Based on physiology parameters to design lie detector

Abstract

Objective-Multi-parameters are employed to design a device of lie detector, including Skin Temperature, electrocardiogram (ECG), Pressure of End-Tidal Carbon Dioxide (PETC02), Oxygen Saturation and other physiologicalparameters. Methods: Skin Temperature is measured by temperature sensor, and it is used to monitor the difference during the lie detection procedure. Standard CMS 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 PETC02 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.Keywords-lie detector; physiology parameters; signal processing I. BACKGROUNDWhen people lie, he can involuntarily produce a certain psychological pressure, which will cause rapid heartbeat, blood pressure, palms sweating, body temperature rose slightly, muscle trembling, respiratory rate and capacity slightly abnormal and a series of physiology responses [1 ,2].These physiological responses are controlled by human autonomic nervous system, also be used as a reference lieThe world's first polygraph is invented by Larson and Keeler in the United States in 1921, by measuring blood pressure, breathing and skin resistance three physiological parameters, use three ink document recorder draw curve, mainly used to detected then some theft, and succeed [4].This also confirmed that psychological a physiological parameters index in polygraph technology has great value. Polygraph-related physiological parameters there are many, such as blood pressure, breathing, pulse, skin electricity, body temperature, sound and so on. Conventional physiological lie detection system mostly chooses three parameters: breathing, blood pressure, and skin resistance. With the development of modern electronic technology, more parameters synchronous detection are feasible [5,6].The lie detection system designed in this paper include: ECG, can be extracted heart rate, heart rate variability (HRV) and other parameters, HRV is the rapid response of autonomic nervous system regulation;, pulse information, blood oxygen content and respiratory oxygen exchange information can be extracted from oxygen saturation signal; PETC02, can detect the breathing status, blood gas exchange; skin temperature signals, and also can detec...

Verification of using radar vital sign monitors in deception tests (2023)

“…Recent studies have explored the use of neural networks to directly classify such bioelectricity waves rather than simply analyzing their frequencies [3]. Despite progresses in signal processing methods [4], however, the fundamental signal measuring techniques have remained largely unchanged, with testees still experiencing discomfort from the use of multiple electrodes, and testers being confounded by the potential Hawthorne effect and the need for complex instrumentation.…”