Medtronic, Inc.

Glenn M Roline

David L Thompson

Lucy M Nichols

Tommy Dean Bennett

Paul B Wyborny

James D Reinke

Jonathan P Roberts

Brian Bruce Lee

Michael W Heinks

Donald R Merritt

Tom Dean Bennett

Shohan T Hossain

Keith Alan Miesel

Mark A Christopherson

William G Howard

Kenneth M Anderson

John G Keimel

Michael B Terry

George Patras

John J Grevious

Dennis A Brumwell

Anthony J Varrichio

Paul M Skarstad

James W Busacker

Lee Stylos

Hailiang Zhao

Steven Joseph May

Robert A Corey

Douglas J Weiss

Jeffrey S Lund

Stephen R Duggan

Louis E Halperin

Joseph A Ballis

Robert M Bennett, Jr

Richard Penn

Sudha Nagavarapu

David E Dalluge

Christine M Blanchette

Frank Walmsley

Richard J Harrington

An implantable pacemaker detects delivery of an anti-tachyarrhythmia shock by another device. The implantable pacemaker delivers cardiac stimulation therapy within a patient. The implantable pacemaker senses, via the electrode pair, an electrical signal. The implantable pacemaker detects the anti-tachyarrhythmia shock based on the sensed electrical signal by detecting DC voltage polarization across the electrode pair within the patient. The implantable pacemaker alters the cardiac stimulation therapy based on the detected anti-tachyarrhythmia shock.

Anti-tachyarrhythmia shock detection

An implantable medical device includes an energy storage device with an internal component and an outer case that encloses the internal component. The outer case is electrically connected to the internal component. The energy storage device includes a first electrode that is electrically connected to the internal component. Furthermore, the device includes a control assembly with a control component and a control case that encloses the control component. The control case is coupled to and electrically connected to the outer case. The control component is electrically coupled to the first electrode and the outer case to be powered by the internal component of the energy storage device. The control component controls transmission of an electrical signal between the implantable medical device and biological tissue. Also, an outer surface of the outer case and the outer surface of the control case are exposed to the biological material.

Implantable medical device with exposed generator

This disclosure relates to fault tolerant instantiations of a cardiac therapy delivery device such as an implantable cardiac stimulator (e.g., an implantable pulse generator, IPG, and/or an implantable cardioverter-defibrillator, ICD) coupled to an implantable physiologic sensor (IPS). According to the disclosure delivery of cardiac pacing and/or cardioversion-defibrillator therapy delivery can cause errors in output signals from an IPS. Resolution of such errors involves selectively energizing (or disconnecting the output signal from) the IPS during pacing and/or defibrillation therapy delivery. Programmable signal 'blanking' in lieu of or in addition to the foregoing also improves the integrity of the output signal (i.e., continuously energize the IPS and ignore parts of the output signal). An ICD having a transient weakness in an insulated conductor used for the IPS signal can likewise have the IPS de-energized and/or blank the IPS output signal during high voltage therapy delivery.

Fault tolerant implantable pulse generators and implantable cardioverter-defibrillators incorporating physiologic sensors and methods for implementing fault tolerance in same

A system and method for measuring and communicating parameters of a brain, tissue, or other organs is disclosed. The system includes a sensor to sense the parameter of interest, an external device where the parameter may be displayed, processed or cause action to be taken, and a communication system to communicate the sensed parameter from the sensor to the external device. In another embodiment, the system includes a processing system for processing the sensed parameters and controlling an associated medical device.

Device and method to measure and communicate body parameters

An implantable dual transducer apparatus for use with an implantable medical device and control method are disclosed. The dual transducer assembly includes two physiologic sensors coupled to the medical device via a pair of lead conductors. Switching circuitry is controlled by the medical device to selectively activate and deactivate the two physiologic sensors by application of a supply voltage of an appropriate polarity. Each sensor of the dual transducer assembly is connected to the pair of lead conductors through a respective power switch. In response to the polarity of the supply voltage applied to the lead conductors, the power switches activate or deactivate their respective sensor in an alternating manner. Selective activation of one of the sensor while concurrently deactivating the other sensor of the dual transducer assembly provides for reduced power consumption and reliable communication of sensor data and other information transmitted over the pair of lead conductors. The power switches may be constructed using diodes, including discrete or substrate diodes, or transistors, such as n-channel and p-channel transistors. A wide variety of physiologic sensors may be incorporated into the dual transducer assembly.

Circuit and method for implantable dual sensor medical electrical lead

A capacitive pressure and temperature sensing system for providing signals representative of the magnitude of body fluid absolute pressure at a selected site and ambient operating conditions, including body temperature, at the site. An implantable lead having a sensor module formed in its distal end is coupled to a monitor that powers a sensor circuit in the sensor module and demodulates and stores absolute pressure and temperature data derived from signals generated by the sensor circuit. The sensor module is formed with a pickoff capacitor that changes capacitance with pressure changes and a reference capacitor that is relatively insensitive to pressure changes. The sensor circuit provides charge current that changes with temperature variation at the implant site, alternately charges and discharges the two capacitors, and provides timing pulses having distinguishable parameters at the end of each charge cycle that are transmitted to the demodulator. The demodulator detects and synchronizes the timing pulses and derives pressure and temperature analog voltage values representative of the intervals between the timing pulses which are digitized and stored in the monitor. The monitor may also be coupled with other sensors for measuring and storing related patient body parameters, e.g. blood gas, EGM, and patient activity.

Implantable capacitive absolute pressure and temperature monitor system

A pacemaker capable of automatically adjusting the sensitivity of its sense amplifier to electrical cardiac signals is disclosed. In one embodiment, a pacemaker having a pressure sensor disposed on the distal end of its pacing/sensing lead counts the number of pressure events and electrical events which occur during an autosensitivity timing period. If the number of electrical events exceeds the number of pressure events by more than a predetermined margin, the sense amplifier's sensitivity threshold is decreased. If the number of electrical events does not exceed the number of pressure events by more than the predetermined margin, the sense amplifier's sensitivity threshold is increased. In another embodiment, the pacemaker maintains a running average of the peak voltages of sensed electrical events over a predetermined history period. Periodically, the pacemaker computes the ratio of the running average of peak voltages to a preprogrammed sense margin value, and adjusts the sensitivity threshold of the sense amplifier according to this computation. By basing the adjustment of the sense amplifier's sensitivity threshold on a long-term average of peak sense values, the effects of cycle-to-cycle variation in sensed values are minimized. In still another embodiment of the invention, a pressure sensor alone is employed to detect natural cardiac events.

Automatic sensitivity adjust for cardiac pacemakers

A method of and apparatus for telemetering analog and digital data transcutaneously between an implantable medical device and an external receiver, such as between an external programmer and an implantable cardiac pacer. A damped carrier at 175 kilohertz is pulse position modulated by digital data. The data, along with synchronization and identification codes, are positioned into predefined ranges within predefined frames as measured by individual time periods. The data is uniquely identified by the position of one or more bursts of the carrier within the predefined range. An automatically initiated hand shake protocol maintains the link over slight variations in programmer head position with an indicator notifying the operator when repositioning is required. Analog data may be transferred in digital form or alternatively transferred using phase modulation of the carrier bursts. A cyclic redundancy code is used for link error detection. The digital data may be encoded/decoded in bit or byte format using hardware and/or software elements.

Telemetry system for an implantable medical device

A method and apparatus for determination of battery end-of-service in a medical device in which the medical device comprises a cathode limited electrochemical cell having an active metal anode and a manganese dioxide cathode and means for digital telemetry of cell voltage. The sloped, well defined voltage curve of such a cell during cell discharge combined with precise information available through digital telemetry allows for improved determination of battery end-of-service for the medical device.

Method and apparatus for determination of end-of-service for implantable

An implantable physiologic device, e.g., a multi-programmable, microprocessor based cardiac pacemaker, is provided with data storage and transmission capabilities for transmitting out certain current operating parameters and sensed events and for storing counted events for transmission of counts, histograms and real-time clock data out on command. The device preferably comprises a rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least one selected rate control parameter. Each rate control parameter has a value which varies as a function of changes in a patient's physiologic demand and includes a sensor system for sensing the rate control parameter value and for providing a sensor output representative thereof. The cardiac pacemaker also includes control circuitry which includes a rate response defining means for deriving desired pacing rates as a function of the sensor output signal(s) modified by sensor gain and selective weighting coefficient values. An achievement monitoring means that has a predetermined achievement criterion monitors the relationship between the derived pacing rates and the achievement criterion over an optimization period. Output circuitry providing optimized pacing rates as a function of optimization is accomplished by adjusting the rate response gain for each sensor as a function of the monitored achievement relationship. Another optimization function is provided by adjusting a sensor weighting coefficient value which weights or regulates the relative contribution each sensor's derived desired pacing rates will contribute toward the pacemaker-derived optimized pacing rate.

Diagnostic function data storage and telemetry out for rate responsive

An automatic capture restoration and threshold-seeking method and apparatus for use with a cardiac pacemaker derives control signals for restoring cardiac capture from a cardiac pressure sensor. The pressure sensor also provides input control signals for a threshold-seeking apparatus. Both pulse width and amplitude thresholds can be changed contemporaneously during both capture restoration and threshold seeking.

Automatic cardiac capture restoration and threshold-seeking method and

A monitoring system for an oxygen sensing, dual-wavelength, reflectance oximetry based, rate responsive cardiac pacemaker, is capable of automatically and continually adjusting an oxygen sensor signal comparator threshold such that the effects of noise, sensitivity and drift on oximeter output signals sent to the pacemaker are minimized. A comparator and related circuitry are configured to sample and compare supply excitations for multiple oxygen sensor light sources. The comparator threshold is adjusted as a function of supply excitation for each light source independently of one another, thereby providing an oxygen sensing pacemaker with optimal noise immunity since one of the more vulnerable portions of the pacing system is the transfer of the light source signals which are susceptible to noise.

Apparatus and method of automatically adjusting a sensor signal

A method of and apparatus for telemetering both analog and digital data transcutaneously between an implantable medical device and an external receiver, such as between an external programmer and an implantable cardiac pacer. A damped carrier at 175 kilohertz is pulse position modulated by digital data. The data, along with synchronization and identification codes, are positioned into predefined ranges within predefined frames as measured by individual time periods. The data is uniquely identified by the position of a burst of the carrier within the predefined range. An automatically initiated hand shake protocol maintains the link over slight variations in programmer head position with an indicator notifying the operator when repositioning is required. Analog data may be transferred in digital form or alternatively transferred using phase modulation of the carrier bursts. A cyclic redundancy code is used for link error detection.

Hand shake for implanted medical device telemetry

A rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least one selected rate control parameter. Each rate control parameter has a value which varies as a function of changes in a patient's physiologic demand and includes a sensor system for sensing the rate control parameter value and for providing a sensor output representative thereof. The cardiac pacemaker also includes a rate response defining means for deriving desired pacing rates as a function of the sensor output, an achievement monitoring means that has a predetermined achievement criterion (primary criterion), for monitoring the relationship between the derived pacing rates and the achievement criterion over an optimization period, and either one of Average Activity level or Average Activity Difference level monitoring means that has a corresponding predetermined minimum and a predetermined maximum Average Activity level or Average Activity Difference level (secondary criterion), for monitoring the relationship between the derived pacing rates and the secondary criterion over an optimization period. Another optimization function is provided by adjusting a sensor weighting value which weights or regulates the relative contribution each sensor's derived desired pacing rates will contribute toward the pacemaker-derived optimized pacing rates.

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Anoka, MN, United States of America

Glenn M Roline