Blood Pressure Measurement of All Five Fingers by Strain Gauge Plethysmography

The aim of the present paper was to study the methodological problems involved in measuring systolic blood pressure in all five fingers by the strain gauge technique. In 24 normal subjects, blood pressure at the proximal phalanx of finger I and both at the proximal and the intermediate phalanx of the other fingers was measured using a 24-mm-wide cuff. Blood pressure at the proximal phalanx was higher than that at the intermediate phalanx in all fingers except finger V. The difference of blood pressure values corresponded well with circumference of the finger. In 15 normal subjects, blood pressure at the proximal phalanx was compared in fingers I, III, IV, and V, using 16, 20, 24 and 24 mm wide cuffs. Finger blood pressure was closest to arm systolic blood pressure when a 24-mm or 27-mm-wide cuff was used in fingers I, III, and IV, and with a 20-mm-wide cuff in finger V. As the standard deviation of the mean values was larter with the 27-mm-wide cuff than with the 24-mm-wide cuff, the 24-mm-wide cuff was considered to be most suitable for clinical use in fingers I, II, III, and IV. By using the 20-mm-wide cuff in finger V and the 24-mm-wide cuff in the other fingers, normal value of finger blood pressure was determined for both proximal and intermediate phalanxes.