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:
According to certain examples, an implanted medical device is used to determine a mass attribute of a patient. The patient's phrenic nerve is stimulated, and the diaphragmatic response is measured by an accelerometer. The measured response is analyzed in certain embodiments to determine a mass attribute. This information can help in the diagnosis of, and efficient response to, edema.
摘要:
A neural stimulator senses a reference signal indicative of cardiac cycles each including a predetermined type timing reference event using a sensor external to the heart and blood vessels. The delivery of the neural stimulation pulses are synchronized to that timing reference event. Examples of the timing reference event include a predetermined cardiac event such as a P-wave or an R-wave detected from a subcutaneous ECG signal, a predetermined type heart sound detected from an acoustic signal, and a peak detected from a hemodynamic signal related to blood flow or pressure.
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 for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.
摘要:
An atrioventricular delay (AVD) for cardiac pacing therapy is determined based, at least in part, on one or more cardiac activation signals sensed using body-implantable electrodes providing non-local sensing. A conduction delay is estimated using a non-local cardiac activation signal and the AVD is determined based on the conduction delay. Estimating the conduction delay may involve measuring a P-wave width or measuring a QRS complex width of the non-local signal. If multiple signals are sensed, the conduction delay may be estimated from a selected signal or may be estimated by forming a representative signal such as through averaging or other methods. The AVD may be determined as a function of the estimated conduction delay.
摘要:
A system comprises a cardiac signal sensing and a processing circuit. The cardiac signal sensing circuit senses a first cardiac signal segment that includes a QRS complex and a second cardiac signal segment that includes a fiducial indicative of local ventricular activation. The processor circuit includes a site activation timer circuit configured to determine a time duration between a fiducial of the QRS complex of the first cardiac signal segment and the fiducial of the second cardiac signal segment. The processor circuit is configured to generate, using the determined time duration, an indication of optimality of placement of one or more electrodes for delivering therapy and provide the indication to at least one of a user or process.
摘要:
Various aspects of the present subject matter relate to a method. According to various method embodiments, cardiac activity is detected, and neural stimulation is synchronized with a reference event in the detected cardiac activity. Neural stimulation is titrated based on a detected response to the neural stimulation. Other aspects and embodiments are provided herein.
摘要:
Various aspects of the present subject matter relate to a method. According to various method embodiments, cardiac activity is detected, and neural stimulation is synchronized with a reference event in the detected cardiac activity. Neural stimulation is titrated based on a detected response to the neural stimulation. Other aspects and embodiments are provided herein.
摘要:
An improved technique is described for dealing with the detection of fusion beats when capture verification is performed by a cardiac pacing device such as during a capture threshold determination procedure. Schemes for classifying heart beats may misclassify beats as fusion beats due to feature/m orphology changes in the test electrogram waveform that may occur even when capture is achieved.
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.