Abstract: Systems and methods for detecting heart failure by monitoring the time-sequence of physiological changes of a subject using a state machine circuit configured to receive information about physiological characteristics of the subject is described. The current state transitions between a first and a second state in response to a first transition trigger. The current state transitions between the second and first states in response to at least one of the expiration of a first timer or ceasing of the first transition trigger. The current state transitions between the second and third states in response to a second transition trigger. The current state transitions between the third and second states in response to at least one of expiration of a second timer or ceasing of the second transition trigger.

Abstract: An implantable or other ambulatory medical apparatus comprises a posture sensing circuit, a physiologic sensing circuit that senses a time varying physiologic signal, and a processor circuit. The processor circuit includes a posture calculation circuit and a measurement circuit. The posture calculation circuit determines a posture of the subject using posture data obtained using the posture signal and determines when the posture of the subject is steady state. The measurement circuit derives a physiologic measurement using physiologic data extracted from the physiologic signal during at least one time period when posture is determined to be steady state and provides the physiologic measurement to at least one of a user and a process in association with the determined steady state posture.

Abstract: The present subject matter includes apparatus, methods and device-readable media for using impedance and heart sounds to classify events and alerts. An apparatus can include a processor circuit configured to receive a physiological indication, classify the indication, and generate a multi-dimensional heart failure decompensation status indication. A method can include obtaining a physiological indication, classifying the indication and generating a multi-dimensional heart failure decompensation status indication. A device-readable medium can include instructions that, when performed by the device can obtain a physiological indication, classify the indication, and generate a multi-dimensional heart failure decompensation status alert.

Abstract: A device can include at least a first physiologic sensor circuit configured to provide a first physiologic signal, a second physiologic sensor circuit configured to provide a second physiologic signal, and a processor circuit. The processor circuit includes a principal component analysis circuit configured to represent data determined from the at least first and second physiologic sensor circuits as at least first and second axes, respectively, in a multidimensional space, determine one or more principal components in the multidimensional space, determine a quantitative attribute of the first and the second physiologic signals using at least one of the determined principal components or a projection of the data along the at least one determined principal component, and provide an indication of heart failure status according to the quantitative attribute to at least one of a user or a process.

Abstract: Physiological data, such as thoracic impedance data, can be obtained over a first time window to establish a baseline, or can be used to form one or more data clusters. Additional physiological data, such as thoracic impedance test data acquired over a later time window, can be obtained and compared to the baseline or data clusters to determine an indication of worsening heart failure. In an example, a quantitative attribute of one or more data clusters can be monitored and used to provide an indication of worsening heart failure. A posture discrimination metric can be obtained, such as using the physiological data obtained over the first time window. The additional physiological data, such as can be obtained over a second time window, can be compared to the posture discrimination metric to provide a patient posture status.

Abstract: A contractile reserve indicator, corresponding to a predicted value of a maximum change in myocardial contractility that can be achieved by a subject, can be determined using a detected indication of cardiac contractility across various different physical activity levels.

Abstract: A system and method to sense heart sounds with one or more implantable medical devices according to one or more signal processing parameters. The method alters one or more of the parameters as a function of one or more physiologic triggering events. The method then senses heart sounds with the one or more implantable medical devices according to at least the one or more altered signal processing parameters.

Abstract: A cardiac rhythm management system provides for ambulatory monitoring of hemodynamic performance based on quantitative measurements of heart sound related parameters for diagnostic and therapeutic purposes. Monitoring of such heart sound related parameters allows the cardiac rhythm management system to determine a need for delivering a therapy and/or therapy parameter adjustments based on conditions of a heart. This monitoring also allows a physician to observe or assess the hemodynamic performance for diagnosing and making therapeutic decisions. Because the conditions of the heart may fluctuate and may deteriorate significantly between physician visits, the ambulatory monitoring, performed on a continuous or periodic basis, ensures a prompt response by the cardiac rhythm management system that may save a life, prevent hospitalization, or prevent further deterioration of the heart.

Abstract: An apnea classification system provides for apnea monitoring and differentiation based on several sleep apnea related parameters for diagnostic and therapeutic purposes. Monitoring of such sleep apnea related parameters allows the apnea classification system to differentiate among the different types of apnea and hypopnea and to identify an occurrence of periodic respiration. This information may then be used to determine the best method of therapy, or adjust current therapy parameters to more effectively treat a subject.

Abstract: A system comprising an implantable medical device (IMD). The IMD includes an implantable sensor operable to produce an electrical signal representative of mechanical activity of a heart of a subject and a controller circuit coupled to the sensor. The controller circuit includes a wavelet filter module and a valvular regurgitation (VR) calculation module. The wavelet filter module is configured to extract signal energy information from the electrical signal. The energy information includes variation of signal amplitude with frequency and time. The VR calculation module is configured to calculate a measurement of VR for one or more heartbeats using the energy information.

Abstract: A system and method to sense heart sounds with one or more implantable medical devices according to one or more parameters. The system alters one or more of the parameters as a function of one or more triggering events. The system then senses heart sounds with the one or more implantable medical devices according to at least the one or more altered parameters.

Abstract: The health state of a subject is automatically evaluated or predicted using at least one implantable device. In varying examples, the health state is determined by sensing or receiving information about at least one physiological process having a circadian rhythm whose presence, absence, or baseline change is associated with impending disease, and comparing such rhythm to baseline circadian rhythm prediction criteria. Other chronobiological rhythms beside circadian may also be used. The baseline prediction criteria may be derived using one or more past physiological process observation of the subject or population of subjects in a non-disease health state. The prediction processing may be performed by the at least one implantable device or by an external device in communication with the implantable device. Systems and methods for invoking a therapy in response to the health state, such as to prevent or minimize the consequences of predicted impending heart failure, are also discussed.

Abstract: Physiological sensor data can be combined with external biomarker assays, such as a bedside assay for B-type natriuretic peptide (BNP), to improve the sensitivity and specificity of heart failure detection.

Abstract: A cardiac rhythm management system provides for ambulatory monitoring of hemodynamic performance based on quantitative measurements of heart sound related parameters for diagnostic and therapeutic purposes. Monitoring of such heart sound related parameters allows the cardiac rhythm management system to determine a need for delivering a therapy and/or therapy parameter adjustments based on conditions of a heart. This monitoring also allows a physician to observe or assess the hemodynamic performance for diagnosing and making therapeutic decisions. Because the conditions of the heart may fluctuate and may deteriorate significantly between physician visits, the ambulatory monitoring, performed on a continuous or periodic basis, ensures a prompt response by the cardiac rhythm management system that may save a life, prevent hospitalization, or prevent further deterioration of the heart.

Abstract: A system including an implantable trigger event detector and an implantable ischemia detector. The implantable trigger event detector is adapted to detect at least one first condition and to output a responsive trigger signal including information about whether the first condition has been detected. The implantable ischemia detector is adapted to detect a second condition indicative of one or more physiologic cardiovascular events in a subject that are indicative of ischemia. The ischemia detector is coupled to the trigger event detector to receive the trigger signal, and the ischemia detector is enabled upon the trigger signal indicating that the first condition has been detected.

Abstract: The health state of a subject is automatically evaluated or predicted using at least one implantable device. In varying examples, the health state is determined by sensing or receiving information about at least one physiological process having a circadian rhythm whose presence, absence, or baseline change is associated with impending disease, and comparing such rhythm to baseline circadian rhythm prediction criteria. Other chronobiological rhythms beside circadian may also be used. The baseline prediction criteria may be derived using one or more past physiological process observation of the subject or population of subjects in a non-disease health state. The prediction processing may be performed by the at least one implantable device or by an external device in communication with the implantable device. Systems and methods for invoking a therapy in response to the health state, such as to prevent or minimize the consequences of predicted impending heart failure, are also discussed.

Abstract: An apnea classification system provides for apnea monitoring and differentiation based on several sleep apnea related parameters for diagnostic and therapeutic purposes. Monitoring of such sleep apnea related parameters allows the apnea classification system to differentiate among the different types of apnea. This information may then be used to determine the best method of therapy, or adjust current therapy parameters to more effectively treat a subject.

Abstract: Optimizing cardiac preload based on measured pulmonary artery pressure involves varying, for each repetition of an acute burst protocol, a parameter of pacing applied to a patient's heart during the acute burst protocol. Pulmonary artery pressure is measured during the repetitions of the acute burst protocol. The length of the repetitions is chosen so that the patient's baroreflex system does not adjust to the varied parameter of pacing during the repetitions of the acute burst protocol. An optimum ventricular preload is determined based on the measured pulmonary artery pressure. Pacing therapy is provided using a value of the parameter that is selected based on the determination of optimum ventricular preload.

Abstract: A contractile reserve indicator, corresponding to a predicted value of a maximum change in myocardial contractility that can be achieved by a subject, can be determined using a detected indication of cardiac contractility across various different physical activity levels.

Abstract: A differential or relative measurement between an orthogonal measurement vector and another measurement vector can be used to determine the location where fluid accumulation is occurring or the local change in such fluid accumulation. This can help diagnose or treat infection or hematoma or seroma at a pocket of an implanted cardiac rhythm management device, other implanted medical device, or prosthesis. It can also help diagnose or treat pulmonary edema, pneumonia, pulmonary congestion, pericardial effusion, pericarditis, pleural effusion, hemodilution, or another physiological condition.