Li Wang

US Patent:

6512949, Jan 28, 2003

Filed:

Jul 12, 1999

Appl. No.:

09/352179

Inventors:

William J. Combs - Eden Prarie MN
Catherine R. Condie - St. Anthony MN
Roy Martin - Maple Grove MN
Dwight H. Warkentin - St. Paul MN
John D. Wahlstrand - Shoreview MN
David L. Thompson - Fridley MN
Li Wang - White Bear Township MN

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61B 500

US Classification:

600547, 607 9

Abstract:

An impedance monitor for discerning edema through evaluation of respiratory rate. Preferred embodiment includes edema monitor and trigger to initiate diagnostic reporting or corrective action when activated. Recording of Long Term Average and Short Term Average values for secondary edema measure based on DC signal level are described as are methods and apparatus for removing unwanted recurring noise.

US Patent:

6922584, Jul 26, 2005

Filed:

Nov 28, 2001

Appl. No.:

09/998553

Inventors:

Li Wang - White Bear Lake MN, US
Mark L. Brown - North Oaks MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61B005/0452

US Classification:

600515, 600518

Abstract:

A method and apparatus for method for discriminating heart rhythms includes computing a first predetermined number of RR intervals from received QRS intervals, and computing a median RR interval corresponding to a predetermined number of the first predetermined number of RR intervals. A predetermined beat-to-beat variation and a corresponding predetermined count are determined based on the computed median RR interval. Beat-to-beat variation differences between the first predetermined number of RR intervals are computed and a determination is made as to whether the computed beat-to-beat variation differences are greater than the predetermined beat-to-beat variation, and as to whether a number of the computed beat-to-beat variation differences that are greater than the predetermined beat-to-beat variation is greater than the predetermined count. The heart rhythm is identified as an irregular rhythm in response to the number being greater than or equal to the predetermined count.

US Patent:

7149573, Dec 12, 2006

Filed:

Apr 25, 2003

Appl. No.:

10/423118

Inventors:

Li Wang - White Bear Township MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61B 5/05

US Classification:

600547, 600301, 600512

Abstract:

A patient monitoring system including an implantable medical device for monitoring a plurality of physiological factors contributing to physiological conditions of a patient's heart by measuring a first impedance affected by the plurality of physiological factors, across one of a plurality of vectors, and a second impedance affected by the plurality of physiological factors, across a second one of the plurality of vectors subsequent to determining the first impedance. A change in impedance is determined based upon the first impedance and the second impedance measurements. Using an equation ΔZ=α*Q+α*Q, where Qis a fractional resistivity change of a first contributing physiological impedance factor, Qis a fractional resistivity change of a second physiological impedance factor, αis an impedance sensitivity factor for physiological impedance factor Q, and αis an impedance sensitivity factor for physiological impedance factor Q, the value of one of the contributing physiological impedance factors is determined. The contributing physiological impedance factors may include lung resistivity, blood resistivity, heart muscle resistivity, skeletal muscle resistivity, heart volume and lung volume.

US Patent:

7236825, Jun 26, 2007

Filed:

Apr 30, 2004

Appl. No.:

10/836359

Inventors:

Li Wang - White Bear Township MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 1/00
A61B 5/04

US Classification:

607 19, 607 9, 607 4, 607 2, 607 27, 607115, 607116, 600372, 600373, 600374, 600377, 600381, 600510

Abstract:

A method and device for sensing cardiac activity that includes a first plurality of electrodes forming a first electrode configuration to sense cardiac activity, a second plurality of electrodes forming a second electrode configuration to sense cardiac activity, and a third plurality of electrodes to deliver a stimulation pulse in response to the sensed cardiac activity. A microprocessor determines whether an escape interval associated with the delivered stimulation pulse is less than a rate limit interval, and a control circuit switches from the first plurality of electrodes to the second plurality of electrodes in response to the escape interval being less than the rate limit interval.

US Patent:

7289851, Oct 30, 2007

Filed:

Apr 5, 2004

Appl. No.:

10/818098

Inventors:

Bruce D. Gunderson - Plymouth MN, US
Amisha S. Patel - Maple Grove MN, US
Chad A. Bounds - St. Paul MN, US
Li Wang - White Bear Township MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 1/08

US Classification:

607 27

Abstract:

A method and apparatus for detecting a lead-related condition that includes determining whether a first oversensing criteria is satisfied, determining whether a second oversensing criteria is satisfied, determining whether an impedance criteria has been satisfied, and generating an alert in response to more than one of the first oversensing criteria, the second over sensing criteria and the impedance criteria being satisfied.

US Patent:

7826896, Nov 2, 2010

Filed:

Nov 2, 2006

Appl. No.:

11/555918

Inventors:

Li Wang - White Bear Township MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61B 5/05

US Classification:

600547, 600301, 600512

Abstract:

Method and apparatus for monitoring a plurality of physiological factors contributing to physiological conditions of a heart, that determines a first impedance, corresponding to the plurality of physiological factors, across a plurality of vectors, and a second impedance, corresponding to the plurality of physiological factors, across the plurality of vectors subsequent to determining the first impedance. A relative change in impedance corresponding to the plurality of vectors is determined in response to the first impedance and the second impedance, first minimally contributing physiological factors of the plurality of physiological factors associated with a first physiological factor of the plurality of physiological factors are determined, and relative change in tissue resistivity corresponding to the first physiological factor in response to physiological factors of the plurality of physiological factors other than the first minimal contributing physiological factors and the relative change in impedance are determined.

US Patent:

7848807, Dec 7, 2010

Filed:

Dec 30, 2005

Appl. No.:

11/323314

Inventors:

Li Wang - White Bear Township MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 1/362

US Classification:

607 9, 607 1, 607 2, 607 11, 607 17, 607115, 607116, 607119

Abstract:

Embodiments of close loop optimization of atrio-ventricular (A-V) delay interval and/or inter-ventricular (V-V) timing are disclosed. An implantable medical device includes a housing that supports a processing means adapted for implantation in a patient. There can be two or more electrodes electrically coupled to the processing means where the two or more electrodes can be used for sensing a patient's cardiac signals, which include a far-field EGM. The processing means can determine a width of a P-wave from the sensed far-field EGM. Also included can be a means for delivering an adapted cardiac pacing therapy based upon the width of the P-wave, including revised A-V delay and/or V-V temporal intervals.

US Patent:

7986994, Jul 26, 2011

Filed:

Dec 3, 2003

Appl. No.:

10/727008

Inventors:

Robert W. Stadler - Shoreview MN, US
Li Wang - White Bear Township MN, US

Assignee:

Medtronic, Inc. - Minneapolis MN

International Classification:

A61N 1/365

US Classification:

607 17, 607 28, 600506, 600507, 600547, 600484

Abstract:

A method and apparatus for detection of changes in impedance a patient that includes generating measured impedances, generating an adaptive baseline trend of the measured impedances corresponding to a first time period, generating a short term trend of the measured impedances corresponding to a second time period less than the first time period, and generating a metric of impedance change between the adaptive baseline trend and one of a most recent measured impedance and the short term trend of the measured impedances.