Based on physiology parameters to design lie detector

Objective—Multi-parameters are employed to design a device of lie detector, including Skin Temperature, electrocardiogram (ECG), Pressure of End-Tidal Carbon Dioxide (PETCO2), Oxygen Saturation and other physiological parameters. Methods: Skin Temperature is measured by temperature sensor, and it is used to monitor the difference during the lie detection procedure. Standard CM5 ECG lead, used to extract the signal of heart rate, re-extracted heart rate variability and other autonomic nervous system characterized by the parameters. Oxygen Saturation and PETCO2 detection were tested late changes of respiration and respiratory status. 300Hz sampling rate was used to capture the channel signal. Through the low-power microcontroller MSP430, the signal was sent into computer via USB communication. Result: After debugging and verifying, reliable physical parameters can be collected from multi-parameter detection system. It provided a set of physiological information monitoring for the hardware system. Discussion: Signal analysis software needed further design, at the same time adjust the acquisition parameters of front-end signal, and a reasonable configuration, all of them are lay the foundation of software system design. The result shows that the lie detector system based on physiological parameters is cheaper and more convenient than others.