GB1520408A - Cardiographic method - Google Patents

Abstract

1520408 Cardiography D J ACKROYD 23 June 1975 [21 June 1974] 59331/73 Heading A5K A method of recording heartbeat comprises applying, to the region of the diaphragm of a patient I, a fluid-filled bag 2 having flexible walls, and detecting pulsations generated in the fluid by the pulse of the patient by means of a recording element responsive to the said pulsations and a progressively moving recording medium, the recording element recording on said medium a trace corresponding to the said pulsations. The pulsations may be transmitted to a further smaller fluid-filled bag 5 in communication with bag 2 and having flexible walls. The pulsations in bag 5 cause the free end of a lever 7, which is pivoted at 8 and in contact with bag 5, to move, the movements of the lever being recorded. The free end of the lever may carry a stylus which traces out a graph on a moving sheet of paper, or the paper may be impregnated with ink which is drawn to the paper surface by a metal nib on the lever. Alternatively the recording may be made by a light beam which is deflected from a mirror moving with said pulsations, onto photographic paper. Further the lever may take the form of a fibre optic element through which light is directed. In further embodiments, the recording is made by cooperation of a magnetic pointer with carbon-covered paper, or a device employing static electricity may be used. The bag 5 may be replaced by a bellows or by a dome of rubber mounted on surface 6 and communicating through tube 4 with bag 2, or by a piston and cylinder arrangement. Bags 2, 5 may be connected by one or more diaphragms or pistons instead of through tube 4. A band 3 retains the bag 2 in position and may be integral therewith. Bags 2, 5 may be of rubber or plastics. Bag 2 may have a rigid convex upper surface, and a soft flexible lower bodycontacting surface. All the components may be stored in a box of adjustable height, the lever, which may be telescopic or capable of being coiled, being detachably mounted on a hinged flap of the box.