摘要:
An implantable system for the antitachycardia pacing of the heart of a patient in need of such treatment comprises a plurality of primary electrodes, a power supply, and a control circuit. At least one of the primary electrodes is configured for positioning through the coronary sinus ostium and in a vein on the left surface of the patient's heart.
摘要:
An implantable system for the cardioversion of the heart of a patient in need of such treatment comprises a plurality of primary electrodes, a power supply, and a control circuit. Preferably, at least one auxiliary electrode is also included. The plurality of primary electrodes are configured for delivering a cardiversion pulse along a predetermined current pathway in a first portion of the heart, the current pathway defining a weak field area in a second portion of the heart.
摘要:
An implantable system for the defibrillation or cardioversion of the heart of a patient in need of such treatment comprises a plurality of primary electrodes, a power supply, and a control circuit. Preferably, at least one auxiliary electrode is also included. The plurality of primary electrodes are configured for delivering a defibrillation pulse along a predetermined current pathway in a first portion of the heart, the current pathway defining a weak field area in a second portion of the heart. The at least one auxiliary electrode is configured for delivering an auxiliary pulse to the a portion of the heart where the primary shock field intensity is at or near a minimum. The control circuit is operatively associated with the primary electrodes, the auxiliary electrode, and the power supply, with the control circuit configured for delivering a cardioversion sequence comprising an auxiliary pulse sufficient to induce a cessation of propagation in the weak field area through the auxiliary electrode, followed by a defibrillation pulse through the primary electrodes delivered during the cessation of propagation in the weak field area.
摘要:
The present invention provides apparatus and methods for delivering an optimum electrical shock in treating cardiac arrhythmias. The apparatus comprises means for producing an electrical waveform signal at least two electrodes The voltage or current of the signal is then detected to determine the signal time constant. The signal time constant is then used in conjunction with a model time constant to determine when the peak amplitude is reached. The waveform is then interrupted when the peak amplitude is reached. Also provided are methods of selecting a cardiac defibrillator by measuring the impedance of implanted electrodes and then selecting a defibrillator having a capacitor which provides an RC time constant equal to that of a model time constant.
摘要:
The present invention provides apparatus and methods for delivering an optimum electrical shock in treating cardiac arrhythmias. The invention comprises apparatus for producing an electrical waveform signal at least at two electrodes. The voltage or current of the signal is then detected to determine the signal time constant. The signal time constant is then used in conjunction with a model time constant to determine when the peak amplitude is reached. The waveform is then interrupted when the peak amplitude is reached. Also provided are methods of selecting a cardiac defibrillator by measuring the impedance of implanted electrodes and then selecting a defibrillator having a capacitor which provides an RC time constant equal to that of a model time constant.
摘要:
According to an embodiment of a method performed by an implantable medical device to deliver a neural stimulation therapy to a patient, a lower dose of the neural stimulation therapy is delivered to the patient. The dose of the neural stimulation therapy is automatically increased from the lower dose to a higher dose, and the higher dose of the neural stimulation therapy is delivered to the patient. A trigger that is controlled by the patient is detected, and the dose of the neural stimulation therapy is automatically returned from the higher dose back to the lower dose in response to detecting the trigger.
摘要:
A method and apparatus for converting an arrhythmia of a heart using a biphasic truncated exponential waveform wherein the first phase is of shorter duration than the second phase.
摘要:
Implantable electrodes for defibrillation are formed of pluralities of electrode segments. Each of the segments is relatively long and narrow. The electrode segments can be parallel and spaced apart from one another a distance at least ten times the nominal width, with one end of each segment mounted to a transverse distal portion of an electrically conductive lead coupling the electrode to a defibrillation pulse generator. Alternatively, segments can branch or radiate outwardly from a common junction. In yet another arrangement, electrode segments are portions of a single conductive path at the distal end of a lead from a pulse generator, arranged in either a spiral configuration or a serpentine configuration which can align electrode segments side by side, parallel and spaced apart. The electrode segments can be formed of composite conductors in the form of titanium ribbons or wires with a sputtered outer layer of platinum, or a silver core in a stainless steel tube, with a platinum layer formed onto the tube. The electrodes are highly compliant yet can provide large effective areas for defibrillation, enabling a transthoracic pulsing arrangement of two electrodes on opposite sides of the heart, implanted subcutaneously outside of the thoracic region.
摘要:
Some embodiments provide a system for delivering neurostimulation. Some system embodiments comprise a lead configured to be implanted in the body, a stimulation output circuit configured to deliver neurostimulation pulses to the vagus nerve through the lead, an EMG sensing circuit configured to use the lead to sense EMG signals from laryngeal muscle activity, and an evoked muscular response detection circuit configured to use the EMG signals sensed by the EMG sensing circuit to detect evoked laryngeal muscle activity evoked by the neurostimulation pulse.
摘要:
A neurostimulation system measures a cardiac parameter at various cardiac intervals and analyzes its restitution, including computing a restitution slope being a rate of change of the restitution parameter with respect to change in the cardiac interval. In various embodiments, the system uses the restitution slope to provide for adaptive control of neurostimulation. In various embodiments, one or more cardiac parameters such as action potential duration (APD), conduction velocity (CV), QT interval (QT), and/or T-wave morphology (TM) parameter are measured and analyzed for restitution of each parameter, which is then used to control the delivery of the neurostimulation.