The first practical polygraph was invented by John A. Larsen in 192 1, when he was a medical student at the University of California. Larsen's multi-recorder was invented by combining sphygmomanometer and respirometer, which can continuously record blood pressure and respiration. 1926, Leonard Kira, an American inventor, applied for another lie detector patent. Kira was successfully invented by combining Larsen polygraph with GSR device. Among them, GSR is the abbreviation of current skin reflex, which is the change of skin current conductivity caused by mental stress. The measurement technology of this physiological index was invented as early as the end of 19. In the 1920s, police officer Kira was Larson's early assistant when he took a polygraph test at the Berkeley Police Department in California. Kira-type polygraph with three input channels was soon approved for criminal pre-trial and control of employee recruitment or theft in commercial organizations. During the period of 1945, john reid, Kira's assistant, summarized his previous work and conducted a lie detector experiment with his own reed multinomial recorder. The instrument can record the blood pressure, pulse, respiration, skin current and muscle activity of the subject at the same time. At that time, pneumatic recording was used, and the reed multinomial recorder was also called the second generation polygraph.
In the early 1960s, due to the rapid development of electronic technology, modern tape recorders and multichannel instruments appeared. Thermistors, photoresistors and piezoelectric crystals can all be used as sensors. An electronic multispectral recorder with strong anti-interference ability is composed of transducer, amplifier, filter and electromagnetic induction pen, which can be called the third generation polygraph. 1966, the American polygraph association was jointly established by several polygraph institutions. The association helps to check the use of polygraph.
In 1960s, the US military developed a hidden lie detector, which used a complicated optical scanner to measure pupil dilation, an infrared scanner to monitor skin temperature, a microwave interferometer to measure respiratory stability, and even a human body odor detector. The polygraph is characterized by complex equipment and high price, which can be used for non-contact polygraph, but not for people who are not present. Among them, Baender found in 1933 that the iris of the eye is controlled by autonomic nerves, and strong emotions will make it expand. In 195 1, car-loving proves that strong emotions can lower the temperature of hands and face. In 1970s, the new breakthrough in the history of lie detection was two kinds of voice tension analyzers called the fourth generation side liars. 1972, Allen bell and others in the United States invented the psychological stress tester, which was patented in the mid-1970s. It detects the frequency modulation caused by the slight jitter of sound, and can be used to interpret the lie detector. A few years later, Flanders Flores invented the speech stress analyzer. It detects the low frequency amplitude modulation in the voice of the subject. Voice polygraph can use recording equipment, so the subject is allowed to be absent from the scene.
198 1 year, the relevant departments of our country introduced two Mark-II speech analysis lie detectors from the United States, and initially carried out lie detection experiments and research work. 1O years later, the first polygraph developed by China-PG-I psychological tester came out. .
200 1 Scientists of the U.S. Department of Defense are developing a laser polygraph, which can record a person's psychological stress level from a distance. At present, the frontier of research and design of polygraph is computer-aided processing, and the physiological indexes of recording and processing range from 2 to 12.
On April 3, 2002, the director of the Federal Bureau of Investigation (FBI) announced that the FBI would take management measures to strengthen internal security, including more use of psychological testing technology for employees. Miller said that the FBI is studying how to expand the scope of psychological tests among its employees and will conduct new psychological tests on more than 1000 employees. Especially after "9. 1 1", many non-governmental organizations also brewed and began to implement psychological tests. For example, the safety precautions proposed by aviation safety consulting service companies for aviation safety rank third, the first is police dogs, and the second is manual inspection (police dog training/police dog search, manned, Polyraph test, psychological test, recruitment, risk analysis, training: aircrew, training: airport personnel, training: computer-based, training AIDS). In South Africa, psychological testing technology ranks first among the preventive measures against terrorist crimes.
In 2005, Israel developed a new polygraph technology, which can determine whether the tester is lying to the greatest extent. This polygraph technology is authorized by an American company, and now a new type of polygraph glasses has been manufactured. It is understood that this kind of glasses integrates the core lie detection technology and displays the test results through the built-in LED indicator light. What's more worth mentioning is that its accuracy of lie detection is as high as 95%.