| 摘要 |
932,363. Electrocardiographs. AMALGAMATED DENTAL CO. Ltd. May 18, 1962 [March 20, 1961], No. 10107/61. Class 81 (2). An apparatus for use with an electrocardiograph provides audible signals indicative of the peaks of the signals representing the heart beat rate. The equipment is connected through a balanced transformer 1 to the vertical deflection plates of the electrocardiograph and the output of the transformer is passed through an amplifying transistor 5 to a mono-stable flipflop circuit comprising two transistor 6, 7. The signal voltage required to cause the transistors to pass current is determined by a potentiometer 18 and this is adjusted so that only the peaks of the signals are effective to trigger the flip-flop and cause transistor 7 to become conductive. Such a signal causes transistor 13 in turn to become conductive and this oscillates through feedback transformer 14 and produces an audible signal in a loudspeaker 17. |
