| 摘要 |
<p>1,095,361. Apparatus for assisting the heart. UNITED AIRCRAFT CORPORATION Feb. 19, 1965 [Feb. 26, 1964; Oct. 27, 1964], No. 7396/65. Heading A5R. [Also in Divisions F1 and G3] Apparatus used to assist the action of a defective heart by alternatively withdrawing and pumping blood through catheters communicating with the arteries, comprises a a hydraulically actuated pump (Figure 1) whose pumping cycle is controlled by a computing system responsive to the patient's heart action. The apparatus monitors the cardiac waveform and computes new pumping rates as the heart rate changes so that within set safety limits the volume of blood pumped is constant. The apparatus accommodates different numbers of catheters. As shown, the pump comprises a cylinder containing a working chamber 18 and an actuating chamber 19 separated by a free moving piston 17 and flexible diaphragms 20, 21. The piston is surrounded by saline solution introduced through a valve 28. The hydraulic actuator (Figure 3) for the pump is controlled by servo coils (147, 154) forming part of the control circuit (Figure 4, not shown) monitoring the heart, the coils moving valves in an assembly 91 so that fluid is directed through passages 96, 97 to either side of the actuator piston 92. A plunger 93 is connected to the piston 92 and moves fluid through a coupling 94 to actuate the pump. The actuator includes a transducer potentiometer 118 which feeds back to the control system the position of the pump and provides for error correction and reversing the direction of the pump. The apparatus includes a manual control and also an inlet 62 in the pump for adding extra fluids to the blood stream. If the patient's heart action is weak a pacemaker 132 (Figure 4, not shown) may be used to actuate the pumping cycle. Provision is also made for the pump to operate on only a selected fraction of the beats of the patient's heart.</p> |
