微小カフ圧変動および血管体積変化の特性

抄録

To make clear the characteristics of cuff-pressure fluctuation ΔP_c, which is the base of oscillometric method, real phenomena occurring in human brachial artery under the cuff were examined using various non-invasive techniques. In the experiment the following factors were measured. Cuff-pressure P_c, local arterial volume change, blood velocity, finger arterial pressure, etc. From the experiments following results are obtained. ΔP_c wave-forms agree well with those of arterial volume change, but their amplitude ratio is a function of cuff-pressure whose changing rate is high in low cuff-pressure region. When wave reflection at near the cuff downstream margin does not occur, the shape of the artery under the cuff tapers off downstream and, hence, static model analysis is not good for this P_c region. The wave reflection is caused by recovery of arterial pressure distal to the cuff and increases arterial volume change of distal half and changes the ΔP_c profile. Hence the arterial pressure distal to the cuff is one of important factors to be considered.