Abstract: A system and method for delivering both anti-tachy pacing (ATP) therapy and high-voltage shock therapy in response to detection of abnormal cardiac rhythms is disclosed. The system controls the time between delivering ATP therapy and the charging of high-voltage capacitors in preparation for shock delivery based on a predetermined set of criteria. In one embodiment, the inventive system operates in an ATP During Capacitor Charging (ATP-DCC) mode wherein all, or substantially all, of the ATP therapy is delivered during charging of the high-voltage capacitors. Based on evaluation of the predetermined set of criteria, the system may switch to an additional ATP Before Capacitor Charging (ATP-BCC) mode, wherein substantially all of the ATP therapy is delivered prior to charging of the high-voltage capacitor. According to one aspect of the invention, the predetermined set of criteria is based, at least in part, on the effectiveness of previously-delivered ATP therapy.

Abstract: A power supply comprises transistors whose conduction paths are connected in series and whose control terminals receive a reference voltage. The common terminal at one end of the series-connected conduction paths provides a regulator output whereas output terminals of the transistors are connected to charge storage capacitors, which are charged by respective power generators for scavenging energy from the environment. The transistors begin conducting in sequence so that the storage capacitors begin contributing sequentially to the output current as each transistor conducts in sequence. The capacitors are charged up when they are not contributing to the output current.

Abstract: A transcutaneous energy transfer system, transcutaneous charging system, external power source, external charger and methods of transcutaneous energy transfer and charging for an implantable medical device and an external power source/charger. The implantable medical device has a secondary coil adapted to be inductively energized by an external primary coil at a carrier frequency. The external power source/charger has a primary coil and circuitry capable of inductively energizing the secondary coil by driving the primary coil at a carrier frequency adjusted to the resonant frequency to match a resonant frequency of the tuned inductive charging circuit, to minimize the impedance of the tuned inductive charging circuit or to increase the efficiency of energy transfer.

Abstract: An implantable microstimulator configured for implantation beneath a patient's skin for tissue stimulation to prevent and/or treat various disorders, uses a self-contained power source. Periodic or occasional replenishment of the power source is accomplished, for example, by inductive coupling with an external device. A bidirectional telemetry link allows the microstimulator to provide information regarding the system's status, including the power source's charge level, and stimulation parameter states. Processing circuitry automatically controls the applied stimulation pulses to match a set of programmed stimulation parameters established for a particular patient. The microstimulator preferably has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end.

Abstract: A power control circuit for an implantable medical device is presented. The power control circuit includes a first high rate cell, a second high rate cell, at least one resistive load, and at least one control circuit. The at least one resistive load is connected between the first and the second high rate cells. The at least one control circuit is coupled to the first and the second high rate cells.

Abstract: An integrated activation system for an implantable medical device (IMD) sharing a power source, the activation system comprising a switching circuit having first and second inputs and having an output coupled to the acute use device, a gating element coupled to the first input and configured to gate power from the power source to the switching circuit, and a sensing element coupled to the second input of the switching circuit. The sensing element is configured to sense an activation condition, enable an operation interval of the switching circuit, and transmit a signal to the switching circuit during the activation condition. The switching circuit is configured to transmit power to the acute use device upon receipt of a pre-determined number of signals from the sensing element.

Abstract: An ultrasound measurement system including a handheld display and processing means, an ultrasound transducer, a processing means of a substantially similar weight to the handheld display and processing means, and a transmission cable interconnecting the handheld display and processing means with the ultrasound transducer and processing means, the cable being of sufficient length to provide a means to mechanically locate the system around the neck of a user.

Abstract: A medical system with a medical device and with a supply unit. The supply unit is designed to be separably connected to the medical device and to supply the medical device with electric energy without interruption. The medical system has an isolating transformer and a changeover device, wherein the changeover device is connected to the isolating transformer and to the medical device and is designed to connect the medical device or the supply unit to an electric supply network via the isolating transformer as desired.

Abstract: Implantable medical device power circuits are disclosed. Multiple batteries may be provided, along with a number of switches, enabling a plurality of battery and power circuit configurations to be defined. Configurations of the power circuit may be changed in response to changes in battery status as the batteries are used and/or near end-of-life. Configurations of the power circuit may also be performed in response to changes in device operation. Methods associated with operating such circuits and implantable medical devices are also disclosed.

Abstract: Methods are provided for treating a subject for a condition. In accordance with the subject methods, at least a portion of a subject's autonomic nervous system is modulated during at least one predetermined phase of the subject's menstrual cycle to alter the parasympathetic activity/sympathetic activity ratio in a manner that is effective to treat the subject for the condition. The subject methods find use in the treatment of a variety of different conditions, including various disease conditions, that increase in severity and/or occurrence during one or more phases of the menstrual cycle. Also provided are systems and kits for use in practicing the subject methods.

Abstract: A sensor is located within the body of a subject, such as for capturing pacing pulses transmitted as part of cardiac therapy from an implanted cardiac function management device. Counted pulses may be used to derive the onset of pulmonary edema within the body through pulse characteristics such as frequency and amplitude. The sensor may be anchored within mediastinal pleura or the airway of the body with the ability to communicate wirelessly to one or more other medical devices, such as an implanted cardiac function management device. It may also adjust transmission of the communication to discriminate among multiple sensors. Methods of use are also described.

Abstract: A device for altering cardiac performance includes an energy absorbing element which absorbs cardiac pumping energy from at least a portion of the heart. The energy may be delivered to another part of the body, such as another portion of the heart, to perform useful work such as providing blood pumping assistance.

Abstract: A defibrillator, equipped with a battery power source, is described which is arranged to operate in any one of both a first mode and a second mode, the battery power source comprising at least two voltage sources. The voltage sources are arranged to be connected in parallel to each other when the defibrillator is operating in a first mode, and in series with each other when the defibrillator is operating in a second mode. The invention can be implemented by a battery pack for a defibrillator. This arrangement allows both voltage sources to be drawn down at the same rate which lengthens the overall life of the batteries. A more efficient use of battery power is thereby obtained. The invention ultimately extends the projected life of the batteries and when applied to an automatic external defibrillator increases the shelf life of the defibrillator.

Abstract: Methods include determining whether an infection is in proximity to an implanted rechargeable medical device. If an infection is determined to be present, the recharge process is allowed to sufficiently heat the device to facilitate clearing of the infection. Additional methods include monitoring temperature in proximity to an implantable rechargeable device in connection with recharging the device. If the monitored temperature falls outside a desired range, one or more parameters associated with recharge energy are modified to cause the temperature to reside within the desired range. The desired temperature range, may be a range that can facilitate treatment of a condition in proximity to the implanted device without causing undesired damage to the patient's tissue surrounding the implanted device.

Abstract: A medical device includes a pulse generator that selectively generates pulses. A control module selectively controls the pulses A power distribution system supplies power to said medical device. The power distribution system includes N batteries, where N is an integer greater than one, a common node, and N protection modules. The N protection modules communicate with the control module, selectively connect a respective one of the N batteries to the common node based on control signals from the control module, and monitor current provided by the respective one of the N batteries. The control module generates the respective control signals based upon the current.

Abstract: Techniques for controlling one or more modular circuits (“satellites”) that are intended for placement in a subject's body. The one or more satellites are controlled by sending signals over a bus that includes first and second conduction paths. Also coupled to the bus in system embodiments is a device such as a pacemaker that provides power and includes control circuitry. Each satellite includes satellite circuitry and one or more effectors that interact with the tissue. The satellite circuitry is coupled to the bus, and thus interfaces the controller to the one or more effectors, which may function as actuators, sensors, or both. The effectors may be electrodes that are used to introduce analog electrical signals (e.g., one or more pacing pulses) into the tissue in the local areas where the electrodes are positioned (e.g., heart muscles) or to sense analog signals (e.g., a propagating depolarization signal) within the tissue.

Abstract: Techniques for controlling one or more modular circuits (“satellites”) that are intended for placement in a subject's body. The one or more satellites are controlled by sending signals over a bus that includes first and second conduction paths. Also coupled to the bus in system embodiments is a device such as a pacemaker that provides power and includes control circuitry. Each satellite includes satellite circuitry and one or more effectors that interact with the tissue. The satellite circuitry is coupled to the bus, and thus interfaces the controller to the one or more effectors, which may function as actuators, sensors, or both. The effectors may be electrodes that are used to introduce analog electrical signals (e.g., one or more pacing pulses) into the tissue in the local areas where the electrodes are positioned (e.g., heart muscles) or to sense analog signals (e.g., a propagating depolarization signal) within the tissue.

Abstract: An implantable medical device (IMD) may include a battery dedicated to providing cardiac stimulation therapy and a separate power source that provides power for electrical stimulation therapy. Such a configuration preserves the battery dedicated for providing cardiac stimulation therapy even if the second power source is depleted. As an example, the IMD may comprise a cardiac stimulation module configured to deliver at least one stimulation therapy selected from a group consisting of pacing, cardioversion and defibrillation. The IMD further comprises a electrical stimulation module configured to deliver electrical stimulation therapy, a first power source including a battery, wherein the first power source is configured to supply power to the cardiac stimulation module and not to the electrical stimulation module, and a second power source. The second power source is configured to supply power to at least the electrical stimulation module.

Abstract: A system and method for powering an implantable cardiac therapy device (ICTD) uses a hybrid battery system. In an embodiment, the hybrid battery system includes of a first type of power cell and a second type of power cell. The first power cell is configured to power low voltage, low current background operations of the ICTD. The second power cell is configured to power high voltage, high current cardiac shocking. The second power cell is further configured to be charged by the first power cell via a continuous, non-regulated charging process, thereby reducing the complexity of the charging circuitry. The system is further configured so that when cardiac shocking is in progress, only the secondary power cell powers the shocking capacitor(s) of the ICTD, and the first power cell is electrically isolated from the shocking capacitor(s). This configuration contributes to longer battery life of the hybrid battery system.

Abstract: A power supply comprises transistors whose conduction paths are connected in series and whose control terminals receive a reference voltage. The common terminal at one end of the series-connected conduction paths provides a regulator output whereas output terminals of the transistors are connected to charge storage capacitors, which are charged by respective power generators for scavenging energy from the environment. The transistors begin conducting in sequence so that the storage capacitors begin contributing sequentially to the output current as each transistor conducts in sequence. The capacitors are charged up when they are not contributing to the output current.

Abstract: An apparatus for powering an implant includes first energy interface elements, a removeably attachable holding device and a first energy source, such as a battery. An energy conversion circuit converts first energy into second energy which is transmitted within the body of the patient to the implant. Also, an apparatus for providing information to an implant that includes first energy interface elements and a housing that includes a processor operatively coupled to the first energy interface elements and an energy source operatively coupled to the processor. The processor is structured to generate an information signal and cause the signal to be transmitted within the body of the patient for delivery to the implant. Associated methods are also provided.

Abstract: An implantable medical device includes a control circuit for controlling the operation of the device and for obtaining physiological data from a patient in which the medical device is implanted. The implanted device also includes a communication circuit for transmitting the physiological data to an external device. A first power source is coupled to the control circuit and provides power to the control circuit. A second power source is coupled to the communication circuit and provides power to the communication circuit.

Abstract: Techniques for controlling one or more modular circuits (“satellites”) that are intended for placement in a subject's body. The one or more satellites are controlled by sending signals over a bus that includes first and second conduction paths. Also coupled to the bus in system embodiments is a device such as a pacemaker that provides power and includes control circuitry. Each satellite includes satellite circuitry and one or more effectors that interact with the tissue. The satellite circuitry is coupled to the bus, and thus interfaces the controller to the one or more effectors, which may function as actuators, sensors, or both. The effectors may be electrodes that are used to introduce analog electrical signals (e.g., one or more pacing pulses) into the tissue in the local areas where the electrodes are positioned (e.g., heart muscles) or to sense analog signals (e.g., a propagating depolarization signal) within the tissue.

Abstract: Techniques for controlling one or more modular circuits (“satellites”) that are intended for placement in a subject's body. The one or more satellites are controlled by sending signals over a bus that includes first and second conduction paths. Also coupled to the bus in system embodiments is a device such as a pacemaker that provides power and includes control circuitry. Each satellite includes satellite circuitry and one or more effectors that interact with the tissue. The satellite circuitry is coupled to the bus, and thus interfaces the controller to the one or more effectors, which may function as actuators, sensors, or both. The effectors may be electrodes that are used to introduce analog electrical signals (e.g., one or more pacing pulses) into the tissue in the local areas where the electrodes are positioned (e.g., heart muscles) or to sense analog signals (e.g., a propagating depolarization signal) within the tissue.

Abstract: Implantable medical device adapted to provide a therapeutic output to a patient. A therapy module, operatively coupled to a battery, is adapted to provide the therapeutic output. A control circuit provides an action indicative of recharging the battery when the voltage of the battery reaches a recharge voltage wherein the recharge voltage is varied as the battery ages. Also a method of providing a therapeutic output to a patient using an implantable medical device having a battery having a voltage. An action indicative of recharging the battery is provided when the voltage of the battery reaches a recharge voltage. The recharge voltage is varied as the battery ages.

Abstract: In some embodiments, the power generator for converting mechanical energy to electrical energy is described may include a compressible element adapted and configured to be placed in an environment having a variable compressive force such as varying ambient pressures. The compressible element may be compressed by a force applied by the variable pressure to the compressible element. The power generator may further include a transducer that may be coupled to the compressible element and that may convert mechanical energy from the compression of the compressible element to electrical energy. In some embodiments, the power generator may be adapted to be an implantable power generator for converting mechanical energy from a patient to electrical energy, such that the compressible element adapted and configured to be placed between two adjacent tissue layers of the patient and to be compressed by a force applied from the two adjacent tissue layers to the compressible element.

Abstract: Systems and methods for automatically powering and communicating with an implantable medical device through an inductive link are disclosed. A preferred embodiment comprises an inductive coil or set of such coils. One coil may be mounted or installed on or near the bed of a patient as a component of a transmission module. Another coil may a component of an implantable medical device. The coils are energized by a resonant circuit to generate an electromagnetic field in the vicinity of the bedside. Without any action on the patient's part, the implantable device receives the inductively transmitted energy to power its immediate operation or recharge its battery, thereby extending its longevity, potentially indefinitely. The inductive link also enables data transfer communication between the transmission module and implantable device.

Abstract: An implantable microstimulator configured to be implanted beneath a patient's skin for tissue stimulation to prevent and/or treat various disorders, e.g., neurological disorders, uses a self-contained power source such as a primary battery, a rechargeable battery, or other energy sources. For the rechargeable battery, and other energy sources that may require a periodic or occasional replenishment, such recharging or replenishment is accomplished, for example, by inductive coupling with an external device. A suitable bidirectional telemetry link allows the microstimulator system to inform the patient or clinician regarding the status of the system, including the charge level of the power source, and stimulation parameter states. Processing circuitry within the microstimulator automatically controls the applied stimulation pulses to match a set of programmed stimulation parameters established for a particular patient.

Abstract: An implantable medical device configured to be compatible with the environment inside an MRI machine. The implantable medical device includes a housing constructed of an electrically conductive material and pulse generation circuitry within the housing for generating electrical voltage pulses. The implantable medical device further includes a first conductor that is configured to transmit the electrical voltage pulses from the pulse generation circuitry to a patient's cardiac tissue and a second conductor that is configured to provide an electrically conductive path from the patient's cardiac tissue back to the pulse generation circuitry. The implantable medical device further includes a selectively interruptible electrically conductive path connecting the pulse generation circuitry with the housing.

Abstract: A combination, voltage converter circuit for use within an implantable device, such as a microstimulator, uses a coil, instead of capacitors, to provide a voltage step up and step down conversion functions. The output voltage is controlled, or adjusted, through duty-cycle modulation. In accordance with one aspect of the invention, applicable to implantable devices having an existing RF coil through which primary or charging power is provided, the existing RF coil is used in a time-multiplexing scheme to provide both the receipt of the RF signal and the voltage conversion function. This minimizes the number of components needed within the device, and thus allows the device to be packaged in a smaller housing or frees up additional space within an existing housing for other circuit components. In accordance with another aspect of the invention, the voltage up/down converter circuit is controlled by a pulse width modulation (PWM) low power control circuit.

Abstract: An implantable medical electronic tissue stimulating device is formed of two hermetically sealed, fluid impervious housings, one containing an electronic pulse generator and the other a battery power supply. The two are adapted to be mechanically and electrically coupled together through a coupler/connector whereby current from the battery in one sealed housing is fed to the electronic pulse generator in the other sealed housing.

Abstract: An implantable medical device includes a control circuit for controlling the operation of the device and for obtaining physiological data from a patient in which the medical device is implanted. The implanted device also includes a communication circuit for transmitting the physiological data to an external device. A first power source is coupled to the control circuit and provides power to the control circuit. A second power source is coupled to the communication circuit and provides power to the communication circuit.

Abstract: An implantable medical device (“IMD”) as described herein includes adjustable power characteristics such as variable transmitter output power and variable receiver front end gain. These power characteristics can be adjusted in a dynamic manner based upon various operating aspects of the intended or actual IMD telemetry environment. These operating aspects may include the external telemetry device type, the IMD device type, and/or the type, context, or meaning of the telemetry data transmitted by the IMD. The IMD may process information related to these operating aspects to generate power scaling instructions or control signals that are interpreted by the IMD transmitter and/or the IMD receiver. Such adjustability enables the IMD to satisfy minimum telemetry requirements in a manner that does not waste power, thus extending the IMD battery life.

Abstract: Circuitry for and method of power efficient operation of, and energy recovery from, tissue-stimulating electrodes having high charge capacities. Post-stimulation energy is recovered from the electrodes through a variety of techniques into circuit elements such as other electrodes, an intermediate distribution system, a power supply or any other elements, through the use of sequential switching. Energy is also recoverable from the intermediate distribution system, which preferably is comprised of one or more storage capacitors operating a different voltages. Efficient power transfer among circuit elements is effected by transferring energy while limiting element-element voltage differences and/or voltage differences between the elements and the capacitances of the electrodes.

Abstract: In general, the invention is directed to a patient programmer for an implantable medical device. The patient programmer may include one or more of a variety of features that may enhance performance, support mobility and compactness, or promote patient convenience.

Abstract: Systems and methods for providing a power signal to one or more implantable devices include a number of dynamic range amplifiers each having a multiplicity of output drivers. Each of the output drivers is configured to generate an output signal. The systems and methods further include control circuitry configured to select at least one of the amplifiers to provide a number of output signals used to generate the power signal that is to be provided to the one or more implantable devices. The control circuitry is further configured to disable the output drivers corresponding to a remaining number of amplifiers. A matching circuit is configured to generate the power signal based on the output signals provided by the at least one selected amplifier. The systems and methods further include means to transmit the power signal to the one or more implantable devices.

Abstract: A Permanent Pacemaker and Implantable Cardioverter-Defibrillator with a rechargeable battery with recharging facility This PPM/ICD has systems which can be programmed or serviced from a distant center.

Abstract: A method and apparatus for measuring battery depletion in an implantable medical device is presented. The apparatus includes first and second switch pairs disposed in series between the battery and a load, and connected in a parallel arrangement with respect to one another. A capacitor is connected in a first polarity between the battery and the load when only first and fourth switches are closed and in a second polarity when only second and third switches are closed. A comparator circuit causes the switches to reverse the capacitor's polarity based on a comparison of the voltage drop across the capacitor to a threshold value. A counter counts the number of times the capacitor reverses polarity, which is proportional to the amount of charge transferred from the battery during its lifetime in the device and indicative of the battery's level of depletion.

Abstract: Techniques for controlling one or more modular circuits (“satellites”) that are intended for placement in a subject's body. The one or more satellites are controlled by sending signals over a bus that includes first and second conduction paths. Also coupled to the bus in system embodiments is a device such as a pacemaker that provides power and includes control circuitry. Each satellite includes satellite circuitry and one or more effectors that interact with the tissue. The satellite circuitry is coupled to the bus, and thus interfaces the controller to the one or more effectors, which may function as actuators, sensors, or both. The effectors may be electrodes that are used to introduce analog electrical signals (e.g., one or more pacing pulses) into the tissue in the local areas where the electrodes are positioned (e.g., heart muscles) or to sense analog signals (e.g., a propagating depolarization signal) within the tissue.

Abstract: A wireless communication method and protocol, and wireless devices and systems for stimulation, are provided for communication between a wireless device and a charging device. During active wireless charging, communications (data transmission) from the wireless device to the charging device occurs via pulse loading the receive antenna of the receiving device. Because switching regulation in the receiving device may interfere with the communications, the switching regulation is disabled during a communications window. To further reduce the likelihood of misinterpretation of signals detected in the charging device resulting from the switching regulation or noise, the data bit rate of the pulse loading communications is maintained higher than the switching regulation frequency.

Abstract: The prophylactic pacer/defibrillator is configured to deliver shocking therapy in response to a single episode of ventricular fibrillation, as well as delivering otherwise conventional pacing therapy. By providing “one shot” defibrillation capabilities a patient who is not at significant risk of ventricular fibrillation—and hence is not a candidate for a full-service implantable cardioverter defibrillator (ICD)—can receive defibrillation therapy in the event ventricular fibrillation should nevertheless occur. Once the prophylactic pacer/defibrillator has delivered shocks to terminate the single episode of ventricular fibrillation, the patient returns to his or her physician to have the device removed and a full-service ICD implanted, so that any additional episodes of ventricular fibrillation may be addressed by the full-service ICD.

Abstract: The prophylactic pacer/defibrillator is configured to deliver shocking therapy in response to a single episode of ventricular fibrillation, as well as delivering otherwise conventional pacing therapy. By providing “one shot” defibrillation capabilities a patient who is not at significant risk of ventricular fibrillation—and hence is not a candidate for a full-service implantable cardioverter defibrillator (ICD)—can receive defibrillation therapy in the event ventricular fibrillation should nevertheless occur. Once the prophylactic pacer/defibrillator has delivered shocks to terminate the single episode of ventricular fibrillation, the patient returns to his or her physician to have the device removed and a full-service ICD implanted, so that any additional episodes of ventricular fibrillation may be addressed by the full-service ICD.

Abstract: An implantable medical device includes a control circuit for controlling the operation of the device and for obtaining physiological data from a patient in which the medical device is implanted. The implanted device also includes a communication circuit for transmitting the physiological data to an external device. A first power source is coupled to the control circuit and provides power to the control circuit. A second power source is coupled to the communication circuit and provides power to the communication circuit.

Abstract: An implantable energy supply system having at least two cells is disclosed. The system may have a switch with a first state in which the cells are electrically connected to a load, and a second state in which each cell is electrically connected with its own charger. A measurer may be electrically connected to a cell to provide an indication of the charge on the cell.

Abstract: A circuit for delivering a back-up stimulation voltage in a cycle to cycle capture test for an active implantable medical device such as a pacemaker, defibrillator and/or cardiovertor or a multisite device having an enhanced circuit for delivering back-up stimulation pulses.

Abstract: A method of operating an implantable medical device containing a Lithium Silver Vanadium Oxide battery. In response to a detected need for therapy, a current flow is delivered from the battery to a charge storage device. After the battery is at least partly depleted by one or more such deliveries of current or other power consumption, the battery is recharged. The recharging may be initiated in response to a selected time threshold, a selected number of current flow delivery events, a selected voltage level, an excess charge time duration, or other operating characteristics. A limited number of recharging cycles may be provided if the charging is done under controlled conditions with respect to charge current and voltage.

Abstract: A method and an apparatus for performing a device component failure analysis in an implantable medical device using current consumption data. A current consumption signal relating to current consumption in an implantable medical device is generated. The current consumption signal is then processed. A defect of a component in the implantable medical device is assessed in response to the processing of the current consumption signal and appropriate action is taken, such as selecting alternate therapies, generating an alert signal, and turning off circuits corresponding to the assessed defect.

Abstract: It is important in cardiac pacing devices and systems to achieve efficient power utilization and conservation to extend the life of the battery cells, thereby extending the intervals between invasive medical procedures to replace components in the cardiac pacing system. A device and method are provided. The cardiac pacing device comprises a battery, a discrete time switched capacitor pacing power supply comprising a charge transfer capacitor bank comprising at least two capacitors, and a pace output supply capacitor which can discharge current to the tissue of a patient. A pacing supply design has a multiplicity of battery voltage multiplication factors and operating frequency settings. The pacing supply, voltage multiplier settings and operating frequency are automatically adjusted to compensate for changing pace output settings, load, cardiac cycle rate, and/or battery condition.

Abstract: An improved dual battery power system uses two separate battery power sources for an implantable cardioverter defibrillator, each having optimized characteristics for monitoring functions and for output energy delivery functions, respectively. The monitoring functions are supplied electrical power by a first battery source, such as a conventional pacemaker power source in the form of a lithium iodide battery which is optimized for long life at very low current levels. The output energy delivery functions are supplied by a separate second battery source, such as a pair of lithium vanadium pentoxide batteries, which is optimized for high current drain capability and low self-discharge for long shelf life. The first battery source provides electrical power only to the monitoring functions of the implantable cardioverter defibrillator, and the second battery source provides all of the electrical power for the output energy delivery functions.

Abstract: The implantable, electrically operated medical device system comprises an implanted radio frequency (RF) receiving unit (receiver) incorporating a back-up rechargeable power supply and an implanted, electrically operated device, and an external RF transmitting unit (transmitter). RF energy is transmitted by the transmitter and is coupled into the receiver which is used to power the implanted medical device and/or recharge the back-up power supply. The back-up power supply within the receiver has enough capacity to be able to, by itself, power the implanted device coupled to the receiver for at least 24 hours during continual delivery of medical therapy. The receiver is surgically implanted within the patient and the transmitter is worn externally by the patient. The transmitter can be powered by either a rechargeable or non-rechargeable battery. In a first mode of operation, the transmitter will supply power, via RF coupled energy, to operate the receiver and simultaneously recharge the back-up power supply.