ELECTRONIC HEMOMANOMETER

PURPOSE:To form the sampling pulse synchronous to the peak part of a pulse wave signal with high accuracy, by separately detecting the peak parts of a pulse wave signal by a comparator and a differentiation circuit to apply AND operation thereto. CONSTITUTION:After a signal containing both of the pulse wave data and pressure data of blood pressure is obtained by a pressure sensor 1, said signal is amplified by a differential amplifier 2 to output a signal (a). This signal (a) is converted to digital quantity by a A/D converter 4 to be successively stored. Further, said signal becomes a pulse wave signal (b) by removing the DC component thereof through a low-pass filter 6. The pulse wave signal (b) inputted to a comparator 9 is compared with threshold value voltage VTH1 becoming reference and the pulse corresponding to the peak part of the pulse wave signal (b) is outputted from the comparator 9. The pulse wave signal (b) inputted to a differentiation circuit 7 is differentiated and a signal (c) having the peak value of the pulse wave signal (b) as a cross point is outputted from the differentiation circuit 7 and the AND of the signal (c) and a pulse signal (d) is taken by an NAND circuit 10 performing AND operation to output a pulse having a fine pulse width.