Patents by Inventor William J. Combs
William J. Combs has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5957861Abstract: 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.Type: GrantFiled: January 31, 1997Date of Patent: September 28, 1999Assignee: Medtronic, Inc.Inventors: William J. Combs, Catherine R. Condie, Roy Martin, Dwight H. Warkentin, John D. Wahlstrandl
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Patent number: 5902325Abstract: A method and apparatus for automatic determination of a pacemaker patient's pacing stimulation threshold. Circuitry is provided in a pacemaker for obtaining a signal reflecting cardiac impedance, which is known to reliably reflect certain aspects of cardiac function. Circuitry is also provided for monitoring the cardiac impedance waveform during a predetermined capture detect window following delivery of stimulating pulses. One or more values are derived which characterize the morphology of the impedance waveform during the capture detect window associated with each stimulation pulse delivered. These values are compared to predetermined control values in order to assess whether a stimulation pulse has achieved cardiac capture. The assessment of whether cardiac capture has been achieved is also based partly upon the conventional sensing of atrial and/or ventricular cardiac signals occurring during the capture detect window.Type: GrantFiled: July 30, 1998Date of Patent: May 11, 1999Assignee: Medtronic, Inc.Inventors: Catherine R. Condie, Daniel J. Baxter, William J. Combs, Daniel J. Greeninger, Karen J. Kleckner, H. Toby Markowitz, John C. Stroebel, John D. Wahlstrand
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Patent number: 5843137Abstract: A method and apparatus for automatic determination of a pacemaker patient's pacing stimulation threshold. Circuitry is provided in a pacemaker for obtaining a signal reflecting cardiac impedance, which is known to reliably reflect certain aspects of cardiac function. Circuitry is also provided for monitoring the cardiac impedance waveform during a predetermined capture detect window following delivery of stimulating pulses. One or more values are derived which characterize the morphology of the impedance waveform during the capture detect window associated with each stimulation pulse delivered. These values are compared to predetermined control values in order to assess whether a stimulation pulse has achieved cardiac capture. The assessment of whether cardiac capture has been achieved is also based partly upon the conventional sensing of atrial and/or ventricular cardiac signals occurring during the capture detect window.Type: GrantFiled: January 22, 1997Date of Patent: December 1, 1998Assignee: Medtronic, Inc.Inventors: Catherine R. Condie, Daniel J. Baxter, William J. Combs, Daniel J. Greeninger, Karen J. Kleckner, H. Toby Markowitz, John C. Stroebel, John D. Wahlstrand
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Patent number: 5782888Abstract: This is a method and apparatus for the automated discrimination of cardiac events of interest, including P-waves, R-waves, T-waves and specific arrhythmic sequences, in EGM signals for data storage in an implantable monitor or to control operations of an implantable cardiac stimulator through the use of Hidden Markov Modeling techniques and a reduced set of observations.Type: GrantFiled: March 21, 1997Date of Patent: July 21, 1998Assignee: Medtronic, Inc.Inventors: Weimin Sun, Eric J. Panken, William J. Combs
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Patent number: 5778881Abstract: This is a method and apparatus for the automated discrimination of cardiac events of interest, including P-waves, R-waves, T-waves, and specific arrhythmic sequences, in EGM signals for data storage in an implantable monitor or to control operations of an implantable cardiac stimulator through the use of Hidden Markov Modeling techniques and a reduced set of observations. The number of computations and computation time during a heart cycle is reduced by timing the frames of A-EGM samples to the detection of A-SENSE events by the atrial sense amplifier. The A-EGM sample frame is defined in a window preceding and following each A-SENSE event. The A-EGM sample frames are wavelet transformed, and a number of selected W.T. coefficients for each sample frame are saved in a buffer. Each set of saved W.T. coefficients therefore represents either a P-wave or an intrinsic or paced far field R-wave (including fusion beats) unless noise continuously causes A-SENSE events to occur.Type: GrantFiled: December 4, 1996Date of Patent: July 14, 1998Assignee: Medtronic, Inc.Inventors: Weimin Sun, Eric J. Panken, William J. Combs
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Patent number: 5755739Abstract: The present invention is a method and apparatus for processing a sensed atrial electrogram in conjunction with a sensed ventricular electrogram. The present invention permits accurate discrimination of atrial P-waves from far field ventricular events such as far field R-waves and avoids oversensing such far field ventricular events as atrial sense events and undersensing atrial events occurring within a fusion beat masked by a far field ventricular event in the atrial electrogram. Atrial channel trigger signals are generated in response to sensed P-waves and far field R-waves in the atrial electrogram, and ventricular trigger signals are generated in response to sensed R-waves in the ventricular electrogram.Type: GrantFiled: December 4, 1996Date of Patent: May 26, 1998Assignee: Medtronic, Inc.Inventors: Weimin Sun, Pamela A. Abshire, Eric J. Panken, William J. Combs
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Patent number: 5730142Abstract: A method and apparatus for detecting tachycardia in a patient employs a digitally-sampled electrocardiographic signal input to a digital processor employing a Hidden Markov Modeling algorithm to eliminate confusion between far-field and near-field cardiac events to provide a more accurate measurement of cardiac rate for diagnosis and treatment.Type: GrantFiled: March 21, 1997Date of Patent: March 24, 1998Assignee: Medtronic, Inc.Inventors: Weimin Sun, Eric J. Panken, William J. Combs
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Patent number: 5713933Abstract: A method and apparatus for automatic determination of a pacemaker patient's pacing stimulation threshold. Circuitry is provided in a pacemaker for obtaining a signal reflecting cardiac impedance, which is known to reliably reflect certain aspects of cardiac function. Circuitry is also provided for monitoring the cardiac impedance waveform during a predetermined capture detect window following delivery of stimulating pulses. One or more values are derived which characterize the morphology of the impedance waveform during the capture detect window associated with each stimulation pulse delivered. These values are compared to predetermined control values in order to assess whether a stimulation pulse has achieved cardiac capture. The assessment of whether cardiac capture has been achieved is also based partly upon the conventional sensing of atrial and/or ventricular cardiac signals occurring during the capture detect window.Type: GrantFiled: November 30, 1994Date of Patent: February 3, 1998Assignee: Medtronic, Inc.Inventors: Catherine R. Condie, Daniel J. Baxter, William J. Combs, Daniel J. Greeninger, Karen J. Kleckner, H. Toby Markowitz, John C. Stroebel, John D. Wahlstrand
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Patent number: 5674251Abstract: A pacemaker system adapted to deliver pacing pulses in the presence of fibrillation. The pacing pulses are delivered via large surface area electrodes of the type normally used to accomplish defibrillation or cardioversion using high voltage pulses. An extended pulse train is delivered in order to gradually entrain greater portions of heart tissue, until a sufficient percentage of tissue is entrained to interrupt fibrillation. The invention is believed most applicable to treatment of atrial fibrillation.Type: GrantFiled: March 26, 1996Date of Patent: October 7, 1997Assignee: Medtronic, Inc.Inventors: William J. Combs, Edwin G. Duffin, T. V. Rao
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Patent number: 5562711Abstract: A body-implantable rate-responsive cardiac pacemaker is provided with circuitry for sensing a plurality of physiologic parameters known to be indicative of a patient's metabolic demand for increased cardiac output. In one embodiment, a rate-responsive pacemaker is provided with an activity sensor for detecting the patient's level of physical activity, and is further provided with an impedance sensing circuit for detecting the patient's level of minute ventilation by monitoring cardiac impedance. A rate-response transfer function, implemented by the pacemaker's control circuitry, periodically computes a rate-responsive pacing rate as a function of the outputs from both physiologic sensing circuits. The pacemaker's pacing rate is variable within a rate range defined by predetermined (programmable) upper and lower limits. In the preferred embodiment, the influence of activity sensing and minute ventilation parameters varies in accordance with the current pacing rate.Type: GrantFiled: November 30, 1994Date of Patent: October 8, 1996Assignee: Medtronic, Inc.Inventors: Charles G. Yerich, William J. Combs, Karen J. Kleckner, Eric J. Panken, Richard S. Schallhorn, John D. Wahlstrand
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Patent number: 5562708Abstract: A pacemaker system adapted to deliver pacing pulses in the presence of fibrillation. The pacing pulses are delivered via large surface area electrodes of the type normally used to accomplish defibrillation or cardioversion using high voltage pulses. An extended pulse train is delivered in order to gradually entrain greater portions of heart tissue, until a sufficient percentage of tissue is entrained to interrupt fibrillation. The invention is believed most applicable to treatment of atrial fibrillation.Type: GrantFiled: April 21, 1994Date of Patent: October 8, 1996Assignee: Medtronic, Inc.Inventors: William J. Combs, Edwin G. Duffin, T. V. Rao
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Patent number: 5331966Abstract: A method and apparatus for providing an enhanced capability of detecting and gathering electrical cardiac signals via an array of relatively closely spaced subcutaneous electrodes (located on the body of an implanted device) which may be employed with suitable switching circuits, signal processors, and memory to process the electrical cardiac signals between any selected pair or pairs of the electrode array in order to provide a leadless, orientation insensitive means for receiving the electrical signal from the heart.Type: GrantFiled: December 16, 1993Date of Patent: July 26, 1994Assignee: Medtronic, Inc.Inventors: Tom D. Bennett, William J. Combs, Kallok, Michael J., Brian B. Lee, Rahul Mehra, George J. Klein
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Patent number: 5312453Abstract: 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.Type: GrantFiled: May 11, 1992Date of Patent: May 17, 1994Assignee: Medtronic, Inc.Inventors: Michael B. Shelton, William J. Combs, Tommy D. Bennett, Michael R. Tollinger, Kenneth M. Riff
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Patent number: 4577633Abstract: A self-adapting demand pacemaker that recognizes the tachycardia from the intrinsic signals and initiates treatment in the following manner: First, the escape interval of the demand pacemaker is shortened to be identical to the cycle length of the tachycardia, then to overdrive the tachycardia the pacemaker escape interval is continuously shortened with each subsequent beat, for a predetermined number of beats, by a small programmable decrement. Thereafter, the escape interval is restored to its original value and protects against a potential bradycardia. It has to be emphasized that the pacemaker remains in demand mode all of the time; thus stimulation in a vulnerable zone is prevented and some of the hazards that accompany overdrive pacing are reduced.Type: GrantFiled: March 28, 1984Date of Patent: March 25, 1986Assignee: Medtronic, Inc.Inventors: Barouh V. Berkovits, Menashe B. Waxman, William J. Combs