Patent application number | Description | Published |
20090264783 | SYSTEMS AND METHODS FOR IMPROVED ATRIAL FIBRILLATION (AF) MONITORING - Methods and systems described herein are especially useful wherein monitoring for atrial fibrillation (AF) is based on RR interval variability as measured from an electrocardiogram (ECG) signal. An activity threshold, which can be patient specific, is obtained. Patient activity is monitored. Based on the monitored patient activity and the activity threshold, there is a determination of when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity. When it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, whether and/or how AF monitoring is performed is modified. | 10-22-2009 |
20090287268 | METHODS AND SYSTEMS FOR IMPROVED ARRHYTHMIA DISCRIMINATION - A non-implanted system receives, from an implantable cardiac device implanted within a patient, data corresponding to detected potential episodes of tachycardia. A representation of the data corresponding to the detected potential episodes of tachycardia is displayed to a user, and the user that observes the displayed representation of the data is allowed to enter a user diagnosis for each of the detected potential episodes of tachycardia. The non-implanted system simulates how the implantable cardiac device can use its discriminators to produce device diagnoses, based on the data for the detected potential episodes of tachycardia, including how adjustments to the discriminators affect how the device diagnoses match the user diagnoses. Thereafter, the non-implanted system can reprogram the implantable cardiac device to increase a likelihood that future device diagnoses produced by the implantable cardiac device would more closely match future user diagnoses produced by the user. | 11-19-2009 |
20100160800 | SYSTEM AND METHOD FOR MONITORING MYOCARDIAL INSTABILITY - A method of monitoring myocardial stability includes determining a window length representing an acceptable time period between potential start times associated with at least two physiologic indices and monitoring multiple physiologic indices representative of myocardial stability. Predetermined variations in each of the physiologic indices denote the potential start times and potential end times for candidate events that are indicative of myocardial instability. The method further includes identifying the potential start times associated with at least two of the physiologic indices and declaring at least one of the candidate events to be an actual event of myocardial instability based on the window length and a time period between the potential start times identified by the identifying operation. | 06-24-2010 |
20100305641 | SYSTEM AND METHOD FOR DETECTING PULMONARY EDEMA BASED ON IMPEDANCE MEASURED USING AN IMPLANTABLE MEDICAL DEVICE DURING A LEAD MATURATION INTERVAL - Techniques are provided for use by implantable medical devices such as cardiac resynchronization therapy (CRT) devices for detecting pulmonary edema based on transthoracic impedance sensed using cardiac pacing/sensing leads, wherein detection can be performed while lead maturation occurs. Briefly, the implantable device determines whether the leads are within an initial post-implant interval following implant during which lead maturation generally occurs. The device then detects pulmonary edema or related medical conditions within the patient based on transthoracic impedance using a set of detection parameters adjusted for use during the post-implant interval. Thus, rather than “blanking” impedance data during lead maturation, the device instead detects and processes impedance during this period to identify possible episodes of pulmonary edema so that appropriate measures can be undertaken, such as delivery of warnings or titration of appropriate medications. | 12-02-2010 |
20110213261 | SYSTEMS AND METHODS FOR USE WITH SUBCUTANEOUS IMPLANTABLE MEDICAL DEVICES FOR DETECTING ELECTRODE/TISSUE CONTACT PROBLEMS - Techniques are provided for detecting problems involving electrode/tissue contact with extracardiac electrodes of subcutaneous monitoring devices, such as atrial fibrillation (AF) monitors. Briefly, subcutaneous impedance signals are detected using extracardiac sensing electrodes of the subcutaneous device. Problems involving poor electrode/tissue contact are then detected within the subcutaneous impedance signals. Depending upon its programming, the device can then inhibit the recording of subcutaneous electrocardiogram (ECG) data during periods of poor contact. Additionally, the device can identify the particular contact problem based on the impedance signals. In one example, the device identifies one or more of: acute instability of impedance indicative of intermittent electrode/tissue contact; impedance signal saturation indicative of loss of electrode/tissue contact; and impedance signal dropout indicative of the presence of liquids surrounding the electrodes (such as blood or edema accumulation.) Techniques for programming various modes of operation of the subcutaneous device are also provided. | 09-01-2011 |
20110319957 | EARLY DETECTION OF LEAD FAILURE USING AN IMPEDANCE HISTOGRAM - Testing lead conditions in an implantable medical device includes continuously sampling the impedance values of a lead associated with the implantable medical device. The sampling is conducted over a predetermined period of time. An impedance histogram is then generated using the sampled impedance values by separating each measured impedance value into a specific bin assigned to contain a particular range of impedance levels. The lead condition of the tested lead can then be determined based on one or more characteristics of the impedance histogram. | 12-29-2011 |
20120158079 | SYSTEMS AND METHODS FOR ASSESSING THE SPHERICITY AND DIMENSIONAL EXTENT OF HEART CHAMBERS FOR USE WITH AN IMPLANTABLE MEDICAL DEVICE - Techniques are provided for use with an implantable medical device for assessing left ventricular (LV) sphericity and atrial dimensional extent based on impedance measurements for the purposes of detecting and tracking heart failure and related conditions such as volume overload or mitral regurgitation. In some examples described herein, various short-axis and long-axis impedance vectors are exploited that pass through portions of the LV for the purposes of assessing LV sphericity. In other examples, impedance measurements taken along a vector between a right atrial (RA) ring electrode and an LV electrode implanted near the atrioventricular (AV) groove are exploited to assess LA extent, biatrial extent or mitral annular diameter. The assessment techniques can be employed alone or in conjunction with other heart failure detection techniques, such as those based on left atrial pressure (LAP.) | 06-21-2012 |
20120165884 | FLUID ACCUMULATION MONITORING DEVICES, SYSTEMS AND METHODS - Provided herein are implantable systems, and methods for use therewith, for monitoring a patient's fluid accumulation level. A thoracic impedance signal for the patient is obtained. Based on the thoracic impedance signal, a duration metric indicative of a duration of drop of the thoracic impedance signal, a magnitude metric indicative of a magnitude of drop of the thoracic impedance signal, and a rate metric indicative of a rate of drop of the thoracic impedance signal is determined. The patient's fluid accumulation level is monitored based on the duration metric, the magnitude metric and the rate metric. | 06-28-2012 |
20120190957 | SYSTEM AND METHOD FOR MONITORING CARDIAC DISEASE - A method of monitoring progression of cardiac disease includes applying stimulus pulses to the heart and sensing electrophysiological responses of the heart at a plurality of different monitoring locations of the heart. The method also includes comparing a previously and subsequently sensed electrophysiological responses that are sensed near a first location of the monitoring locations and comparing previously and subsequently sensed electrophysiological responses that are sensed near a second location of the monitoring locations. The method further includes identifying a change in progression of cardiac disease of the heart based on a difference between the previously and subsequently sensed electrophysiological responses at the first location and based on a difference between the previously and subsequently sensed electrophysiological responses at the second location. | 07-26-2012 |
20120221066 | Systems and Methods for Activating and Controlling Impedance-Based Detection Systems of Implantable Medical Devices - Techniques are provided for use with implantable medical devices for addressing encapsulation effects, particularly in the detection of cardiac decompensation events such as heart failure (HF) or cardiogenic pulmonary edema (PE.) In one example, during an acute interval following device implant, cardiac decompensation is detected using heart rate variability (HRV), ventricular evoked response (ER) or various other non-impedance-based parameters that are insensitive to component encapsulation effects. During the subsequent chronic interval, decompensation is detected using intracardiac or transthoracic impedance signals. In another example, the degree of maturation of encapsulation of implanted components is assessed using impedance frequency-response measurements or based on the frequency bandwidth of heart sounds or other physiological signals. In this manner, impedance-based HF/PE detection systems can be activated as soon as component encapsulation has matured, without necessarily waiting until completion of a preset post-implant maturation interval, often set to forty-five days or more. | 08-30-2012 |
20120221069 | Systems and Methods for Activating and Controlling Impedance-Based Detection Systems of Implantable Medical Devices - Techniques are provided for use with implantable medical devices for addressing encapsulation effects, particularly in the detection of cardiac decompensation events such as heart failure (HF) or cardiogenic pulmonary edema (PE.) In one example, during an acute interval following device implant, cardiac decompensation is detected using heart rate variability (HRV), ventricular evoked response (ER) or various other non-impedance-based parameters that are insensitive to component encapsulation effects. During the subsequent chronic interval, decompensation is detected using intracardiac or transthoracic impedance signals. In another example, the degree of maturation of encapsulation of implanted components is assessed using impedance frequency-response measurements or based on the frequency bandwidth of heart sounds or other physiological signals. In this manner, impedance-based HF/PE detection systems can be activated as soon as component encapsulation has matured, without necessarily waiting until completion of a preset post-implant maturation interval, often set to forty-five days or more. | 08-30-2012 |
20120239104 | METHOD AND SYSTEM TO CORRECT CONTRACTILITY BASED ON NON-HEART FAILURE FACTORS - A method is provided for trending heart failure based on heart contractility information comprises measuring cardiogenic impedance (CI) measurements along at least a first vector through a heart over a period of time. The method determines contractility estimates from the CI measurements, the contractility estimates relating to contractility of the heart. The method further obtains physiologic and/or surrogate signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. The method identifies correction factors based on the physiologic and/or surrogate signals and applies the correction factors to the contractility estimates to produce contractility trend values over the period of time. A system is provided for trending heart failure based on heart contractility information which comprises inputs to receive cardiogenic impedance (CI) measurements taken along at least a first vector through a heart over a period of time. The system includes a contractility module to determine contractility estimates from the CI measurements, the contractility estimates relating to contractility of the heart and a collection module to receive physiologic and/or surrogate signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. A factor module is also provided to identify correction factors based on the physiologic and/or surrogate signals and a correction module to apply the correction factors to the contractility estimates to produce contractility trend values over the period of time. | 09-20-2012 |
20130261473 | DEVICES, SYSTEMS AND METHODS FOR EFFICIENT IDENTIFICATION OF IMPROVED CRT PARAMETERS - Methods, systems and devices efficiently identify cardiac resynchronization therapy (CRT) pacing parameter set(s) that provide improved hemodynamic response relative to an initial CRT pacing parameter set, wherein each CRT pacing parameter set includes at least two CRT pacing parameters. User input(s) are accepted that specify a maximum amount of time and/or parameter sets that can be used to perform testing, and specify relative importance of parameters within the sets. Based on the accepted user input(s), there is a determination of how many different variations of each of the CRT pacing parameters can be tested, and based on this determination different CRT pacing parameter sets are selected and tested to obtain a hemodynamic response measure corresponding to each of the different sets tested. Additionally, one or more of the tested CRT pacing parameter sets, if any, that provide improved hemodynamic response relative to the initial CRT pacing parameter set is/are identified. | 10-03-2013 |
20130261492 | SYSTEM AND METHOD FOR DETECTING PULMONARY EDEMA BASED ON IMPEDANCE MEASURED USING AN IMPLANTABLE MEDICAL DEVICE DURING A LEAD MATURATION INTERVAL - Techniques are provided for use by implantable medical devices such as cardiac resynchronization therapy (CRT) devices for detecting pulmonary edema based on transthoracic impedance sensed using cardiac pacing/sensing leads, wherein detection can be performed while lead maturation occurs. Briefly, the implantable device determines whether the leads are within an initial post-implant interval following implant during which lead maturation generally occurs. The device then detects pulmonary edema or related medical conditions within the patient based on transthoracic impedance using a set of detection parameters adjusted for use during the post-implant interval. Thus, rather than “blanking” impedance data during lead maturation, the device instead detects and processes impedance during this period to identify possible episodes of pulmonary edema so that appropriate measures can be undertaken, such as delivery of warnings or titration of appropriate medications. | 10-03-2013 |
20130261687 | SYSTEMS AND METHODS FOR SELECTING PACING VECTORS BASED ON SITE OF LATEST ACTIVATION FOR USE WITH IMPLANTABLE CARDIAC RHYTHM MANAGEMENT DEVICES - Techniques are provided for use with an implantable cardiac stimulation device equipped with a multi-pole left ventricular (LV) lead and a right ventricular (RV) lead for identifying suitable pacing vectors. In one example, RV-LV delay times are measured while using different electrodes of the LV lead as cathodes for sensing. The LV electrode having the longest RV-LV delay time is identified and LV capture thresholds and diaphragmatic stimulation thresholds are measured for pacing vectors that employ that LV electrode as a cathode. Assuming at least one vector employing the selected LV electrode is found to have acceptable thresholds, the vector is selected for use in delivering pacing therapy with the selected LV electrode. If none of the pacing vectors employing the selected LV electrode has acceptable thresholds, another LV electrode is selected and the procedure is repeated. Examples with a multi-pole RV lead are also described. | 10-03-2013 |
20130268016 | SYSTEMS AND METHODS FOR CONTROLLING SPINAL CORD STIMULATION TO IMPROVE STIMULATION EFFICACY FOR USE BY IMPLANTABLE MEDICAL DEVICES - Techniques are provided for controlling spinal cord stimulation (SCS) or other forms of neurostimulation. In one example, SCS treatment is delivered to a patient and nerve impulse firing signals are sensed along the spinal cord following the SCS treatment. The nerve impulse signals are analyzed to determine whether the signals are associated with effective SCS and then the delivery of additional SCS is controlled to improve SCS efficacy. For example, the nerve impulse signals can be analyzed to determine whether the signals are consistent with a positive patient mood associated with pain mitigation and, if not, SCS control parameters are adjusted to improve the efficacy of the SCS in reducing pain. In other examples, heart rate variability (HPV) is also used to control SCS. Still further, adjustments may be made to SCS control parameters to improve antiarrhythmic or sympatholytic effects associated with SCS. Techniques employing baseline/target calibration procedures are also described. | 10-10-2013 |
20130268020 | SYSTEM FOR NERVE SENSING AND STIMULATION EMPLOYING MULTI-ELECTRODE ARRAY - A nerve stimulation system includes a pulse generator and implantable lead. The pulse generator includes a sensing module and a pace circuit. The lead has an electrode array near the distal end and a connector at the proximal end for connection to the pulse generator. Conductors in the lead electrically connect the electrode array with the sensing module and pace circuit. The electrode array includes a first pair of small electrodes and a large electrode close to each other. The small electrodes and large electrode are physically separated from each other by insulative spaces extending generally transversely to a longitudinal axis of the lead. When the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit only. | 10-10-2013 |
20140005739 | METHOD AND SYSTEM TO SELECT A NEUROSTIMULATION SYSTEM CONFIGURATION BASED ON CARDIAC RHYTHM FEEDBACK | 01-02-2014 |
20140276151 | SYSTEMS AND METHODS FOR OBTAINING SUBSTANTIALLY SIMULTANEOUS MULT-CHANNEL IMPEDANCE MEASUREMENTS AND RELATED APPLICATIONS - An implantable system includes terminals, a pulse generator, a sensing circuit, separate signal processing channels, and first, second and third multiplexers. The terminals are connected to electrodes via conductors of leads. Different subsets of the electrodes are used to define different electrical pulse delivery vectors, and different subsets of the electrodes are used to define different sensing vectors. The pulse generator produces electrical pulses, and the sensing circuit senses a signal indicative of an impedance associated with a selected sensing vector. The first multiplexer selectively connects outputs of the pulse generator to a selected one of the different electrical pulse delivery vectors at a time. The second multiplexer selectively connect inputs of the sensing circuit to a selected one of the different sensing vectors at a time. The third multiplexer selectively connects an output of the sensing circuit to one of the plurality of separate signal processing channels at a time. | 09-18-2014 |
20140303685 | SYSTEM FOR NERVE SENSING AND STIMULATION EMPLOYING MULTI-ELECTRODE ARRAY - A nerve stimulation system includes a pulse generator and implantable lead. The pulse generator includes a sensing module and a pace circuit. The lead has an electrode array near the distal end and a connector at the proximal end for connection to the pulse generator. Conductors in the lead electrically connect the electrode array with the sensing module and pace circuit. The electrode array includes a first pair of small electrodes and a large electrode close to each other. The small electrodes and large electrode are physically separated from each other by insulative spaces extending generally transversely to a longitudinal axis of the lead. When the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit only. | 10-09-2014 |