Abstract: A system and method for filtering a pressure signal in a medical device in which a sensor terminal senses the pressure signal, an electrode terminal receives cardiac electrical signals, a signal filtering system filters the sensed pressure signal in response to a determined heart rate to generate a heart-rate dependent frequency response, and a microprocessor derives a respiration signal in response to the heart rate dependent frequency response, and determines metrics of hemodynamic function in response to the derived respiration signal.
Type:
Grant
Filed:
October 31, 2008
Date of Patent:
November 1, 2011
Assignee:
Medtronic, Inc.
Inventors:
Yong K. Cho, Tommy D. Bennett, Mark K. Erickson, Maneesh Shrivastav, Saul E. Greenhut, Karen J. Kleckner, Charles P. Sperling, Robert A. Corey
Abstract: A medical device system for sensing cardiac events that includes a plurality of electrodes sensing cardiac signals utilized to identify a cardiac event, a plurality of light sources capable of emitting light at a plurality of wavelengths, and a detector to detect the emitted light. A processor determines a plurality of light measurements in response to the emitted light detected by the detector, determines changes in perfusion in response to first changes in the plurality of light measurements in a direction indicative of a decrease in blood oxygenation and second changes in a direction indicative of a decrease in blood volume, and adjusts delivery of therapy by the device in response to the determined loss of perfusion.
Abstract: An implantable cardiac pacing device delivering minimum ventricular pacing and an associated method control intervals timed by the device during sensing and pacing. An atrial-only pacing mode is set in response to sensing intrinsic ventricular events in the ventricular chamber. A first post-ventricular atrial refractory period is set following each of a plurality of ventricular events sensed in the ventricular chamber, and atrial events each being sensed during first post-ventricular atrial refractory periods are detected. A second post-ventricular atrial refractory period is set in response to detecting the atrial events each being sensed during the first post-ventricular atrial refractory period.
Abstract: A method and apparatus for detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, advancing from a first state to a second state in response to processing of an interval associated with a cardiac cycle of the sensed cardiac signals, and advancing from the second state in response to processing of a cardiac signal sensed during a predetermined sensing window.
Type:
Grant
Filed:
July 31, 2006
Date of Patent:
August 2, 2011
Assignee:
Medtronic, Inc.
Inventors:
Raja N. Ghanem, Robert W. Stadler, Xusheng Zhang
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.
Abstract: A pressure sensor is deployed in the right atrium and is in contact with the tissue of the fossa ovalis. The fossa ovalis acts as a membrane and the pressure sensor determines the relative and/or absolute pressure within the left atrium while remaining within the right atrium. A variety of embodiment are provided to deploy and anchor the sensor into the proper position.
Abstract: A method and apparatus for verifying a determined cardiac event in a medical device based on detected variation in hemodynamic status that includes a physiologic sensor sensing physiologic signals to generate a plurality of variation index samples corresponding to the sensed signals, and a microprocessor computing a variation index trend associated with a predetermined number of variation index samples of the plurality of variation index samples, determining whether deviations of the predetermined number of variation index samples over predetermined sampling windows are less than a deviation threshold, and determining, in response to the deviations being less than the deviation threshold, a corrected variation index trend in response to the changes in the variation index trend during the predetermined sampling windows.
Abstract: A method and system is provided for responding, from internally within a patient, to an atrial arrhythmia in a heart including measuring from within the patient at least one electrocardiogram characteristic indicative of the atrial arrhythmia, and controlling from within the patient drug therapy delivery to the patient responsive to measuring the at least one electrocardiogram characteristic. Drug therapy is initiated to the patient responsive to measuring the at least one electrocardiogram characteristic. According to one aspect of the present invention, the drug therapy is staged within the patient prior to measuring the at least one electrocardiogram characteristic. According to another example embodiment, the heart is paced from within the patient at a predefined rate responsive to measuring the at least one electrocardiogram characteristic, pacing occurring alone, or in combination with drug therapy.
Type:
Grant
Filed:
October 6, 2005
Date of Patent:
May 31, 2011
Assignee:
Medtronic, Inc.
Inventors:
Rahul Mehra, George J. Klein, Michael R. Ujhelyi
Abstract: Multiple sensing configurations may be qualified based on one induced tachyarrhythmia, e.g., ventricular fibrillation, or other qualification event during an implantation procedure. Each sensing configuration comprises a different combination of two or more electrodes used for sensing electrical signals of the heart of the patient. In some examples, an implantable medical device or other device generates qualification information for each sensing configuration, which may indicate whether the sensing configuration is qualified for subsequent cardiac event detection based on an accuracy of the cardiac event detection for the sensing configuration during the qualification event. One of the qualified configurations may initially be selected as a primary sensing configuration for subsequent cardiac event detection. Switching to an alternate sensing configuration, e.g.
Type:
Grant
Filed:
July 31, 2008
Date of Patent:
May 31, 2011
Assignee:
Medtronic, Inc.
Inventors:
David Casavant, Catherine R. Condie, Jon W. Spence, Nathan Munsterman
Abstract: A method and apparatus for detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes, charging an energy storage device in response to the sensed cardiac signals, determining whether the charging of the energy storage device is completed, and determining whether the cardiac event is confirmed in response to an asynchronous look back.
Abstract: A method and apparatus for determining oversensing in a medical device that includes sensing cardiac signals, determining an oversensing characteristic associated with cardiac signals sensed during a predetermined sensing window, identifying oversensing in response to the oversensing characteristic, determining, in response to oversensing being identified, an adjusting characteristic associated with cardiac signals sensed during the predetermined sensing window, and updating a sensing parameter in response to the determined adjusting characteristic.
Type:
Grant
Filed:
May 1, 2007
Date of Patent:
May 3, 2011
Assignee:
Medtronic, Inc.
Inventors:
Raja N. Ghanem, Robert W. Stadler, Xusheng Zhang, Karen J. Kleckner, Paul G. Krause
Abstract: A method and apparatus for detection of changes in physiologic parameters of a patient that includes generating measured physiologic parameters, generating an adaptive baseline trend of the measured physiologic parameters corresponding to a first time period, generating a short term trend of the measured physiologic parameters corresponding to a second time period less than the first time period, and generating a metric of physiologic parameter change between the adaptive baseline trend and one of a most recent measured physiologic parameter and the short term trend of the measured physiologic parameters.
Type:
Grant
Filed:
December 3, 2003
Date of Patent:
May 3, 2011
Assignee:
Medtronic, Inc.
Inventors:
Robert W. Stadler, Karen J. Kleckner, Robert T. Taepke
Abstract: The present invention provides a system and method for estimating a blood flow waveform contour from a pressure signal. An arterial or ventricular pressure signal is acquired from a pressure sensor. Landmark points are identified on the pressure waveform that correspond to features of a flow waveform. In one embodiment, the landmark pressure waveform points correspond to the onset of flow, the peak flow, and the end of the systolic ejection phase. The landmark pressure waveform points define a contour that approximates the flow contour. Beat-by-beat flow contour estimation can be performed to allow computation of flow-related hemodynamic parameters such as stroke volume or cardiac output for use in patient monitoring and/or therapy management.
Abstract: A medical device system and associated method sample an EGM signal over a processing window having a predetermined time duration. A number of morphology metrics are determined from the sampled EGM signal, and a heart rhythm is detected in response to the morphology metrics without determining depolarization intervals. The morphology metrics include metrics determined from a slope signal derived from the EGM signal in one embodiment.
Abstract: A pressure sensor is deployed in the right atrium and is in contact with the tissue of the fossa ovalis. The fossa ovalis acts as a membrane and the pressure sensor determines the relative and/or absolute pressure within the left atrium while remaining within the right atrium. A variety of embodiment are provided to deploy and anchor the sensor into the proper position.
Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, and determining first heart rate estimates associated with cardiac signals sensed from the first sensing vector and cardiac signals sensed from the second sensing vector in response to a metric of heart rate associated with the sensed cardiac signals. Second heart rate estimates associated with the first sensing vector and with the second sensing vector are generated in response to the determined first heart rate estimates, and a determination is made as to whether both of the second heart rate estimates are greater than a predetermined heart rate threshold.
Type:
Grant
Filed:
April 28, 2006
Date of Patent:
March 15, 2011
Assignee:
Medtronic, Inc.
Inventors:
Raja N. Ghanem, Robert W. Stadler, Xusheng Zhang, Saul E. Greenhut, Karen J. Kleckner, Paul G. Krause, Veerdhaval Mahajan
Abstract: A subcutaneously implantable lead includes a coil disposed along a portion of the lead, and a lead tip coupled to a distal end of the lead. The lead tip includes at least one component that is movable relative to the distal end of the lead and configured to anchor the lead tip in subcutaneous tissue.
Type:
Grant
Filed:
July 31, 2008
Date of Patent:
March 15, 2011
Assignee:
Medtronic, Inc.
Inventors:
Markus J. C. Lazeroms, Jean J. G. Rutten, Karel F. A. A. Smits
Abstract: An implantable medical device system and associated method select subcutaneous sensing electrodes for use in monitoring the heart rhythm. A subset of multiple sensing vectors is selected from a number of electrodes positioned at a first subcutaneous location and one electrode positioned at a second subcutaneous location. The subset of sensing vectors includes one vector that includes the electrode positioned at the second location. A signal quality parameter corresponding to each of the sensing vectors of the subset is determined.
Type:
Grant
Filed:
April 27, 2007
Date of Patent:
March 8, 2011
Assignee:
Medtronic, Inc.
Inventors:
Saul E. Greenhut, Robert W. Stadler, Karen J. Kleckner
Abstract: A method and apparatus for detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes, the plurality of electrodes forming a first sensing vector and a second sensing vector different from the first sensing vector, determining a characteristic associated with cardiac signals sensed along the first sensing vector during a predetermined sensing window, determining the characteristic associated with cardiac signals sensed along the second sensing vector during the predetermined sensing window, comparing the determined characteristic associated with cardiac signals sensed along the first sensing vector and the determined characteristic associated with cardiac signals sensed along the second sensing vector, and delivering a therapy in response to the comparing.
Type:
Grant
Filed:
March 16, 2007
Date of Patent:
February 22, 2011
Assignee:
Medtronic, Inc.
Inventors:
Robert W. Stadler, Raja N. Ghanem, Xusheng Zhang
Abstract: An implantable device for terminating ventricular tachycardia is disclosed. The device includes a processor configured to determine a first antitachycardia pulse routine of N pulses. In the routine the first N?1 pulses are separated by a first cycle length and the Nth pulse is separated by a second cycle length that is shorter than the first cycle length. The device also comprises a lead coupled to the processor. The lead comprises an electrode configured to sense a tachycardia and further configured, under control of the processor, to administer the antitachycardia pulse routine.