Primoz Strojnik

Bio: Primoz Strojnik is an academic researcher. The author has contributed to research in topics: Signal & Current source. The author has an hindex of 9, co-authored 12 publications receiving 2121 citations.

Structure and method of manufacture of an implantable microstimulator

Abstract: An implantable microstimulator has a structure which is manufactured to be substantially encapsulated within a hermetically-sealed housing inert to body fluids, and of a size and shape capable of implantation in a living body, by expulsion through a hypodermic needle. The internal structure of the microstimulator comprises a coil adapted to function as the secondary winding of a transformer and receive power and control information. Circuit means, including control electronics, a capacitor and electrodes are provided. The electrodes, which may be made one of iridium and the other of tantalum and placed on opposite ends of the microstimulator, or alternatively, an iridium electrode at each end of the microstimulator, are at least partially exposed and provide electrical, stimulating pulses to the body.

Implantable microdevice with self-attaching electrodes

Abstract: An implantable microminiature stimulator and/or sensor (microdevice) is housed within a sealed housing that includes all the requisite electronic circuitry for inductively receiving power and control signals to sense of biopotential or other biomedical signals and/or to generate electrical stimulation pulse(s) between opposing electrodes. In a preferred embodiment, the housing of the microdevice is tubular, with opposing electrodes extending from each end. The electrodes are self-attaching electrodes that attach to a nerve or muscle without suturing. The electrodes are configured to helically curl around the desired nerve, thereby permitting the microdevice to stimulate the nerve or muscle, or sense signals associated with the nerve or muscle, using a minimal amount of energy. The electrodes and microdevice are sufficiently small to allow attachment to a single nerve, thereby preventing tethering of the nerve or muscle, and to allow their implantation within living tissue through small incisions or puncture holes. The muscle or nerve to which the microdevice is attached may be of any type, e.g., skeletal, smooth or cardiac.

Micromodular implants to provide electrical stimulation of paralyzed muscles and limbs

Abstract: Describes the design, fabrication, and output capabilities of a microminiature electrical stimulator that can be injected in or near nerves and muscles. Each single channel microstimulator consists of a cylindrical glass capsule with hermetically sealed electrodes in either end (2-mm diameter/spl times/13-mm overall length). Power and digital control data can be transmitted to multiple implants (256 unique addresses) via a 2-MHz RF field created by an external AM oscillator and inductive coil. In vitro testing demonstrated accurate control of output pulsewidth (3-258 /spl mu/s in 1-/spl mu/s steps) and current (0-30 mA in two linear ranges of 16 steps each, up to 8.5 V available compliance voltage). Microstimulators were used successfully for chronic stimulation in hindlimb muscles of cats. Design and fabrication issues affecting yield and reliability of the packaging and electronics are discussed.

Multichannel cochlear implant system including wearable speech processor

Abstract: A tissue stimulating system including an external transmitter for transmitting data to an implanted stimulator including a processor for generating stimulation signals for application to a plurality of tissue stimulating electrodes. The processor selectively monitors the electrodes and/or voltages generated in the stimulator and generates stimulator status indicating signals for transmission to the external transmitter. The external processor receives and processes such status indicating signals.

Voltage/current control system for a human tissue stimulator

Abstract: A tissue stimulating system includes an external transmitter for transmitting a data signal to an implanted stimulator. The implanted stimulator includes a processor for generating stimulation signals for application to a plurality of tissue stimulating electrodes through respective isolated output channels. The implanted stimulator also includes a power supply that extracts a raw power signal from the data signal. A voltage downconverter generates at least four separate voltages from the extracted raw power signal by alternately connecting at least four capacitors in series across the raw power signal, thereby providing at least four output voltages, and then connecting the capacitors in parallel to transfer the charge stored thereon to a storage capacitor, which serves as the power source for portions of the stimulator. A selected one of the output voltages from the voltage downconverter is applied to an isolated refresh voltage capacitor in each output channel, where it controls a voltage controlled current source. The processor selectively monitors the electrodes and/or voltages generated in the stimulator and generates status indicating/measurement signals for transmission to the external transmitter. The external processor receives and processes the status indicating/measurement signals and uses the information therefrom to control the amount of power transmitted to the stimulator.

Analyte Monitoring Device And Methods Of Use

Abstract: An analyte monitor includes a sensor, a sensor control unit, and a display unit. The sensor has, for example, a substrate, a recessed channel formed in the substrate, and conductive material disposed in the recessed channel to form a working electrode. The sensor control unit typically has a housing adapted for placement on skin and is adapted to receive a portion of an electrochemical sensor. The sensor control unit also includes two or more conductive contacts disposed on the housing and configured for coupling to two or more contact pads on the sensor. A transmitter is disposed in the housing and coupled to the plurality of conductive contacts for transmitting data obtained using the sensor. The display unit has a receiver for receiving data transmitted by the transmitter of the sensor control unit and a display coupled to the receiver for displaying an indication of a level of an analyte. The analyte monitor may also be part of a drug delivery system to alter the level of the analyte based on the data obtained using the sensor.

Rechargeable spinal cord stimulator system

Abstract: A spinal cord stimulation (SCS) system includes multiple electrodes, multiple, independently programmable, stimulation channels within an implantable pulse generator (IPG) which channels can provide concurrent, but unique stimulation fields, permitting virtual electrodes to be realized. The SCS system includes a replenishable power source (e.g., rechargeable battery), that may be recharged using transcutaneous power transmissions between antenna coil pairs. An external charger unit, having its own rechargeable battery can be used to charge the IPG replenishable power source. A real-time clock can provide an auto-run schedule for daily stimulation. An included bi-directional telemetry link in the system informs the patient or clinician the status of the system, including the state of charge of the IPG battery. Other processing circuitry in the IPG allows electrode impedance measurements to be made. Further circuitry in the external battery charger can provide alignment detection for the coil pairs.

Combined dissecting, cauterizing, and stapling device

Abstract: A medical device (1) for simultaneously cutting tissue with a heating element (16), cauterizing the tissue with sealing elements (14, 15), and stapling the tissue together. The heating elements comprise bipolar RF electrodes.

Electrosurgical generator with adaptive power control

Abstract: An electrosurgical generator has an output power control system that causes the impedance of tissue to rise and fall in a cyclic pattern until the tissue is desiccated. The advantage of the power control system is that thermal spread and charring are reduced. In addition, the power control system offers improved performance for electrosurgical vessel sealing and tissue welding. The output power is applied cyclically by a control system with tissue impedance feedback. The impedance of the tissue follows the cyclic pattern of the output power several times, depending on the state of the tissue, until the tissue becomes fully desiccated. High power is applied to cause the tissue to reach a high impedance, and then the power is reduced to allow the impedance to fall. Thermal energy is allowed to dissipate during the low power cycle. The control system is adaptive to tissue in the sense that output power is modulated in response to the impedance of the tissue.

System of implantable devices for monitoring and/or affecting body parameters

Abstract: A system for monitoring and/or affecting parameters of a patient's body and more particularly to such a system comprised of a system control unit (SCU) and one or more other devices, preferably battery-powered, implanted in the patient's body, i.e., within the envelope defined by the patient's skin. Each such implanted device is configured to be monitored and/or controlled by the SCU via a wireless communication channel. In accordance with the invention, the SCU comprises a programmable unit capable of (1) transmitting commands to at least some of a plurality of implanted devices and (2) receiving data signal from at least some of those implanted devices. In accordance with a preferred embodiment, the system operates in closed loop fashion whereby the commands transmitted by the SCU are dependent, in part, on the content of the data signals received by the SCU. In accordance with the invention, a preferred SCU is similarly implemented as a device capable of being implanted beneath a patient's skin, preferably having an axial dimension of less than 60 mm and a lateral dimension of less than 6 mm. Wireless communication between the SCU and the implanted devices is preferably implemented via a modulated sound signal, AC magnetic field, RF signal, or electric conduction.