It is the recording of changes in the volume of a limb of digit as blood moves in and out of it with each cardiac cycle.

Pneumatic plethysmogaphy uses a pneumatic cuff wrapped around an extremity or digit. By standardizing the injected volume of air and therefore the pressure inside the cuff, momentary volume changes are detected by a transducer and displayed as waveforms also called "pulse volume recordings."

These waveforms correspond closely with the waveforms obtained by intra-arterial recording at the same level.

BIBLIOGRAPHY:

Darling, R.C., Raines, J.K. et al. Quantative Segmental Pulse Volume Recorder. A

Clinical Tool.

Surgery 72 - 873 - 887; December 1972.

Winsor, T. - Winsor, D. W. Plethysmography; History and Recent Advances

Angiology; 209 - 218; March 1987.

Birch, G. E. A New Sensitive Portable Plethysmography.

Am Heart J; 23 - 664, 1942