摘要:
A system and method for managing and inhibiting cardiac remodeling in MI patients. Bi-ventricular stimulation is constantly provided with and without sensing to encourage normal pumping of the heart on a consistent basis. Pulses are administered using an anodal pulse followed by a cathodal pulse to stimulate cardiac muscle contraction. Stem cells are administered to MI areas to encourage regeneration of cardiac tissue in the damaged area. Stimulation may be provided to both healthy and compromised cardiac tissue.
摘要:
A system and method for treating ischemic heart disease by increasing heart efficiency. By application of an anodal pulse at or above threshold, the efficiency of the heart is improved by increasing the resting membrane potential of the myocardial cells, increasing the size of the anodal virtual stimulatory electrode, or reducing the ventricular stretching during filling of the ventricle.
摘要:
Protocols for antitachycardial pacing including biphasic stimulation administered at, or just above, the diastolic depolarization threshold potential; biphasic or conventional stimulation initiated at, or just above, the diastolic depolarization threshold potential, reduced, upon capture, to below threshold; and biphasic or conventional stimulation administered at a level set just below the diastolic depolarization threshold potential. These protocols result in reliable cardiac capture with a lower stimulation level, thereby causing less damage to the heart, extending battery life, causing less pain to the patient and having greater therapeutic effectiveness. In those protocols using biphasic cardiac pacing, a first and second stimulation phase is administered. The first stimulation phase has a predefined polarity, amplitude and duration. The second stimulation phase also has a predefined polarity, amplitude and duration. The two phases are applied sequentially. Contrary to current thought, anodal stimulation is first applied and followed by cathodal stimulation. In this fashion, pulse conduction through the cardiac muscle is improved together with the increase in contractility.
摘要:
Atrial sensing and stimulation as intervention for atrial fibrillation. The present invention relates to a method of atrial defibrillation using an implanted electronic stimulator. In a variety of protocols varying combinations of conventional and biphasic stimulation are applied at threshold and sub-threshold levels. In a preferred embodiment, the implantable electronic stimulator of the present invention includes multiple electrodes having stimulating and sensing capabilities. The small size of these electrodes allows for intravenous insertion into the patient.
摘要:
An anti-reentry apparatus and method for reverting ventricular arrhythmias. Biphasic stimulation is applied at multiple ventricular sites to revert arrhythmias caused by reentry, particularly multiple random reentry. In the preferred embodiment, the first phase of biphasic stimulation is anodal, and is at a maximum subthreshold amplitude. The anodal phase preconditions the myocardium to accept the second phase (cathodal) such that less electrical energy is required to reach the threshold amplitude to produce depolarization. The anodal phase stimulation may have a shape over time that is square wave, ramped, or a series of short square wave pulses. Multiple electrodes located at multiple ventricular sites may be stimulated simultaneously, or they may be sequentially stimulated over time in a manner mimicking the normal progress pattern of cardiac depolarization. The multiple ventricular electrodes may stimulate from internal or external surfaces. One or both ventricles may receive biphasic stimulation from multiple electrodes. The invention also may be practiced with respect to atria.
摘要:
To prevent electrical conductors which connect a patient-implanted high energy electrode to a pulse generator from short circuiting at locations where a tubular lead body in which the conductors are contained encounters a sharp bend, the lead body has an oval cross section and the conductors are disposed on the major axis of the oval. This arrangement promotes preferential bending of the lead body about the major axis, rather than the minor axis of the oval body, tending to maintain the spacing between the conductors and thereby minimizing short circuits. The lead body can be resiliently compressed, however, for insertion into a patient in a cylindrical catheter of circular cross section.
摘要:
A method of determining a defibrillation threshold for an implantable cardiac defibrillator, based upon determining the 50% probability of reaching the upper limit of vulnerability. The 50% probability of reaching the upper limit of vulnerability at the mid-upslope of the T-wave is found to closely approximate the 50% probability of successful defibrillation used to set the shock energy level of the defibrillator. A delayed up-down algorithm is used to determine the shock strength associated with 50% probability of reaching the upper limit of vulnerability.
摘要:
A method and apparatus for cardioverter/pacemaking utilizing neurosensing. The invention utilizes the baroreceptor nerves found in the body. A neurosense electrode is placed around the carotid sinus nerve and a sense amplifier with automatic gain control and an integral band pass filter provides a frequency-to-voltage converter with a frequency proportional to the stimulus received from the carotid sinus nerve. The voltage from the frequency-to-voltage converter is sent to the analog-to-digital converter where it is bussed to a microprocessor. The microprocessor then drives a pacing lead and in the presence of a cardiac signal the microprocessor provides a cardioverting signal to the cardioverting lead if ventricular arrhythmia is sensed. The microprocessor also drives a telemetry coil and receives ventricular information from the ventricular sensing lead.
摘要:
A method of treating hemodynamic disfunction by simultaneously pacing both ventricles of a heart. At least one ECG amplifier is arranged to separately detect contraction of each ventricle and a stimulator is then activated for issuing stimulating pulses to both ventricles in a manner to assure simultaneous contraction of both ventricles, thereby to assure hemodynamic efficiency. A first ventricle is stimulated simultaneously with contraction of a second ventricle when the first fails to properly contract. Further, both ventricles are stimulated after lapse of a predetermined A-V escape interval. One of a pair of electrodes, connected in series, is placed through the superior vena cava into the right ventricle and a second is placed in the coronary sinus about the left ventricle. Each electrode performs both pacing and sensing functions. The pacer is particularly suitable for treating bundle branch blocks or slow conduction in a portion of the ventricles.
摘要:
A pad for electrically stimulated wound healing, including a pad configured to be placed on a wound, at least one anode disposed on the pad to contact the wound, and at least one cathode disposed on the pad to contact the wound, the at least one cathode being disposed separately from the at least on anode. The pad wherein the at least one anode and the at least one cathode in contact with the wound provide a flow of electrical current in an intended direction through the wound based on the separate locations of the at least one anode and the at least one cathode.