Abstract: An apparatus and method for treating post-defibrillation electromechanical dissociation (“EMD”). A first embodiment comprises an implantable defibrillator, which may include cardioversion and pacemaker capabilities, which has the capability of detecting and treating post defibrillation EMD. The stimulator/defibrillator has one or more leads with electrodes. At least one electrode for defibrillation may be an endocardial or epicardial electrode or other suitable defibrillation electrode. A sense circuit senses the electrical condition of the heart of the patient. A hemodynamic sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator/defibrillator detects ventricular tachyarrhythmia including fibrillation and terminates ventricular tachyarrhythmia. After termination of the ventricular tachyarrhythmia, the stimulator/defibrillator can detect the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life.

Abstract: An apparatus and method for treating post-defibrillation electromechanical dissociation (“EMD”). A first embodiment comprises an implantable defibrillator, which may include cardioversion and pacemaker capabilities, which has the capability of detecting and treating post defibrillation EMD. The stimulator/defibrillator has one or more leads with electrodes. At least one electrode for defibrillation may be an endocardial or epicardial electrode or other suitable defibrillation electrode. A sense circuit senses the electrical condition of the heart of the patient. A hemodynamic sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator/defibrillator detects ventricular tachyarrhythmia including fibrillation and terminates ventricular tachyarrhythmia. After termination of the ventricular tachyarrhythmia, the stimulator/defibrillator can detect the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life.

Abstract: An apparatus and method for treating post-defibrillation electromechanical dissociation (“EMD”). A first embodiment comprises an implantable defibrillator, which may include cardioversion and pacemaker capabilities, which has the capability of detecting and treating post defibrillation EMD. The stimulator/defibrillator has one or more leads with electrodes. At least one electrode for defibrillation may be an endocardial or epicardial electrode or other suitable defibrillation electrode. A sense circuit senses the electrical condition of the heart of the patient. A hemodynamic sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator/defibrillator detects ventricular tachyarrhythmia including fibrillation and terminates ventricular tachyarrhythmia. After termination of the ventricular tachyarrhythmia, the stimulator/defibrillator can detect the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life.

Abstract: A cardiac pacemaker includes circuitry which receives a raw impedance signal from the sensor leads of the pacemaker, derives data from the impedance signal that is descriptive of the impedance signal over an entire (or a large part of the) cardiac cycle, develops first order parameters which define that cycle, and provides these parameters to a microprocessor for control of the pacing signal. These parameters may also be used to determine other information about the functioning of the pacemaker. The present invention may also be applied to the determination of tachycardia of an intrinsically paced heart, as well as other applications.

Abstract: A method and apparatus for classifying and treating tachyarrhythmias. A cardiac stimulator includes an algorithm that uses dual chamber sensing to determine the type of tachyarrhythmia detected. If the tachyarrhythmia is of a type that responds well to ventricular therapy, such as a tachyarrhythmia originating in the ventricle rather than the atrium, the tachyarrhythmia is grouped into a treatable category. Accordingly, the cardiac stimulator applies therapy, or therapies, to the ventricle to remedy the ventricular tachyarrhythmia.

Abstract: A hydraulic actuator is described which has a layered structure and a flattened piston assembly to enhance production speed and reduce the costs of assembly. A system for performing surgery is also described incorporating the hydraulic actuator, having a sensory glove, a computer, and a slender robot manipulator which can be inserted into the human body through a small incision. The robot manipulator has a layered structure with integrated hydraulic pistons. This design allows the use of a novel manufacturing process in which all of the parts are formed from laminated sheets of material. Seals are formed to prevent leakage of hydraulic fluid by introducing castable rubber into enclosed channels in the structure.

Abstract: A method and apparatus for monitoring balanced biphasic current pulses used for measuring impedance in cardiac stimulators involves detecting imbalances between the pulses of opposite polarity. Such imbalances are potentially harmful to cardiac stimulator users. By converting the two different pulse phases into potentials, a determination can be made as to whether adequately balanced pulses are being generated. If an imbalance is detected, corrective action can be taken quickly enough to avoid harmful effects to the stimulator user.