methods for coupling the mechanical transducer oscillations to the intact middle ear or the inner ear directly to the rehabilitation of a pure inner ear hearing and also to remaining ossicles of the middle ear in artificially or pathologically altered middle ear to supply a Conductive deafness and their combinations have been described.

In principle, all physical conversion principles such as electromagnetic, electrodynamic, magnetostrictive, dielectric and piezoelectric are suitable as the electromechanical transducer method. Several research groups have focused on two of these methods in recent years: electromagnetically and piezoelectrically. An overview of these converter variants can be found at HP Zenner and H. Leysieffer (HNO 1997 Vol. 45, pp. 749-774 ).

In the piezoelectric method, a mechanically direct coupling of the output-side transducer oscillations to the central ossicles or directly to the oval window is necessary; In the electromagnetic principle, the power coupling on the one hand via an air gap ("contactless"), that is, only the permanent magnet is brought by permanent fixation in direct mechanical contact with a Mittelohrossikel. On the other hand there is the Possibility to realize the converter completely in a housing (coil and magnet are coupled with the smallest possible air gap) and to transmit the output-side vibrations via a mechanically rigid coupling element with direct contact to the middle ossicles ( H. Leysieffer et al. 1997 (HNO 1997, Vol. 45, pp. 792-800 ).

In the patent literature, some of the above implementation variants of both electromagnetic and piezoelectric hearing aid transducers can be found: US-A-5,707,338 (Adams et al. ) WO 98/06235 (Adams et al. ) WO 98/06238 (Adams et al. ) WO 98/06236 (Kroll et al. ) WO 98/06237 (Bushek et al. ) US-A-5 554 096 (Ball ) U.S. Patent 3,712,962 (Epley ) U.S. Patent 3,870,832 (Fredrickson ) U.S. Patent 5,277,694 (Leysieffer et al. ) DE-C-198 40 211 (Leysieffer ) DE-A-198 40 212 (Leysieffer ) US-A-5 015 224 (Maniglia ) US-A-3,882,285 (Nunley et al. ) US-A-4,850,962 (Schaefer ).

The semi-implantable, piezoelectric hearing system of the Japanese group of Suzuki and Yanigahara requires for the implantation of the transducer the absence of Mittelohrossikel and a free tympanic cavity in order to couple the piezoelectric element to the stapes can ( Yanigahara et al .: "Efficacy of the partially implantable middle ear implant in middle and inner ear disorders", Adv. Audiol., Vol. 4, Karger Basel (1988), pp. 149-159 , Suzuki et al .: "Implantation of partially implantable middle ear implant and the indication", Adv. Audiol., Vol. 4, Karger Basel (1988), pp. 160-166 ). Likewise, in the method of an implantable hearing system for inner ear hearing loss according to Schaefer ( US-A-4,850,962 ) In principle, the anvil removed in order to couple a piezoelectric transducer element to the stapes can. This essentially also applies to further developments which are based on Schaefer technology and are documented in the abovementioned patents ( US-A-5,707,338 (Adams et al. ) WO 98/06235 (Adams et al. ) WO 98/06238 (Adams et al. ) WO 98/06236 (Kroll et al. ) WO 98/06237 (Bushek et al. )).

The ball-type electromagnetic transducer ("Floating Mass Transducer FMT"; U.S. Patent 5,624,376 (Ball et al. ) US-A-5 554 096 (Ball )) is fixed with intact middle ear with titanium clips directly to the long extension of the anvil. The electromagnetic transducer of the partially implantable Fredrickson system ( Fredrickson et al .: "Ongoing investigations into an implantable electromagnetic hearing aid for moderate to severe sensorineural hearing loss", Otolaryngologic Clinics of North America, Vol ) is mechanically coupled directly to the anvil body with also intact ossicular chain of the middle ear. The same applies to the piezoelectric and electromagnetic transducers according to Leysieffer ( Leysieffer et al .: "An implantable piezoelectric hearing aid transducer for people with inner ear hearing loss", HNO 1997/45, p. 792-800 . DE-C-41 04 358 . DE-C-198 40 211 . DE-A-198 40 212 ). Also in the electromagnetic transducer system according to Maniglia ( Maniglia et al .: "Contactless semi-implantable Electromagnetic Middle Ear Device for the Treatment of Sensorineural Hearing Loss, Otolaryngologic Clinics of North America, Vol. 28/1 (1995), pp. 121-141 In the case of an intact ossicle chain, a permanent magnet is permanently mechanically fixed to the latter, but is mechanically driven by a coil via an air gap coupling.

1. a) Einerseits befindet sich der elektromechanische Wandler mit seinem aktiven Wandlerelement selbst im Mittelohrbereich in der Paukenhöhle, und er ist dort mit einem Ossikel oder dem Innenohr direkt verbunden ( US-A-4 850 962 , US-A-5 707 338 , WO 98/06235 , WO 98/06238 , WO 98/06236 , WO 98/06237 , US-A-5 624 376 , US-A-5 554 096 ).
2. b) Andererseits befindet sich der elektromechanische Wandler mit seinem aktiven Wandlerelement außerhalb des Mittelohrbereiches in einer artifiziell geschaffenen Mastoidhöhle; die ausgangsseitigen mechanischen Schwingungen werden dann mittels mechanisch passiver Koppelelemente über geeignete operative Zugänge (natürlicher aditus ad antrum, Eröffnung des chorda-facialis-Winkels oder über eine artifizielle Bohrung vom Mastoid aus) zum Mittelbeziehungsweise Innenohr übertragen ( Fredrickson et al.: "Ongoing investigations into an implantable elektromagnetic hearing aid for moderate to severe sensorineural hearing loss", Otolaryngologic Clinics Of North America, Vol. 28/1 (1995), S. 107-121 ; DE-C-41 04 358 , DE-C-198 40 211 , DE-A-198 40 212 ).

In principle, two implantation principles should be distinguished in the described converter and coupling variants:

1. a) On the one hand, the electromechanical transducer with its active transducer element is located in the middle ear region in the tympanic cavity, where it is directly connected to an ossicle or the inner ear ( US-A-4,850,962 . US-A-5,707,338 . WO 98/06235 . WO 98/06238 . WO 98/06236 . WO 98/06237 . U.S. Patent 5,624,376 . US-A-5 554 096 ).
2. b) On the other hand, the electromechanical transducer with its active transducer element outside of the middle ear area is located in an artificially created mastoid cavity; the mechanical vibrations on the output side are then transferred to the central or inner ear by means of mechanically passive coupling elements via suitable operative approaches (natural aditus ad antrum, opening of the chorda facialis angle or via an artificial bore from the mastoid). Fredrickson et al .: "Ongoing investigations into an implantable electromagnetic hearing aid for moderate to severe sensorineural hearing loss", Otolaryngologic Clinics of North America, Vol ; DE-C-41 04 358 . DE-C-198 40 211 . DE-A-198 40 212 ).

An advantage of the variants according to a) is that the transducer can be designed as a so-called "floating mass" converter, that is, the transducer element does not require "Reactio" via a fixed screw with the skull bone, but it oscillates due to inertia laws with its converter housing and transfers it directly to a Mittelohrossikel ( U.S. Patent 5,624,376 . US-A-5 554 096 . US-A-5,707,338 . WO 98/06236 ). On the one hand, this means that advantageously an implantable fixation system on the skull can be dispensed with; On the other hand, this variant is disadvantageous in that voluminous artificial elements have to be introduced into the tympanic cavity and their long-term and biostability, especially in the case of temporary pathological changes of the middle ear (for example otits media), are not known or guaranteed today. Another major disadvantage is that the transducers are brought from the mastoid with their electrical lead into the middle ear and there must be fixed by means of suitable surgical tools; this requires an extended access through the chorda-facialis angle and thus entails a latent danger to the facial nerves (nervus facialis) in the immediate vicinity. Furthermore, such "floating-mass converters" are then only very limited or not applicable at all, if the inner ear, for example, directly stimulated through the oval window should, because due to pathological changes, for example, the anvil is significantly damaged or even no longer exists and thus such a transducer can no longer be mechanically connected to a vibrating and the inner ear associated ossicles.

A certain disadvantage of the converter variants according to b) is the fact that the converter housings with implantable positioning and fixation systems have to be fastened to the skullcap (advantageous embodiment) US-A-5 788 711 ). A further disadvantage of the variants according to b) is that, preferably by means of suitable lasers, depressions must be introduced into the target ossicles in order to be able to apply the coupling element. On the one hand, this is technically complicated and expensive, and on the other hand it entails risks for the patient. Both in the partially implantable system according to Fredrickson ("Ongoing Investigation into an Implantable Electromagnetic Hearing Aid for Moderate to Severe Sensorineural Hearing Loss", Otolaryngologic Clinics of North America, Vol. 28/1 (1995), pp. 107-121 ) as well as in the fully implantable hearing aid Leysieffer and Zenner (ENT 1998, Vol. 46, pp. 853-863 and 844-852 ) is assumed in the coupling of the oscillating transducer part to the anvil body for permanent and mechanically safe vibration transmission that the tip of a coupling rod, which is introduced into a laser-induced depression of Mittelohrossikels long-term undergoes osseointegration, that is, the coupling rod with the ossicle firmly fuses, thus ensuring a secure transmission of dynamic compressive and tensile forces. However, this long-term effect is currently not scientifically proven. Furthermore, with this type of coupling in the case of a technical converter defect, there is the disadvantage that decoupling from the ossicle for removal of the transducer can only be carried out with mechanically-based operating methods, which can represent a considerable hazard to the middle ear and in particular to the inner ear. Therefore, additional coupling elements have been developed with in part new operational access paths that minimize or no longer have the mentioned disadvantages ( DE-C-197 38 587 . DE-A-199 23 403 . DE-A-199 31 788 . DE-A-199 35 029 . DE-A-199 48 336 . DE-A-199 48 375 ).

The main advantage of this converter embodiments according to b), however, is that the middle ear remains largely free and the coupling access to the middle ear can be done without greater risk potential of the facial nerve. A preferred operational procedure for this is in US-A-6 077 215 (Leysieffer ). Basic advantageous forms of passive coupling elements for transmitting the output side transducer oscillations from the mastoid to the middle or inner ear are in US-A-5,277,964 and US-A-5,941,814 described.

• bei der Implantation des "Floating Mass Transducers (FMT)" und der Verwendung eines Teilimplantates konnte statistisch signifikant nachgewiesen werden, dass das Resthörvermögen durch die Implantation des FMT bei ausgeschalteter Treiberelektronik des Implantates nicht oder nur unwesentlich verschlechtert wird, da dieser Wandler eine sehr geringe Masse aufweist, die im Bereich der Masse der Ossikel selbst liegt, und dass eine Versteifung der Ossikelkette aufgrund des "floatenden" Prinzips des Wandlers nicht oder nur unwesentlich auftritt (zum Beispiel aufgrund der Steifigkeit der Wandlerzuleitung).
• bei der Implantation von mechanisch direktgekoppelten Wandlern gemäß den oben genannten Varianten nach b) zeigt sich, dass insbesondere bei Wandlern auf der Basis des piezoelektrischen Prinzips und mit hoher mechanischer Ausgangsimpedanz ( US-A-5 277 694 ) das Resthörvermögen bei ausgeschalteter Treiberelektronik des Implantatsystems deutlich herabgesetzt sein kann, da in diesem Fall die hohe mechanische Ausgangsimpedanz des Wandlers an der Ankoppelstelle an der Ossikelkette dominiert und somit die über das Trommelfell eingestrahlte akustische Energie an der Koppelstelle weitgehend reflektiert wird.

In recent years, such described partially and fully implantable hearing systems implanted chronically in humans. The long-term results show the following effects:

• in the implantation of the "Floating Mass Transducer (FMT)" and the use of a partial implant could be statistically significantly demonstrated that the residual hearing is not or only slightly deteriorated by the implantation of the FMT with switched driver electronics of the implant, as this transducer has a very low mass which is in the range of the mass of the ossicle itself, and that a stiffening of the ossicle chain due to the "floating" principle of the transducer does not or only slightly occurs (for example, due to the stiffness of the converter lead).
• In the case of the implantation of mechanically direct-coupled transducers according to the abovementioned variants according to b), it is evident that in particular with transducers based on the piezoelectric principle and with a high mechanical output impedance ( US-A-5,277,694 ), the residual hearing with the driver electronics of the implant system switched off can be markedly reduced, since in this case the high mechanical output impedance of the transducer at the coupling site on the ossicle chain dominates and thus the radiated over the eardrum acoustic energy is largely reflected at the coupling point.

The aspect of largely maintaining residual acoustic hearing is considered to be important today, especially when due to the entire implant system design, an ossicle chain interruption to avoid feedback and / or to optimize the energy input into the inner ear ( US-A-6 113 531 ) is not provided. An implant design in this regard may be, for example, using software-based algorithms to avoid or largely minimize feedback effects when using a digital signal processor ( DE-A-198 02 568 ).

Basically, therefore, there is a desire, especially when using mechanically directly coupled electromechanical transducers for implantable hearing systems with a mechanical output impedance that is higher than the mechanical load impedance of the coupled biological middle and / or inner ear structure to use a device that ensures that by Avoidance of a "stalling" of the ossicles by the coupled transducer the remaining hearing is largely retained when the electronic implant system is not in operation. The preservation of residual hearing is understood here as meaning that the sound energy incident on the outer ear is absorbed as unimpaired as possible via the eardrum and transmitted to the inner ear as mechanical vibration energy.

Possible solutions for this are in DE-A-199 23 403 and DE-A-199 35 029 in which the oscillating output element of an electromechanical transducer with high mechanical output impedance is not directly metallically hard coupled to the target ossicle, but a coupling via adhesion forces or via an entropy-elastic intermediate layer, such as silicones, takes place. This reduces the mechanical source impedance of the transducer. Another advantage of such adhesion coupling, for example, is that the ossicle is not "constrained" primarily in the direction of vibration of the driving transducer, which may result in a nonoptimal waveform of the stapes footplate in the oval window (optimal waveform: plunger-shaped vibration of the stapes footplate perpendicular to its plane). but adjusts its (frequency-dependent) direction of vibration itself due to the dynamic properties of the intact middle ear. This advantage also applies to non-intact, (partially) degraded ossicular chain and coupling to the inner ear facing "remainder" of the chain even in extreme cases with only remaining stirrup or stirrup sole plate, as this (r) by the so-called ligament (elastic Ring band that "holds" the stirrup in the oval window) is suspended. However, practical experience and thus the proof of the functionality regarding the main aspect of the present application are not yet available.

Furthermore, the document US6099462 be quoted. This document shows a hearing aid as in the preamble of claim 1. In particular, a hearing aid with a transducer for stimulating a Mittelohrossikels is disclosed via a passive coupling element.

The invention has for its object to provide an at least partially implantable hearing system that maintains a residual hearing of the hearing aid wearer in non-operational electronic implant system in a particularly reliable manner.

This object is achieved in that in an at least partially implantable hearing system with at least one sound-absorbing sensor for receiving sound signals and their conversion into corresponding electrical signals, an electronic signal processing unit for audio signal processing and amplification, an electrical power supply unit, the individual components of the system with power supplied, as well as at least one an active electromechanical element having, driven by a driving electronic assembly of the signal processing unit output side electromechanical transducer for stimulation of any middle ear Zielossikels via a passive coupling element, according to the invention between the active electromechanical element of the converter and the passive coupling element, a switchable coupling arrangement is provided in the inactive state of the electronic assembly driving the converter, the passive coupling element of the Output side of the electromechanical transducer so largely decoupled that the mechanical output impedance of the transducer has no or only a minor effect on the natural ability to vibrate the ossicular chain of the middle ear and thus the natural residual hearing for airborne sound as much as possible.

If, in the hearing system according to the invention, the electronic implant system for whatever reason inactive (that is not in operation), via the switchable coupling arrangement, the active electro-mechanical element of the transducer of the passive coupling element and thus decoupled from the ossicular chain. In this pasture it is avoided that oscillations of the ossicular chain originating from acoustic signals are prevented or prevented by the otherwise directly mechanically coupled electromechanical transducers with the ossicular chain, or in other words by the eardrum radiated acoustic sound Energy is reflected to a considerable extent at the coupling point. The sound energy incident on the outer ear and absorbed by the eardrum is thus transmitted to the inner ear substantially unimpeded. As a result, the remaining hearing of the hearing aid wearer is largely retained.

The solution according to the invention is particularly important when the mechanical output impedance of the hearing system is higher than the mechanical load impedance of the coupled biological middle and / or inner ear structure.

The term "switchable" used herein in connection with the coupling arrangement is to be understood broadly. It is by no means limited to a positive and / or positive connection in the "on" state and a complete separation of the active electromechanical transducer element from the passive coupling element in the "off" state of the clutch assembly, but should generally include all cases in which between the " switched "and the" off "state of the" switchable "coupling arrangement a significant difference in terms of the mechanical output impedance of the output side transducer - based on the transducer side remote from the clutch assembly - is present. Preferably, the switchable coupling arrangement is designed so that between the switched on and the off state of the coupling assembly, a mechanical impedance difference of at least 10 dB.

The switchable coupling arrangement is preferably made microsystem technology in view of the limited space available at the implantation site and for keeping the vibrating masses small. It expediently has an electromechanically active component, in particular a piezoelectric element. In a further embodiment of the invention, the active electromechanical element of the converter and the switchable coupling arrangement are accommodated in a common housing. This simplifies the control of the clutch assembly and avoids an additional clutch housing.

The passive coupling element can be in mechanical connection with the active electromechanical element of the transducer in a manner known per se via a coupling rod. In this case, the switchable coupling arrangement can be inserted into the coupling rod or arranged between the active electromechanical element of the transducer and the transducer facing the end of the coupling rod.

According to a further embodiment of the invention, the electronic signal processing unit is also designed to control the switchable clutch assembly. The signal processing unit advantageously has a digital signal processor for processing the sound sensor signals and / or for generating digital signals for tinnitus masking and for driving the switchable clutch arrangement.

The signal processor can be designed statically in such a way that corresponding software modules are stored once on the basis of scientific findings in a program memory of the signal processor and remain unchanged. But later, for example, based on recent scientific findings improved algorithms for speech signal processing and processing before and should they be used by an invasive, surgical patient intervention, the entire implant or implant module containing the corresponding signal processing unit, against a new with the changed Operating software to be replaced. This procedure brings new medical risks for the patient and is associated with high costs.

This problem can be addressed by the fact that in a further embodiment of the invention, the signal processor for recording and playback of an operating program is associated with a repeatedly writable, implantable memory device, and at least parts of the operating program can be changed or replaced by transmitted from an external unit via a telemetry device data , In this way, after implantation of the implantable system, the operating software, including software for controlling the switchable coupling arrangement described above, as such change or even completely exchange, as for otherwise known systems for the rehabilitation of hearing in DE-C-199 15 846 is explained.

Preferably, the design is such that, moreover, in fully implantable systems in a conventional manner operating parameters, ie patient-specific data, such as audiological fitting data, or changeable implant system parameters (for example, as a variable in a software program for controlling the switchable clutch assembly or to control a Battery recharge) after implantation transcutaneously, that is wirelessly transmitted through the closed skin, into the implant and can be changed with it. In this case, the software modules are preferably dynamic, or in other words adaptive, designed to come to the best possible rehabilitation of the respective hearing impairment. In particular, the software modules may be designed to be adaptive, and parameter adjustment may be done by "training" by the implant carrier and other aids.

Furthermore, the signal processing electronics may include a software module having a optimal stimulation achieved on the basis of a learning neural network. The training of this neural network can be done by the implant wearer and / or with the help of other external aids.

The memory arrangement for storing operating parameters and the memory arrangement for recording and reproducing the operating program can be implemented as independent memories; However, it can also be a single memory in which both operating parameters and operating programs can be stored.

The present solution allows an adaptation of the system to conditions that are detectable only after implantation of the implantable system. For example, in an at least partially implantable hearing system for the rehabilitation of a monaural or binaural inner ear disorder and a tinnitus with mechanical stimulation of the inner ear, the sensory (sound sensor or microphone) and actuator (output stimulator) biological interfaces are always dependent on the anatomical, biological and neurophysiological conditions, for Example of the interindividual healing process. These interface parameters can be individual and also time-variant, in particular. Thus, for example, the transmission behavior of an implanted microphone due to tissue layers and the transmission behavior of a coupled to the inner ear electromechanical transducer due to different coupling quality vary individually and individually. Such differences in the interface parameters, which can not even be reduced or eliminated in the devices known from the prior art by exchanging the implant, can be optimized here by changing or improving the signal processing of the implant.

• Sprachanalyseverfahren (zum Beispiel Optimierung einer Fast-Fourier-Transformation (FFT)),
• statische oder adaptive Störschallerkennungsverfahren,
• statische oder adaptive Störschallunterdrückungsverfahren,
• Verfahren zur Optimierung des systeminternen Signal-Rauschabstandes,
• optimierte Signalverarbeitungsstrategien bei progredienter Hörstörung,
• ausgangspegelbegrenzende Verfahren zum Schutz des Patienten bei Implantatfehlfunktionen beziehungsweise externen Fehlprogrammierungen,
• Verfahren zur Vorverarbeitung mehrerer Sensor-(Mikrofon-)signale, insbesondere bei binauraler Positionierung der Sensoren,
• Verfahren zur binauralen Verarbeitung zweier oder mehrerer Sensorsignale bei binauraler Sensorpositionierung, zum Beispiel Optimierung des räumlichen Hörens beziehungsweise Raumorientierung,
• Phasen- beziehungsweise Gruppenlaufzeit-Optimierung bei binauraler Signalverarbeitung,
• Verfahren zur optimierten Ansteuerung der Ausgangsstimulatoren, insbesondere bei binauraler Positionierung der Stimulatoren.

In an at least partially implantable hearing system, it may be useful or necessary to implement improved signal processing algorithms after implantation. Here are in particular to call:

• Speech analysis method (for example, optimization of a Fast Fourier Transform (FFT)),
• static or adaptive noise detection methods,
• static or adaptive noise reduction methods,
• Method for optimizing the system-internal signal-to-noise ratio,
• optimized signal processing strategies for progressive hearing impairment,
• Output level limiting method for protecting the patient in case of implant malfunction or external fault programming,
• Method for preprocessing a plurality of sensor (microphone) signals, in particular for binaural positioning of the sensors,
• Method for the binaural processing of two or more sensor signals in the case of binaural sensor positioning, for example optimization of spatial hearing or spatial orientation,
• Phase or group delay optimization in binaural signal processing,
• Method for optimized control of the output stimulators, in particular for binaural positioning of the stimulators.

• Verfahren zur Rückkopplungsunterdrückung beziehungsweise -minderung,
• Verfahren zur Optimierung des Betriebsverhaltens des beziehungsweise der Ausgangswandler (zum Beispiel Frequenz- und Phasengangoptimierung, Verbesserung des Impulsübertragungsverhaltens),
• Sprachsignal-Kompressionsverfahren bei Innenohrschwerhörigkeiten,
• Signalverarbeitungsmethoden zur Recruitment-Kompensation bei Innenohrschwerhörigkeiten.

With the present system, the following signal processing algorithms can also be implemented after implantation, inter alia:

• Method for feedback suppression or reduction,
• Method for optimizing the operating behavior of the output transducer (for example frequency and phase response optimization, improvement of the pulse transmission behavior),
• Speech signal compression method for inner ear hearing loss,
• Signal processing methods for recruitment compensation for inner ear hearing loss.

Furthermore, in implant systems with a secondary power supply unit, that is to say a rechargeable battery system, but also in systems with a primary battery supply, it can be assumed that these electrical energy stores with ever-advancing technology enable ever longer lifetimes and thus increasing residence times in the patient. It can be assumed that fundamental and application research for signal processing algorithms is making rapid progress. The need or the patient's desire for an operating software adaptation or change is therefore likely to occur before the end of the life of the internal implant energy source. The system described here allows such an adaptation of the operating programs of the implant even in the already implanted state.

Preferably, a buffer memory arrangement is further provided, in which data transmitted by the external unit via the telemetry device can be buffered before forwarding to the signal processor. In this way, the Complete the transmission process from the external unit to the implanted system, before the data transmitted via the telemetry device are forwarded to the signal processor.

Furthermore, a check logic may be provided which subjects the data stored in the latch arrangement to a check prior to routing to the signal processor. It can be a microprocessor module, in particular a microcontroller, provided for implant-internal control of the signal processor and the switchable coupling arrangement via a data bus, expediently the verification logic and the buffer arrangement are implemented in the microprocessor module and wherein via the data bus and the telemetry device also program parts or entire software modules between the outside world, the microprocessor chip and the signal processor can be transmitted.

The microprocessor chip is preferably associated with an implantable memory device for storing a work program for the microprocessor chip, and at least parts of the work program for the microprocessor chip may be changed or replaced by data transmitted from the external device via the telemetry device.

In a further embodiment of the invention, at least two memory areas may be provided for recording and reproducing at least the operating program of the signal processor. This contributes to the error safety of the system, in that by the multiple presence of the memory area which contains the operating program (s), for example after a transmission from external or when the implant is switched on, a check can be carried out for the correctness of the software.

Analogously to this, the buffer arrangement can also have at least two memory areas for recording and reproducing data transmitted by the external unit via the telemetry device, so that a check of the accuracy of the transmitted data can still be carried out after a data transmission from the external unit in the area of the buffer. The memory areas can be designed for, for example, complementary storage of the data transmitted by the external unit. However, at least one of the memory areas of the buffer arrangement can also be designed to accommodate only a part of the data transmitted by the external unit, in which case the checking of freedom from error of the transmitted data takes place in sections.

To ensure that transmission errors are restarted can be assigned to the signal processor also has a preprogrammed, non-rewritable memory area in which the required for a "minimum operation" of the system instructions and parameters are stored, for example, after a "system crash" at least a faultless operation of the telemetry device for receiving an operating program and instructions for storing it in the control logic ensure.

As already mentioned, in addition to receiving operating programs from the external unit, the telemetry device is also advantageously designed for the transmission of operating parameters between the implantable part of the system and the external unit, such that on the one hand such parameters are provided by a physician, a hearing healthcare professional or the wearer On the other hand, the system can also transmit parameters to the external unit, for example, to check the status of the system.

A fully implantable hearing system of the type described here can have at least one implantable sound sensor and a rechargeable electric storage element next to the actuator stimulation arrangement and the signal processing unit, in which case a wireless, transcutaneous charging device for charging the storage element can be provided. However, it is understood that for power supply, a primary cell or another power supply unit may be present, which does not require transcutaneous recharge. This is especially true when one considers that in the near future, especially by further development of the processor technology with substantial reduction of the energy demand for electronic signal processing is to be expected, so that for implantable hearing systems new forms of energy are practically applicable, for example, a Seebeck effect using energy supply as they are in DE-C 198 27 898 is described. Preferably, a wireless remote control for controlling the implant functions by the implant carrier is also present.

In teilimplantierbarer training of the hearing system at least one sound sensor, the electronic signal processing unit, the power supply unit and a modulator / transmitter unit in a externally on the body, preferably on the head above the implant to be worn external module included. The implant has the output side electromechanical transducer and the switchable clutch assembly, but is energetically passive and receives its operating power and control data for the output transducer and the switchable clutch assembly via the modulator / transmitter unit in the external module.

The system described can be used in fully implantable design as well as in teilimplantierbarem Structure be designed monaural or binaural. A binaural system for rehabilitation of hearing impairment in both ears has two system units, each associated with one of the two ears. In this case, the two system units can be substantially equal to each other. However, one system unit may also be designed as the master unit and the other system unit as a slave unit controlled by the master unit. The signal processing modules of the two system units can communicate with each other in any way, in particular via a wired implantable line connection or via a wireless connection, preferably a bidirectional high-frequency link, a structure-borne sound-coupled ultrasound link or a data transmission path utilizing the electrical conductivity of the tissue of the implant carrier, such that in both system units an optimized binaural signal processing and transducer array drive is achieved.

FIG. 1

beispielhaft ein piezoelektrisches ausgangsseitiges Wandlersystem zur Stimulation eines Mittelohr-Zielossikels mit elektrisch betätigter Kupplungsanordnung,

FIG. 2

beispielhaft eine mögliche Ausführungsform der schaltbaren Kupplungsanordnung unter Verwendung eines aktiven Piezoelementes,

FIG. 3

ein Blockschaltbild eines teil- oder vollimplantierbaren Hörsystems,

FIG. 4

ein vollimplantierbares Hörsystem mit einem elektromechanischen Wandler zur Mittel- ohranregung sowie mit Fernbedienung und Ladegerät, sowie

FIG. 5

ein teilimplantierbares System mit einem elektromechanischen Wandler zur Mittelohr- anregung.

Preferred embodiments of the hearing system according to the invention or of possible partially and fully implantable overall systems are described in more detail below with reference to the accompanying drawings. Show it:

FIG. 1

by way of example a piezoelectric output-side transducer system for stimulating a middle ear target ossicle with an electrically actuated clutch arrangement,

FIG. 2

by way of example a possible embodiment of the switchable clutch arrangement using an active piezoelectric element,

FIG. 3

a block diagram of a partially or fully implantable hearing system,

FIG. 4

a fully implantable hearing system with an electromechanical transducer for middle ear excitation as well as remote control and charger, as well

FIG. 5

a partially implantable system with an electromechanical transducer for middle ear stimulation.

The in FIG. 1 shown, in total labeled 10 implantable output-side electromechanical transducer has a biocompatible, cylindrical housing 11 made of electrically conductive material, such as titanium, which is filled with inert gas. In the housing 11 a vibratable, electrically conductive membrane 12 is arranged. The membrane 12 is preferably circular, and it is fixedly connected at its outer edge to the housing 11. At the in FIG. 1 lower side of the diaphragm 12 is seated a thin disc 13 of piezoelectric material, for example lead zirconate titanate (PZT). The membrane 12 facing the side of the piezoelectric disk 13 is connected to the membrane 12 in electrically conductive connection, and suitably via an electrically conductive adhesive bond. On the side facing away from the membrane 12 side of the piezoelectric disk 13 is contacted with a thin, flexible wire, the part of a Signal line 14 and which in turn is connected via a hermetic housing feedthrough 15 with a lying outside the housing 11 transducer lead 16. At 17 is in FIG. 1 a Polymerverguss between the outside of the housing 11, the housing feedthrough 15 and the transducer lead 16 indicated. A ground connection 18 is guided by the converter feed line 16 via the housing feedthrough 15 to the inside of the housing 11.

The application of an electrical voltage between the signal line 14 and the ground terminal 18 causes a bending of the hetero-composite of membrane 12 and piezoelectric disk 13 and thus leads to a deflection of the membrane 12. Also in the present arrangement advantageously applicable details of such a piezoelectric transducer are in remaining in the U.S. Patent 5,277,694 explained. An output-side electromechanical transducer of this type typically has a relatively high mechanical output impedance, in particular a mechanical output impedance, which is higher than the mechanical load impedance of the implanted in the transducer to the transducer biological central and / or inner tube structure.

In the illustrated embodiment, a coupling rod 20 and a passive coupling element 21 are provided for connecting the transducer 10 with any middle ear ossicle, which is attached to the remote from the transducer 10 end of the coupling rod 20 or is formed by this coupling rod end itself. The direct coupling of the output side of the transducer 10 to the Zielossikel takes place via a switchable coupling assembly 22, with the in FIG. 1 upper side of the membrane 12, preferably in the center of the membrane, in mechanical communication. The coupling assembly 22 can attack with its diaphragm-side end directly to the membrane 12 and with its other end to the membrane-side end of the coupling rod 20; but it can also be inserted into the coupling rod 20.

The coupling rod 20 extends in the illustrated embodiment at least approximately perpendicular to the membrane 12 through an elastically flexible polymer seal 23 through from the outside into the interior of the housing 11. The polymer seal 23 is such that it allows axial vibrations of the coupling rod 20 in the implanted state. The clutch assembly 22 is housed within the housing 11. A control line 24 leads from the converter feed line 16 via the housing feedthrough 15 and a housing-internal passage 25 to the clutch assembly 22. The latter is also connected via a ground terminal 26 to the housing 11 and via this housing to the ground terminal 18 in electrically conductive connection.

In normal operation with the arrangement according to FIG. 1 equipped hearing system, the clutch assembly 22 is turned on under the influence of a signal applied via the control line 24 signal. By "turned on" is to be understood that the clutch assembly 22 for an at least approximately positive and / or positive connection between the membrane 12 and the coupling rod 20 with respect to the necessary for an adequate hearing impression, caused by electrical signals on the signal line 14 vibrational movements ensures.

However, due to the relatively high mechanical output impedance of the transducer 10 as compared to the mechanical load impedance of the biologic center and / or inner ear structure coupled to the transducer, the ossicles are "stalled" by the transducer 10 when the hearing aid is inactive for some reason, for example the power supply of the hearing system is exhausted, a defect of the hearing system is present or the hearing system is intentionally switched off. This means that in such a case, the hearing aid hinders or completely suppresses any residual hearing of the implant wearer.

In the present case, this can be effectively counteracted by means of the coupling arrangement 22 in that, when the hearing system is inactive, the coupling arrangement 22 is switched off and thus the transducer 10 is disconnected from the biological middle and / or inner ear structure. The term "switched-off" clutch arrangement or "disconnected" output-side converter should be understood here to mean a state in which the mechanical output impedance of the converter has no or only a slight influence on the natural oscillatory capability of the ossicular chain of the middle ear. When the clutch assembly 22 is turned off, therefore, the natural residual hearing for airborne sound is largely retained. Preferably, the coupling arrangement 22 is designed so that between on and off state there is a mechanical impedance difference of at least 10 dB.

FIG. 2 shows a possible embodiment of an inserted into the coupling rod 20 clutch assembly 22. The coupling rod 20 has two axially aligned, at a small axial distance from each other coupling rod parts 28 and 29. Mutually facing end portions 30 and 31 of the coupling rod parts 28, 29 are tubular with the same inner and outer diameter. The two tubular end portions 30, 31 receive an active piezoelectric element 33, which in the present embodiment has an annular cross-section. The lengths of the end sections 30, 31 and of the piezoelement 33 are dimensioned so that the free ends of the piezoelement 33 are held axially at a distance from the transition of the end sections 30, 31 to the subsequently formed massively formed section of the coupling rod sections 28, 29. The outer diameter of the piezoelectric element 33 is only slightly smaller than the inner diameter of the tubular end portions 30, 31 of the coupling rod. The remaining gap is filled with a compressible polymer 34, which is soft in the uncompressed state and thus has a low mechanical impedance. If the piezoelectric element 33 electrically activated, that is, the clutch assembly 22 is turned on, the piezoelectric element 33 expands and generates a high radial force on the polymer 34, which is thus highly compressed. The material of the polymer 34 is chosen so that it has a significantly higher stiffness and thus higher mechanical impedance in the compressed state than in the non-compressed state with not electrically activated piezoelectric element 33 (clutch assembly 22 switched off).

It will be understood by those skilled in the art that the design of the shiftable clutch assembly can be varied in many ways. The clutch is preferably made by microsystem technology.

FIG. 3 shows a schematic block diagram of one with an arrangement according to the Figures 1 and 2 equipped, at least partially implantable hearing system for the rehabilitation of middle ear and / or inner ear disorder or tinnitus with direct mechanical stimulation of Mittelohrossikels.

Via one or more sound sensors (microphones) 38a to 38n, the external sound signal is recorded and converted into analog electrical signals. In the case of an implant realization for the exclusive rehabilitation of a tinnitus by masking or Noiserfunktion without additional hearing aid function accounts for these sensor functions. The electrical sensor signals are passed to a unit 39 which is part of an implantable electronic module 40 and in which the sensor signal or signals are selected, preprocessed and converted into digital signals (A / D conversion). The preprocessing may, for example, consist in an analogue linear or non-linear preamplification and filtering (for example antialiasing filtering). The digitized sensor signal (s) are applied to a digital signal processor (DSP) 41 that performs the intended function of the hearing implant, such as audio signal processing in a system for inner ear hearing loss and / or signal generation in the case of a tinnitus masker or noise. The signal processor 41 contains a non-rewritable read-only memory area So, in which the instructions and parameters required for a "minimum operation" of the system are stored, and a memory area S ₁ , in which the operating software of the intended function or functions of the implant system are stored. Preferably, this memory area will be duplicated (S ₁ and S ₂ ). The rewritable program memory for holding the operating software may be based on EEPROM or RAM cells, in which case care should be taken to ensure that this RAM area is always "buffered" by the on-board power system.

The digital output signals of the signal processor 41 are in a digital-to-analog converter (D / A) 43 converted to analog signals. Depending on the implant function, this D / A converter can also be designed several times or can be completely dispensed with if, for example, in the case of a hearing system with electromagnetic output transducer, a pulse-width-modulated, serial digital output signal of the signal processor 41 is transmitted directly to the output transducer. The analog output signal of the digital-to-analog converter 43 is then fed to a driver unit 44 which, depending on the implant function, actuates the output-side electromechanical transducer 10 for the stimulation of the middle or inner ear. Another output signal of the signal processor 41 controls via a further digital-to-analog converter 45 and an associated driver unit 46 which housed in the housing 11 of the converter 10 switchable clutch assembly 22nd

At the in FIG. 3 In the embodiment shown, the signal processing components 39, 41, and 43 to 46 are controlled by a microcontroller 48 (μC) with one or two associated memories S ₄ and S ₅ via a bidirectional data bus 49. In particular, the operating software portions of the implant management system may be stored in the memory area S ₄ and S ₅ , for example, administrative monitoring and telemetry functions. In the memories S ₁ and / or S ₂ also externally variable, patient-specific, such as audiological fitting parameters can be stored. Furthermore, the microcontroller 48 has a repeatedly writable memory S ₃ , in which a work program for the microcontroller 48 is stored.

The microcontroller 48 communicates via a data bus 50 with a telemetry system (TS) 51. This telemetry system 51 in turn communicates through the indicated at 52 closed skin, for example via an unillustrated inductive coil coupling wirelessly bidirectional with an external programming system (PS) 53. The programming system 53 can advantageously be a PC-based system with appropriate programming, editing, presentation and management software. The operating software of the implant system to be changed or exchanged completely is transmitted via this telemetry interface and initially stored temporarily in the memory area S ₄ and / or S _{5 of} the microcontroller 48. For example, the memory area S _{5 may be used} for complementarily storing the data transmitted from the external system, and a simple verification of the software transmission by a telemetry read operation may be performed to determine the coincidence of the contents of the memory areas S ₄ and S ₅ before the content of the rewritable memory S _{3 is} changed or exchanged.

The operating software of the at least partially implantable hearing system should according to the nomenclature used here both the operating software of the microcontroller 48th (For example, housekeeping functions such as energy management or telemetry functions) and the operating software of the digital signal processor 41 include. Thus, for example, a simple verification of the software transmission can be carried out by a read operation via the telemetry interface before the operating software or the corresponding signal processing components of this software are transferred to the program memory area S _{1 of} the digital signal processor 41 via the data bus 49. Furthermore, the work program for the microcontroller 48, which is stored, for example, in the repeatedly writable memory S ₃ , can be changed or replaced completely or partially via the telemetry interface 51 with the aid of the external unit 53.

All electronic components of the implant system are powered by a primary or secondary battery 54 with electrical operating energy.

FIG. 4 schematically shows the structure of a fully implantable hearing system, as an actuator stimulation arrangement an output-side electromechanical transducer 10, for example, the transducer according to FIG. 1 , having. The output side electromechanical transducer may generally be formed as any electromagnetic, electrodynamic, piezoelectric, magnetostrictive or dielectric (capacitive) transducer. Among other things, the in FIG. 1 shown converter also in the in DE-C-198 40 211 explained manner be modified so that at the in FIG. 1 the lower side of the piezoelectric ceramic disc 13, a permanent magnet is mounted, which cooperates in the manner of an electromagnetic transducer with an electromagnetic coil. Such a combined piezoelectric / electromagnetic transducer is particularly advantageous in view of a broad frequency band and to achieve relatively large vibration amplitudes with relatively small power input. The output-side electromechanical transducer can also be an electromagnetic transducer arrangement as described in US Pat EP-A-0 984 663 is described. In any case, the presently described switchable clutch assembly 22 is additionally provided.

Coupling arrangements of the electromechanical transducer 10 to the middle or inner ear are particularly suitable US-A-5,941,814 in which a coupling element except for a coupling part for the respective Ankoppelort has a crimp sleeve, which is first slid loosely onto a provided with a rough surface rod-shaped part of a coupling rod, which is connected in the manner previously explained with the transducer. When implanting the crimping sleeve can be easily moved relative to the coupling rod and rotated in order to align the coupling part of the coupling element with the intended Ankoppelort exactly. Then the crimping sleeve is fixed by being plastically cold-worked by means of a crimping tool. Alternatively, the coupling element with respect to the coupling rod also be determined by means of a zugziehbaren belt loop.

Other presently preferred coupling arrangements are in detail in the DE-A-199 23 403 . DE-A-199 35 029 . DE-C-199 31 788 . DE-A-199 48 336 and DE-A-199 48 375 described. So according to DE-A-199 23 403 a coupling element at its Ankoppelende have a contact surface having an adaptable to the surface shape of the Ankoppelstelle or adapted surface shape and such a surface finish and surface size, that it by applying the Ankoppelendes to the Ankoppelstelle to a dynamic train-pressure power coupling of coupling element and ossicle chain Surface adhesion comes, which is sufficient for a secure mutual connection of coupling element and ossicle chain. The coupling element may be provided with an attenuator in the implanted state at the coupling point with entropy-elastic properties in order to achieve an optimal waveform of Stirrupfußplatte or the round window or an artificial window in the cochlea, in the vestibule or labyrinth final membrane and the risk to minimize damage to the natural structures in the area of the coupling site during and after implantation ( DE-A-199 35 029 ).

The coupling element can accordingly DE-C-199 31 788 with an adjusting device for selectively displacing the coupling element between an open position, in which the coupling element can be brought into and out of engagement with the Ankoppelstelle, and a closed position to be provided, in which the coupling element is in the implanted state with the Ankoppelstelle in force and / or positive connection ,

For the mechanical coupling of the electromechanical transducer to a preselected coupling site on the ossicular chain, a coupling arrangement ( DE-A-199 48 336 ), which has a coupling rod displaceable by the converter into mechanical vibrations and a coupling element which can be brought into connection with the preselected coupling point, wherein the coupling rod and the coupling element are connected to one another via at least one coupling and at least one section of the coupling element abutting the coupling point in the implanted state is designed for low-loss vibration introduction into the coupling point, wherein a first coupling half of the clutch has an outer contour with at least approximately the shape of a spherical cap, which is accommodated in an outer contour at least partially complementary inner contour of a second coupling half, and wherein the coupling reversibly pivotable against frictional forces and / or rotatable, but is substantially rigid when occurring in the implanted state dynamic forces. According to a modified embodiment of such a coupling arrangement ( DE-A-199 48 375 ) has a first coupling half the coupling has an outer contour with at least approximately cylindrical, preferably circular-cylindrical, shape which can be received in an inner contour of a second coupling half which is at least partially complementary to the outer contour, a section of the coupling element abutting the coupling point in the implanted state being designed for low-loss oscillation introduction into the coupling point, wherein in the implanted state, a transmission of dynamic forces between the two coupling halves of the coupling takes place substantially in the direction of the longitudinal axis of the first coupling half, and wherein the coupling reversibly on and uncoupled and reversible linear and / or rotational with respect to a longitudinal axis of the first coupling half adjustable, but is rigid when occurring in the implanted state dynamic forces.

To the in FIG. 4 The illustrated fully implantable hearing system further includes an implantable microphone (sound sensor) 38, a wireless remote control 56 for implant functionality by the implant carrier, and a wireless transcutaneous charging system with a charger 57 and a charging coil 58 for recharging the implanted secondary battery 54 (FIG. FIG. 3 ) for the power supply of the hearing system.

The microphone 38 may be advantageous in the EP-A-0 831 673 known manner and provided with a microphone capsule, which is hermetically sealed on all sides in a housing, as well as with an electrical feedthrough arrangement for performing at least one electrical connection from the interior of the housing to the outside thereof, wherein the housing has at least two legs which in an angle with respect to each other are aligned, wherein the one leg receives the microphone capsule and is provided with a sound inlet diaphragm, wherein the other leg contains the electrical feedthrough assembly and is set back from the plane of the sound inlet diaphragm, and wherein the geometry of the microphone housing is selected such that upon implantation of the microphone in the mastoid cavity, the leg containing the sound inlet membrane protrudes from the mastoid into an artificial bore in the posterior, bony canal wall and the sound entry membrane penetrates the skin of the ear canal and touches. Laying down the implanted microphone 38 may expediently a fixation of the US-A-5,999,632 be known, which has a sleeve which encloses the legs containing the sound inlet membrane with a cylindrical housing part and provided with against the ear canal facing the side of the ear canal wall engageable, projecting, elastic flange parts. In this case, the fixing element preferably includes a holder, which holds the said flange prior to implantation against an elastic restoring force of the flange in a bent-through the bore of the ear canal wall permitting the bent position. The charging coil 58 connected to the output of the charger 57 preferably forms in the US-A-5,279,292 known type part of a transmission series resonant circuit, which can be inductively coupled to an unillustrated receive series resonant circuit. The receive-series resonant circuit may be part of an implantable electronic module 34 (FIG. FIG. 2 ) and accordingly US-A-5,279,292 a constant current source for the battery 25 ( FIG. 2 ) form. In this case, the reception series resonant circuit is located in a battery charging circuit, which is closed in dependence on the respective phase of the charging current flowing in the charging circuit via one or the other branch of a full-wave Gletchrichterbrücke.

The electronic module 40 is in the arrangement according to FIG. 4 connected via a microphone line 59 to the microphone 38 and the transducer lead 16 to the electromechanical transducer 10 and preferably also housed in the converter housing switchable coupling assembly 22.

FIG. 5 shows schematically the structure of a partially implantable hearing system. In this partially implantable system, a microphone 38, an electronic module 62 for electronic signal processing are largely as appropriate FIG. 3 (But without the telemetry system 51), the power supply (battery) 54 and a modulator / transmitter unit 63 in a externally on the body, preferably on the head above the implant to be worn external module 64 included. The implant is energetically passive as in known partial implants. Its electronic module 65 (without battery 54) receives operating power and control signals for the transducer 10 and coupling assembly 22 via the modulator / transmitter unit 63 in the external portion 64.

Both the fully implantable and the partially implantable hearing system can monoaural (as in the FIGS. 4 and 5 shown) or be designed binaurally. A binaural system for rehabilitation of hearing impairment in both ears has two system units, each associated with one of the two ears. In this case, the two system units can be substantially equal to each other. However, one system unit may also be designed as the master unit and the other system unit as a slave unit controlled by the master unit. The signal processing modules of the two system units can communicate with each other in any way, in particular via a wired implantable line connection or via a wireless connection, preferably a bidirectional high-frequency link, a structure-borne sound-coupled ultrasound link or a data transmission path utilizing the electrical conductivity of the tissue of the implant carrier, such that in both system units an optimized binaural signal processing is achieved.

• Beide Elektronikmodule können jeweils einen digitalen Signalprozessor gemäß vorstehender Beschreibung enthalten, wobei die Betriebssoftware beider Prozessoren wie beschrieben transkutan veränderbar ist. Dann sorgt die Verbindung beider Module im wesentlichen für den Datenaustausch zur optimierten binauralen Signalverarbeitung zum Beispiel der Sensorsignale.
• Nur ein Modul enthält den beschriebenen digitalen Signalprozessor, wobei dann die Modulverbindung neben der Sensordatenübertragung zur binauralen Schallanalyse und -verrechnung auch für die Ausgangsignalübermittlung zu dem kontralateralen Wandler sorgt, wobei in dem kontralateralen Modul der elektronische Wandlertreiber untergebracht sein kann. In diesem Fall ist die Betriebssoftware des gesamten binauralen Systems nur in einem Modul abgelegt und wird auch nur dort transkutan über eine nur einseitig vorhandene Telemetrieeinheit von extern verändert. In diesem Fall kann auch die energetische Versorgung des gesamten binauralen Systems in nur einem Elektronikmodul untergebracht sein, wobei die energetische Versorgung des kontralateralen Moduls drahtgebunden oder drahtlos geschieht.

The following combination options are foreseeable:

• Both electronic modules can each contain a digital signal processor according to the above description, wherein the operating software of both processors as described transcutaneously changeable. Then, the connection of both modules essentially ensures the exchange of data for optimized binaural signal processing, for example of the sensor signals.
• Only one module contains the digital signal processor described, in which case the module connection, in addition to the sensor data transmission for binaural sound analysis and accounting, also provides the output signal transmission to the contralateral converter, wherein the electronic converter driver can be accommodated in the contralateral module. In this case, the operating software of the entire binaural system is stored only in one module and is only transactively changed externally via a single-sided telemetry unit. In this case, the energetic supply of the entire binaural system can be accommodated in only one electronic module, wherein the energetic supply of the contralateral module is wired or wireless.

Claims (10)

1. An at least partially implantable hearing system comprising at least one sound-receiving sensor (38) for picking up sound signals and converting them into corresponding electrical signals, an electronic signal processing unit (40, 62, 65) for audio signal processing and amplification, an electrical power supply unit (54) which supplies individual components of the system with power, and at least one electromechanical output transducer (10) for stimulating an arbitrary middle ear target ossicle via a passive coupling element (21), said transducer being provided with an active electromechanical element (12, 13) and being controlled by an electronic driver arrangement (44) of the signal processing unit, characterized in that a switchable coupling arrangement (22) is disposed between the active electromechanical element (12, 13) of the transducer (10) and the passive coupling element (21), which coupling arrangement in the inactive state of the electronic driver arrangement (44) for the transducer disconnects the passive coupling element from the output member (12) of the transducer (10) to such an extent that the mechanical output impedance of the transducer substantially has no influence on the natural capability of the ossicular chain of the middle ear to vibrate, which results in the residual acoustic hearing capacity being largely preserved.
2. The system according to claim 1, characterized in that the hearing system comprises a mechanical output impedance which is higher than the mechanical load impedance of the biological middle and/or inner ear structure which in the implanted state is coupled to said system.
3. The system according to one of the preceding claims, characterized in that the switchable coupling arrangement (22) is designed such that the mechanical impedance difference between the activated and the deactivated state of the coupling arrangement is at least 10 dB.
4. The system according to one of the preceding claims, characterized in that the switchable coupling arrangement (22) comprises an electromechanically active element (33), particularly a piezoelement.
5. The system according to one of the preceding claims, characterized in that the active electromechanical element (12, 13) of the transducer (10) and the switchable coupling arrangement (22) both are accommodated within a transducer housing (11).
6. The system according to one of claims 1 to 4, wherein the passive coupling element (21) is mechanically connected via a coupling rod (20) to the active electromechanical element (12, 13) of the transducer (10), the switchable coupling arrangement (22) being incorporated into the coupling rod (20) or being located between the active electromechanical element (12, 13) of the transducer (10) and the end of the coupling rod (20) facing the transducer.
7. The system according to one of the preceding claims, characterized in that the signal processing unit (40, 62, 65) comprises a digital signal processor (41) for processing sound sensor signals and/or for generating digital signals for tinnitus masking and for controlling the switchable coupling arrangement (22).
8. The system according to claim 7, characterized in that a rewritable implantable storage arrangement (S1, S2) is assigned to the signal processor (41) for storage and retrieval of an operating program, and at least parts of the operating program are adapted to be changed or replaced by data transmitted by an external unit (53) via a telemetry means (51).
9. The system according to claim 7 or 8, characterized by a microprocessor component (44), particularly a microcontroller, for controlling the signal processor (42) and the switchable coupling arrangement (22) via a data bus (49) within the implant.
10. The system according to claims 8 and 9, characterized in that also program portions or entire software modules may be transmitted between the exterior, the microprocessor component (48) and the signal processor (41) via the data bus (49) and the telemetry means (51).

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