Abstract: The present invention relates to a monolith for processing fluid samples, and methods of making and using the monolith. The monolith can contain certain monomers or combinations of monomers that can be polymerized to give a polymeric monolith that can efficiently self-wick fluid. The self-wicking polymeric monolith can be used as a convenient tool for point of care/on site diagnostics and analytics. The monolith is easily stored and transported, comparatively cost-efficient to make, permits good detection of analyte molecules and is readily functionalizable by impregnation of and/or covalently grafting additional chemical moieties to either the whole monolith or in zones.

Abstract: A multiple output current stimulator circuit with fast turn on time is described. At least one pair of input side and output side transistors is arranged in a current mirror connected to a supply transistor by cascode coupling. The output side transistor supplies stimulation current to an electrode in contact with tissue. An operational amplifier connected to a reference voltage and to the output side transistor drives the supply transistor to maintain the voltage at the output side transistor equal to the reference voltage. The at least one pair of transistors includes multiple pairs of transistors whose output side transistors drive respective electrodes with stimulation currents. The stimulator determines the initiation and duration of stimulation current pulses supplied to each electrode. At circuit activation, large currents are generated which discharge capacitances in the output side transistors causing rapid output side transistor turn on.

Abstract: An upper airway stimulator for treating obstructive sleep apnea is described. In some embodiments, the upper airway stimulator monitors the phase difference between ribcage expansion and abdomen expansion to detect apneic events and stimulates to alleviate those events. In some embodiments, the upper airway stimulator applies primary stimulation when an apneic event is not detected and secondary stimulation when an apneic event is detected. In some embodiments, the upper airway stimulator applies primary stimulation when the patient is not in an apneic position and secondary stimulation when the patient is in an apneic position.

Abstract: An upper airway stimulator for treating obstructive sleep apnea is described. In some embodiments, the upper airway stimulator monitors the phase difference between ribcage expansion and abdomen expansion to detect apneic events and stimulates to alleviate those events. In some embodiments, the upper airway stimulator applies primary stimulation when an apneic event is not detected and secondary stimulation when an apneic event is detected. In some embodiments, the upper airway stimulator applies primary stimulation when the patient is not in an apneic position and secondary stimulation when the patient is in an apneic position.

Abstract: An upper airway stimulator for treating obstructive sleep apnea is described. In some embodiments, the upper airway stimulator monitors the phase difference between ribcage expansion and abdomen expansion to detect apneic events and stimulates to alleviate those events. In some embodiments, the upper airway stimulator applies primary stimulation when an apneic event is not detected and secondary stimulation when an apneic event is detected. In some embodiments, the upper airway stimulator applies primary stimulation when the patient is not in an apneic position and secondary stimulation when the patient is in an apneic position.

Abstract: A multiple output current stimulator circuit with fast turn on time is described. At least one pair of input side and output side transistors is arranged in a current mirror connected to a supply transistor by cascode coupling. The output side transistor supplies stimulation current to an electrode in contact with tissue. An operational amplifier connected to a reference voltage and to the output side transistor drives the supply transistor to maintain the voltage at the output side transistor equal to the reference voltage. The at least one pair of transistors includes multiple pairs of transistors whose output side transistors drive respective electrodes with stimulation currents. The stimulator determines the initiation and duration of stimulation current pulses supplied to each electrode. At circuit activation, large currents are generated which discharge capacitances in the output side transistors causing rapid output side transistor turn on.

Abstract: A multi-branch stimulation electrode is disclosed herein. The multi-branch stimulation electrode can include a plurality of branches that extend from a hub. The branches can each include one or several stimulation contacts that can deliver an electrical current to tissue contacting the stimulation contacts. The stimulation contacts can be electrically connected with the lead. The lead can extend from the hub and can be connected with the pulse generator. The branches can include features to facilitate implantation including, for example, one or several removable stiffening elements.

Abstract: An inductive wireless power transfer and communication system includes an electrostatic shield for one of the coils. The electrostatic shield is inductively coupled with the coil and is configured as an open circuit. A signal processing element or elements, especially a modulator or a demodulator, are connected across the electrical discontinuity in the electrostatic shield. Because the electrostatic shield is inductively coupled to the coil, the modulator or demodulator can operate on the signal on the coil. A variable impedance element is connected across the electrical discontinuity in the electrostatic shield. Because the electrostatic shield is inductively coupled to the coil, the variable impedance element can tune the impedance of the system.

Abstract: Described herein are monoliths for processing fluid samples, and methods of making and using such monoliths.

Abstract: Methods and systems for applying charge to a piezoelectric element include and/or facilitate implementation of processes including cyclical multi-stage processes for: providing a piezoelectric element with an accumulated charge; providing one or more charge holding elements with a scavenged charge from the piezoelectric element; substantially removing or discharging a remaining charge from the piezoelectric element; and applying the scavenged charge to the piezoelectric element with an opposite polarity in relation to the polarity of the remaining charge.

Abstract: Systems, methods, and devices for wireless recharging of an implanted device. In response to receiving identification information from an implanted device, a charger can set an electrical field to a first field strength and receive first field strength information from the implanted device. The charger can then set the electrical field to a second field strength and receive second field strength information from the implanted device. This information relating to the first and second field strengths can be used to determine whether to recharge the implanted device.

Abstract: Methods and systems for applying charge to a piezoelectric element include and/or facilitate implementation of processes including cyclical multi-stage processes for: providing a piezoelectric element with an accumulated charge; providing one or more charge holding elements with a scavenged charge from the piezoelectric element; substantially removing or discharging a remaining charge from the piezoelectric element; and applying the scavenged charge to the piezoelectric element with an opposite polarity in relation to the polarity of the remaining charge.

Abstract: An inductive wireless power transfer and communication system includes an electrostatic shield for one of the coils. The electrostatic shield is inductively coupled with the coil and is configured as an open circuit. A signal processing element or elements, especially a modulator or a demodulator, are connected across the electrical discontinuity in the electrostatic shield. Because the electrostatic shield is inductively coupled to the coil, the modulator or demodulator can operate on the signal on the coil.

Abstract: A microfluidic flow rate sensor includes a droplet within a channel and a droplet movement detector that generates a signal based on the position and/or movement of the droplet within the channel. A processor determines the flow rate of a fluid through the channel based on the signal received from the droplet movement detector. In one example, the droplet movement detector is an optical detector, such as a combination of a lens and an image capturing device. In other examples, the droplet is electrically conductive, and at least a portion of the channel is conductive or includes electrical contacts. The position of the droplet within the channel is determined by observing the electrical characteristics of the channel.

Abstract: A successive approximation ADC made of a low voltage configurable differential amplifier and low voltage logic circuits which can convert a high voltage analog input to a digital equivalent. The differential amplifier can be configured as either an op amp or a comparator depending upon the mode of operation. An input capacitor C1 is switchably coupled to an electrode selected for voltage sampling. A switched capacitor array C2 is coupled across the differential amplifier input and output. A SAR coupled to the switched capacitor array provides a digital output corresponding to the sampled analog voltage. During a sampling interval and a charge transfer interval, the differential amplifier is configured as an op amp. During the transfer interval, the voltage on the input capacitor multiplied by the ratio C1/C2 is transferred to the switched capacitor array. During an analog to digital conversion interval, the ADC converts the analog voltage to an equivalent digital output.

Abstract: Methods of making an implantable pulse generator are disclosed herein. The implantable pulse generator can include a body defining an internal volume and a plurality of wires extending from out of the internal volume of the body. Some of these wires can be connected, either directly or indirectly to a lead via a welded joint. The welded joint can be created by first resistance welding and then laser welding some of the wires to a connector.

Abstract: Systems and devices for a high-efficiency magnetic link for implantable devices are disclosed herein. These devices can include a charging coil located in the implantable device and a charging coil located in a charge head of a charger. The charging coils can each include an elongate core and wire windings wrapped around a longitudinal axis of the elongate core. The charging coil of the charge head can be attached to a rotatable mount, which can be used to align the longitudinal axis of the charging coil of the charge head with longitudinal axis of the implantable device such that the axes of the charging coils are parallel.

Abstract: A feedback controlled coil driver with ASK modulation is disclosed. A class E coil driver drives an LC circuit to generate a magnetic signal via the inductor. A modulation capacitor is coupled to the LC circuit to modulate the coil driver signal. The voltage across the coil driver switch is sampled. The difference between the sampled voltage and a reference voltage is integrated and compared to a ramp voltage to obtain an optimal on time for the coil driver switch such that coil current is maximized.

Abstract: A charger including a class E power driver, a frequency-shift keying (“FSK”) module, and a processor. The processor can receive data relating to the operation of the class E power driver and can control the class E power driver based on the received data relating to the operation of the class E power driver. The processor can additionally control the FSK module to modulate the natural frequency of the class E power transformer to thereby allow the simultaneous recharging of an implantable device and the transmission of data to the implantable device. The processor can additionally compensate for propagation delays by adjusting switching times.

Abstract: A charger that evaluates the effectiveness of the charging field generated by the charger at an implantable device. The charger includes a charging coil, a communication module, and a processor. The processor can include instructions to determine the effectiveness of the charging field based on one or several signals or communications received from the implantable device. The charger can use the determination of the effectiveness of the charging field to vary the strength of the charging field and/or to prompt the user to move the charger with respect to the implantable device.