A gravimetric plethysmograph and its evaluation in clinical use

A gravimetric plethysmograph, the technique of its use and its evaluation in vascular surgical practice are described. The instrument measures flow by the increase in leg weight (rather than volume) produced by an increase in blood content resulting from venous occlusion. The instrument was found to be convenient to use and satisfactory records were obtained in 88% of patients. Values for flow at rest and during reactive hyperaemia were clearly related to the presence of indications for surgical treatment and were similar to those reported by other workers. It is suggested that a peak hyperaemic flow of greater than 15 g 100 ml-1 min-1 may indicate that there are no indications for surgical treatment. The changes in hyperaemic flow values after treatment were clearly related to the symptomatic improvement resulting from it. It is concluded that the gravimetric plethysmograph is suitable for use in the assessment of patients with obliterative arterial disease of the legs.