| 摘要 |
PURPOSE: To provide a circuit which faithfully records the max. amplitude of acute pace maker waveforms in an electrocardiographic waveform recorder without changing present hardware. CONSTITUTION: The output of a differential amplifier 1 for amplifying the electrocardiogram signals detected from electrodes mounted on a testee is inputted via a main amplifier 2 to an A/D converter 4 and is subjected to sampling at which a sampling rate attains >=2 times the frequency possessed by the pace maker waveforms, then to A/D conversion. The value thereof is stored as data by every 250μs in a memory 6 by interruption processing. The transfer speed of the conventional recorder is about 1ms and, therefore, the samples are extracted at every 1ms from the data of the samples and are written into the recording section in the case of recording the ordinary waveforms. The max. amplitude is detected from the data before and after the detection point and the data to be transferred at every 1ms is changed to its peak data and is transferred to the recording section when the pace maker is detected by a pace maker detecting circuit. |
