Research
Radar Based Lie Detection Technique
The need for lie detection is to resolve disputes that arise over inheritance, forgery, impersonation as well as in forensic science which deals with application of science to law aiding to deliver justice by eliciting truth, scientific evaluation of physical evidence usually encountered in many civil, criminal regulatory and statutory cases. All the methods for lie detection including the most popular polygraph testing depend on the measurement of variation of physiological conditions like heart beat rate, respiratory rate (breath rate), etc. by establishing physical contact of some medical device with the person’s body and thus are invasive and obtrusive. But these physiological conditions vary due to the effect on the autonomic nervous system (ANS) for any reason irrespective of whether the person tells a lie or the person is innocent but feels nervous for being under test. This leads to an ambiguous and/or inaccurate decision about the person telling lies. A radar based lie detector proposed recently can be a remote, non-contact, non-invasive and unobtrusive method. This review paper summarizes the common signs of deceptive behavior, major non-radar based methods used earlier and finally, the radar based technique for lie detection that has emerged as a technical breakthrough in lie detection.
Frequency Dependent Planar Electromagnetic Modeling of Human Body and Theoretical Study on Attenuation for Power Budget Estimation of UWB Radar
Detection of the heartbeat rate and/or respiration rate are very important for most radar based applications like lie-detection, life-detection etc. The prediction of signal losses is a fundamental aspect in the design of ultra wide-band radars. The effect of body tissues surrounding the heart is important in the design of a radar system used for heartbeat detection. The broad variety of tissues and their frequency dependent behavior makes accurate attenuation prediction very difficult without the support of an appropriate model. In this paper, two frequency dependent planar electromagnetic models viz. intrinsic impedance model (a classical model) and impedance transformation model, both incorporating dispersive dielectric properties are discussed. Signal attenuations in both models are estimated and compared. This estimation can be helpful in the design of an ultra wideband (UWB) radar system meant for cardio-pulmonary activity related applications.
