| 摘要 |
<p>PURPOSE:To enable highly accurate measurement of a blood pressure with limited erroneous recognition of a K sound by arranging a means to alter a threshold level for judging a Korotkov sound (K sound) in response to a size of a blood current sound detected in a specified time zone before the generation of the Korothkov sound. CONSTITUTION:A K sound detecting section 10 is made up of a microphone 11, an amplifier 12, a bandpass filter 13 and an A/D converter and a pressure of a pressure cuff and bag/pulse wave detecting section 20 is made up of a pressure sensor 21, an amplifier 22 and an A/D converter 23. A control section 30 is equipped with a CPU 31 for computation and control connected with a bus and an ROM 32 for storing a control program. At a first beat of a pulse wave, maximum and minimum values of the K sound signal are detected within a gate 80a with a threshold level below T1 and following a second beat thereof, a K sound signal 81a with a threshold level exceeding Ts determined of a gate 80b with a threshold level of above T2 is recognizd as K sound. The threshold level Ts is a criterion level of the K sound for recognizing a maximum blood pressure.</p> |
