Abstract: A system includes an ensemble of wirelessly networked intracranial implants, and a compact external epidermal wearable skin patch radio frequency (RF) transceiver and data processing hub, the network of intracranial implants wirelessly linked to the skin patch RF transceiver and data processing hub.

Abstract: A low-power wake-up receiver. The receiver includes a transformer/filter resonating at a pre-selected frequency to realize passive RF voltage gain. A pseudo-balun envelope detector is coupled to an output of the transformer filter. A comparator or other quantizer is coupled to an output of the active pseudo-balun envelope detector (ED) for comparing the ED output to a comparison threshold voltage. The pseudo-balun envelop detector can be an active detector. The pseudo-balun detector can also be a passive detector.

Abstract: A DC-DC converter converts voltage from a battery source providing a voltage Vin to 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 Vin/3. The stress reduction transistors can also limit switching transistor voltages to Vin/3. Freewheel switches can be used to limit ringing in the output inductor.

Abstract: 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.

Abstract: A biosensor of the invention is a capacitive noncontact sensor with two sensor channels split into a plurality of physically interdigitated symmetrical electrodes and shield sections. Two capacitive plates are electrically connected to the two sensor channels. The capacitive noncontact sensor is sized and packaged to be worn by a person to place the capacitive plates close to the skin of the person and form first and second channel input capacitors with the skin. A signal reconstruction circuit obtains a bio signal from the first and second channel input capacitors through the electrodes by reconstructing differences in the two sensor channels. The circuit includes different parasitic input capacitance in the two channels to create channel-specific outputs that depend on input coupling capacitance.

Abstract: 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.

Abstract: 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.

Abstract: A hearing assistance and/or noise suppression device leverages computing power of an external device with a digital signal processor, such as a special unit that is configured to communicate with a smart device (e.g., a smart phone, smart watch or smart pendant) or a smart phone with a digital signal processor. Methods include having a hearing transducer communicate with and offload computing tasks to an external device with a digital signal processor. Systems include a hearing transducer with transducer circuitry that receives, amplifies and outputs digital signal processed audio from another device. Methods provide self-adjustment and fitting through a touch screen interface, which can be conducted outside of a clinical setting in a real world environment, and method can include remote data collection and communications with clinicians.

Abstract: A charging to digital converter sensor in a CMOS integrated circuit includes a sensor responding to a sensed property, a converter that converts the sensed property into a charging time, a digitizer for digitizing the charging time, and digital feedback to reset the converter to restart the charging time. Preferred methods for sensing match the rising time of the first ramp voltage to a second ramp voltage generated by a reference current mirrored from a common current generator via the tuning of DAC capacitors driven by an LSB-first SAR logic feedback; or match rising times of the first and second ramp voltages to a reference voltage and providing a digital signal that translates the relationship of the first ramp voltage and the reference voltage to a digital quantification of the sensed property.

Abstract: The invention provides a body area network. A first coil is configured to be worn on a body portion of a human, and the first coil is configured and positioned to use a body leveraged magnetic field. A transmitter drives the first coil to generate a magnetic body field through the first magnetic coil at a frequency selected such that the body leveraged magnetic field simultaneously includes near-field and far-field components and the far-field components are enhanced by a high dielectric constant of bodily tissue. A second coil couples to the signal transmitted via the first coil, and the second coil is configured and positioned to receive both of the near- and far-field components. A receiver receives the signal from the second coil.

Abstract: 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.

Abstract: A frequency scaled gear train switching voltage regulator and charge feedback integrated circuit includes cascaded capacitive cells configured such that flying capacitance of a given stage does not commence gathering new charge until the flying capacitor of a next stage retrieves a present stored charge of the given stage.

Abstract: A scalable controller circuit that provides faster and simpler regulation of a DC-to-DC converter is provided. Unlike such prior techniques, preferred embodiments do not require any threshold-level generation circuitry or analog compensation circuitry. Preferred embodiments implement a simple control law that requires only a few digital gates. Preferred embodiments can therefore significantly reduce the overhead power consumption and area of the controller in DC-to-DC converters to new levels.

Abstract: A method for adiabatic charging of a capacitive load sequentially connects outer switches between a voltage VDD and ground and inner switches to at least one capacitance that self-balances between VDD and ground. A voltage waveform is provided to the capacitive load from a common node of the outer switches and the inner switches. An adiabatic charging circuit includes outer transistor switches between a voltage VDD and ground. Inner transistor switches are connected to at least one capacitance that self-balances between VDD and ground. A control signal generating circuit generates control signals for the inner and outer transistor switches that sequentially turn the inner and outer switches on and off to create a multi-level voltage staircase waveform at a common node of the inner and outer transistor switches.

Abstract: A low-power wake-up receiver. The receiver includes a transformer/filter resonating at a pre-selected frequency to realize passive RF voltage gain. A pseudo-balun envelope detector is coupled to an output of the transformer filter. A comparator or other quantizer is coupled to an output of the active pseudo-balun envelope detector (ED) for comparing the ED output to a comparison threshold voltage. The pseudo-balun envelop detector can be an active detector. The pseudo-balun detector can also be a passive detector.

Abstract: 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.

Abstract: 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.

Abstract: A low power voltage regulator includes a weighted transistor array having a plurality of transistor switches with a total conductance of G, corresponding to bits from a MSB to LSB. A transistor switch corresponding to the MSB has a conductance of G/2 and remaining bits have a consecutive descending conductance of G/2N to the LSB, and search time takes a low number of cycles by starting with the MSB. A redundant LSB transistor switch has the same G/2N conductance of the LSB. The redundant LSB is used to correct steady-state errors, and a proportional derivative controller compensates output voltage. The compensation in a method eliminates an output pole of the voltage regulator to provide a stable voltage regulator operation irrespective of load current, load capacitance, or sampling frequency. Voltage can be regulated via the additional LSB below the resolution limit via pulse width modulation.

Abstract: A method of designing an imaging system including an optical system having a longitudinal optical axis, an image sensor and a spatial filter, the imaging system being configured to form an image of a focusing plane on the image sensor. The optical transfer function of the optical system combined with the spatial filter is calculated as a function of the image spatial frequencies, and of the focusing defect (?), so as to determine a contrast map and a phase map of the optical system combined with the pupil function of the spatial filter, the contrast map and the phase map being a function, of the spatial frequency (f), and of the focusing defect (?), and it is determined, based on these maps, a value of longitudinal extension (|P|) of the imaging system focusing depth domain in the useful range of spatial frequencies ([?fc; fc]) and an average contrast C.

Abstract: The invention provides a body area network that uses a near magnetic field for communications. A first coil is configured to be worn on a body portion of a human. A transmitter drives the first coil to generate a magnetic body field through the first magnetic coil. A second coil couples to the signal transmitted via the first coil matched to the magnetic field and first coil. A receiver for receiving the signal from the second coil. A method for establishing network communications using the human body as a magnetic field includes associating a transmitter coil with a portion of a human body, the transmitter coil being configured to couple to a receiver coil in a near field of the human body; driving the transmitter coil to generate a magnetic near field around the human body; and coupling to the magnetic near field with a receiver coil.