Medtronic, Inc.

Edwin G Duffin

Lawrence J Mulligan

David L Thompson

Gregory John Haubrich

D Curtis Deno

Tommy Dean Bennett

William J Combs

Steven D Goedeke

David E Euler

David A Igel

T V Rao

Jeffrey M Gillberg

Karen J Kleckner

John E Burnes

Bruce D Gunderson

Vincent E Splett

Amisha Somabhai Patel

Kenneth M Anderson

John C Rueter

Karel F Smits

Ruth N Klepfer

Barbro M Kjellstrom

Glenn C Zillmer

Chad A Bounds

Kathleen A Prieve

Robert Cushing Hamlen

Harold Toby Markowitz

Ren Zhou

Curtis D Deno

Wael Abo-Auda

Warren S Watson

A method of stimulation therapy and an apparatus for providing the therapy which addresses cardiac dysfunction including heart failure. The therapy employs atrial pacing pulses delivered to a heart after the atrial refractory period and timed so that they will not cause a ventricular contraction. These atrial pacing are timed to achieve beneficial effects on myocardial mechanics (efficacy) while maintaining an extremely low level of risk of arrhythmia induction. These methods may be employed individually or in combinations in an external or implantable ESS therapy delivery device.

Secure and efficacious therapy delivery for a pacing engine

A system and method are provided for determining an index of autonomic nervous system (ANS) or sympathetic nervous system (SNS) activity for use in patient monitoring or therapy delivery control. An ANS or SNS index is calculated as a function of multiple monitored physiological variables that strongly correlate to changes in autonomic or sympathetic tone. These ANS-influenced variables are derived from selected hemodynamic and/or electrical signals and may include variables relating to any of: the maximum rate of pressure rise (dP/dt), the maximum rate of pressure decline (dP/dt), pulse pressure (PP), pre-ejection time interval (PEI) and/or systolic time interval (STI), heart rate (HR), heart rate variability (HRV), and baro-reflex gain. Changes in the ANS or SNS index may be used to automatically adjust a device delivered therapy.

Method and apparatus to provide diagnostic index and therapy regulated by subject's autonomic nervous system

A medical device, e.g., an implantable medical device, delivers one or more neurally-excitable stimulation pulses to myocardial tissue during a period when the tissue is refractory. The width of the pulses is less than or equal to approximately one half millisecond. In some embodiments, the current amplitude of the pulses is less than or equal to approximately twenty milliamps. In exemplary embodiments, the medical device delivers a pulse train of six or fewer pulses separated from each other by an interval that is greater than or equal to approximately ten milliseconds. In some embodiments, the medical device delivers pulses according to a schedule stored in a memory, or as a function of a monitored physiological parameter of a patient, such as an intracardiac pressure. In some embodiments, the medical device suspends or withholds delivery of neurally-excitable based on detection of cardiac ischemia.

Cardiac stimulation during a refractory period

A method and apparatus for automatically detecting and diagnosing lead-related conditions is provided. Specifically, relatively short-term and relatively long-term impedance parameters are determined for detecting an impedance trend indicative of a lead-related condition such as an open circuit, which may be due to a conductor fracture or poor connection to an associated implantable medical device, or a short circuit due to an insulation breach. Monitoring of multiple lead impedance parameters is performed to diagnose a lead-related condition based on a number of diagnostic criteria. Supplementary analysis of multiple lead impedance parameter trends may be performed to identify lead-specific conditions, such as metal ion oxidation induced insulation degradation. A lead-related condition diagnosis and supporting data are stored in memory for uplinking to an external device for review by a clinician. A recommended corrective action and/or a patient notification signal for a lead-related condition may optionally be provided.

Method and apparatus for identifying lead-related conditions using lead impedance measurements

An implantable heart monitor (IHM) implanted in a patient's body having electrogram (EGM) sense electrodes coupled with EGM sense circuitry to generate sense events upon detection of cardiac depolarizations and a blood pressure measurement transducer disposed in a heart chamber and coupled with blood pressure measurement circuitry operates to assess heart failure state as a function of mechanical pulsus alternans (MPA). MPA episodes are detected, and MPA characteristics of the MPA episode are used alone or as a group as a diagnostic marker of HF state. The MPA episode data set can be stored in memory associated with a time and date stamp. The MPA characteristics of each MPA data set in a series of MPA data sets collected over time can be compared or plotted to determine if a trend indicative of change in HF state is discernible.

Implantable medical device for assessing heart failure state from Mechanical Pulsus Alternans

A system for communicating with a medical device implanted in an ambulatory patient and for locating the patient in order to selectively monitor device function, alter device operating parameters and modes and provide emergency assistance to and communications with a patient. The implanted device includes a telemetry transceiver for communicating data and operating instructions between the implanted device and an external patient communications control device that is either worn by or located in proximity to the patient within the implanted device transceiving range. The control device preferably includes a communication link with a remote medical support network, a global positioning satellite receiver for receiving positioning data identifying the global position of the control device, and a patient activated link for permitting patient initiated personal communication with the medical support network. A system controller in the control device controls data and voice communications for selectively transmitting patient initiated personal communications and global positioning data to the medical support network, for initiating telemetry out of data and operating commands from the implanted device and transmission of the same to the medical support network, and for receiving and initiating re-programming of the implanted device operating modes and parameters in response to instructions received from the medical support network. The communications link between the medical support network and the patient communications control device may comprise a world wide satellite network, hard-wired telephone network, a cellular telephone network or other personal communications system.

World wide patient location and data telemetry system for implantable medical devices

An implantable medical device (IMD) capable of monitoring physiologic data, distinguishing relatively noisy and noise free physiologic data, and recording noisy and relatively noise free segments of physiologic data in separate memory registers of a limited memory for retrieval and analysis at a later time. Preferably the physiologic data comprises the sampled EGM of the heart detected from sense electrode pairs that are implanted in the patient at sites where extraneous electrical noise, e.g., electromyographic signals, are also capable of being detected. The sense electrode pairs can constitute one or both sense electrodes located on or adjacent to the atrial and/or ventricular heart chambers and coupled to the IMD by a lead body or sense electrode pairs that are located remotely from the heart, e.g. at a subcutaneous implantation site of the IMD. A plurality of noisy EGM episode data registers store a corresponding plurality of noisy EGM episode data sets on a FIFO basis and another plurality of noise free EGM episode data registers to store a corresponding plurality of relatively noise free EGM episode data sets on a FIFO basis. Any form of discrimination of noisy data from relatively noise free data can be employed at the time of recording, but because the stored EGM episode data sets are subsequently viewed and analyzed by a physician, discrimination with absolute certainty is not required, and the physician can alter the detection criteria to fine tune it.

Implantable monitor

A system and method for communicating with a medical device implanted in an ambulatory patient and for locating the patient in order to selectively monitor device function, alter device operating parameters and modes and provide emergency assistance to and communications with a patient. The implanted device includes a telemetry transceiver for communicating data and operating instructions between the implanted device and an external patient communications control device that is either worn by or located in proximity to the patient within the implanted device transceiving range. The control device preferably includes a communication link with a remote medical support network, a global positioning satellite receiver for receiving positioning data identifying the global position of the control device, and a patient activated link for permitting patient initiated personal communication with the medical support network. A system controller in the control device controls data and voice communications for selectively transmitting patient initiated personal communications and global positioning data to the medical support network, for initiating telemetry out of data and operating commands from the implanted device and transmission of the same to the medical support network, and for receiving and initiating re-programming of the implanted device operating modes and parameters in response to instructions received from the medical support network. The communications link between the medical support network and the patient communications control device may comprise a world wide satellite network, hard-wired telephone network, a cellular telephone network or other personal communications system.

World wide patient location and data telemetry system for implantable

A pacemaker system adapted to deliver pacing pulses in the presence of fibrillation. The pacing pulses are delivered via large surface area electrodes of the type normally used to accomplish defibrillation or cardioversion using high voltage pulses. An extended pulse train is delivered in order to gradually entrain greater portions of heart tissue, until a sufficient percentage of tissue is entrained to interrupt fibrillation. The invention is believed most applicable to treatment of atrial fibrillation.

Method and apparatus for treatment of atrial fibrillation

A medical electrical pulse generator having a switchable connector assembly. The connector assembly is provided with connector bores, each intended to receive a medical electrical lead or a sealing plug, if no lead is provided. Electrical connectors located within the bores are arranged such that interconnection of the pulse generator circuitry within the device and electrodes on the leads and/or housing of the device can be altered by means of connector pins located on the electrical leads or the sealing plugs, which may be employed to interconnect electrical connectors within a connector bore.

Switchable connector block for implantable defibrillator

A pacemaker system adapted to delivery pacing pulses in the presence of tachycardia or bradycardia. The pacing pulses are delivered via large surface area electrodes of the type normally used to accomplish defibrillation or cardioversion. Delivery of pacing pulses using the large surface area electrodes results in a more simultaneous depolarization of the heart tissue and is believed beneficial to improve hemodynamic efficiency of paced heart beats and in terminating detected tachyarrhythmias.

Method and apparatus for wide area antitachycardia pacing

A method and apparatus for discriminating among the various normal and pathologic tachycardias. In response to the detection of tachycardia, far-field ventricular electrograms sensed using atrial electrodes and far-field atrial electrograms sensed using ventricular electrodes are analyzed in order to categorize the source and type of tachyarrhythmia detected. The detection method and apparatus may be employed in conjunction with dual chamber anti-bradycardia pacemakers to avoid pacemaker mediated tachycardias or may be employed to mediate the delivery of pacing energy or cardioversion/defibrillation shock energy to a malfunctioning heart, in the context of an implantable antitachycardia device.

Method and apparatus for discriminating among normal and pathological

A mode switching bradycardia pacemaker especially adapted for incorporation in an antitachyarrhythmia pacing and/or cardioversion/defibrillation system, provides AAI pacing in the absence of an intrinsic atrial rate exceeding the pacing lower rate and as long as the patient's heart is capable of normal AV conduction. The pacemaker switches to VVI mode any time that the patient's ventricular rate falls below a predetermined value. The mode switching may be implemented in a DDD pacing system or in a pacing system employing an atrial and ventricular sense amplifier and a single pacing output circuit and switching circuitry for switching its output between atrial and ventricular leads. This bimodal operation allows use of AAI pacing for the antiarrhythmic and hemodynamic benefits of maintaining atrial function in patients with sinus node disease, by obviates the risk of ventricular asystole should the AAI mode become ineffective due to transiant or newly evolving permanent impairment of AV conduction in those patients where atrial synchronous tracking is considered undesirable. In the AAI/VVI bimodal operation, only a single chamber of the patient's heart is paced at any given time, AAI pacing occurs in the presence of spontaneous or conducted ventricular depolarization, and VVI pacing is resorted to in AV dissociation or in the absence of a ventricular rhythm exceeding the lower pacing rate.

Mode switching pacemaker

A pacing system analyzer is constructed to provide verification that an implantable cardiac pacer operating in a demand mode will not itself produce tachycardia in a patient because of abnormally long patient retrograde conduction time. The analyzer when performing the retrograde conduction test provides an intercardiac electrogram, changes the ventricular sense amplifier to asynchronous and samples to determine the maximum amplitude signals over a sampling period to select an amplifier gain factor. After the gain factor is set additional signal samples are collected, peak-to-peak amplitude is measured and interpolation between data is made to provide waveform 'segments' and the best waveform segment to employ for testing for retrograde conduction is selected. The time periods from pacing to these segments are measured and utilized to determine if retrograde conduction is present.

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North Oaks, MN, United States of America

Edwin G Duffin