| 摘要 |
PURPOSE:To enable to give the driver warning against dozing off at the wheel, etc., by means of generating the original heartbeat fluctuation waveform from the intervals of the heartbeats, by further generating a relative displacement heartbeat fluctuation waveform through finding the difference of intervals between the adjacent waveforms, and by estimating the frequency components. CONSTITUTION:Output signals such as the R wave, etc., of electrocardiogram are amplified by a differential-mode input amplifier at the alternating current amplifier section 24, of which only the R waves are selectively picked up by a band-pass filter 2. After being amplified by an amplifier 3, the R waves are sample held by a sample holding circuit 4, converted to digital signals by an A/D converter 5 and taken into a CPU 10 through a data bus 7. The CPU 10 reads the R waveform data and detects the R wave time. Based on the R wave time the CPU calculates the difference between the adjoining RRIs such as RRI1-RRIn and generates a waveform. Calculation results are sotred in a RAM 8 translating RRIn-RRI (n-1) as RRI'n. CPU 10 is previously set up with parameters covering from the beginning point of the analysis to the ending point, data RRI' are read into the CPU and the calculation of spectrum is performed. |
