Abstract: In accordance with the present invention, various embodiments of neurostimulators and stimulation systems are disclosed that provide different shapes and patterns of stimulus pulses and trains of pulses with fixed and no fixed frequencies. The neurostimulator can be configured to provide high frequency stimulation and also be implantable in the head or neck regions in order to stimulate nerves and nerve ganglions in the head and neck regions and also stimulate the brain.

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 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: An electrode lead may comprise a flexible circuit that includes a planar dielectric substrate including an elongated lead substrate portion having opposing ends, an electrode carrying substrate portion disposed on one end of the lead substrate portion, and a connector substrate portion disposed on the other end of the lead substrate portion, wherein the lead substrate portion is pre-shaped into a three-dimensional structure. The flexible circuit may further include an electrically conductive trace extending from the connector substrate portion to the electrode carrying substrate portion, a first window formed in the connector substrate portion to expose the electrically conductive trace to form a connector pad, and a second window formed in the electrode carrying substrate portion to expose the electrically conductive trace to form an electrode pad. The electrode lead may further comprise a lead connector that incorporates the connector substrate portion.

Abstract: An electrode lead may comprise a flexible circuit that includes a planar dielectric substrate including an elongated lead substrate portion having opposing ends, an electrode carrying substrate portion disposed on one end of the lead substrate portion, and a connector substrate portion disposed on the other end of the lead substrate portion, wherein the lead substrate portion is pre-shaped into a three-dimensional structure. The flexible circuit may further include an electrically conductive trace extending from the connector substrate portion to the electrode carrying substrate portion, a first window formed in the connector substrate portion to expose the electrically conductive trace to form a connector pad, and a second window formed in the electrode carrying substrate portion to expose the electrically conductive trace to form an electrode pad. The electrode lead may further comprise a lead connector that incorporates the connector substrate portion.

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: 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: 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 medical device of a medical system is configured for communicating with an external programmer over a wireless communications link. The medical device comprises a wireless communications module configured for receiving a first unencrypted version of a random number and a first encrypted version of the random number from the external programmer over the wireless communications link. The medical device further comprises control circuitry configured for performing an authentication procedure on the external programmer based on the first unencrypted version of the random number and the first encrypted version of the random number, and preventing the external programmer from commanding the medical device to perform an action unless the authentication procedure is successful.

Abstract: Systems and method utilizing microelectronic devices for determining relative positions such as distances and/or angles between at least two points is described. The points may be locations of parts of the body such as the fingers on a person's hand. A first microelectronic device is adapted to emit magnetic signals and at least one second microelectronic device is adapted to receive the magnetic signals, wherein a controller is adapted to communicate with the first and second microelectronic devices. The second microelectronic device and/or the controller are adapted to determine a distance and angle between the first and the second microelectronic devices based on the strength of the magnetic signals received by the second microelectronic device.

Abstract: A fully integrated feedback controlled coil driver is disclosed for inductive power transfer to electronic devices. For efficient power transfer, a voltage across a switch that switchably couples the coil between a DC input power source and ground is sampled and compared with a preselected reference voltage to generate an error voltage. The error voltage is integrated over time and compared to a voltage ramp. The value of the integrated error voltage relative to the voltage ramp is used to obtain an optimal on time for the switch such that coil current is maximized for a given DC input power. The coil driver can also provide ASK modulation on the coil current by changing the size of the switch according to input data.

Abstract: An interface for coupling with a percutaneously implantable lead is described. The interface includes a rotation based system to engage the terminal connector of the lead. The interface includes a brake which retains the lead in the lead port through friction, but allows the lead to exit the lead port if sufficient force is applied. The interface can be coupled with the lead without removing a stylet or stiffening wire from the lead.

Abstract: A pressure sensor module configured for implant at a desired site at which a pressure is to be measured. The pressure sensor module includes a pressure sensitive membrane which is in direct contact with the environment at which a pressure is to be measured. The pressure sensor module forms a part of a pressure measuring system which uses a telemetry link between the pressure sensor module and an external controller for data transmission and transfer. The pressure measuring system provides a dual stage power and data transfer capability for use with an implantable system. An exemplary use is in a three pressure sensor system including a flow control valve in a shunt to treat hydrocephalus. An embodiment of the invention includes a pressure sensor and associated electromagnetic coils embedded in the tip portion of the shunt for measuring the pressure of fluid externally of the shunt at the tip portion.

Abstract: A timing controlled converter and method for converting a time varying input signal to a regulated DC output voltage for application to a load circuit. A feedback loop is employed as a control means for switchably coupling the time varying input signal to the load circuit for controlled periods of time in a manner so as to provide an average load voltage equal to a reference voltage. The duration of the controlled periods of time is a function of: the difference between the time varying input signal and the output voltage; and the integral of the difference between the output voltage and the reference voltage.

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: An implantable pressure sensor device and devices incorporating an implantable pressure sensor are disclosed. The implantable pressure sensor may include a housing with a deflectable wall, and may be incorporated into a housing of an implantable medical device such as an implantable pulse generator. The pressure sensor may monitor respiration by measuring the deflection of the deflectable wall caused by expansion of the thoracic wall or ribcage.

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.