What is the principle of polygraph?

The working principle of polygraph is to judge whether to lie by measuring the changes of pulse, respiration and skin resistance.

When people lie, there will be some changes in their physiological consciousness, some of which can be observed by the naked eye, such as scratching their ears and cheeks, shaking their legs and feet and a series of unnatural human movements. There are some physiological changes that are not easy to detect.

Such as: abnormal respiratory frequency and blood volume, respiratory depression and breath holding; Pulse is accelerated, blood pressure is increased, blood volume is increased and composition changes, resulting in obvious pallor or redness of face and neck skin.

Psychological testing technology

The function of the upper computer is to convert the analog signals collected by the sensor into digital signals, which are stored and analyzed in the computer. It is precisely the deceleration technology, which is a psychological test technology.

The so-called psychological test is to combine Nappe technology with bioelectronics and psychology, and complete the analysis process of human psychology by computer means. According to psychological theory, everyone has experienced a certain event and left an inevitable mark without exception.

Whenever the details of some cases are mentioned in the scene, the crimes of this brand will be exposed through various biological reactions, such as breathing due to shock, pulse and skin. After recording the test instrument, record this subtle reaction and form or inform or involve conclusions.