Non-invasive psychological signal measurement with photoelectric sensor

A medical device for measuring psychological signals includes a substrate, a light emitting unit, a photoelectric sensor and a microprocessor. The substrate includes a surface that is divided into an emission area and a reception area. The light emitting unit is arranged in the emission area and includes a plurality of light emitting sections. Each of the plurality of light emitting sections includes at least one micro light-emitting diode. The plurality of light emitting sections is capable of irradiating a plurality of lights with different wavelengths on a predetermined location. The photoelectric sensor is arranged in the reception area. The photoelectric sensor is capable of detecting a plurality of reflected lights from the predetermined location and generating an electrical signal accordingly. The microprocessor is electrically connected to the photoelectric sensor and is capable of receiving the electrical signal and converting the electrical signal into a waveform signal. Thus, the detection accuracy can be improved.