medical electronics III

Plethysmography
Definition:
Plethysmography is a test used to measure changes in blood flow or air volume in different parts of the body. It may be done to check for blood clots in the arms and legs, or to measure how much air you can hold in your lungs.

A plethysmography test is performed by placing blood pressure cuffs on the extremities to measure the systolic pressure. The cuffs are then attached to a pulse volume recorder (plethysmograph) that displays each pulse wave. The test compares the systolic blood pressure of the lower extremity to the upper extremity, to help rule out disease that blocks the arteries in the extremities.