GB1040753A - Resuscitation apparatus - Google Patents

Abstract

1, 040, 753. Resuscitation massage apparatus. APPLIED CONTROLS Ltd. June 14, 1963 [June 22, 1962], No. 24156/62. Headings A5R and A5T. A cardiac massage device comprises a pressure applicator including a piston and cylinder 6, bellows or capsule (not shown) connected to a source of pressure fluid through a valve 8<SP>1</SP>, the valve being operated under the control of a timing mechanism including interconnected relay valves 11, 12 and associated pilot valves 13, 14, 15 and 16 to cyclically vary the pressure at heartbeat frequency. A pressure pad 7 is reciprocated at heartbeat frequency to repeatedly apply mechanical pressure to the chest to effect massage of the heart. The pad is connected to a piston reciprocated in a cylinder 6 which receives pressure fluid supplied through a main pressure regulator 18, an adjustable secondary pressure regulator 19 and a control valve 8. Each relay valve 11, 12 is controlled by two pilot valves 13, 14, 15, 16 each including a needle valve which determines the frequency of its associated relay valve. A pilot fluid pressure supply to the valves of the timing mechanism is received through the main pressure regulator and a pilot fluid pressure regulator 17. One relay valve 11 is set to operate at heartbeat frequency and the second relay valve 12 operates at respiration frequency. The arrangement of the valves is such that for one half cycle of each cycle of the second relay valve, with the shut-off valve 21 in the pilot fluid supply to the second relay valve open the first relay valve is inoperative to enable the patient to breathe normally and for the other half cycle of the second relay valve the first relay valve operates normally. Thus the pressure pulses applied to the pad 7 are interrupted periodically at respiration frequency. When the shutoff valve 26 is closed both relay valves are inoperative. Supply of gas at respiration frequency to a face mask or intratracheal tube for assisting the breathing of the patient may be derived from a bleed connection in a line between the second relay valve and one of its pilot valves. The components of the device are mounted on a beam 4 (Fig. 1 not shown) adjustably supported over the patient by uprights 2, 3 interconnected by a base plate 1 placed beneath the patient.