Abstract: A hearing aid is disclosed, which, in a test mode, can determine the impedance of the transducer that stimulates the anatomy of the patient. Impedance may be determined by simultaneous determination of the current flowing through the transducer and the voltage across the transducer. In some cases, the output amplifier of the hearing aid includes two outputs, with one being a scaled and/or summed replica of the other. The amplifier is driven with a periodic signal with a particular frequency and a known peak voltage. The periodic signal may be sinusoidal. The primary output of the amplifier is electrically connected to the transducer, with a known voltage given by the peak input voltage and a known gain of the amplifier. The current from the secondary output of the amplifier is measured. In an example measurement scheme, the secondary output is sent through a rectifier and then through a low-pass filter.
Abstract: A hearing aid is disclosed, having the ability to generate its own open-loop feedback scan of amplitude (as gain or attenuation) and phase, as a function of frequency. The hearing aid has a sensor that receives ambient sound from near a patient, and a driver that stimulates the anatomy of the patient. The hearing aid has an operational mode in which the driver stimulates the anatomy of the patient in response to the sound received at the sensor. The hearing aid has a test mode in which a test frequency is stepped through a predetermined range of frequencies. At each test frequency, the driver is driven with a sinusoidal driver signal at the test frequency, the sensor detects a sinusoidal sensor signal at the test frequency, and a comparison of the sensor signal to the driver signal produces an amplitude (gain or attenuation) and a phase for the test frequency.
Abstract: The present disclosure includes methods, devices, and systems for cochlear implants. One method embodiment for cochlear implant signal processing includes processing a differential analog audio signal using amplitude modulation and pulse-width modulation. The method includes driving a transmission coil on an external unit of the cochlear implant with the pulse-width and amplitude modulated signal. The method also includes driving a reception coil on an internal unit of the cochlear implant with an output of the transmission coil.
Abstract: Embodiments of the invention provide an amplifier including a gain control circuit having a gain measurement circuit as part of a feedback loop. The gain measurement circuit generates an attenuated output signal, based on the gain of the amplifier circuit, which is used to generate a gain control signal. One amplifier includes a first attenuator enabling primary compression and a second attenuator as part of a gain measurement circuit. In some cases the attenuation factors of the first and second attenuators may be proportional or substantially the same. In some embodiments one or more output stages (e.g., differential amplifiers) are provided to generate the gain control signal based on differential combinations of an audio output, the attenuated output signal, and a primary threshold signal. A ratio of the gains of the two or more comparing amplifiers can set a primary compression ratio in some cases.
Abstract: A rechargeable battery system and method are disclosed, in which an implantable medical device (IMD) regulates its transfer of energy from a separate charger unit. For recharging, a charger unit is brought into proximity to the implanted device. An oscillating current is generated in a primary coil, located in the charger. By inductive coupling through an oscillating magnetic field, an alternating current is generated in a secondary coil, which is implanted in or near the implanted device. The alternating current then passes through a half-wave or full-wave rectifier to form a one-sided current, then passes through a regulator to form an essentially direct current, which is in turn directed to the rechargeable battery in the implanted device. The secondary coil has a controllable damped resonant frequency, which can be dynamically tuned away from the driving frequency of the primary coil by a variable resistor and/or by varying a duty cycle of a rapidly switched electrical element.
Abstract: Apparatus, systems, and methods having or using an improved implantable middle ear transducer for driving an ossicular chain bone to assist in aiding hearing. One embodiment of the present invention is a transducer assembly for converting electrical signals to mechanical vibrations which can be coupled, for example, to the stapes to provide audible frequency vibrations to the cochlea. One transducer assembly includes a pair of fins or gussets coupled to opposite sides of a transducer in the direction of unwanted movement of the transducer. The base of the transducer may be coupled to a base member while the fins have free edges that are near to but not coupled to the base member. Some fins are triangular shaped. The fins may not substantially inhibit vibration in the preferred plane, but can inhibit unwanted vibrations in a plane orthogonal to the preferred direction which can substantially include a plane containing the fins.
Abstract: A driver and sensor assembly that is hermetically sealed so that the assemblies may be fully implanted in a being. The assemblies employ a transducer that has a longitudinal axis and that vibrates or picks up vibration in a direction substantially transverse to its longitudinal axis. A sheath covers the transducer and is hermetically sealed to a housing. Leads from a sound processor are coupled to the housing and the entire assembly is hermetically sealed.
Abstract: Methods and structures for placing sensing and driver assemblies in a middle ear of a patient are disclosed. Methods and structures according to various embodiments of the invention provide minimally invasive techniques and devices that facilitate placement of sensing/driver assemblies in a middle ear using a trans-canal implantation technique. Certain embodiments include placement of a longitudinal body through the ear canal for mounting in the middle ear, and for supporting a sensing/driving assembly subsequently coupled thereto.
January 17, 2006
Date of Patent:
November 20, 2007
Envoy Medical Corporation
Johann J. Neisz, Eric Kraus, Michael Glasscock, Aaron Thornton, John F. Kveton