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 |
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 |
20100030292 | DETECTING WORSENING HEART FAILURE BASED ON IMPEDANCE MEASUREMENTS - Techniques for processing impedance data to provide an early warning for heart failure decompensation are described. An example device may be configured to measure intrathoracic impedance values, and increment an index when a determined impedance is less than a reference impedance. The incrementing may be based on the difference between the reference impedances and the determined impedance. In some examples, the amount of incrementing is reduced based on a variability of the impedances, or increased over time so long as the index remains above a threshold, e.g., zero. In some examples, the manner is which the reference impedances are determined changes over time to, for example, address rapid changes in impedance after device or system implantation. In some examples, the index is compared to a threshold to determine whether to provide an alert. In some examples, two thresholds are used to provide hysteresis. | 02-04-2010 |
20100030293 | USING MULTIPLE DIAGNOSTIC PARAMETERS FOR PREDICTING HEART FAILURE EVENTS - Techniques for using multiple physiological parameters to provide an early warning for worsening heart failure are described. A medical device monitors a primary diagnostic parameter that is indicative of worsening heart failure, such as intrathoracic impedance or pressure, and one or more secondary diagnostic parameters. The medical device detects worsening heart failure in the patient based on the primary diagnostic parameter when an index that is changed over time based on the primary diagnostic parameter value is outside a range of values, termed the threshold zone. When the index is within the threshold zone, the medical device detects worsening heart failure in the patient based on the one or more secondary diagnostic parameters. Upon detecting worsening heart failure, the medical device may, for example, provide an alert that enables the patient to seek medical attention before experiencing a heart failure event. | 02-04-2010 |
20100113888 | HEART FAILURE DECOMPENSATION DETERMINATION - Heart failure decompensation is detected by sensing at least one physiological signal. Values of at least two different heart failure variables are derived using one or more physiological signals and a threshold for the first heart failure variable is adjusted in response to the value of the second heart failure variable. The value of the first heart failure variable is compared to first threshold for detecting a heart failure condition. | 05-06-2010 |
20100113962 | SYSTEM AND METHOD TO LOCALIZE CHANGES IN INTRATHORACIC FLUID CONTENT USING MEASURED IMPEDANCE IN AN IMPLANTABLE DEVICE - An implantable medical device and associated methods monitor thoracic fluid status and discriminate thoracic fluid conditions. Intrathoracic impedance is measured along multiple intrathoracic measurement vectors using implanted electrodes. A map of thoracic conductivity is computed using the measured intrathoracic impedances. A thoracic fluid condition is detected in response to the computed map. | 05-06-2010 |
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 |
20120109243 | HEART FAILURE MONITORING AND NOTIFICATION - Techniques for generating a heart failure risk score with detected patient metrics are described. An implantable medical device (IMD) may collect and store patient data regarding therapy use statistics, thoracic impedance, heart rate, patient activity, and other patient metrics. Based on the number of patient metrics exceeding their respective metric thresholds, the IMD may automatically generate a risk score that indicates the likelihood that the patient will suffer from heart failure. The risk score may identify a patient as requiring immediate medical attention to reduce the risk of heart failure. The IMD may push an alert of the heart failure risk score to a clinician, and the clinician may review the patient metric data on an external device. In some examples, a clinician may prioritize patient treatment with a presented list ranking patients with the most severe heart failure risk scores. | 05-03-2012 |
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 |
20120109675 | SYSTEM AND METHOD FOR IDENTIFYING A PROSPECTIVE CLINICAL THERAPY FOR A PROSPECTIVE PATIENT HAVING A MEDICAL DEVICE - System and method for identifying a prospective clinical therapy for a prospective patient. The patient has a medical device, performed with a medical apparatus. The system has a historical database and an analyzer. The historical database incorporates information relating to a multiplicity of patients, each of the multiplicity of patients having a medical device and each of the multiplicity of patients having undergone a clinical therapy, the information including, for each of the multiplicity of patients, device characteristics of the medical device and an assessment of efficacy of clinical therapy. The analyzer correlates device characteristics of the prospective patient with the device characteristics and the assessment of efficacy of clinical therapy of the multiplicity of patients using the historical database to identify a prospective clinical therapy for the prospective patient associated with the device characteristics in the historical database having a relatively greater efficacy than the clinical therapy. | 05-03-2012 |
20120238891 | METHODS FOR ECTOPY REJECTION FOR ATRIAL FIBRILLATION DETECTION BASED ON VENTRICULAR CYCLE LENGTHS - A medical device performs a method to classify a cardiac rhythm. Differences between cycle lengths in a first heart chamber are determined during an established time interval. Evidence of ectopy associated with irregular coupling intervals is detected from the signal during the established time interval. A rhythm classification output corresponding to a second heart chamber at the expiration of the established time interval is provided in response to the consecutive cycle length differences and the evidence of ectopy associated with irregular coupling intervals. | 09-20-2012 |
20120238892 | METHOD AND APPARATUS FOR NOISE REJECTION IN ATRIAL ARRHYTHMIA DETECTION - A medical device performs a method for determining a cardiac event by obtaining a signal comprising cardiac cycle length information in a patient and determining cardiac cycle lengths during an established time interval. Noise is detected during the time interval and a cardiac cycle length corresponding to a time of the detected noise is rejected. Cycle length differences are determined from the cycle lengths not rejected during the time interval. The cardiac event is determined in response to the cycle length differences. | 09-20-2012 |
20120253207 | HEART FAILURE MONITORING - Techniques for transmitting diagnostic information stored in an implantable medical device (IMD) based on patient hospitalization are described. For example, the IMD may transmit higher resolution diagnostic information to a clinician and/or an external device during a hospitalization period to aid the clinician in evaluating heart failure treatment and when discharge is proper. This higher resolution diagnostic information may include one or more patient metrics automatically generated and transmitted by the IMD at least once every two hours. During a post-hospitalization period, the IMD may transmit lower resolution diagnostic information to a clinician that indicates a risk level of re-hospitalization. The lower resolution diagnostic information may include the risk level and/or patient metrics once a day, for example. In this manner, the IMD transmitted diagnostic information may be tailored to the specific heart failure monitoring needed by the patient. | 10-04-2012 |
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 |
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 |
20150088216 | METHOD AND APPARATUS FOR AUTOMATIC CONFIGURATION OF IMPLANTABLE MEDICAL DEVICES - A system including a programmable implantable monitoring device and a programmer for programming the device and a method of use thereof. The programmer may be configured to transmit programming commands responsive to entry of a reason for monitoring to the implantable device including a prioritization of an arrhythmia storage criterion. The implantable may be configured to thereafter store and/or transmit records of the arrhythmia according to the prioritization. The programmer may be configured to transmit the patient's age to the implantable device and the implantable may be configured to thereafter apply arrhythmia detection criteria based upon the patient's age. | 03-26-2015 |