Abstract: Physiological signals such as ECG signals are obtained from a patient. In accordance with one or more embodiments, an apparatus, system and/or method is directed to at least two ECG sensing electrodes that adhere to remote locations on a patient and sense ECG signals from the patient. An amplifier circuit amplifies the sensed ECG signals to provide amplified ECG signals, and a digitizing circuit digitizes the amplified ECG. A computing circuit processes the digitized ECG signals (e.g., by removing noise). A battery powers the aforesaid circuits, and a housing houses the battery and aforesaid circuit. A fastener mechanically fastens and electrically couples the housing to one of the electrodes, and the other electrodes are coupled to the amplifier via a flexible insulated lead wire.

Abstract: Various embodiments are directed to signal processing. In accordance with example embodiments, methods and apparatuses involve using at least two electrodes that sense an ECG signal. A denoising module is communicatively coupled to the at least two electrodes, and receives the ECG signal sensed by the sensing electrodes. The denoising module includes circuitry that conditions and digitizes the ECG signal, and a computing circuit that processes the digitized ECG signal to denoise the ECG signal. A communications circuit generates a communication including the denoised ECG signal for access by a remote device.

Abstract: A parameter value is computed for a segment of a cardiac-related signal. In accordance with various example embodiments, a system includes a computer circuit configured to identify cardiac cycles within a segment of a cardiac-related signal, such as an ECG. At least one feature point is identified within the cardiac cycles. For each identified feature point, a signal-to-noise ratio (SNR) representative of the ratio of signal energy to noise energy is computed for a cardiac cycle subsegment containing the identified feature point. A validity characteristic of the feature point is determined based upon the signal-to-noise ratio, and a parameter value is computed by combining feature points contained within the segment, based upon the determined validity characteristics of the feature points.

Abstract: A T-wave offset point of an ECG signal is provided. In accordance with various example embodiments, a location of a QRS complex in the ECG signal is identified and used to determine a first time window of the ECG signal in which to search for a T-wave offset point. The T-wave offset point is identified within the first time window, and the identified T-wave offset point is provided as an output based upon a noise characteristic of the ECG signal in a second time window that includes at least a portion of the T-wave.

Abstract: An implantable device and method for monitoring S1 heart sounds with a remotely located accelerometer. The device includes a transducer that converts heart sounds into an electrical signal. A control circuit is coupled to the transducer. The control circuit is configured to receive the electrical signal, identify an S1 heart sound, and to convert the S1 heart sound into electrical information. The control circuit also generates morphological data from the electrical information. The morphological data relates to a hemodynamic metric, such as left ventricular contractility. A housing may enclose the control circuit. The housing defines a volume coextensive with an outer surface of the housing. The transducer is in or on the volume defined by the housing.

Abstract: Implantable medical devices and techniques are implemented that use bio-impedance to measure aspects of patient physiology. A signal separation method is performed at least in part in an implantable device. The method involves detecting a plurality of impedance signals using a plurality of implantable electrodes coupled to the implantable device. The method further involves separating one or more signals from the plurality of impedance signals using a signal separation technique, such as an algorithm-based separation technique.

Abstract: An ambulatory repeater for use in automated patient care is presented. A local memory store includes a cryptographic key, sensitive information, and physiological measures. The cryptographic key is uniquely assigned to the implantable medical device prior to implant of the implantable medical device into a patient. The sensitive information is preencrypted under the cryptographic key and physiological measures are measured by the implantable medical device. An authentication module is in receipt of the cryptographic key. A permissions module confirms authorization of an external data processing device against the cryptographic key. A decryption module decrypts the sensitive information with the cryptographic key into decrypted information. A processor is operatively coupled to the local memory store. A communications module exchanges the decrypted information and the physiological measures with the external data processing device over a wireless interface contingent upon the authorization confirmation.

Abstract: Implantable medical devices and techniques are implemented that use bio-impedance to measure aspects of patient physiology. A signal separation method is performed at least in part in an implantable device. The method involves detecting a plurality of impedance signals using a plurality of implantable electrodes coupled to the implantable device. The method further involves separating one or more signals from the plurality of impedance signals using a signal separation technique, such as an algorithm-based separation technique.

Abstract: A plurality of chronic sensors are used to facilitate diagnosis and medical decision making for an individual patient. An expert system evaluates the sensor data, combines the sensor data with stored probability data and provides an output signal for notification or medical intervention.

Abstract: Cardiac systems and methods using ECG and blood information for arrhythmia detection and discrimination. Detection circuitry is configured to produce an ECG. An implantable blood sensor configured to produce a blood sensor signal is coupled to a processor. The processor is coupled to the detection and energy delivery circuitry, and used to evaluate and treat cardiac rhythms using both the cardiac electrophysiologic and blood sensor signals. The blood sensor is configured for subcutaneous non-intrathoracic placement and provided in or on the housing, on a lead coupled to the housing, and/or separate to the housing and coupled to the processor via hardwire or wireless link. The blood sensor may be configured for optical sensing, using a blood oxygen saturation sensor or pulse oximeter. A cardiac rhythm may be evaluated using the electrocardiogram signal and the blood sensor signal, and tachyarrhythmias may be treated after confirmation using the blood sense signal.

Abstract: An implantable device and method for monitoring S1 heart sounds with a remotely located accelerometer. The device includes a transducer that converts heart sounds into an electrical signal. A control circuit is coupled to the transducer. The control circuit is configured to receive the electrical signal, identify an S1 heart sound, and to convert the S1 heart sound into electrical information. The control circuit also generates morphological data from the electrical information. The morphological data relates to a hemodynamic metric, such as left ventricular contractility. A housing may enclose the control circuit. The housing defines a volume coextensive with an outer surface of the housing. The transducer is in or on the volume defined by the housing.

Abstract: Cardiac systems and methods using ECG and blood information for arrhythmia detection and discrimination. Detection circuitry is configured to produce an ECG. An implantable blood sensor configured to produce a blood sensor signal is coupled to a processor. The processor is coupled to the detection and energy delivery circuitry, and used to evaluate and treat cardiac rhythms using both the cardiac electrophysiologic and blood sensor signals. The blood sensor is configured for subcutaneous non-intrathoracic placement and provided in or on the housing, on a lead coupled to the housing, and/or separate to the housing and coupled to the processor via hardwire or wireless link. The blood sensor may be configured for optical sensing, using a blood oxygen saturation sensor or pulse oximeter. A cardiac rhythm may be evaluated using the electrocardiogram signal and the blood sensor signal, and tachyarrhythmias may be treated after confirmation using the blood sense signal.

Abstract: An ambulatory repeater for use in automated patient care is presented. A local memory store includes a cryptographic key, sensitive information, and physiological measures. The cryptographic key is uniquely assigned to the implantable medical device prior to implant of the implantable medical device into a patient. The sensitive information is preencrypted under the cryptographic key and physiological measures are measured by the implantable medical device. An authentication module is in receipt of the cryptographic key. A permissions module confirms authorization of an external data processing device against the cryptographic key. A decryption module decrypts the sensitive information with the cryptographic key into decrypted information. A processor is operatively coupled to the local memory store. A communications module exchanges the decrypted information and the physiological measures with the external data processing device over a wireless interface contingent upon the authorization confirmation.

Abstract: Cardiac methods and devices that separate signals using at least two composite signals acquired at least at two input impedances. A target source impedance may be selected, and a cardiac signal may be separated from composite signals using the selected target source impedance. Medical systems include a cardiac device having a housing that provides amplification circuitry configured to have a first amplifier input impedance and a second amplifier input impedance, such as using two separate circuits or switching between two input impedances. One or more electrode assemblies are coupled to the amplification circuitry. A signal processor is provided in the housing configured to separate a source signal using a first composite signal detected at the first input impedance and a second composite signal detected at the second input impedance. The phase response of the first input amplifier circuit is about equal to that of the second input amplifier circuit.

Abstract: Systems and methods involve use of a medical device comprising sensing circuitry. One or more respiratory parameters are detected using the device. Patient baseline weight is provided, and an output signal indicative of a patient's congestive heart failure status is generated based on a change in the one or more respiratory parameters and a change in the patient's measured weight or predicted weight relative to the patient baseline weight. The respiratory parameters may include one or more of respiration rate, relative tidal volume, an index indicative of rapid shallow breathing by the patient, an index derived by computing a respiration rate and a tidal volume for each patient breath, and an index indicative of dyspnea, for example.

Abstract: An ambulatory repeater for use in automated patient care is presented. A local memory store includes a cryptographic key, sensitive information, and physiological measures. The cryptographic key is uniquely assigned to the implantable medical device prior to implant of the implantable medical device into a patient. The sensitive information is preencrypted under the cryptographic key and physiological measures are measured by the implantable medical device. An authentication module is in receipt of the cryptographic key. A permissions module confirms authorization of an external data processing device against the cryptographic key. A decryption module decrypts the sensitive information with the cryptographic key into decrypted information. A processor is operatively coupled to the local memory store. A communications module exchanges the decrypted information and the physiological measures with the external data processing device over a wireless interface contingent upon the authorization confirmation.

Abstract: An external data processing device to interface with an ambulatory repeater and method thereof is presented. An external data processing device is interfaced in far field telemetric communication with an ambulatory repeater. The external data processing device receives sensitive information preencrypted prior to implant under a cryptographic key uniquely assigned to an implantable medical device over a secure connection from the ambulatory repeater. Physiological measures retrieved from the implantable medical device by the ambulatory repeater are received by the external data processing device over a non-secure connection.

Abstract: A cardiac rhythm management system provides for assessment of cardiac mechanical dyssynchrony based on heart sound morphology and optimization of pacing parameters based on the effect of pacing on the cardiac mechanical dyssynchrony assessment. A degree of cardiac mechanical dyssynchrony is measured by the time delay between tricuspid valve closure and mitral valve closure and/or the time delay between pulmonary valve closure and aortic valve closure. A cardiac resynchronization therapy is optimized by determining therapy parameters to provide an approximately minimum degree of cardiac mechanical dyssynchrony by cardiac pacing.

Abstract: Cardiac monitoring and/or stimulation methods and systems provide monitoring, defibrillation and/or pacing therapies. A signal processor receives a plurality of composite signals associated with a plurality of sources, separates a signal using a source separation algorithm, and identifies a cardiac signal using a selected vector. The signal processor may iteratively separate signals from the plurality of composite signals until the cardiac signal is identified. The selected vector may be updated if desired or necessary. A method of signal separation involves detecting a plurality of composite signals at a plurality of locations, separating a signal using source separation, and selecting a vector that provides a cardiac signal. The separation may include a principal component analysis and/or an independent component analysis.

Abstract: Systems and methods provide for assessing a patient's hemodynamic response to a drug therapy. A patient's hemodynamic response to a drug therapy is monitored using sensor data acquired using one or more sensors. The patient's hemodynamic response to the drug therapy is quantified, such as by quantifying a patient's sensitivity or refractoriness to the drug therapy. The quantified data may be used to optimize a patient's drug therapy, among other uses.