Digital photoplethysmography in the diagnosis of traumatic vasospastic disease.

By means of the photoplethysmographic method including the cold test, skin blood flow was recorded in the fingers of 42 chain-saw operators and 36 control subjects. The essential difference between the groups pertained to the height of the pulse wave amplitude after the cold test and to the fall in amplitude expressed as a percentage of its initial value. A limit of a 90% fall in amplitude after the cold test is proposed as a criterion for differentiating a normal from a pathological vasospastic reaction. A fall in amplitude is correlated with the intensity of subjective disorders, i.e. the attack of vibration-induced white fingers. The obstructive form and loss of amplitude of the pulse wave form are accepted as pathological.