Medtronic, Inc.

Other

James W Busacker

Todd Jon Sheldon

James D Reinke

John D Wahlstrand

Saul E Greenhut

H Toby Markowitz

James Kevin Carney

Jonathan L Kuhn

David Jerome Peichel

Vincent E Splett

Robert A Betzold

Michael F Hess

Vincent P Ganion

Juliana E Pronovici

Greggory R Herr

Carleen J Juran

David L Thompson

Karen J Kleckner

Craig L Schmidt

Can Cinbis

John J Grevious

Glenn M Roline

John C Rueter

Ann M Crespi

Donald R Merritt

Lucy M Nichols

Robert John Schuelke

Mukul Jain

Russell E Anderson

Michael B Shelton

Gregory A Younker

Michael L Hudziak

Kevin L Bright

Christopher M Manrodt

Ren Zhou

Keelia M Escalante

Anthony W Schrock

Paul B Wyborny

Keelia Doyle

David W Hoffman

Kevin E Baumgart

Virginia De La Riva

Kathleen U Crandall

David E Dalluge

Thomas P Edery

Charles R Brynelsen

Robert A Hochban

Terrence G Ryan

Christine M Blanchette

A pacemaker is configured to operate in an atrial synchronous ventricular pacing mode and, after expiration of a conduction check time interval, switch to an asynchronous ventricular pacing mode that includes setting a ventricular pacing interval to a base pacing rate interval. The pacemaker is further configured to determine when atrioventricular block detection criteria are satisfied during the asynchronous ventricular pacing mode and, responsive to the atrioventricular block detection criteria being satisfied, switch back to the atrial synchronous ventricular pacing mode.

Mode switching in a ventricular pacemaker to promote atrioventricular conduction

Systems, devices, and techniques for establishing communication between two medical devices are described. In one example, an implantable medical device comprises communication circuitry, therapy delivery circuitry, and processing circuitry configured to initiate a communication window during which the implantable second medical device is capable of receiving the information related to a cardiac event detected by a first medical device, the communication window being one of a plurality of communication windows defined by a communication schedule that corresponds to a transmission schedule in which the first medical device is configured to transmit the information, control the communication circuitry to receive, from the first medical device, the information related to the cardiac event that is indicative of a timing of the cardiac event with respect to a timing of the communication window, schedule and control delivery of a therapy according to the information related to the cardiac event.

Low power wireless communication

In an example, an implantable medical device (IMD) includes a hold capacitor configured to deliver an electrical therapy pulse, and charge pump circuitry configured to transfer energy from the battery to the hold capacitor. In this example, the charge pump circuitry comprises a plurality of capacitors, and switching circuitry configured to put the charge pump circuitry into a K-factor mode selected from a group of K-factor modes by opening and closing a combination of switches connected to the plurality of capacitors.

Pacing output K-factor improvements

A system and method is provided for reliably indicating that an implantable medical device is in need of replacement. An implantable medical device includes a battery and a replacement indicator timer. The battery provides power to the implantable medical device. The replacement indicator timer counts a replacement time period to a determined replacement date for the implantable medical device. The replacement indicator timer starts the counting when an operational characteristic of the battery reaches a selected value.

Replacement indicator timer for implantable medical devices

Methods for estimating a remaining service life of an implantable medical device (IMD) battery are presented. In one embodiment, a characteristic discharge model of the battery is employed. Systems employing the methods may include an external device coupled to the IMD, for example, via a telemetry communications link, wherein a first portion of a computer readable medium included in the IMD is programmed to provide instructions for the measurement, or tracking, of time and the measurement of battery voltage, and a second portion of the computer readable medium included in the external device is programmed to provide instructions for carrying out the calculations when the voltage and time data is transferred via telemetry from the IMD to the external device.

Estimating remaining battery service life in an implantable medical device

In bi-ventricular pacing devices (including CRT devices) analysis of myocardial electrogram signals in one ventricle (e.g., a left ventricle, or 'LV') can be used to infer capture or loss-of-capture (LOC) of an earlier stimulus pulse in the same ventricle, on a continuous (every pacing cycle), triggered, aperiodic and/or periodic basis. Rather than using an evoked-response principle as has been the basis of capture detection in prior art and other systems, a principle employed via the present invention uses evidence of inter-ventricular conduction (i.e., from the opposite chamber) and/or atrio-ventricular conduction as evidence of LOC, since a non-capturing pacing stimulus provided to a first chamber will allow the myocardial tissue of the first chamber to remain non-refractory and thus inter-ventricular and atrio-ventricular wavefront propagation and conduction can commence and be detected thereby revealing whether LOC has occurred.

Method of continuous capture verification in cardiac resynchronization devices

A capture detection algorithm detects and distinguishes atrial capture. Atrial chamber reset (ACR) and AV conduction (AVC) algorithms are implemented to measure an atrial pacing threshold The data that is used to choose between ACR and AVC methods is used to determine the progression of the patient's disease state. Some of the significant aspects of the invention include enablement of accurate threshold measurements, including calculation of stability criteria, precise interval measurements and the use of reference interval to determine capture and loss of capture.

Capture management improvements

A system and method is provided for reliably indicating that an implantable medical device is in need of replacement. The system and method measures the operational characteristics of the battery and the operational parameters of the implantable device itself. When these characteristics and parameters reach a defined level, the implantable medical device starts a replacement indicator timer. The replacement indicator timer starts and counts a replacement time period, with the replacement time period ending at a determined replacement date. The determined replacement date is the date at which the implantable medical device should be replaced.

A system and method for determining a remaining life estimate of the remaining battery life of a battery of an implantable medical device (IMD). The IMD battery preferably exhibits a highly reproducible monotonically decreasing discharge curve. The estimated remaining life estimates are derived by periodically measuring battery voltage, and estimating the estimated past current drain of the IMD comprising an average of the sum of the quiescent current drain and therapy delivery current drain, and determining the estimated remaining longevity from the measured voltage and the estimated past current drain.

System and method for determining remaining battery life for an implantable medical device

An automatic, body-implantable medical device having at least two modes of operation is disclosed. The device is provided with circuitry for automatically detecting when the device has been implanted in a patient, so that the device can automatically switch from a first mode to a second mode of operation upon implantation. In one embodiment, the first mode is a power conserving mode in which one or more non-essential sub-systems of the device are disabled. Prior to detection of implant, at least two conditions of the device known to reflect whether the device has been implanted are monitored. After implant has been detected, situations in which power to the device is disrupted and then restored will cause the device to enter a predefined 'power-on-reset' mode of operation. Prior to detection of implant, however, such conditions do not result in the device entering the power-on-reset mode, or this mode is reset. An Elective Replacement Indicator mode is also used which is based on measured impedance against a target battery impedance. When the measured battery impedance reaches the target level, the voltage of the battery that precipitates an ERI condition is modified.

Resetting ERI/POR/PIR/indicators in implantable medical devices

Two mechanisms work together to adjust two variables independently so that the gain of an input amplifier used to find physiologic signals in an implantable medical device can be automatically adjusted to enhance the signal to noise ratio of the electrical input to said amplifier. The first determines whether there has been too long a time between senses found in the body's electrical input to the amplifier and if true, and no other conditions override that consideration, it adjusts the value of a long term average parameter which is used as a referent parameter to adjust the actual parameter that is used as the referent for making either a threshold level adjustment or gain change, depending on the structure of the particular design's circuitry and/or software. One set of adjustments to the gain referent parameter depends on the relative size of the long term average parameter and the gain referent parameter. The mechanisms preferably employ counting registers, the one which adjusts the gain referent having a process to weight input signals such that those of different types get different weights, and the other mechanism only accepting certain of the input signals. Input signals to the two mechanisms can be either physiologically based or from stimulation pulses issued from an implanted device, such as, for example a pacemaker.

Method for automatically adjusting the sensitivity of cardiac sense

Multilevel ERI for implantable medical devices

Growing community of inventors

St. Anthony, MN, United States of America

James W Busacker