Pacesetter, Inc.

Other

Alfred E. Mann Foundation for Scientific Research

Pacesetter Infusion, Ltd.

Bell Microsensors, Inc.

Medtronic Minimed, Inc.

Minimed, Inc.

Herman Lee Renger

James D Causey, Iii

Sam William Bowman

Robert L Bell

Mark W Kroll

Gabriel A Mouchawar

Brian M Mann

Cary D Talbot

William H Stutz, Jr

John P Pelmulder

John T Meador

Michi E Garrison

Moberg Sheldon

Methods and systems for applying charge to a piezoelectric element include and/or facilitate implementation of processes including cyclical multi-stage processes for: providing a piezoelectric element with an accumulated charge; providing one or more charge holding elements with a scavenged charge from the piezoelectric element; substantially removing or discharging a remaining charge from the piezoelectric element; and applying the scavenged charge to the piezoelectric element with an opposite polarity in relation to the polarity of the remaining charge.

Methods and systems for applying charge to a piezoelectric element

An improved reservoir is provided for use in a medication infusion device for operating the reservoir to administer a fluid to a patient. The reservoir comprises a hollow barrel adapted to receive a supply of fluid for delivery through infusion tubing or the like to the patient, in combination with a reservoir plunger. The reservoir plunger is designed to engage a motor-driven lead screw of the medication infusion device. The reservoir plunger has an integral split nut connector formed on the end of the plunger, which is in co-axial alignment with the lead screw whereby the split nut connector can be engaged directly to the lead screw.

Lead screw driven reservoir with integral plunger nut and method of using the same

A safety circuit system for a DC driven device for use with a fluid delivery system includes a first voltage potential DC power line, a second voltage potential DC power line, a controller and a safety circuit. The first voltage potential DC power line is coupled to provide a first voltage potential to the DC driven device, and the second voltage potential DC power line is coupled to provide a second voltage potential to the DC driven device such that the second voltage potential is different relative to the first potential. The controller controls at least the first voltage potential on the first voltage potential DC power line. The safety circuit has an enable state and a disable state, in which the default state is the disable state. The safety circuit is coupled to the controller, and the controller controls the safety circuit to place the safety circuit in the enable state independently of controlling the first voltage potential on the first voltage potential DC power line. The safety circuit is operatively coupled to at least one of the first and second voltage potential DC power lines to inhibit DC flow and operation of the DC driven device when the safety circuit is in the disable state and to permit DC flow and operation of the DC driven device when the safety circuit is in the enable state such that the operation of the DC driven device will occur when the safety circuit is in the enable state. In one version the DC driven device is a DC motor in an infusion pump, while in other versions the DC driven device is a gas generator in an infusion pump. Preferably, the safety circuit is controlled by an AC signal from the controller such that the safety circuit is enabled by the AC signal to permit DC flow and enable the forward motion of the DC motor while the AC signal is provided by the controller.

Direct current motor safety circuits for fluid delivery systems

In an ICD, a highly efficient biphasic defibrillation pulse is generated by switching at least two charged capacitors, e.g., three capacitors, from a parallel connection to various combinations of a parallel/series connection or a series connection during the first phase of the defibrillation pulse. Such mid-stream parallel/series connection changes of the capacitors steps up the voltage applied to the cardiac tissue during the first phase. A stepped-up voltage during the first phase, in turn, gives an extra boost to, and thereby forces additional charge (current) into, the cardiac tissue cells, and thereby transfers more charge to the membrane of the excitable cardiac cell than if the capacitors were continuously discharged in series. Phase reversal is timed with the cell membrane reaching its maximum value at the end of the first phase.

System and method for generating a high efficiency biphasic defibrillation waveform for use in an implantable cardioverter/defibrillator (ICD).

An annunciator for an organ stimulating system implantable in the body of a person comprises a hollow canister having a cylindrical internal cavity, first and second electrically conductive coils encircling the canister lying in transverse, preferably perpendicular, planes which intersect along the longitudinal axis of the internal cavity, and a cylindrical permanent magnetic roller having an outer peripheral surface engageable with an inner peripheral surface of the canister and being freely rotatable within the canister. The roller is magnetized at right angles to the roller axis producing a permanent magnetic field and signal generators, either AC or DC, sequentially energize the electrically conductive coils to produce a rotating magnetic field interacting with the permanent magnetic field of the roller and causing the roller to roll about the inner peripheral surface of the canister. The permanent magnetic roller, by its movement, produces vibrations which are imparted to the casing of the organ stimulating system. Specifically, the rolling motion of the roller results in a movement of its center of gravity in a vibration producing orbit. The orbital frequency, &OHgr;, of the center of gravity of the roller is b &ohgr;&middot;d/(D&minus;d), where &ohgr;&equals;rate of rotation of said roller, d&equals;diameter of said roller, and D&equals;inner diameter of the cavity of said canister. In another embodiment, the roller may be replaced by a ball and the internal cavity may be spherical or ellipsoidal.

Magnetic annunciator

An annunciator for an implantable medical device encapsulated within a casing comprises a magnetically permeable stationary ring member including an integral inwardly projecting peripheral flange having opposed sides on which electrically conductive coils are mounted. An oscillating member encompassed by the stationary ring member includes a planar magnet member having opposed surfaces of opposite polarity and planar pole pieces are mounted to the first and second surfaces, respectively, in a sandwich-like construction. The oscillating member is movable along a longitudinal axis between extreme positions whereat the first pole piece, then the second pole piece is proximate the ring flange. Cyclic energization of the electrically conductive coils generates a cyclically alternating magnetic field, which interacts with the magnetic field of the oscillating member causing its oscillation between the first and second extreme positions. In another embodiment, the casing includes opposed walls and the first and second pole pieces impact against the opposed walls when the oscillating member reaches the first and second extreme positions, respectively. In another embodiment, opposed spider members have a central portion fixed to their respective polar pieces and a plurality of radially extending legs have terminal ends fixed, respectively, to the ring member at peripherally spaced locations, the spider members being axially compliant and biasing the oscillating member toward a neutral position and being substantially non-compliant transversely of the longitudinal axis for centering the oscillating member relative to the ring member throughout travel thereof between the first and second extreme positions.

Pancake annunciator

A flow sensor adapted for placement along a pacing lead or other catheter comprises a thermopile formed on the outer surface of a tubular substrate. The thermopile comprises a plurality of interconnected conductors of an alternating metal type. Junctions between conductors of the thermopile are alternately located near the longitudinal ends of the flow sensor, so that a voltage generated by the thermopile indicates the difference in temperature between the ends of the flow sensor. To measure blood flow with the flow sensor, an alternating current is induced through the thermopile to heat the flow sensor in a generally symmetrical manner. A voltage generated by the thermopile is then measured to obtain a sample of the magnitude and direction of the velocity of blood flow.

Thermopile flow sensor

A magnetic field sensor comprises a substantially planar core member having flux concentrating fins, and relatively narrow segments that interconnect the fins so that an external magnetic field becomes concentrated within the segments. A quality factor (Q) of a single coil which is wrapped around the segments is monitored to measure or detect the presence of an external magnetic field. To measure an external field, a current is passed through the coil to charge the coil with a known quantity of energy. A circuit of the sensor then measures the quantity of energy returned by the coil to measure the Q of the coil, and to thereby measure the external magnetic field. The magnetic sensor is suitable for pacemaker applications as a substitute for reed switches.

Coil return energy measurement magnetic field sensor and method thereof

An annunciator is provided for an organ stimulating system which is implantable in the body of a patient. A tubular support member is mounted at one end on the casing for the organ stimulating system and extends to a free end and an electrically conductive coil encircles the support member. An elongated oscillating member includes a field return member of magnetically permeable material which is spaced from and generally encircles the support member. The field return member extends between an integral head member at a proximal end generally proximate the free end of the support member and a distal end generally proximate the casing. A stack member is mounted on the head member and extends away therefrom toward the casing for the organ stimulating system. The stack member has an outer peripheral surface which is spaced from the support member and includes a magnetically permeable pole piece and a permanent magnet member, the pole piece and the magnet member being in stacked relationship which together produce a radial magnetic field which extends through the coil and to the field return member. A resilient member intermediate the stack member and the casing of the organ stimulating system biases the oscillating member to an initial position. With this construction, cyclic energization of the coil interacts with the radial magnetic field to cause the oscillating member to oscillate relative to the initial position. A similarly constructed activity sensor is also disclosed for relating patient movement.

An implantable blood flow sensor for measuring a blood flow rate through a blood vessel within a person's body. The flow sensor includes a rigid cylindrical tube, sized to fit within the blood vessel, a heater attached to the tube, and a pyroelectric detector located within the tube. A predetermined amount of heat energy is produced by the heater and the pyroelectric detector monitors the resultant temperature change and generates a temperature signal based on the temperature change. A processor generates a data signal, based on the temperature change, that indicates the blood flow rate through the blood vessel or artery. The rigid tube protects the pyroelectric detector from external forces that may produce unwanted signals due to piezoelectric effects. Additionally, the heater may be incorporated into one of the electrodes of the pyroelectric detector as a serpentine path in the electrode that forms a resistive heating element. Also, a switch may be provided that prevents induced voltage signals caused by currents through the heater from reaching the processor.

Implantable flow sensor apparatus and method

A two-conductor bus system is provided to electrically interconnect a plurality of physiologic sensors to a pacemaker, each sensor being adapted for placement along a pacing lead. The conductors of the bus extend longitudinally through the insulating material of the lead, connecting to each sensor. The pacemaker provides a supply voltage on the bus to provide power to the sensors. The sensors modulate the supply voltage on the bus to transmit information to the pacemaker. This information may be used by the pacemaker to adaptively pace the heart. In one embodiment, the sensors include bus monitoring circuitry for receiving control signals from the pacemaker.

Bus system for interconnecting an implantable medical device with a

An implantable medical device including a piezoelectric accelerometer activity sensor. The activity sensor includes a thin film piezoelectric cell within a frame structure. A mass imposes a load based upon acceleration to apply lateral or transverse forces which cause the generation of an electrical potential within the piezoelectric cell, which can be used by a rate control algorithm within the device to control operation of the device.

Activity sensors for implantable medical devices

A fluid flow rate measuring apparatus having a thermistor exposed to a flow of fluid and a driver circuit operable in an initial constant-voltage mode, in which it applies a substantially constant voltage across the thermistor, and a subsequent constant-current mode, in which it applies a substantially constant current through the thermistor, such current corresponding to the current level at the end of the constant-voltage mode. A voltage sensor measures the resultant voltage drop across the thermistor, which is a direct measurement of the fluid flow rate and which is substantially insensitive to variations in ambient temperature.

Growing community of inventors

Calabasas, CA, United States of America

Herman Lee Renger