University of California

Other

Massachusetts Institute of Technology

Massachusetts Eye and Ear Infirmary

Patrick Mercier

Joseph Wang

Hui Wang

Loai Galal Bahgat Salem

Jiwoong Park

Dinesh Bharadia

Po-Han Wang

Anantha P Chandrakasan

Gert Cauwenberghs

Amay Jairaj Bandodkar

Sohmyung Ha

Chul Kim

Manideep Dunna

Abraham Akinin

Harinath Garudadri

Saurav Bandyopadhyay

James F Buckwalter

Truong Q Nguyen

Konstantina Stankovic

Drew A Hall

Chung-Kuan Cheng

Christoph Hans Maier

Sally Amin

Miao Meng

Dukju Ahn

Nader Fathy

Haowei Jiang

Shih-Hung Weng

Xiaoyang Wang

Arthur Boothroyd

Shih-Kai Kuo

Carol Mackersie

Andrew Lysaght

Somayeh Imani

Ali Fazli Yeknami

Jiannan Huang

A beam-steering backscatter circuit in an integrated tag device. The circuit includes an antenna array and SP4T reflector array configured to receive and transmit through the antenna array. A baseband phase-shifting module modulates an incident signal based upon tag data to create an output signal and re-radiates the output signal with a controllable angle of direction through the SP4T reflector array. A phase locked loop synchronized with a wake-up receiver provides an intermediate frequency (IF) clock to the baseband phase shifting-module.

Beam-steering backscatter circuit for integrated tag device

A method for obtaining neural signals from a neural signal sensor includes extracting sensor offset from a neural input signal. Sensor offset is removed from N-channels that share a single amplifier. The neural input signal is acquired from the analog domain by neural electrodes with varying DC-offset and the method includes multiplexing the N-channels via a time divisional multiple access procedure into a single neural amplifier An integrated digitally assisted neural recording system includes an analog multiplexer structured to receive N-channels and to multiplex the N-Channels into a single neural amplifier. A feedback loop is configured to cancel electrode offset voltage in the digital domain by generating electrode offset voltage samples and adding delay to align each electrode offset voltage sample to be subtracted at the neural amplifier in the analog domain.

Digitally assisted sensor recording circuit with continuous offset cancellation

A method for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device is provided. The method includes sensing an incident Wi-Fi? compliant wake-up signal. The method than reflects the incident Wi-Fi-complaint wake-up signal by encoding data from the tag device such that the reflected signal follows the Wi-Fi standard compliant and can be decoded by another WiFi-device. An integrated device includes a downlink Wi-Fi compatible wake-up receiver that checks timing of Wi-Fi compatible signals for a wake-up packet. The device has a modulator that is turned on in response to the wake-up packet and a mixer in the modulator hat mixes tag data with a payload packet from received Wi-Fi payload. Backscatter switches backscatter the response.

Low power Wi-Fi backscatter communication

An analog to digital conversion (ADC) circuit includes a voltage-controlled oscillator (VCO)-based quantizer that receives a voltage input signal to be quantized and provides a digital output. A predictor samples the digital output, evaluates correlation between successive samples, and predicts a predicted input sample from the correlation to minimize voltage-to-frequency transfer of the VCO. A feedback loop L1 with a digital to analog converter (DAC) receives the predicted input sample, converts it and subtracts it from the voltage input signal. A feedback loop L2 adds the predicted sample to the digital output.

High resolution VCO-based ADC

Termination circuits for backscatter communication in an integrated wake-up receiver tag device. A reflective termination circuit includes a first branch having an open load and a shorted load with first branch offset reflection coefficients and with a connection to an antenna. A second branch has a capacitive load and an inductive load with second branch offset reflection coefficients and with a connection to an antenna. A MIMO termination circuit includes plurality of transmission lines each providing a unique delay that is offset compared to other ones of the plurality of transmission lines. Switched connections to a corresponding array of antennas introduce a delay between a received and backscattered signal at each antenna in the array of antennas.

Termination circuit for low power backscatter communication

A transmitter for a magnetic body area network includes a power oscillator that directly uses a body coil as a resonant element. Shunt transistor circuitry is between the power oscillator and the body coil, the shunt transistor circuitry selectively shunts current from the body coil in response to a data signal provided to the transmitter. Power injection circuitry is synchronized to the power oscillator to selectively inject power into the body coil in response to the data signal. A tuning capacitor array is disposed to tune frequency in the body coil. A frequency-locked-loop responds to a frequency in the body coil and tunes the tuning capacitor array to lock to a carrier frequency. Very high Q coils can be used while achieving high data transmission rates of 5 mbps to 10 mbps. Transmitters and methods are applicable to on-off-key modulation, frequency-shift modulation and amplitude-shift modulation.

Low power magnetic field body area network with quenching and quick start

A non-invasive epidermal electrochemical sensor device includes an adhesive membrane; a flexible or stretchable substrate disposed over the adhesive membrane; and an anodic electrode assembly disposed over the flexible or stretchable substrate including an iontophoretic electrode. The device includes a cathodic electrode assembly disposed adjacent to the anodic electrode assembly over the flexible or stretchable substrate and includes an iontophoretic electrode. Either the cathodic electrode assembly or the anodic electrode assembly also includes a sensing electrode that includes a working electrode and at least one of a counter electrode or a reference electrode. The iontophoretic electrode in either the anodic electrode assembly or the cathodic electrode assembly that includes the sensing electrode is disposed on the substrate to at least partially encompass the working electrode and the at least one of the counter electrode or the reference electrode. The device includes an electrode interface assembly including independent electrically conductive contacts.

Non-invasive and wearable chemical sensors and biosensors

Methods, systems, and devices are disclosed mouth-based biosensors and biofuel cells. In one aspect, an electrochemical sensor device for detecting analytes in saliva includes a substrate including an electrically insulative material, a first electrode disposed on the substrate at a first location, in which the first electrode includes a surface including a chemical agent (e.g., a catalyst or a reactant) corresponding to an analyte in saliva; and a second electrode disposed on the substrate at a second location separated from the first electrode by a spacing region, the first and second electrodes capable of sustaining a redox reaction involving the chemical agent and the analyte to produce an electrical signal, such that, when the device is present in the mouth of a user and electrically coupled to an electrical circuit, the device is operable to detect the analyte in the user's saliva.

Salivary biosensors and biofuel cells

Disclosed are self-powering biofuel cell and sensor devices, systems and techniques. In some aspects, a self-powered biosensing system includes an electronic circuit; an anode including an enzymatic layer electrically coupled to a power supply voltage terminal of the electronic circuit and configured to interact with an analyte in a fluid, such as glucose or lactate; and a cathode electrically coupled to a ground voltage terminal of the electronic circuit, where the electronic circuit is operable to control and use the electrical energy generated at the anode and cathode for powering the biosensing system and detecting a concentration of the analyte in the fluid.

Self-powered biosensors

A low-power wake-up receiver includes a mixer-based two-stage heterodyne architecture that provides multi-stage channel filtering, including a combination of circuits and a digital signal processor that process energy in a plurality of advertising channels to detect a four-dimensional wake-up signature via frequency-hopping among the plurality of advertising channels. One receiver is a BLE/Wi-Fi dual-mode wake-up receiver.

BLE and/or WiFi compliant and blocker-resilient wake-up receiver and method

A charging to digital converter sensor in a CMOS integrated circuit digitizes a sensed property by comparing charging time between two paths and adjusting the charging rate of one of the two paths by increasing or decreasing the amount of capacitance in that path, until both of the two paths have the same charging time to reach respective constant with sensed property and proportional with sensed property reference voltages or currents. Sub nanowatt operation is achieved with preferred circuits. A method directly digitizes, on-chip, a charging time comparison of two ramp voltages that are compared to respective constant with sensed property and proportional with sensed property reference voltages or currents.

Near zero power fully integrated digital conversion, sensors and sensing methods

A DC-DC converter converts voltage from a battery source providing a voltage Vto a lower level. A four-level transistor stack selectively connects an input voltage and flying capacitor voltages to an output inductor. Stress reduction transistors limit the charging of the flying capacitors to V/3. The stress reduction transistors can also limit switching transistor voltages to V/3. Freewheel switches can be used to limit ringing in the output inductor.

Li-ion-compatible fully-integrated hybrid converter

An ultra-low-power voltage reference generator in an integrated CMOS circuit includes a regular MOS transistor reference current source connected to a line voltage and a regular MOS transistor resistor between the regular MOS transistor reference current source and ground. A constant with temperature reference voltage VREF is generated from a terminal inter-connecting the regular MOS transistor reference current source and the regular MOS transistor resistor. An ultra-low-power current reference generator receives a reference voltage and generated ultra-low level current from the reference voltage with a temperature compensated gate-leakage array.

Stabilized voltage and current reference generator and circuits

Methods, systems, and devices are disclosed for wearable, real-time multimodal sensing of electrochemical and electrophysiological and/or physical parameters of a user. In some aspects, a multimodal sensor device includes a flexible substrate; an electrochemical sensor disposed on the substrate and including electrochemical sensing electrodes operable to measure an electrical signal corresponding to a reaction including a chemical substance via an electrochemical sensing electrode and an analyte at the electrochemical sensor; and an electrophysiological sensor including two or more electrodes disposed on the substrate to acquire an electrophysiological signal of the user, such that when the multimodal sensor device is electrically coupled to an electronics unit and adhered to the user, the device is operable to simultaneously monitor an electrochemical parameter and an electrophysiological parameter of the user.

Flexible epidermal multimodal health monitor

A fast startup power oscillator transmitter includes a transistor pair that drives a resonant circuit including a tunable capacitance. A capacitor array preferably forms the tunable capacitance. A voltage booster activates the capacitor array. A clamped body bias voltage booster can set the body bias voltage of the transistor pair in one circuit. Control circuitry activates the resonant circuit through a triode-mode switch transistor in response to an input in a range of 0.3-0.6V, and preferably while controlling the substrate bias voltage of the transistor pair to increase transconductance of the cross-coupled transistor pair. In a variation, a circuit pushes a top plate voltage of one of the two capacitors to 2Vand pulls the top plate voltage of the other to zero to give the oscillator an initial condition. In a variation, a shaped pulse drives the transistor pair to switch to a class D oscillator mode, and the triode mode switch transistor is only turned on when the oscillation signal voltage is in the range of 0.3-0.6V.

Growing community of inventors

San Diego, CA, United States of America

Patrick Mercier