GB1447394A - Heart pump - Google Patents

Abstract

1447394 Artificial heart pumps PACIFIC ROLLER DIE CO Inc 28 Nov 1973 [6 Dec 1972] 55251/73 Heading F1A [Also in Division A5] An implantable heart pump comprising a housing 17, 18, at least one chamber 100 or 101 for blood, partially defined by a portion of said housing, an inlet 23, 25 and an outlet 24, 26 for each said chamber, and a pumping element associated with each chamber and defining a portion thereof, the pump further characterized in that the reciprocating displacement of the pumping element relative to said portion of said housing is variable and dependent on the volume and pressure of blood at each said inlet. As shown in Fig. 1, a blood-pumping unit 11, which is implantable, is connected to an external air-driven assembly 12 incorporating a spool-type valve assembly 117 by a multiple channel conduit 13, a source 16 of compressed air being connected via a pressure regulator 15 to the assembly 12. At the end of a diastolic phase when the chambers 100, 101 are filled with blood and air-cylinders 55, 59 are fully retracted, air from a line 14 flows into a passage 94 communicating with areas behind pistons 42, 43 and passes through 110, 132, 152 back to valve assembly 117 where it initiates shifting of main spool 122 towards left of Fig. 9. When the main spool has shifted to a position so that the supply line 14 is in communication with line 131, the directions of flow of air (full-line arrows) are reversed and air flows through 105, 93 to the areas in front of pistons 42, 43 thereby initiating extension of the air-cylinders 55, 59 and hollow pistons 67, 85 (beginning of systolic phase). At the end of the systolic phase, Fig. 10 (not shown), the air entering 93 flows through 104, 110, 111, 132 and 154 to the front of piston 123 and thereby initiating the reverse displacement of the main spool 122. As the main spool 122 shifts further, it opens supply line 14 to passage 145 communicating with 134, 94, 99 and 104 and the areas behind the pistons 42, 43 to initiate the retraction of the air-cylinders 55, 59. Retraction of hollow pistons 67, 85 is controlled by the pressure differential between the venous blood pressure and the air-pressure in the space defined by 55, 42, the latter pressure being the same as the pressure behind the piston 42. The other embodiments include a heart pump with a single pumping unit Figs. 11 A, B, 17, 18 (not shown) as an assistdevice, a double-chamber heart pump with a dualpressure valve assembly (201), Fig. 12 (not shown) wherein the pressure applied to the air-cylinders 55, 59 during the diastolic phase is maintained low relative to the pressure during the systolic phase thereby extending the duration of the former phase, a double chamber heart pump utilizing three different working pressures, Fig. 23 (not shown) wherein the extension of the aircylinder 55 and piston 67 is caused earlier than that of the cylinder 59 and piston 85. A device for recording the rate of heart beats is also disclosed.