Scott E Morrison

US Patent:

59547561, Sep 21, 1999

Filed:

Apr 9, 1998

Appl. No.:

9/058378

Inventors:

Michael Todd Hemming - Champlin MN
Bradley C. Peck - Coon Rapids MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

D61N 137

US Classification:

607 28

Abstract:

The present invention employs software programmable device means such as a microprocessor to discriminate between evoked response signals and post-pace polarization signals sensed by an implantable medical device. The polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes is monitored during a short period of time immediately following a paced event. It has been discovered that the post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and that the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined by the design of the specific output circuitry. The evoked response signal may reverse the polarity of the sensed signal in either case, from positive to negative or from negative to positive, during the time window of interest.

US Patent:

58610138, Jan 19, 1999

Filed:

Apr 29, 1997

Appl. No.:

8/841095

Inventors:

Bradley C. Peck - Ham Lake MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN
Michael Todd Hemming - Champlin MN
Robert John Schuelke - Lakeville MN

Assignee:

Medtronic Inc. - Minneapolis MN

International Classification:

A61N 137

US Classification:

607 28

Abstract:

The present invention permits discrimination between evoked response signals and post-pace polarization signals sensed by an implantable medical device by noting the polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes during a short period of time immediately following a paced event. It has been discovered that the post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and that the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined by the design of the specific output circuitry. The evoked response signal may reverse the polarity of the sensed signal in either case, from positive to negative or from negative to positive, during the time window of interest. In another embodiment of the present invention, and when the magnitude of the post-pace polarization is so great that the evoked response does not reverse the polarity of the waveform, discrimination of the evoked response is achieved by noting an acceleration (or increasing magnitude of dv/dt) in the sensed signal or waveform.

US Patent:

58738983, Feb 23, 1999

Filed:

Apr 29, 1997

Appl. No.:

8/841064

Inventors:

Michael Todd Hemming - Champlin MN
Bradley C. Peck - Ham Lake MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN
Robert John Schuelke - Lakeville MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 137

US Classification:

607 28

Abstract:

The programmable device means such as a microprocessor are employed to discriminate between evoked response signals and post-pace polarization signals sensed by an implantable medical device. The polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes is monitored during a short period of time immediately following a paced event. It has been discovered that the post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and that the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined by the design of the specific output circuitry. The evoked response signal may reverse the polarity of the sensed signal in either case, from positive to negative or from negative to positive, during the time window of interest. When magnitude of the post-pace polarization is so great that the evoked response does not reverse the polarity of the waveform, discrimination of the evoked response may be achieved by noting an acceleration (or increasing magnitude of dv/dt) in the sensed signal or waveform.

US Patent:

61448818, Nov 7, 2000

Filed:

Sep 18, 1998

Appl. No.:

9/157220

Inventors:

Michael Todd Hemming - Champlin MN
Bradley C. Peck - Coon Rapids MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN
Robert John Schuelke - Lakeville MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61H 137

US Classification:

607 28

Abstract:

A method and apparatus for discriminating between evoked response signals and post-pace polarization signals sensed by a sense amplifier of an implantable medical device. The polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes is monitored during a short period of time immediately following a paced event. The post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined. The evoked response signal may reverse the polarity of the sensed signal from positive to negative or from negative to positive, during the time window of interest. When the magnitude of the post-pace polarization is so great that the evoked response does not reverse the polarity of the waveform, discrimination of the evoked response is achieved by noting an acceleration (or increasing magnitude of dv/dt) in the sensed signal or waveform.

US Patent:

58715126, Feb 16, 1999

Filed:

Apr 9, 1998

Appl. No.:

/058422

Inventors:

Michael Todd Hemming - Champlin MN
Bradley C. Peck - Coon Rapids MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN
Robert John Schuelke - Lakeville MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 137

US Classification:

607 28

Abstract:

Software programmable device means such as a microprocessor are employed to discriminate between evoked response signals and post-pace polarization signals sensed by an implantable medical device. The polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes is monitored during a short period of time immediately following a paced event. It has been discovered that the post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and that the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined by the design of the specific output circuitry. The evoked response signal may reverse the polarity of the sensed signal in either case, from positive to negative or from negative to positive, during the time window of interest. When the magnitude of the post-pace polarization is so great that the evoked response does not reverse the polarity of the waveform, discrimination of the evoked response may be achieved by noting an acceleration (or increasing magnitude of dv/dt) in the sensed signal or waveform.

US Patent:

61344737, Oct 17, 2000

Filed:

Apr 14, 1999

Appl. No.:

9/291514

Inventors:

Michael Todd Hemming - Champlin MN
Bradley C. Peck - Coon Rapids MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN
Robert John Schuelke - Lakeville MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 137

US Classification:

607 28

Abstract:

A software programmable microprocessor discriminates between evoked response signals and post-pace polarization signals sensed by an implantable medical device. The polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes is monitored during a short period of time immediately following a paced event. It has been discovered that the post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and that the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined by the design of the specific output circuitry. The evoked response signal may reverse the polarity of the sensed signal in either case, from positive to negative or from negative to positive, during the time window of interest. In another embodiment, when the magnitude of the post-pace polarization is so great that the evoked response does not reverse the polarity of the waveform, discrimination of the evoked response is achieved by noting an acceleration (or increasing magnitude of dv/dt) in the sensed signal or waveform.

US Patent:

61637246, Dec 19, 2000

Filed:

Aug 27, 1999

Appl. No.:

9/385655

Inventors:

Michael Todd Hemming - Champlin MN
Bradley C. Peck - Ham Lake MN
Brian A. Blow - Maple Grove MN
Scott M. Morrison - Lino Lakes MN
Robert John Schuelke - Lakeville MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 137

US Classification:

607 28

Abstract:

A software programmable device means such as a microprocessor discriminates between evoked response signals and post-pace polarization signals sensed by an implantable medical device. The polarity of the positive or negative change in voltage in respect of time (or dv/dt) of the waveform incident on the lead electrodes is monitored during a short period of time immediately following a paced event. It has been discovered that the post-pace polarization signal exhibits a relatively constant polarity during the capture detect window, and that the evoked response signal may cause the polarity of post-pace polarization signal to reverse during the capture detect window. The sign of the post-pace polarization polarity, either positive or negative, is determined by the design of the specific output circuitry. The evoked response signal may reverse the polarity of the sensed signal in either case, from positive to negative or from negative to positive, during the time window of interest. In another embodiment of the present invention, and when the magnitude of the post-pace polarization is so great that the evoked response does not reverse the polarity of the waveform, discrimination of the evoked response is achieved by noting an acceleration (or increasing magnitude of dv/dt) in the sensed signal or waveform.