Proper attachment of polygraph machine in human body?

A polygraph instrument measures three basic bodily functions but may also measure additional (optional) features. At a minimum, the polygraph must measure (1) relative blood pressure by placing a blood pressure cuff on the upper arm, (2) electrodermal response by placing metal plates on the fingers or self-stick pads on the palm of the hands, and (3) breathing patterns by placing two soft rubber tubes across the upper and lower abdomen. Additional features may also be measured, but these are the basics. - Michael Martin (President, Global Polygraph Network)