INFRARED OPTOELECTRONIC VOLUMETRY, THE IDEAL WAY TO MEASURE LIMB VOLUME

Objectives: The aim of the study was to compare a novel infrared optoe lectronic system (Perometer) of limb volume measurement with water dis placement and two indirect measurement techniques. Design: A prospecti ve experimental study. Methods: In 10 healthy male volunteers (20 limb s) we compared limb volume measurements obtained by water displacement , infrared perometry, the disc model method and the frustrum method. I n a further 17 patients with swollen limbs due to lymphatic (9 limbs) or venous (II limbs) disease, perometry was compared to the disc model method and the frustrum method only. Results: In normal limbs, mean /- S.D. limb volume using water displacement was 1802 +/- 268 mi. Pero meter values agreed almost exactly (1809 +/- 262 ml, r = 0.97, variati on +/- 7% by limits of agreement) but both the disc (1923 +/- 306 ml, r = 0.90, variation +/- 14%) and frustrum (1905 +/- 372 ml, r = 0.72, variation +/- 28%) methods significantly overestimated limb volumes (p < 0.05 (ANOVA, Fisher's Least Significant Difference). In diseased li mbs perometer, disc method and frustum method results were 2415 +/- 99 5 ml, 2494 +/- 969 ml, and 2413 +/- 870 ml representing variation of /- 17% and +/- 23% for disc method and frustrum method respectively co mpared to perometry. Conclusions: Perometry is a novel, extremely accu rate and easy method for assessing limb volume. It provides more accur ate results than traditional indirect measurement of limb volume and p otentially is a very useful clinical and research tool.