Patent GB-715612-A (GB)
Title: Apparatus for the circulation and gasification of a liquid such as blood
IPC: A61M60/835
Filed: 1951-01-25
Abstract: 715,612. Surgical pumping apparatus. THOMAS, A., and BEAUDOUIN, P. Jan. 25, 1951 [Feb. 3, 1950], No. 1916/51. Class 81(2) Apparatus for producing and gasifying a pulsating flow of liquid such as blood comprises a compartment for injecting bubbles of gas into a liquid, a defrothing device for periodically directing air under pressure towards the froth developing at the surface of the liquid, means for effecting entry of liquid into the compartment and a pump for drawing gas - treated liquid from the compartment and delivering it to a utilization circuit and transmission and control members including means for driving the pump. The gasification compartment comprises a cylindrical chamber 17 surmounted by a wider cylindrical chamber 16 into which blood is drawn from an artificial vein 18 through an orifice 19. A subatmospheric pressure is maintained in the wider chamber 16 by a suction pump 93, Fig. 2. connected to the latter chamber through a duct 95 and a filter 30. Oxygen is supplied to a conduit 23 provided with a filter 25 and arranged along the axis of the two chambers 16, 17 and is discharged at the lower end of the narrower chamber 17 through calibrated needles 21. The blood moves downwardly through the narrow chamber 17 as it is oxygenated and is extracted through an orifice 37 by an artificial heart 1. The artificial heart 1 comprises a housing 2 containing a corrugated tube 3 connected to one end of the housing 2 and to a piston 5 which is caused to reciprocate in the housing 2. On its compression stroke the piston 5 drives blood into the housing 10 of an auxiliary pump which is similar in construction to the artificial heart 1. A piston 14 of the auxiliary pump forces blood through a filter 40 constituted by a grid of platinum wires, silk or other suitable material which may be wound up like a photographic film when it is necessary to expose fresh surfaces to the blood flow. After passing through the filter 40 the blood flows into the artificial artery 11. Blood leaving the auxiliary pump may if desired be diverted by way of a branch duct 41 and a threeway cock 42 to the artificial vein 18 and returned to the gasification compartment. A duct 47 connected with the three-way cock 42 allows the introduction of a supplementary liquid to the gasification compartment. A flexible tube in the duct 41 allows if desired the creation of an annexed circuit for the irrigation of the outer surface of organs operated upon. A pump 101 is connected with apertures 27 in the top of the wider chamber 16 for producing an intermittent increased pressure for defrothing. The piston 5 is provided with connecting rod 6 which is attached to levers 53, Figs. 1 and 2. A lever 58 is pivoted to the levers 53. The upper end of the lever 58 is secured to a belt 67 which passes round a drum 68 rotated by a motor 71 so that the lever 58 is drawn in such a direction that suction is produced in the artificial heart. A cam 76 rotated by a motor 77 releases the belt 67 from the drum 68 periodically so that the levers 58, 53 resume their initial positions under the acion of a spring 59 and the piston 5 performs a compression stroke. A corrugated tube 80 fixed to the levers 53 is connected with the atmosphere through a oneway inlet valve 83 and acts as a compensating device for maintaining constant the pressure applied to the blood through the piston 5. The tension of spring 59 and the speeds of the motors 71, 77 may be adjusted to give desired characteristics to the blood flow. The piston 14 of the auxiliary pump is caused to perform a suction stroke as blood is forced into the housing 10 from the artificial heart 1. As the artificial heart is receiving blood from the gasification compartment, the piston 14 is returned to its initial position by the action of an adjustable spring 84 connected to a lever 85 secured to a connecting rod 15 of the piston 14. The defrothing pump 101 is actuated intermittently by a pivoted lever 103 which is rocked against the action of a spring 104 by a rising and falling plate 106 connected intermittently by studs 108, 110 with a shaft 109 rotated by the motor 71. The pump 93 which produces a subatmospheric pressure within the gasification compartment is operated by rocking a pivoted lever 96 connected with the plate 106 by a stud. In an alternative form of the apparatus (not shown)' the narrower part of the gasification compartment is replaced by coils through which blood passes in the same direction as oxygen introduced into the coils.