High compliance output stage for a tissue stimulator
AssigneeCochlear Pty. Ltd.
InventorDavid Money
Life of this patent
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Abstract
The output stage of a tissue stimulating apparatus, for example a cochlear implant prosthesis, operating at a low supply voltage (35) incorporates a multiplier circuit (54, 62, 63, 64) for ensuring that voltage compliance is maintained in the event that high intensity stimulations are required. The multiplier circuit makes use of compliance monitoring so that multiplication is only used as required. Also described is a method for operating a tissue stimulating apparatus incorporating a multiplier circuit.
Claims13
A cochlear prosthesis system comprising:
- a power supply;
- a programmable current source provided to generate a stimulation current of predetermined amplitude;
- a booster circuit for selectively boosting the supply voltage of said power supply when said power supply is insufficient to allow said current source to provide a predetermined current,
- said booster circuit having a sensor that monitors a parameter indicative of whether said supply voltage is sufficient to provide said stimulation current;
- wherein said booster circuit further comprises an energy storage device which is arranged to be charged during periods in which lower or zero stimulation current is flowing and is arranged to supplement the supply voltage during periods in which said supply voltage is insufficient to allow said current of predetermined magnitude to flow.
A cochlear prosthesis system including:
- a microphone for picking up ambient sounds;
- signal processing circuitry coupled to the microphone for determining stimulation signals corresponding to said ambient sounds;
- an electrode array for applying said stimulation signals to the nervous system of a patient;
- a power supply for providing energy for the generation of said stimulation signals;
- an energy storage device arranged and constructed to selectively supplement said power supply;
- a sensing means for monitoring the generation of said stimulation signals to determine if said power supply requires supplementation by said energy storage device in order to enable generation of said determined stimulus signals;
- and
- a multiplier switching circuit for selectively switching said energy storage device so that it supplements the power provided by the power supply in order to ensure that stimulation signals as determined by the signal processor are generated.
A method for improving the compliance of the stimulation current output stage of a tissue stimulating system, said output stage including at least one programmable current source and a power source, and at least one stimulation electrode, said method including the steps of:
- a) determining if the voltage across each said current source is sufficient to allow generation of a stimulation current of desired amplitudes;
- b) in the event that said voltage is determined to be insufficient in step a) for generating one stimulation current having a particular amplitude, connecting a charged energy storage device to said power supply so as to increase the potential voltage across said programmable current source.
A tissue stimulating system comprising:
- a power supply having an output;
- a programmable current source coupled to said output and adapted to generate current signals of several predetermined magnitudes;
- a sensor arranged to monitor power supply and to generate a parameter indicative of whether said power supply is capable of generating said output sufficiently to allow said current source to generate one of said current signals, said current signal having one of said predetermined magnitudes;
- and
- a booster responsive to said parameter and adapted to boost said output sufficiently to allow said current supply to generate said one current signal.
A tissue stimulating system comprising:
- a power supply having an output;
- a programmable current source coupled to said output and adapted to generate current signals of several predetermined magnitudes;
- a sensor arranged to monitor power supply and to generate a parameter indicative of whether said power supply is capable of generating said output sufficiently to allow said current source to generate one of said current signals, said current signal having one of said predetermined magnitudes;
- and
- a booster responsive to said parameter and adapted to selectively boost said output sufficiently to allow said current supply to generate said one current signal.
Dependencies are inferred from the claim text.