Patent application number | Description | Published |
20090270933 | Pressure and Impedance Based Discrimination of Hemodynamic Stability - An implantable cardioverter defibrillator evaluates the hemodynamic stability of an arrhythmia to determine whether or not to defibrillate. The device obtains cardiac pressure and cardiac impedance data and evaluates a phase relationship between these parameters. Hemodynamically stable rhythms will result in an out of phase relationship. | 10-29-2009 |
20090270934 | Pressure and Impedance Based Discrimination of Hemodynamic Stability - An implantable cardioverter defibrillator evaluates the hemodynamic stability of an arrhythmia to determine whether or not to defibrillate. The device obtains cardiac pressure and cardiac impedance data and evaluates a phase relationship between these parameters. Hemodynamically stable rhythms will result in an out of phase relationship. | 10-29-2009 |
20090275855 | MULTI-FREQUENCY IMPEDANCE MONITORING SYSTEM - A system and method is provided to measure intrathoracic complex impedance and to identify and indicate disease conditions based on the impedance measurements. Multiple impedance vectors may betaken into account, and an optimal vector may be selected to provide the most useful impedance measurement for the identification and indication of disease conditions. | 11-05-2009 |
20100030086 | MONITORING HEMODYNAMIC STATUS BASED ON INTRACARDIAC OR VASCULAR IMPEDANCE - This disclosure relates to monitoring intracardiac or vascular impedance to determine a change in hemodynamic status by detecting changes in an impedance parameter over cardiac cycles. An example method includes measuring a plurality of impedance values of a path within a patient over time, wherein the path includes at least one blood vessel or cardiac chamber of the patient, and wherein the impedance values vary as a function of blood pressure within the at least one vessel or chamber, determining a plurality of values of an impedance parameter over time based on the measured impedance values, wherein each of the impedance parameter values is determined based on a respective sub-plurality of the impedance values, comparing at least one of the impedance parameter values to at least one prior impedance parameter value, and identifying a change in a cardiovascular parameter related to the blood pressure based on the comparison. | 02-04-2010 |
20100030087 | ESTIMATING CARDIOVASCULAR PRESSURE AND VOLUME USING IMPEDANCE MEASUREMENTS - Techniques for estimating a cardiac chamber or vascular pressure based upon impedance are described. A device or system may measure an impedance between at least two electrodes implanted within or proximate to a cardiovascular system. The device or system may estimate a pressure of an element of the cardiovascular system based on a relationship between impedance and volume of the element, and based on a empirical relationship between the volume and the pressure. The device or system may also estimate the dimension of the element based on the impedance-volume relationship, or other characteristics based on the impedance. Because the impedance measurements may be obtained, in some examples, by using electrodes and leads implanted within the cardiovascular system and coupled to an implantable medical device, a practical estimation of a cardiovascular pressure can be obtained on a chronic basis without requiring the use other invasive sensors, such as micronanometer transducers. | 02-04-2010 |
20110105858 | METHOD AND APPARATUS TO MONITOR CHANGE IN INSPIRATORY EFFORT USING INTRATHORACIC BLOOD PRESSURE WAVEFORM MORPHOLOGY - An implantable medical device and associated method detect obstructed inspiration by monitoring an blood pressure signal. A respiration signal is monitored and a phase of respiratory inspiration is detected from the respiration signal. A trend in the pressure signal is measured during the inspiration phase. Obstructed inspiration for the inspiration phase is detected in response to the measured the trend. | 05-05-2011 |
20110190654 | QUANTIFYING AUTONOMIC TONE WITH THORACIC IMPEDANCE - The disclosure describes techniques for quantifying the autonomic nervous system (ANS) health of a patient with thoracic impedance measurements. Thoracic impedance may be measured utilizing cardiac electrodes and an implantable medical device housing or other electrodes located on or within the patient. Since greater variability in thoracic impedance may indicate better health of the ANS, monitoring impedance changes in a patient may be used to quantify autonomic tone of the ANS, and ultimately, overall patient health. In some examples, thoracic impedance may be measured in response to a change in patient posture for acute monitoring or at predetermined times over several days, weeks, or months for more chronic monitoring of the patient. An implantable medical device may independently analyze the impedance measurements and transmit an alert to the patient or clinician when impedance changes indicate a change in patient health. | 08-04-2011 |
20120109245 | CARDIAC THERAPY BASED UPON IMPEDANCE SIGNALS - Methods and/or devices are disclosed herein for monitoring cardiac impedance signal and delivering therapy to a patient's heart based upon the monitored cardiac impedance. | 05-03-2012 |
20120150049 | IMPEDANCE MEASUREMENT TO MONITOR ORGAN PERFUSION OR HEMODYNAMIC STATUS - An implantable medical device system and associated method deliver drive signals having different frequencies to establish vector fields comprising an arterial volume and a venous volume corresponding to targeted portion of a patient's body. Impedance signals are determined in response to drive signals having different frequencies. Impedance parameter values are determined over time. A change in the hemodynamic status of a targeted portion of the patient's body is identified in response to the impedance parameter values. | 06-14-2012 |
20130030319 | CARDIAC MONITORING USING SPINAL CORD STIMULATION ELECTRODES - Methods and systems for use in cardiac monitoring may periodically measure intrathoracic impedance using one or more pairs of electrodes and analyze measured impedance values to identify changes in the patient's thoracic fluid content for use in cardiac monitoring. The intrathoracic impedance is measured using at least one spinal cord stimulation electrode. | 01-31-2013 |
20130110188 | METHOD TO ASSESS HEMODYNAMIC PERFORMANCE DURING CARDIAC RESYNCHRONIZATION THERAPY OPTIMIZATION USING ADMITTANCE WAVEFORMS AND DERIVATIVES | 05-02-2013 |
20130197385 | RESPIRATORY FUNCTION DETECTION - A method and system for monitoring respiratory function that includes an impedance sensor configured to sense a first thoracic impedance waveform for at least one breath of a patient, a memory configured to store a first threshold slope value, and a processor configured to determine an first breath slope value in response to the impedance waveform, compare the first breath slope value to a first threshold slope value, and determine an indication of respiratory function of the patient in response to the comparing. | 08-01-2013 |
20140142646 | CARDIAC THERAPY BASED UPON IMPEDANCE SIGNALS - Methods and/or devices are disclosed herein for monitoring cardiac impedance signal and delivering therapy to a patient's heart based upon the monitored cardiac impedance. | 05-22-2014 |
20140148656 | USE OF THORACIC AND EXTRA-THORACIC IMPEDANCE FOR DIAGNOSTIC MONITORING - A medical device and associated method for monitoring a fluid status of a patient that includes determining a first impedance signal along an electrode vector comprising a portion of a thoracic cavity, determining a second impedance signal along an extra-thoracic electrode vector, and determining a fluid status measurement in response to the determined first impedance signal and the determined second impedance signal | 05-29-2014 |
20140148867 | USE OF THORACIC AND EXTRA-THORACIC IMPEDANCE FOR DIAGNOSTIC MONITORING - A medical device and associated method for delivery of a cardiac therapy that includes determining a first impedance signal along a thoracic electrode vector extending within a portion of a thoracic cavity, determining a second impedance signal along an extra-thoracic electrode vector extending outside the thoracic cavity, comparing first amplitude measurements corresponding to the first impedance signals and second amplitude measurements corresponding to the second impedance signals, comparing first slope measurements corresponding to the first impedance signals and second slope measurements corresponding to the second impedance signals, and determining delivery of the cardiac therapy in response to the comparing. | 05-29-2014 |
20140288455 | MULTI-FREQUENCY IMPEDANCE MONITORING SYSTEM - A system and method is provided to measure intrathoracic complex impedance and to identify and indicate disease conditions based on the impedance measurements. Multiple impedance vectors may be taken into account, and an optimal vector may be selected to provide the most useful impedance measurement for the identification and indication of disease conditions. | 09-25-2014 |