Abstract: Apparatus for use with a medical implant having a receiving coil. A flexible housing to be placed against skin of a subject includes a flexible transmitting coil and control circuitry for driving a current through the transmitting coil to induce a current in the receiving coil. A sensor coupled to the circuitry determines divergence of a resonance frequency of the transmitting coil when flexed from a nominal resonance frequency of the transmitting coil, occurring in the absence of any forces applied to the transmitting coil. One or more electrical components coupled to the circuitry tune the resonance frequency of the transmitting coil. A switch is coupled to each of the electrical components, the switches including transistors having capacitances that depend on the voltage applied to each switch. The circuitry applies a respective DC voltage to each switch. Other applications are also described.

Abstract: A housing placeable against skin of a subject includes a transmitting coil. Battery-powered control circuitry including a power stage transmits power to an implant by activating the power stage to drive a current through the transmitting coil to induce an induced current in a receiving coil of the implant. A sensor indicates divergence of a real-time resonance frequency of the transmitting coil with respect to a reference resonance frequency of the transmitting coil at which (a) efficiency of the power stage is at least 70% of a maximum efficiency as a function of the resonance frequency, and (b) the current driven through the transmitting coil is less than 960 of a maximum current drivable through the transmitting coil as a function of the resonance frequency. The circuitry reduces the divergence by tuning the resonance frequency of the transmitting coil. Other applications are also described.

Abstract: An apparatus includes an implant that includes circuitry and an elongate housing having a first half and a second half. A paresthesia-inducing electrode is disposed on the first half, and a blocking electrode is disposed on the second half. The circuitry has a first mode in which the circuitry simultaneously drives the paresthesia-inducing electrode to apply a paresthesia-inducing current having a frequency of 2-400 Hz, and the blocking electrode to apply a blocking current having a frequency of 1-20 kHz, and a second mode in which the circuitry drives the blocking electrode to apply the blocking current, but does not drive the paresthesia-inducing electrode to apply the paresthesia-inducing current. The implant is injectable into a subject along a longitudinal axis of the implant. Other embodiments are also described.

Abstract: A device for controlling respiration during sleep based on the user physiological characteristic. The device includes an odor disperser for dispersing an odor; at least one detector for detecting a physiological characteristic of a user; and a controller for controlling respiration of the user by instructing the odor dispenser to disperse an odor responsive to detections by the at least one detector.

Abstract: Power is transmitted to an implanted receiving coil oriented such that an axis of the receiving coil is parallel to skin of a subject. A transmitting coil is in a housing, which is placed against the skin. A central axis of the transmitting coil is perpendicular to the skin. A portion of the transmitting coil is over the receiving coil. A first distance, from the axis of the transmitting coil to a center of the receiving coil, is greater than a second distance, from the axis of the transmitting coil to an inner edge of the portion of the transmitting coil. The first distance is less than a third distance, from the axis of the transmitting coil to an outer edge of the portion of the transmitting coil. Circuitry powers the implant by driving current through the transmitting coil that induces current in the receiving coil.

Abstract: A device for controlling respiration during sleep based on the user physiological characteristic. The device includes an odor disperser for dispersing an odor; at least one detector for detecting a physiological characteristic of a user; and a controller for controlling respiration of the user by instructing the odor dispenser to disperse an odor responsive to detections by the at least one detector.

Abstract: Apparatus for use with a medical implant having a receiving coil. A flexible housing to be placed against skin of a subject includes a flexible transmitting coil and control circuitry for driving a current through the transmitting coil to induce a current in the receiving coil. A sensor coupled to the circuitry determines divergence of a resonance frequency of the transmitting coil when flexed from a nominal resonance frequency of the transmitting coil, occurring in the absence of any forces applied to the transmitting coil. One or more electrical components coupled to the circuitry tune the resonance frequency of the transmitting coil. A switch is coupled to each of the electrical components, the switches including transistors having capacitances that depend on the voltage applied to each switch. The circuitry applies a respective DC voltage to each switch. Other applications are also described.

Abstract: Apparatus is provided for use with a medical implant having a receiving coil. A flexible housing to be placed against skin of a subject includes a flexible transmitting coil and control circuitry for driving a current through the transmitting coil to induce a current in the receiving coil. A sensor coupled to the circuitry determines divergence of a resonance frequency of the transmitting coil when flexed from a nominal resonance frequency of the transmitting coil, occurring in the absence of any forces applied to the transmitting coil. One or more electrical components coupled to the circuitry tune the resonance frequency of the transmitting coil. A switch is coupled to each of the electrical components, the switches including transistors having capacitances that depend on the voltage applied to each switch. The circuitry applies a voltage of 30-300 volts to each switch. Other applications are also described.

Abstract: An excitation unit is configured to induce action potentials by applying an excitatory current to a nerve. A blocking unit is configured to block the induced action potentials from propagating along the nerve by applying a blocking current to the nerve. A sensor unit is configured to detect the induced action potentials in the nerve, and to responsively provide a sensor signal that conveys information about the detected induced action potentials. Circuitry is configured (i) to drive the excitation unit to apply the excitatory current, (ii) to drive the blocking unit to apply the blocking current, (iii) while driving the blocking unit to apply the blocking current, to drive the sensor unit to detect the induced action potentials and provide the sensor signal, (iv) to receive the sensor signal, and (v) in response to the sensor signal, to alter a parameter of the blocking current.

Abstract: An excitation unit is configured to induce action potentials by applying an excitatory current to a nerve. A blocking unit is configured to block the induced action potentials from propagating along the nerve by applying a blocking current to the nerve. A sensor unit is configured to detect the induced action potentials in the nerve, and to responsively provide a sensor signal that conveys information about the detected induced action potentials. Circuitry is configured (i) to drive the excitation unit to apply the excitatory current, (ii) to drive the blocking unit to apply the blocking current, (iii) while driving the blocking unit to apply the blocking current, to drive the sensor unit to detect the induced action potentials and provide the sensor signal, (iv) to receive the sensor signal, and (v) in response to the sensor signal, to alter a parameter of the blocking current.

Abstract: A system and method for compensating for electromagnetic (EM) distortion fields caused by one or more distortion objects is provided. A system and method for compensating for electromagnetic (EM) distortion fields caused by one or more distortion objects is provided. For example, an EM compensation device receives a plurality of EM field calibration measurements. The EM compensation device trains a machine learning dataset to compensate for the EM distortion fields from the one or more distortion objects using the plurality of EM field calibration measurements and/or an EM field model. The EM compensation device receives one or more EM field procedure measurements from a medical device performing a medical procedure. The EM compensation device predicts a spatial location of the medical device based on the EM field procedure measurement and the machine learning dataset.

Abstract: Power is transmitted to an implanted receiving coil oriented such that an axis of the receiving coil is parallel to skin of a subject. A transmitting coil is in a housing, which is placed against the skin. A central axis of the transmitting coil is perpendicular to the skin. A portion of the transmitting coil is over the receiving coil. A first distance, from the axis of the transmitting coil to a center of the receiving coil, is greater than a second distance, from the axis of the transmitting coil to an inner edge of the portion of the transmitting coil. The first distance is less than a third distance, from the axis of the transmitting coil to an outer edge of the portion of the transmitting coil. Circuitry powers the implant by driving current through the transmitting coil that induces current in the receiving coil.

Abstract: A device for controlling respiration during sleep based on the user physiological characteristic. The device includes an odor disperser for dispersing an odor; at least one detector for detecting a physiological characteristic of a user; and a controller for controlling respiration of the user by instructing the odor dispenser to disperse an odor responsive to detections by the at least one detector.

Abstract: A system includes a magnetic field transmitter assembly. The magnetic field transmitter assembly has a housing with a first layer comprising an electrically-conductive material, a second layer comprising an electrically-insulating material, and a third layer comprising an electrically-conductive material. The second layer is positioned between the first layer and the third layer. The magnetic field transmitter assembly also includes a plurality of magnetic field generator assemblies positioned within the housing.

Abstract: A device for controlling respiration during sleep based on the user physiological characteristic. The device includes an odor disperser for dispersing an odor; at least one detector for detecting a physiological characteristic of a user; and a controller for controlling respiration of the user by instructing the odor dispenser to disperse an odor responsive to detections by the at least one detector.

Abstract: An excitation unit is configured to induce action potentials by applying an excitatory current to a nerve. A blocking unit is configured to block the induced action potentials from propagating along the nerve by applying a blocking current to the nerve. A sensor unit is configured to detect the induced action potentials in the nerve, and to responsively provide a sensor signal that conveys information about the detected induced action potentials. Circuitry is configured (i) to drive the excitation unit to apply the excitatory current, (ii) to drive the blocking unit to apply the blocking current, (iii) while driving the blocking unit to apply the blocking current, to drive the sensor unit to detect the induced action potentials and provide the sensor signal, (iv) to receive the sensor signal, and (v) in response to the sensor signal, to alter a parameter of the blocking current.

Abstract: Power is transmitted to an implanted receiving coil oriented such that an axis of the receiving coil is parallel to skin of a subject. A transmitting coil is in a housing, which is placed against the skin. A central axis of the transmitting coil is perpendicular to the skin. A portion of the transmitting coil is over the receiving coil. A first distance, from the axis of the transmitting coil to a center of the receiving coil, is greater than a second distance, from the axis of the transmitting coil to an inner edge of the portion of the transmitting coil. The first distance is less than a third distance, from the axis of the transmitting coil to an outer edge of the portion of the transmitting coil. Circuitry powers the implant by driving current through the transmitting coil that induces current is the receiving coil.

Abstract: Apparatus is provided, comprising: (a) an implantable excitation unit, configured to induce action potentials in a nerve of a subject by applying an excitatory current; (b) an implantable blocking unit, configured to block the induced action potentials from propagating along the nerve by applying a blocking current; and (c) an extracorporeal controller, comprising circuitry configured: (i) to wirelessly drive the excitation unit to apply the excitatory current, (ii) in a first mode, to wirelessly drive the blocking unit to apply the blocking current while not driving the excitation unit to apply the excitatory current, (iii) in a second mode, to wirelessly drive the blocking unit to apply the blocking current while driving the excitation unit to apply the excitatory current, and (iv) to wirelessly alter a parameter of the blocking current, based on sensing performed while the extracorporeal controller is in the second mode.

Abstract: Apparatus including an implant is provided, the implant including: a rod-shaped housing, having a distal half and a proximal half, and configured to be injected distally into tissue of a subject; a cathode on the distal half of the housing; an anchor configured to protrude from the proximal half of the housing, no anchor being configured to protrude from the distal half of the housing; an anode; and circuitry disposed within the housing, configured to drive a current between the cathode and the anode. Other embodiments are also described.

Abstract: A system for assisted coughing includes a first sensor for measuring a parameter which can indicate a closed glottis and producing a first signal, a processor for receiving the first signal, determining a state indicating the closed glottis and generating an instruction for a Functional Electric Stimulation (FES) controller based, at least in part, on the determining, and a FES controller for generating an electric stimulation signal.