Lafayette Instruments Plethesemograph Coupler Excellent Start Price USD 25.00 Current Price USD 25.00 Time Left - Bid Count 0 Buy It Now Price - Reserve Price - Start Time Monday, October 06, 2008 End Time Monday, October 13, 2008 Location Kenton, Ohio See more about 'Lafayette Instruments Plethesemograph Coupler Excellent' Description Here is a Lafayette Instruments PLE Coupler. Designed to be used with a lafayette instruments polygraph instrument with an electronic multifunction module. The attachment goes on any finger or a toe for that matter and the readout on the chart is a graphic display of the change in blood flow in skin of that appendage.The theory is that during a sypathetic nervous system reaction blood is shunted from the skin and digestive system to the major muscle groups. The changes can be read as diagnostic for deception. I found this handy both as a substitute for the normal cardio with subjects who complained of the cuff pressure and otherwise with the normal cardio as a separate reading and confirmation. It was also handy in defeating and revealing certain countermeasures. Questions are invited and promptly answered. Place a Bid!