The present invention provides method, apparatus and system for physiological signal acquisition by utilizing portable device. According to an aspect of the present invention, it proposes a system for deriving a physiological signal of a subject, comprising: an apparatus for emitting an optical signal representing a physiological signal of a subject, comprising: a physiological sensor placed on the subject, for acquiring an electrical signal representing the physiological signal of the subject a light source for emitting the optical signal and a modulator for modulating the intensity of the optical signal in accordance with the amplitude of the electrical signal. The system further comprises a portable device, comprising: a camera for acquiring an optical image sequence of the optical signal emitted from the apparatus and a processor for deriving the physiological signal from the optical image sequence of the optical signal. The novel method is featured in low-cost, ease-of-use and portability. These features aim to increase patients awareness of their own risks of diseases, such as arteriosclerosis, and help them improve their compliance. In addition, this device provides desired advantages of instant data assessment functionality, which is of high value for patients caring at home, instant consult service from medical professionals, and convenient data communication and data storing.La présente invention concerne un procédé, un appareil et un système pour une acquisition de signal physiologique à laide dun dispositif portable. Selon un aspect de la présente invention, un système pour obtenir un signal physiologique dun sujet comprend : un appareil pour émettre un signal optique représentant un signal physiologique dun sujet, comprenant : un capteur physiologique placé sur le sujet pour acquérir un signal électrique représentant le signal physiologique du sujet une source de lumière pour émettre le signal optique et un modulateur pour moduler lintensité du signal
