A METHOD FOR CALCULATING THE NUMBER OF THE PULSE AND A PORTABLE DEVICE FOR MEASURING THE NUMBER OF THE PULSE

摘要

A method for calculating a pulse frequency and a portable pulse measuring instrument therefor are provided to improve reliability by generating an emergency signal only when the pulse frequency is out of a predetermined range. A sensor(410) senses a pulse signal of a user at a predetermined time. An A/D converter(440) converts the pulse signal into a digital signal. A microprocessor(450) includes a first measuring device, a second measuring device, a first comparator, a controller and a pulse frequency calculator. The first measuring device measures the amplitude change rate of the digital signal. The second measuring device measures the wavelength change rate of the digital signal. The first comparator outputs a first logic signal according to the determination result by determining whether the amplitude change rate or wavelength change rate is within the first predetermined range. The controller generates the first control signal according to the first logic signal. The pulse frequency calculator calculates the pulse frequency from a digital signal in response to the first control signal.