Raymond L Wilson

US Patent:

58107398, Sep 22, 1998

Filed:

Dec 19, 1996

Appl. No.:

8/770767

Inventors:

Gene A. Bornzin - Simi Valley CA
Alan B. Vogel - Saugus CA
Ali Enayat Zadeh - Sierra Madre CA
Jonathan A. Kleks - Los Altos CA
Raymond J. Wilson - Parker CO

Assignee:

Pacesetter, Inc. - Sylmar CA

International Classification:

A61N 50452

US Classification:

600510

Abstract:

Methods and apparatus are provided for classifying cardiac events with an implantable cardiac device. Cardiac signals are stored in a buffer. When a significant cardiac event is confirmed, a corresponding segment of the stored cardiac signals is processed to generate a set of feature values. The set of feature values is compared to various sets of reference values. Each set of reference values preferably corresponds to a separate type of cardiac event, so that the cardiac device may classify the significant cardiac event by matching its set of feature values to a set of reference values. Feature values include the maximum positive and negative slew rates exhibited by the cardiac signal during the segment, the maximum positive and negative signal amplitudes, the times to reach the maximum positive and negative signal amplitudes, the area under the cardiac signal curve, the area under the cardiac signal curve above zero as compared to the area below zero, and the number of zero crossings made by the cardiac signal. Additional feature values are generated by simultaneously processing the cardiac signals measured along two different vector directions in the heart.

US Patent:

53504100, Sep 27, 1994

Filed:

Nov 23, 1992

Appl. No.:

7/980941

Inventors:

Jonathan A. Kleks - Northridge CA
Stuart W. Buchanan - Saugus CA
Raymond J. Wilson - Palmdale CA
John W. Poore - South Pasadena CA
Brian M. Mann - Beverly Hills CA

Assignee:

Siemens Pacesetter, Inc. - Sylmar CA

International Classification:

A61N 1362

US Classification:

607 28

Abstract:

An autocapture system within an implantable pulse generator automatically maintains the energy of a stimulation pulse at a level just above that which is needed to effectuate capture. The electrical post-stimulus signal of the heart following delivery of a stimulation pulse is compared to a polarization template, determined during a capture verification test. A prescribed difference between the polarization template and the post-stimulus signal indicates capture has occurred. Otherwise, loss of capture is presumed, and a loss-of-capture routine is invoked that increases the energy a prescribed amount to obtain capture. Periodically, and/or at programmed intervals or events, the capture verification test is performed. During the capture verification test, the pulse generator determines a polarization template for a particular stimulation energy and for each of a plurality of sensitivity or threshold settings. A determination is also made as to which sensitivity settings yield capture.