Abstract: A flow control valve is described comprised of first and second rigid members and a resilient single or multi stage valve element disposed between the rigid members. A fluid flow path is defined through the rigid members and through or around the valve element to provide a continuous flow path through the valve. The rigid members are movable relative to each other between a first position and a second position. The valve element is sufficiently compressed by the rigid members when they are in the first position so as to close the flow path through or around the valve element. The valve element is sufficiently relaxed when the rigid members are in the second position to allow fluid flow through the flow path through or around the valve element.

Abstract: Methods and apparatus are disclosed for use in procedures related to the electrophysiology of the heart, such as identifying or evaluating the electrical activity of the heart, diagnosing and/or treating conditions associated with the electrophysiology of the heart. An apparatus having thermocouple elements of different electromotive potential conductively connected at a junction is introduced into the interior of the heart and a section of heart tissue is contacted with the junction. An electrical current is passed through the thermocouple elements to reduce the temperature of the junction in accordance with the Peltier effect and thereby cool the contacted heart tissue. The effect of the cooling may be monitored and, if desired, the section of heart tissue may be treated.