Abstract: Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.

Abstract: A controller-transmitter transmits acoustic energy through the body to an implanted acoustic receiver-stimulator. The receiver-stimulator converts the acoustic energy into electrical energy and delivers the electrical energy to tissue using an electrode assembly. The receiver-stimulator limits the output voltage delivered to the tissue to a predetermined maximum output voltage. In the presence of interfering acoustic energy sources output voltages are thereby limited prior to being delivered to the tissue. Furthermore, the controller-transmitter estimates the output voltage that is delivered to the tissue by the implanted receiver-stimulator. The controller-transmitter measures a query spike voltage resulting from the electrical energy delivered to the tissue by the receiver-stimulator, and computes a ratio of the predetermined maximum output voltage and a maximum query spike voltage. The maximum query spike voltage is computed by detecting a query spike voltage plateau.

Abstract: A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Abstract: Delivery of an implantable wireless receiver-stimulator (R-S) into the heart using delivery catheter is described. R-S comprises a cathode and an anode and wirelessly receives and converts energy, such as acoustic ultrasound energy, to electrical energy to stimulate the heart. Conductive wires routed through the delivery system temporarily connect R-S electrodes to external monitor and pacing controller. R-S comprises a first temporary electrical connection from the catheter to the cathode, and a second temporary electrical connection from the catheter to the anode. Temporary electrical connections allow external monitoring of heart's electrical activity as sensed by R-S electrodes to determine tissue viability for excitation as well as to assess energy conversion efficiency.

Abstract: A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Abstract: A wireless cardiac stimulation device is disclosed comprising a controller-transmitter, a receiver, and a stimulating electrode, wherein the stimulating electrode and the receiver are separately implantable at cardiac tissue locations of the heart and are connected by a local lead. Having separately implantable receiver and stimulating electrodes improves the efficiency of ultrasound mediated wireless stimulation by allowing the receiver to be placed optimally for reception efficiency, thereby resulting in longer battery life, and by allowing the stimulating electrode to be placed optimally for stimulus delivery. Another advantage is a reduced risk of embolization, since the receiver and stimulating electrode ensemble is attached at two locations of the heart wall, with the connecting local leads serving as a safety tether should either the receiver or the stimulating electrode become dislodged.

Abstract: A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Abstract: A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Abstract: Method and systems for determining the location or identify of implantable devices are disclosed. An implantable device generates an electrical output and then modifies the output at a pre-configured interval for a pre-configured period. A sensor detects the modified output and locates or identifies the implantable device based on the modified output.

Abstract: Systems and methods are disclosed to stimulate tissue to treat medical conditions involving tissues such as the bone, spine, stomach, nerves, brain and the cochlea. The disclosed invention uses electrical stimulation of the tissue, where vibrational (or acoustic) energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined tissue sites. The vibrational energy is generated by a controller-transmitter, which could be either implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located at or close to the stimulation site.

Abstract: Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.

Abstract: The present invention relies on a controller-transmitter device to deliver ultrasound energy into cardiac tissue in order to directly improve cardiac function and/or to energize one or more implanted receiver-stimulator devices that transduce the ultrasound energy to electrical energy to perform excitatory and/or non-excitatory treatments for heart failure. The acoustic energy can be applied as a single burst or as multiple bursts.

Abstract: Delivery of an implantable wireless receiver-stimulator (R-S) into the heart using delivery catheter is described. R-S comprises a cathode and an anode and wirelessly receives and converts energy, such as acoustic ultrasound energy, to electrical energy to stimulate the heart. Conductive wires routed through the delivery system temporarily connect R-S electrodes to external monitor and pacing controller. R-S comprises a first temporary electrical connection from the catheter to the cathode, and a second temporary electrical connection from the catheter to the anode. Temporary electrical connections allow external monitoring of heart's electrical activity as sensed by R-S electrodes to determine tissue viability for excitation as well as to assess energy conversion efficiency.

Abstract: Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.

Abstract: A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Abstract: Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.

Abstract: Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.

Abstract: Method and systems for optimizing acoustic energy transmission in implantable devices are disclosed. Transducer elements transmit acoustic locator signals towards a receiver assembly, and the receiver responds with a location signal. The location signal can reveal information related to the location of the receiver and the efficiency of the transmitted acoustic beam received by the receiver. This information enables the transmitter to target the receiver and optimize the acoustic energy transfer between the transmitter and the receiver. The energy can be used for therapeutic purposes, for example, stimulating tissue or for diagnostic purposes.

Abstract: A system for delivering an electrical stimulation pulse to tissue comprises a controller-transmitter and a receiver-stimulator. The controller-transmitter includes circuitry having an energy storage capacitor. The capacitance of the energy storage capacitor is adjusted to improve the efficiency of energy delivered from the receiver-stimulator to tissue by modifying the geometry of an acoustic drive burst from the controller-transmitter.

Abstract: Method and systems for determining the location or identify of implantable devices are disclosed. An implantable device generates an electrical output and then modifies the output at a pre-configured interval for a pre-configured period. A sensor detects the modified output and locates or identifies the implantable device based on the modified output.