Angeion Corporation

Other

Joseph S Perttu

Mark W Kroll

Theodore P Adams

Dennis A Brumwell

Charles G Supino

James E Brewer

Randall S Nelson

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.

Dual battery power system for an implantable cardioverter defibrillator with voltage booster

An automatic transfer switch system controls switching of power from a main source (utility power) to a backup source (generator) by using a state machine controller and low cost relay switches housed in a single electrical panel. The low power automated transfer switch system is well-suited for residential use and is less expensive and easier to install than conventional automatic transfer switches. The key to a low cost transfer switch is delivering power with low cost relays. This is accomplished by employing relay drive techniques that enable these devices to survive rigorous standards compliance testing. Preferably, the state machine controller measures utility and generator source compliance using an optical coupling arrangement, rather than a transformer. The automated transfer switch disconnects the utility and generator means through a circuit breaker providing for fast protection. The relay drive techniques disclosed provide a form of an electrical interlock. This is a key feature when seeking compliance standard approval. Essentially, an automated transfer system should not continuously be capable of backfeeding power from generator to utility, and the electrical interlock of the relays as taught by this invention prevents any such backfeeding.

State machine controlled automatic transfer switch system

The present invention is a pectorally implantable defibrillation system for delivering at least one electrical cardioversion/defibrillation countershock. The system has a housing designed to be implanted in a human patient, wherein the housing has an outer shell and an inner cavity. Pulse generating circuitry is positioned within the cavity for generating the at least one countershock. Circuitry is also positioned within the cavity to control delivery of the at least one countershock. A slew rate limiting circuit is connected between the pulse generating circuitry and one of a plurality of implantable electrodes so as to reduce a slew rate of the electrical countershock. Preferably, one of the implantable electrodes is the housing.

Implantable cardioverter defibrillator with slew rate limiting

An amplified, isolated output control circuit is provided for controlling the output switching network of a self-powered defibrillator that delivers a high voltage electrical countershock through a plurality of electrodes. The defibrillator comprises a low voltage battery system, a high voltage capacitor system, a high voltage transformer connected between the battery system and the capacitor system, and an output switching network, such as an H-bridge switching network, connected between the capacitor system and the plurality of electrodes. The defibrillator is controlled by control circuitry that manages the charging and discharging of the electrical countershock and is connected to the output control circuitry. Preferably, the output control circuitry includes an isolated power supply, at least one optoisolator device and at least one amplifier circuit that is powered by the isolated power supply and is connected between the optoisolator device and a switch of the output switching network. The output control circuitry provides for actual high side control of the output switching network by allowing the high side switches of the output switching network to be turned on and off after the low side switches of the output switching network. Preferably, the isolated power supply also provides a boosted output that powers the control circuitry at least during charging of the capacitor system to insure an adequate supply of power.

Amplified voltage output switching network for a self-powered

A device and method for performing automatic battery maintenance as particularly applied in an implantable cardioverter defibrillator (ICD). The battery is maintained at a predetermined state-of-charge to enable charging a capacitor in the ICD to discharge high voltage pulse into a human patient via electrodes implanted in the patient.

Automatic battery-maintaining implantable cardioverter defibrillator and

An implantable cardioverter defibrillator capable of subcutaneous positioning within a patient delivers at least one electrical cardioversion/defibrillation countershocks to the heart of the patient. The implantable cardioverter defibrillator includes a housing, circuitry positioned within the housing to control delivery of the countershocks, and an energy source coupled with the circuitry to provide electrical energy to a capacitor in the circuitry that stores the electrical energy for delivery of the countershocks. Because the circuitry is susceptible to undesirable electromagnetic coupling effects of origin external to the circuitry, particularly the capacitive coupling effects between the circuitry and the housing of the device when at least a portion of the housing is utilized as an electrode, the implantable cardioverter defibrillator also includes a conductive shield, disposed between the housing and the circuitry, to shield the circuitry against such undesired coupling effects.

Shield for implantable cardioverter defibrillator

An ICD detection method for sensing the occurrence of an R-wave improves the ability to distinguish R-waves from noise through the use of variable declining sensitivity thresholds. The method includes the consideration of the amplitude of at least the previous most recent R-wave to determine a declining threshold of sensitivity used to recognize a subsequent electrical signal as an R-wave. In the method, the amplitude of the previous R-wave may be classified, based upon amplitude, and based upon the classification, a desirable time constant for the declining threshold of sensitivity is provided as an exponential or reverse exponential decay. Alternatively, a piece wise use of various decay formulas may be combined and used to avoid false recognition of noise as an R-wave.

R-wave detection method for implantable cardioverter defibrillators

The present invention is a pectorally implantable defibrillation system for delivering at least one electrical cardioversion/defibrillation countershock. The system has a housing designed to be implanted in a human patient, wherein the housing has an outer shell and an inner cavity. Pulse generating circuitry is positioned within the cavity for generating the at least one countershock. Circuitry is also positioned within the cavity to control delivery of the at least one countershock. At least one surface of the outer shell is electrically conductive to form an electrode for the system. Because of the close proximity between the housing electrode and the circuitry positioned within the housing, the circuitry is susceptible to undesired capacitive coupling effects. To reduce the capacitive coupling effects, a slew rate limiting circuit is connected between the pulse generating circuitry and the electrode formed on the housing.

A defibrillation electrode apparatus which provides defibrillating, pacing, and sensing functions with the use of fewer conductors. Conductor requirements are minimized by solid-state multiplexing that is accomplished at the distal end of the apparatus. The apparatus comprises:

Implantable medical electrode with reduced number of conductors

Dual battery power system for an implantable cardioverter defibrillator

A defibrillation electrode apparatus which provides defibrillating, pacing, and sensing functions with the use of fewer conductors. Conductor requirements are minimized by solid-state multiplexing that is accomplished at the distal end of the apparatus.

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Chanhassen, MN, United States of America

Joseph S Perttu