dc.description.abstract | A lie detector or a polygraph is a device that measures and records physiological variables such as blood
pressure, heart rate, respiration rate, and skin conductivity while a person is being interrogated, toward
establishing a measure of veracity. State-of-the-art polygraphs are expensive (>2,000 USD), and thus, their
traction in developing countries is low. In Uganda, it is common for security agencies to resort to rudimentary
or inhumane interrogation techniques such as torture, as an alternative. To address this challenge, we have
developed and validated a prototype of a low-cost lie detector comprising a Galvanic skin Response Sensor
(GSR), respiratory rate sensor (RRT), and a heart rate sensor (HRT). We developed custom RRT and GSR
sensors and used an off-the-self HRT sensor. We integrated the sensors with power, control, monitoring, and
data transmission circuitry, and developed a user interface for the device, powered by digital signal processing
algorithms. Evaluation of our device on healthy volunteers yielded an accuracy of ~70% which compares to
state-of-the-art devices. Our device could provide a means for low-cost polygraph suited to the needs of
developing countries. | en_US |