Low-cost, four-channel cochlear implant
First Claim
1. A low-cost, multi-channel cochlear stimulation system comprising:
- a passive, implantable receiver/electrode array comprising;
an elongate silicone rubber carrier in which is embedded a plurality of coil assemblies at a proximal end of the carrier and a corresponding plurality of electrodes at a distal end of the carrier,the distal end of the carrier being adapted for insertion into a human cochlea, with the plurality of electrodes being spaced apart along the distal end,the proximal end of the carrier holding the plurality of coil assemblies in a predetermined pattern,the coil assemblies each comprising a prescribed number of turns of a first wire wound to form a coil,a first end of the first wire of each coil assembly being bonded to a second wire that extends the length of the elongate carrier inside of the carrier to a respective electrode at the distal end of the carrier,second end of the first wire of each coil assembly being bonded to a third wire that extends less than the length of the elongate carrier to a common electrode exposed at the surface of the carrier,each electrode at the distal end of the carrier comprising a ball formed by flaming a distal end of the second wire, a portion of which ball is exposed through the surface of the carrier,implantable alignment means for aligning the plurality of coil assemblies with corresponding external coils, andan hermetically sealed case made from a biocompatible material that houses said coil assemblies; and
an external wearable processor comprising;
microphone means for generating an electrical signal representative of sensed audible sounds,filter means for dividing the electrical signal into a plurality of frequency bands, thereby creating a corresponding plurality of frequency band signals, the number of frequency bands being the same as the number of implanted coil assemblies and electrodes, whereby there is an implanted coil assembly and corresponding electrode for each filter means,speech processing means for processing each of the plurality of frequency band signals in accordance with a prescribed speech processing strategy to produce respective biphasic stimulation signals, andan external headpiece having a plurality of external coils, each connected to receive one of the respective biphasic stimulation signals,external alignment means for positioning the external headpiece in alignment with the implantable alignment means to align each of the external coils of the external headpiece with respective ones of the plurality of coil assemblies of the implantable receiver/electrode array;
whereby the biphasic stimulation signals received by each of the plurality of external coils are inductively coupled to respective ones of the plurality of implantable coil assemblies, thereby causing a biphasic stimulation current to flow between respective ones of the implantable electrodes and the common electrode.
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Accused Products
Abstract
A low-cost, four-channel cochlear stimulation system utilizes a completely passive, implantable receiver/electrode array that is inductively coupled to an external wearable processor. The receiver/electrode array is formed in a silicone rubber carrier adapted to be implanted in a deaf patient. At one end of the receiver/electrode array, positioned subcutaneously near the surface of skin above the ear, four receiving coils are arranged in an appropriate pattern. Such receiving coils are held within an hermetically-sealed titanium case. At the other end of the receiver/electrode array, which may be pre-formed in a spiral to match the basal turn of the cochlea, and which is inserted in the cochlea, four ball electrodes are spaced apart along an inner radius of the spiral. Each electrode is electrically connected to a respective receiving coil. Each receiving coil is also electrically connected to a reference electrode typically located near the receiver-coil end of the array. The wearable processor senses audible sounds, converts the sensed sounds to corresponding electrical signals, and splits the electrical signals into four frequency bands or channels. A speech processing strategy applies the processed signals of each channel to each of four external coils, as a series of biphasic current pulses. The four external coils are aligned, using a suitable headpiece, with corresponding coils of the receiver/electrode array, thereby inductively coupling the biphasic current to a respective electrode of the implanted electrode array.
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Citations
20 Claims
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1. A low-cost, multi-channel cochlear stimulation system comprising:
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a passive, implantable receiver/electrode array comprising; an elongate silicone rubber carrier in which is embedded a plurality of coil assemblies at a proximal end of the carrier and a corresponding plurality of electrodes at a distal end of the carrier, the distal end of the carrier being adapted for insertion into a human cochlea, with the plurality of electrodes being spaced apart along the distal end, the proximal end of the carrier holding the plurality of coil assemblies in a predetermined pattern, the coil assemblies each comprising a prescribed number of turns of a first wire wound to form a coil, a first end of the first wire of each coil assembly being bonded to a second wire that extends the length of the elongate carrier inside of the carrier to a respective electrode at the distal end of the carrier, second end of the first wire of each coil assembly being bonded to a third wire that extends less than the length of the elongate carrier to a common electrode exposed at the surface of the carrier, each electrode at the distal end of the carrier comprising a ball formed by flaming a distal end of the second wire, a portion of which ball is exposed through the surface of the carrier, implantable alignment means for aligning the plurality of coil assemblies with corresponding external coils, and an hermetically sealed case made from a biocompatible material that houses said coil assemblies; and an external wearable processor comprising; microphone means for generating an electrical signal representative of sensed audible sounds, filter means for dividing the electrical signal into a plurality of frequency bands, thereby creating a corresponding plurality of frequency band signals, the number of frequency bands being the same as the number of implanted coil assemblies and electrodes, whereby there is an implanted coil assembly and corresponding electrode for each filter means, speech processing means for processing each of the plurality of frequency band signals in accordance with a prescribed speech processing strategy to produce respective biphasic stimulation signals, and an external headpiece having a plurality of external coils, each connected to receive one of the respective biphasic stimulation signals, external alignment means for positioning the external headpiece in alignment with the implantable alignment means to align each of the external coils of the external headpiece with respective ones of the plurality of coil assemblies of the implantable receiver/electrode array; whereby the biphasic stimulation signals received by each of the plurality of external coils are inductively coupled to respective ones of the plurality of implantable coil assemblies, thereby causing a biphasic stimulation current to flow between respective ones of the implantable electrodes and the common electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A passive, implantable receiver/electrode array for use with a four-channel cochlear stimulation system consisting of:
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an elongate silicone rubber carrier in which is embedded four coil assemblies at a proximal end of the carrier and four electrodes at a distal end of the carrier, the distal end of the carrier being formed in the shape of a spiral to match the basal turn of a human cochlea, with the four electrodes being spaced apart along an inner radius of the spiral, the proximal end of the carrier holding the four coil assemblies in a predetermined pattern, the coil assemblies each comprising a prescribed number of turns of a first wire wound to form a coil, a first end of the first wire of each coil assembly being bonded to a second wire that extends the length of the elongate carrier inside of the carrier to a respective electrode at the distal end of the carrier, a second end of the first wire of each coil assembly being bonded to a third wire that extends less than the length of the elongate carrier to a common electrode exposed at the surface of the carrier, each electrode at the distal end of the carrier comprising a ball formed by flaming a distal end of the second wire, a portion of which ball is exposed through the surface of the carrier, implantable alignment means for aligning the four coil assemblies with corresponding external coils, and an hermetically sealed case made from a biocompatible material that houses said four coil assemblies. - View Dependent Claims (16, 17, 18)
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19. A method of optimizing a coil interface used within a low cost, multichannel cochlear implant system, said system having a plurality of implantable receiver coils, and a corresponding plurality of external transmitting coils, the implantable receiving coils being housed within an hermetically-sealed case, the method comprising the steps of:
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(a) developing an electric circuit model and a geometrical model of the coil interface based on empirical data; (b) fabricating a prototype coil interface using the models developed in step (a); (c) validating the prototype coil interface by adjusting the electric circuit model and geometrical model as required to meet desired performance criteria; (d) applying desired interface specifications and constraints to the validated prototype coil interface of step (c); (e) adjusting and configuring space variables associated with the coil interface model in an iterative fashion until the performance of the interface model matches the interface specifications and constraints applied in step (d), said space variables including coil diameter, coil thickness, coil width, wire size and coil spacing; and (f) using the space variables arrived at in step (e) as the design parameters for an optimized coil interface.
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20. A passive, implantable receiver/electrode array for use with a multichannel cochlear stimulation system consisting of:
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a flexible carrier in which is embedded a plurality of coil assemblies at a proximal end of the carrier and a corresponding plurality of electrodes at a distal end of the carrier, the distal end of the carrier being adapted for insertion into a human cochlea, with the plurality of electrodes being spaced apart along the distal end, the proximal end of the carrier holding the plurality of coil assemblies in a predetermined pattern, the coil assemblies each comprising a prescribed number of turns of a first wire wound to form a coil, a first end of the first wire of each coil assembly being electrically coupled to a second wire that extends the length of the carrier to a respective electrode at the distal end of the carrier, a second end of the first wire of each coil assembly being electrically coupled to a third wire that extends less than the length of the carrier to a common electrode exposed at the surface of the carrier, each electrode at the distal end of the carrier comprising a smoothed surface formed by flaming a distal end of the second wire, a portion of which smoothed surface is exposed through the surface of the carrier, implantable alignment means for aligning the plurality of coil assemblies with corresponding external coils, and an hermetically sealed case made from a biocompatible material that houses said plurality of coil assemblies.
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Specification