A new technique for measuring the compliance in conduit venous vessels in human limb was proposed in this study. In our proposed method, the compliance in Popliteal vein was measured from the relationship of the venous pressure (Pv) and its cross sectional area (CSA) using by a B-mode ultrasonography, in order to conquer a problem in the previously proposed estimation method with a venous congested plethysmography (VCPG) in the calf. The main purpose in this study was, therefore, to examine the relationship between both venous compliances derived from the proposed and previous methods. In 12 healthy adult subjects with a supine position, the venous compliances were measured simultaneously via both methods during decreasing venous collecting cuff (around right thigh) pressure at 1 mmHg/s to 0 mmHg (i.e., over 1 min) after 4 min of the inflation at 60 mmHg as an estimate of Pv. The compliance values (Cvc and Cvv) were conventionally derived from Pv vs. CSA and volume (V) over the 20-40 mmHg pressure range with proposed and previous methods, respectively. The V in calf by VCPG showed the gradually increment in all subjects even at the end of 4-min cuff inflation at 60 mmHg, whereas the diameter in Popliteal vein reached the steady state with a rapid expansion. This confirmed the problem which presumably existed in the previous method, that is, the V change with VCPG includes the water amount in intercellular space by capillary filtration in addition to the venous space. The Cvc showed a positive correlation to Cvv significantly (p<0.05). The result indicates that the compliance in conduit vein in human limb can be determined from CSA-Pv relationship noninvasively with our proposed technique under a more plausible physiological assumption

DESCENTE SPORTS SCIENCE Vol.26/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE