摘要:
A system comprising an implantable medical device (IMD) includes an implantable heart sound sensor to produce an electrical signal representative of at least one heart sound. The heart sound is associated with mechanical activity of a patient's heart. Additionally, the IMD includes a heart sound sensor interface circuit coupled to the heart sound sensor to produce a heart sound signal, and a signal analyzer circuit coupled to the heart sound sensor interface circuit. The signal analyzer circuit measures a baseline heart sound signal, and deems that an ischemic event has occurred using, among other things, a measured subsequent change in the heart sound signal from the established baseline heart sound signal.
摘要:
Described herein are methods and devices that utilize electrical neural stimulation to treat heart failure by modulating a patient's autonomic balance in a manner that inhibits sympathetic activity and/or augments parasympathetic activity. Because other therapies for treating heart failure may also affect a patient's autonomic balance, a device for delivering neural stimulation is configured to appropriately titrate such therapy in either an open-loop or closed-loop fashion.
摘要:
Systems and methods to monitor cardiac function using information indicative of lead motion are described. In an example, a system including an implantable medical device can include a receiver circuit configured to be electrically coupled to conductor comprising a portion of an implantable lead and be configured to obtain information indicative of a movement of the implantable lead due at least in part to a motion of a heart. The system can include a sensing circuit configured to obtain information indicative of cardiac electrical activity. The system can include a processor circuit configured to construct a template representative of a contraction of the heart, where the template can be constructed using the information indicative of the movement of the implantable lead due at least in part to the motion of the heart during the contraction, and using the information indicative of the cardiac electrical activity sensed during the contraction.
摘要:
A refractory period for a pacemaker sensing channel refers to a period of time during which the sensing channel is either blind to incoming electrical signals, termed a blanking interval, and/or during which the device is configured to ignore such signals for purposes of sense event detection. Methods and devices for implementing refractory periods in the context of multi-site left ventricular pacing are described.
摘要:
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.
摘要:
An apparatus comprises an implantable sensor and a signal analyzer circuit communicatively coupled to the implantable sensor. The implantable sensor is configured for coupling to an implantable lead and the implantable sensor provides an electrical vibration sensor signal representative of mechanical vibration of the implantable lead. The signal analyzer circuit is configured to determine a baseline of the vibration sensor signal, detect a change in the vibration sensor signal from the baseline vibration sensor signal, and provide an indication of the change to a user or process.
摘要:
An embodiment uses an accelerometer to sense heart sounds, and determines heart rate info nation using the sensed heart sounds. An embodiment uses an accelerometer to sense respiratory activity. An embodiment delivers a programmed neural stimulation therapy with a programmed duty cycle, where the programmed duty cycle includes a stimulation ON portion followed by a stimulation OFF portion. An electrode electrically connected to the implanted neural stimulation device is used to remotely detect cardiac activity. The remotely detected cardiac activity is used to detect heart rate information during the stimulation ON portion and to detect heart rate information during the stimulation OFF portion. The detected heart rate information and/or the detected respiration information are used to control a neural stimulation therapy performed by the neural stimulator device and/or are used to provide diagnostic information for the patient's condition.
摘要:
Described herein are methods and devices that utilize electrical neural stimulation to treat heart failure by modulating a patient's autonomic balance in a manner that inhibits sympathetic activity and/or augments parasympathetic activity. Because other therapies for treating heart failure may also affect a patient's autonomic balance, a device for delivering neural stimulation is configured to appropriately titrate such therapy in either an open-loop or closed-loop fashion.
摘要:
Systems and methods using constant false alarm rate techniques for event detection. One example of an event detection method includes collecting a first distribution of measurements for a first physiological parameter. In another example, the first distribution of measurements includes only non-event measurements. One or more values are determined corresponding to at least a first tail area of the first distribution from at least one measurement of the first physiological parameter toward an end point of the distribution. A threshold is established based on a specified false alarm rate. The one or more values are compared to the threshold. The method includes determining if the measurement is representative of a detected event using the comparison.
摘要:
One way in which cardiac resynchronization therapy may be delivered is to only deliver paces to the left ventricle. If left ventricular pacing is inhibited during a cardiac cycle, it may be desirable to deliver a right ventricular safety pace to prevent asystole. Methods and devices for implementing right ventricular safety pacing in the context of multi-site left ventricular-only pacing are described.