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The polygraph machine ancestor was built
Angelo Mosso used an instrument called a plethysmograph to detect the change in blood pressure in response to certain stimuli. -
First clinical polygraph was constructed
The doctor James Mackenzie constructed the first polygraph. An instrument that could be used during medical examinations. -
The first use of a scientific instrument to measure physiological responses
Cesare Lombroso, modified an existing instrument called a hydrosphygmograph and used it to measure physiological changes in the blood pressure and pulse of a suspect questioned by the police. -
Systolic blood pressure test was designed
Dr. William Moulton Marston invented a primitive form of lie detector, the blood pressure test is a component of the modern polygraph -
The polygraph is officially used
John A Larson a employee of the Police of California created the original polygraph. His instrument provided continuous readings of blood pressure. -
The prototype of modern polygraph was constructed
Leonarde Keeler patented what is considered the prototype of the modern polygraph -
Start the computer age of the polygraph
A software called PolyScore is used to analyze the data generated by the polygraph.