摘要:
Methods and devices are described that allow estimation of an electrostimulation capture threshold, such as a dedicated bipolar pacing vector threshold. In an example, an equal-energy assumption between first and second pacing vectors can be used to estimate an electrostimulation capture threshold of a second pacing vector from a measured electrostimulation capture threshold of the first pacing vector and impedances of the first and second pacing vectors. In an example, a relationship between first and second pacing vectors can be determined from measured data, and a parameter of the relationship can be used with a measurement of an electrostimulation capture threshold of the first pacing vector to estimate an electrostimulation capture threshold of the second pacing vector.
摘要:
Cardiac monitoring and/or stimulation methods and systems provide for monitoring, diagnosing, defibrillation and pacing therapies, or a combination of these capabilities, including cardiac systems incorporating or cooperating with neuro-stimulating devices, drug pumps, or other therapies. Embodiments relate generally to implantable medical devices employing automated cardiac activation sequence monitoring and/or tracking for arrhythmia discrimination. Embodiments are directed to devices and methods involving sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the sensed plurality of composite cardiac signals and the separation produces one or more cardiac signal vectors associated with one or more cardiac activation sequences that is indicative of ischemia. A change of the one or more cardiac signal vectors is detected using the one or more cardiac signal vectors. Cardiac arrhythmias are discriminated using the one or more cardiac signal vectors.
摘要:
Cardiac resynchronization therapy is delivered to a heart using an extended bipolar electrode configuration in accordance with programmed pacing parameters including a non-zero intraventricular delay. The extended bipolar electrode configuration comprises a left ventricular electrode defining a cathode of the extended bipolar electrode configuration and a right ventricular electrode defining an anode of the extended bipolar electrode configuration. A pace pulse is delivered to the left ventricular electrode and anodal stimulation of the right ventricle is detected based on the sensed response to the pace pulse.
摘要:
Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track, and/or trend closed-loop cardiac resynchronization therapy using cardiac activation sequence information. Devices and methods involve sensing a plurality of composite cardiac signals using a plurality of electrodes, the electrodes configured for implantation in a patient. A source separation is performed using the sensed plurality of composite cardiac signals, producing one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences. A cardiac resynchronization therapy is adjusted using one or both of the one or more cardiac signal vectors and the signals associated with the one or more cardiac signal vectors. In further embodiments, the cardiac resynchronization therapy may be initiated, terminated, or one or more parameters of the resynchronization therapy may be altered.
摘要:
The present invention concerns phrenic nerve activation detection algorithms for characterization of phrenic nerve activation and phrenic nerve activation avoidance in cardiac pacing therapy.Various embodiments concern receiving a respiration signal indicative of respiratory activity of the patient, identifying respiratory phases based on the respiration signal, delivering cardiac pacing pulses within each of the identified respiratory phases, receiving a phrenic nerve activation signal indicative of activation of the patient's phrenic nerve, analyzing the phrenic nerve stimulation signal to determine if one or more of the pacing pulses activated the phrenic nerve of the patient, and determining if at least one of the delivered pacing pulses activated the phrenic nerve of the patient based on the phrenic nerve activation signal indicating activation of the patient's phrenic nerve associated with delivery of the at least one cardiac pacing pulse.
摘要:
Systems and methods for determining pacing timing intervals based on the temporal relationship between the timing of local and non-local cardiac signal features are described. A device includes a plurality of implantable electrodes electrically coupled to the heart and configured to sense local and non-local cardiac signals. Sense circuitry coupled to first and second electrode pairs senses a local cardiac signal via a first electrode pair and a non-local cardiac signal via a second electrode pair. Detection circuitry is used to detect a feature of the local signal associated with activation of a heart chamber and to detect a feature of the non-local signal associated with activation of the heart chamber. A control processor times delivery of one or more pacing pulses based on a temporal relationship between timing of the local signal feature and timing of the non-local signal feature.
摘要:
An apparatus comprises a control circuit that initiates a normal pacing mode for delivery of electrostimulation energy to the heart chamber. In response to an indication to initiate a threshold test, the control circuit determines an electrode configuration used to deliver the electrostimulation energy in the normal pacing mode, selects a first threshold test mode when a sensing electrode independent from the set of pacing electrodes is unavailable for the heart chamber, wherein a cardiac activity signal is sensed using a set of sensing electrodes that includes an electrode common to the set of pacing electrodes, and selects a second threshold test mode when a sensing electrode independent from the set of pacing electrodes is available for the heart chamber, wherein the cardiac activity signal is sensed using a set of sensing electrodes that excludes an electrode common to the set of pacing electrodes.
摘要:
An interactive representation of electrostimulation electrodes or vectors can be provided, such as for configuring combinations of electrostimulation electrodes. In an example, electrodes or test parameters can be presented graphically or in a table. A user interface can be configured to receive user-input designating electrode combinations or vectors for test or for use in programming an implantable or ambulatory medical device. The interface can be used to indicate suggested electrode combinations or vectors in response to a first selection of an electrode. Tests can be performed on electrode combinations and vectors, and the results of the tests can be presented to a user using the interactive representation. In an example, test results can be analyzed by a processor and optionally used to program an implantable or ambulatory medical device.
摘要:
An implantable medical device such as an implantable pacemaker or implantable cardioverter/defibrillator includes a programmable sensing circuit providing for sensing of a signal approximating a surface electrocardiogram (ECG) through implanted electrodes. With various electrode configurations, signals approximating various standard surface ECG signals are acquired without the need for attaching electrodes with cables onto the skin. The various electrode configurations include, but are not limited to, various combinations of intracardiac pacing electrodes, portions of the implantable medical device contacting tissue, and electrodes incorporated onto the surface of the implantable medical device.
摘要:
The present invention concerns phrenic nerve activation detection algorithms for characterization of phrenic nerve activation and phrenic nerve activation avoidance in cardiac pacing therapy.Various embodiments concern receiving a respiration signal indicative of respiratory activity of the patient, identifying respiratory phases based on the respiration signal, delivering cardiac pacing pulses within each of the identified respiratory phases, receiving a phrenic nerve activation signal indicative of activation of the patient's phrenic nerve, analyzing the phrenic nerve stimulation signal to determine if one or more of the pacing pulses activated the phrenic nerve of the patient, and determining if at least one of the delivered pacing pulses activated the phrenic nerve of the patient based on the phrenic nerve activation signal indicating activation of the patient's phrenic nerve associated with delivery of the at least one cardiac pacing pulse.