Abstract: An apparatus and method for Cardiac Resuscitation of an arrested heart, for Percutaneous Internal Direct Epicardial Defibrillation, Cardioversion and Pacing with electrodes placeable directly into the chest cavity onto the epicardium via a device entering the chest in a specific area of the anterior chest wall via blunt dissection rapidly creating a passage of negligible size in the chest wall for the introduction of the electrodes, without the need for thoracotomy or for sternotomy and without requiring the use of sharp surgical instruments and without causing pneumothorax. Due to its rapidity of implementation, its safety and simplicity of application, the device can be used by Paramedics in the field at the scene of a cardiac arrest, where the resuscitation efforts are more likely to succeed, for internal direct epicardial defibrillation, cardioversion and pacing.

Abstract: An implantable pacemaker accurately senses the regular atrial rhythm even though some portions of the atrial rhythm, e.g., every other P-wave, may potentially be masked or hidden within the ventricular absolute refractory period. Such sensing includes unmasking or uncovering any hidden P-waves, thereby allowing an accurate atrial rate to be determined. The hidden P-waves are uncovered by: changing the PV delay, not tracking a sensed P-wave, or comparing the incoming morphology of the atrial channel signal to a prior stored baseline morphology signal. The accurate atrial rate, once determined, allows the presence of an atrial tachycardia to be reliably confirmed, thereby enabling appropriate atrial anti-tachycardia pacing (ATP) procedures to be invoked, or mode switching from an atrial synchronous mode of operation, e.g., DDD, to a non-atrial synchronous mode, e.g., VVIR.

Abstract: A method and apparatus for stimulating evoked potentials in a human subject maintains the common mode voltage at the stimulation electrodes substantially constant both before and during application of a stimulus pulse of constant current. A pair of resistors are connected between the stimulation electrodes and are joined at a reference node. One stimulation electrode (e.g., the anode) is connected through a field effect transistor to the power supply voltage and the other electrode (e.g., the cathode) is connected to the supply common return through a transistor which, when turned on, is controlled to conduct a constant current. The voltage at the reference node is supplied to the gate of a second field effect transistor which has its source clamped to a reference voltage. The voltage at the drain of the second field effect transistor is suppled back to the gate of the first field effect transistor.

Abstract: The apparatus incorporates an ultrasonic wave-generating transducer for providing ultrasonic waves, a first and a second ultrasound window, a first guiding device for guiding the ultrasonic waves to the first window, an ultrasonic receiving transducer for transforming an acoustic image field received from the second window into electrical signals, and a second guiding device for guiding ultrasound transmitted through the second window to the receiving transducer. The ultrasound windows define an examination gap for insonifying a patient's organ positioned therein. The apparatus further incorporates a curved mirror for focusing the acoustic image field received from the gap onto the receiving transducer. The mirror is attached to a rocking device. Thus, the curved mirror is also used for scanning or sweeping the acoustic image field across the receiving transducer. Thus, an image of the object plane under examination is obtained.