Medtronic, Inc.

Michael B Shelton

H Toby Markowitz

William J Combs

Kenneth M Riff

Craig L Schmidt

Carleen J Juran

Ross O Starkson

Eric J Panken

Kenneth C Gardeski

Tommy Dean Bennett

James F Kelley

John D Wahlstrand

Orhan Soykan

Michael F Hess

John Charles Stroebel

James W Busacker

Dwight H Warkentin

Trent M Fischer

Lawrence J Mulligan

Daniel Robert Kaiser

Michael Neidert

Nicholas David Skadsberg

Pierce Vatterott

Michael R Tollinger

Thomas P Edery

Charles R Brynelsen

Harry A Strandquist

Kristin Yakimow

A method and system for use in selecting a cardiac pacing site includes sensors for tracking wall motion (e.g., sensors coupled to the right and left ventricular heart wall). The wall motion of one or more non-paced cardiac cycles is compared to the wall motion of one or more paced cardiac cycles to determine the effectiveness of one or more pacing sites. For example, image data may be generated to notify the user as to the effectiveness of the one or more pacing sites.

Methods and systems for use in selecting cardiac pacing sites

An algorithm is implemented in a circuit for sensing P-waves in a pacemaker to ensure ventricular pacing synchronization with sensed atrial depolarization waves. VDD and VDDR pacing (atrial synchronized, ventricular inhibited pacing) are implemented via a single standard ventricular pacing lead (unipolar or bipolar) and preferably a subcutaneous electrode array (SEA). Specifically, an implanted ventricular lead provides ventricular pacing and ventricular sensing while the SEA enable atrial sensing, thus eliminating the need for an implanted atrial lead or a specialized single pass VDD lead. The algorithm manages the sensed cardiac waves to effect a desired pacing regimen based on the input from the single lead and SEA.

Atrial aware VVI: a method for atrial synchronous ventricular (VDD/R) pacing using the subcutaneous electrode array and a standard pacing lead

An apparatus and method for communicating acoustic telemetry data produced by an implantable medical device over a communication channel includes a signal generator, a modulator, and an acoustic transmitter each provided in the implantable medical device. The modulator modulates a carrier signal with an information signal representative of information acquired or produced by the implantable medical device so as to produce a modulated information signal. The modulated information signal may have a frequency content that is readily accommodated by a public exchange communication channel. The transmitter transmits the modulated information signal as an acoustic information signal in a form communicable over the communication channel. The acoustic information signal may constitute telephonic tones which are directly communicable over a conventional telephone connection. The acoustic information signal may constitute digital telephonic tones each having a frequency and format that conforms to one or more telephony standards. In an embodiment in which the communication channel constitutes a public exchange communication channel, the acoustic information signal preferably has a frequency content that is band limited by an audio bandwidth of the public exchange communication channel. A number of different modulation techniques may be employed, including phase modulation, amplitude modulation or frequency modulation. Implantable medical devices which may incorporate telemetry circuitry of the present invention include a pacemaker, a pacemaker/cardioverter/defibrillator (PCD), an oxygen sensing device, an implantable hemodynamic monitor, a muscle stimulator device or a nerve stimulator device.

Method and apparatus for accoustically coupling implantable medical device telemetry data to a telephonic connection

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

Pacemaker implant recognition

An implantable medical device and corresponding system and method are disclosed having programmable operating functions for monitoring a patient condition or delivering a therapy. The device has a primary operating function and a trial operating function. Those functions are enabled or disabled in a time dependent manner to permit their comparison and evaluation in a patient. The device may include a telemetry transceiver for receiving external programmable sequences of operating instructions and for transmitting data externally to a programmer. The device may further include a memory for storing the sequence of operating instructions and for storing data related to the delivery of the therapy or the monitoring function.

Method and apparatus for controlling an implanted medical device in a

A method and apparatus of cardiac pacing, in which pacing at an increased rate is provided in response to a detected rapid drop in detected heart rate, to a stable rate below a defined threshold rate.

Pacemaker with vasovagal snycope detection

There is provided a dual chamber pacemaker system and method for ventricular pacing to provide therapy for a patient with cardiomyopathy, this system being characterized by automatically adjusting the AV escape interval so that ventricular pace pulses are delivered at an AV delay which is optimized for HOCM and/or dialated cardiomyopathy therapy. The pacemaker system continually obtains and stores representations of a QRS wave characteristic such as duration, derived either directly from the QRS signal or from an FFRS signal, and compares duration data from one or more cycles to prior stored duration data. The system then adjusts the AV interval as a function of the duration comparison, and the direction of the last adjustment of AV escape interval. By this means, the AV escape interval is maintained at or just short of the onset of fusion, thereby automatically providing for optimally lengthened AV escape intervals consistent with full capture by the delivered ventricular pace pulse.

Dual chamber pacing system and method with automatic adjustment of the

A rate-responsive cardiac pacemaker implements a novel scheme which detects incipient vasovagal syncope (or other episodes caused by a vasodepressive or cardioinhibitory disorder) when a) the heart rate drops below a programmable minimum size, and b) the rate after said drop is below a programmable maximum drop ending rate. The pacemaker implements a stability and intervention procedure upon the detection of an episode, in which it ignores transient drops in rate, and paces at a predetermined high rate if the drops are stable. The pacemaker then gradually reduces the pacing rate over a predetermined time to the pre-episodic level. A sleep disable feature disables the vasovagal syncope detection and therapy features during the patient's sleeping hours to reduce or eliminate false positive responses.

Pacemaker with vasovagal syncope detection

A pacemaker having a fault-tolerant elective replacement indicator (ERI) triggering scheme in which transient excursions of parameters used as criteria for triggering ERI are rejected as triggering events. Periodic assessments of certain indicia of battery depletion are made, and subjected to a long-term low-pass filtering operation in order to reduce the effects of transient excursions of the indicia which result from non-ERI conditions. Over a long period of time (e.g., a day) predetermined threshold values of the indicia of interest must be exceeded a predetermined number of times in order for the device to issue an ERI. In one disclosed embodiment of the invention, the battery's loaded terminal voltage and internal impedance are used as indicators of the battery's depletion level. Periodically, these values are measured and converted to digital values. The digital values are subjected to a low-pass filtering operation to prevent temporary or transient excursions of the impedance and voltage curves from causing ERI to be triggered. In another disclosed embodiment of the invention, a long term fading average of periodically measured values is maintained. When the measured values are found to fulfill the ERI criteria, assessment of the parameters of interest is performed at an increased rate. While assessments are performed at the increased rate, the continuously updated fading average value must fulfill the ERI triggering criteria at least a predetermined number of times before ERI is triggered. If the fading average fails to fulfill the ERI triggering criteria the required number of times, assessments are resumed at the first, slower periodic rate.

Fault-tolerant elective replacement indication for implantable medical

An implantable cardiac pacemaker having programmable stimulating pulse amplitudes selectable by means of an external programming unit. The pacemaker includes charge pump circuitry for developing a stimulating pulse voltage on an output capacitor. The output capacitor is charged to a selected level identified by a multiple-bit amplitude value communicated to the implanted device from the external programmer. The pacemaker is also provided with circuitry for monitoring the depletion level of its battery and for generating an indicator signal when the battery has depleted beyond a predetermined level. Associated with the charge pump circuitry is a selectively activated comparator circuit for controlling the charging of the output capacitor. Prior to generation of the indicator signal, the charge pump circuitry remains deactivated for some programmed output amplitudes, the level of output capacitor charging being proportional to the battery voltage. After issuance of the indicator signal, the comparator circuit is activated to control the charging of the output capacitor. When the comparator circuit is activated for charging the capacitor, the resulting voltage established on the capacitor is proportional to a predetermined constant reference voltage. Longevity of the device is optimized by not activating the comparator circuit during early stages of battery depletion when the battery's output voltage is relatively stable.

Cardiac pacemaker with programmable output pulse amplitude and method

A rate-responsive cardiac pacemaker in which deceleration of the pacing rate is modulated according to recent patient activity or 'work'. Based on signals provided from an activity sensor in the pacemaker, the pacemaker maintains and periodically recomputes a work value corresponding to the amount of patient activity detected over time. In response to a decrease in or cessation of detected patient activity, the pacemaker reduces the pacing rate, first at a more rapid deceleration rate, then at a lower deceleration rate, and then once again at a more rapid deceleration rate. The length of time during which the pacing rate is reduced at the lower deceleration rate is modulated according to the work value maintained by the pacemaker. The work-modulated pacing rate deceleration occurs only if certain achievement criteria are met, the achievement criteria being specified in terms of the amount of time the pacemaker's target pacing rate exceeds a predetermines rest value, and the difference between the target rate and the rest rate.

Growing community of inventors

Minneapolis, MN, United States of America

Michael B Shelton