Abstract
This study is to attempt the noninvasive measurement of P-V relation in the venous system of human forearm segments through a simultaneous measurement of electrical admittance and cuff pressure change following venous occlusion in 36 healthy subjects (29 males and 7 females ; 20-46 years old). Firstly, volume changes measured by an admittance (⊿V_Y) and a coven-tional type of water-displacement plethysmography (⊿V) were compared. The correlation coefficient and linear regression equation were r=0.986 and ⊿V_Y=0.920 ⊿V+0.44, respectively, and 91.9% of total data (n=242) were within±20% error range. Secondly, venous pressure change measured by inserting hypodermic needle into the vein (⊿P_V) were compared with cuff-pressure changes (⊿P_<cuff>). The results were r=0.967 and P_V=0.790 P_<cuff>+3.55, and 96.4% of the total data (n=192) were within±20% error range. It is suggested through these results that P-V relation in the venous system can be noninvasively determined by the simultaneous measurement of electrical admittance and cuff-pressure in human limb segments.
