| 摘要 |
<p>PROBLEM TO BE SOLVED: To correctly measure the pulse rate by causing a light emitting element to emit light, receiving the changed light transmitted through a part of the human body and distrubance light by a first photo detecting element, and receiving the light from the outside which has been transmitted through a part of the human body by a second photo detecting element to make correction on a signal based on the changed light. SOLUTION: Light from a light emitting element is transmitted through a earlobe and applied to a reflector so that the reflected light enters a photo detecting element 5, and a second photo detecting element 6 is disposed in such a manner that the reflected light does not enter the element 6. Whereupon, a mixing signal of a pulse signal S and noise N of external light enters the photo detecting element 5 and only the noise N of external light enters the second photo detecting element 6, so that they are amplified 11, 12 to be standardized, a mixing signal is sent to a delay circuit 13, and noise N is sent to a timer 16 and a comparator 31. A mixing signal from the delay circuit 13 is sent to a calculating part 15 through a switch 14, the noise N is compared with a reference value of a register 30 by the comparator 31, and if the noise is above a fixed value, a cut-off control signal is sent to an electronic switch 14.</p> |
