A newly devised servo-controlled pump system successfully clamped end-diastolic and end-systolic volumes in 15 isolated canine hearts, enabling precise analysis of instantaneous pressure-volume relations.
We devised a servo-controlled pump system which can clamp both end-diastolic and end-systolic volumes of the left ventricle of an excised, supported canine heart at desirable values in the face of changing patterns of ejection and filling. The system consists of a Bellofram cylinder and a powerful electromagnetic shaker which is driven by a position servo circuit. A water-filled balloon placed in the ventricle was connected to the water housing of the cylinder. As the ECG triggered the system, a fixed amount of water reciprocated between the heart and the cylinder in a programmed manner. The onset, duration, and speed of ejection and those of filling can be programmed separately. The performance of this pump system was tested in experiments on 15 cross-circulated hearts and proved satisfactory for precise analysis of the instantaneous pressure-volume relation in the ventricle.
Suga et al. (Thu,) conducted a other in Isolated canine heart model (n=15). Servo-controlled pump system (ventricular volume clamper) was evaluated on Performance of the pump system for precise analysis of the instantaneous pressure-volume relation. A newly devised servo-controlled pump system successfully clamped end-diastolic and end-systolic volumes in 15 isolated canine hearts, enabling precise analysis of instantaneous pressure-volume relations.
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