Abstract: Described is an inductive compensating network coupled between the differential inputs of an operational amplifier circuit. The inductive compensating network includes at least one inductive element having an inductance value selected so as to provide proper compensation of the operational amplifier circuit. Also described is a feedback compensation scheme which adjusts loop characteristics by introducing zeros into a system with the addition of inductive or capacitive elements in a feedback path.

Abstract: A microchip for performing a neural decoding algorithm is provided. The microchip is implemented using ultra-low power electronics. Also, the microchip includes a tunable neural decodable filter implemented using a plurality of amplifiers, a plurality of parameter learning filters, a multiplier, a gain and time-constant biasing circuits; and analog memory. The microchip, in a training mode, learns to perform an optimized translation of a raw neural signal received from a population of cortical neurons into motor control parameters. The optimization being based on a modified gradient descent least square algorithm wherein update for a given parameter in a filter is proportional to an averaged product of an error in the final output that the filter affects and a filtered version of its input. The microchip, in an operational mode, issues commands to controlling a device using learned mappings.

Abstract: An ultra-low-power circuit for wireless neural recording and stimulation is provided. The circuit includes a neural amplifier with adaptive power biasing for use in multi-electrode arrays and a decoding and/or learning architecture. An impedance-modulation telemetry system provides low-power data telemetry. Also, the circuit includes a wireless link for efficient power transfer, and at least one circuit for wireless stimulation of neurons.

Abstract: A system and method for stimulating an electrode is provided. The stimulator includes a sensor circuit configured to couple to the at least one electrode of a medical device to measure a power characteristic of the at least one electrode. The stimulator includes a control circuit configured to compare the measured power characteristic of the at least one electrode to a desired power characteristic, and, based upon a comparison of the measured power characteristic of the at least one electrode and the desired power characteristic, select between a first operational mode and a second operational mode of the electrode stimulator. The first operational mode includes delivering energy to the at least one electrode to stimulate the tissue and the second operational mode includes recovering energy from the at least one electrode.

Abstract: A system for modeling chemical reactions using analog or hybrid-analog-digital electronic circuits. The system exploits similarities between the kinetic rates of chemical reaction and the rates governing current flow in electronic devices such as bipolar junction transistors (BJTs) and metal oxide semiconductor field effect transistors (MOSFETs) operating at subthreshold conditions. These devices, which accurately model the stochastics of chemical processes, can be networked into large arrays to model chemical reaction networks, including biochemical reactions and genetic processes such as activation, induction, transcription, and translation.

Abstract: An energy-efficient photoreceptor apparatus and a transimpedance amplifier apparatus having high energy-efficiency and low power consumption of which are achieved through multiple distributed gain amplification stages, adaptive loop gain control circuitry and unilateralization, thereby enabling fast and precise performance over a wide range of input-current levels. The high-energy efficiency, robust feedback stability and performance of the present invention can be utilized to achieve sub-milliwatt pulse oximeters and may be employed in other current-to-voltage amplification and conversion applications. The use of analog processing on the outputs of the photoreceptor apparatus also helps lower the overall power of pulse oximeters.

Abstract: A micropower neural amplifier with adaptive power biasing for use in multi-electrode arrays is provided. The micropower neural amplifier includes a low noise gain stage. The low noise gain stage is implemented using an amplifier and pseudoresistor elements.

Abstract: A system and technique for providing to flexible, programmable frequency estimators and spectrum analyzers that can operate over extremely large bandwidths and yet provide high spectral resolution are described. The acquisition time and hardware complexity of one technique scale as O(N), where N denotes the number of frequency bins acquired. Embodiments are disclosed in which architectures are implemented using exponentially-tapered transmission lines and filter cascades.

Abstract: A system and technique for providing to flexible, programmable frequency estimators and spectrum analyzers that can operate over extremely large bandwidths and yet provide high spectral resolution are described. The acquisition time and hardware complexity of one technique scale as O(N), where N denotes the number of frequency bins acquired. Embodiments are disclosed in which architectures are implemented using exponentially-tapered transmission lines and filter cascades.

Abstract: Described is a battery charger circuit for charging a battery. The battery charger circuit comprises a control element having a first input configured to receive an input from a reference source, a second input configured to receive an input from the battery and an output, said control element having an output current response characteristic which varies with respect to the battery input such that said control element implements a saturating function that causes the charging current of the battery to automatically transition between a constant current operating mode and a constant voltage operating mode or a constant voltage operating mode to a constant current operating mode.

Abstract: In one aspect, the invention is a far-field power extraction circuit which includes an integrated antenna and impedance matching portion and a rectifier portion. The antenna and impedance matching portion includes an antenna configured to be responsive to a propagating electromagnetic signal and which provides a resonant response at a resonant frequency. In response to the electromagnetic signal, the antenna provides an electromagnetic output signal at an antenna port. The antenna and impedance matching portion is configured to match an antenna impedance with a remainder of the far-field power extraction circuit including the rectifier portion of the power extraction circuit coupled to the antenna and impedance matching portion. The rectifier is configured to rectify the electromagnetic output signal provided by the antenna to produce a direct current (DC) voltage at an output of the rectifier.

Abstract: A neural prosthetic device is provided that includes one or more ion-selective membranes enabling electrically-controlled local modulation of ion concentrations around a nerve so as to achieve different excitability states of the nerve for electrical stimulation or inhibition of nerve signal propagation.

Abstract: The present invention provides methods and systems for selecting one or more channels of a neural implant to stimulate. A channel selection unit is configured to asynchronously and stochastically select the winning channel or channels based, in part, on the richness of the input sensory environment. Thereafter, the channel selection unit reduces the likelihood that the selected channel or channels will be selected again for a period of time.

Abstract: A spectral enhancement system is disclosed that includes an input node for receiving an input signal, at least one broad band pass filter coupled to the input node and having a first band pass range, at least one non-linear circuit coupled to the filter for non-linearly mapping a broad band pass filtered signal by a first non-linear factor n, at least one narrow band pass filter coupled to the non-linear circuit and having a second band pass range that is narrower than the first band pass range, and an output node coupled to the narrow band pass filter for providing an output signal that is spectrally enhanced.

Abstract: A low power high dynamic range microphone amplification system is disclosed. The system includes a current sensing amplifier for receiving an input current signal representative of auditory information and for providing an amplifier output signal. The current sensing amplifier includes a DC bias network that includes a cascode filter.

Abstract: A speech processing system includes a plurality of signal analyzers that extract salient signal attributes of an input voice signal. A difference module computes the differences in the salient signal attributes. One or more control modules control a plurality of speech generators using an output signal from the difference module in a speech-locked loop (SLL), the speech generators use the output signal to generate a voice signal.

Abstract: A system for modeling chemical reactions using analog or hybrid-analog-digital electronic circuits. The system exploits similarities between the kinetic rates of chemical reaction and the rates governing current flow in electronic devices such as bipolar junction transistors (BJTs) and metal oxide semiconductor field effect transistors (MOSFETs) operating at subthreshold conditions. These devices, which accurately model the stochastics of chemical processes, can networked into large array to model chemical reaction networks, including biochemical reactions and genetic processes such as activation, induction, transcription, and translation.

Abstract: A wearable system for monitoring a plurality of physiological signals is provided. The wearable system includes at least one sensor producing the physiological signals associated with a patient. A processor unit receives the physiological signals from the at least one sensor. The processor unit analyzes the physiological signals to determine the occurrence of a triggered event and produces at least one output signal identifying the triggered event. A transmission unit receives the at least one output signal and prepares for transmission of the at least one output signal.

Abstract: A method and system processes a speech signal. A fast Fourier transform is performed on a speech signal to produce a speech signal having a plurality of frequency bands in a frequency domain.

Abstract: A visual prostheses codes visual signals into electrical stimulation patterns for the creation of artificial vision. In some examples, coding of the information uses image compression techniques, temporal coding strategies, continuous interleaved sampling (CIS), and/or radar or sonar data. Examples of the approach are not limited to processing visual signals but can also be used to processing signals at other frequency ranges (e.g., infrared, radio frequency, and ultrasound), for instance, creating an augmented visual sensation.