PULSE WAVEFORM DETECTOR

• Main Authors: MIZUNO TETSUYA, MATSUDA MORIHIRO, YAMADA MICHIHARU, ITO HIROSHI, MAEDA MITSUTOSHI, INAGAKI MASARU, TERADA SHIGEO, WAKAYAMA SATOSHI
• Format: Patent
• Language: English
• Published: 27.07.1999
• Edition: 6
• Subjects: DIAGNOSIS; HUMAN NECESSITIES; HYGIENE; IDENTIFICATION; MEDICAL OR VETERINARY SCIENCE; SURGERY

PROBLEM TO BE SOLVED: To provide a pulse waveform detector capable of stably obtaining pulse signals at the time of performing measurement without fixing a human body. SOLUTION: An LED 2 irradiates a part of the human body with light and the LED 3 irradiates a part of the human body with the light of a wavelength different from the one of the LED 2. A PD 7 receives reflected light from the human body for the light of the LED 2 and converts it to electric signals corresponding to received light intensity and the PD 8 receives the reflected light from the human body for the light of the LED 3 and converts it to the electric signals corresponding to the received light intensity. A differential amplifier 15 inputs the electric signals by the PD 7 and the electric signals by the PD 8, takes the difference of both signals, removes body movement signals generated by the movement of the human and extracts only the pulse signals. The PD 16 detects the emitted light intensity of the LED 2 and the PD 17 detects the emitted light intensity of the LED 3. A computer 20 controls the emitted light intensity so as to turn the ratio of the emitted light intensity of the LED 2 and the emitted light intensity of the LED 3 to a predetermined fixed value.