Near-infrared optical estimation of o2 supply and o2 consumption in
forearm muscles working at varying intensity.
Homma, Sachiko, Hideo Eda, Sadamasa Ogasawara, and Atsuko Kagaya.
Research Institute of Physical Fitness, Japan Women's College of
Physical Education, 8-19-1 Kitakarasuyama, Setagaya-ku Tokyo 157,
Japan, Analytical Instruments Research Laboratory, Shimadzu Co., 1
Nishinokyo-kuwabaracho, Nakagyo-ku, Kyoto 604, Japan, Aoyama
Hospital, Tokyo Women's Medical College, 2-7-13 Kitaaoyama, Minato-ku
Tokyo 107, Japan
APStracts 2:0541A, 1995.
We estimated a blood flow index, O2 supply index and O2 consumption
index from near-infrared (NIR) signals during venous occlusion
imposed at rest and immediately after handgrip exercise with loads
equal to 5, 10, 15, 20, 25 and 30% of the maximum voluntary
contraction. We also estimated forearm blood flow (BFforearm) by
strain-gauge plethysmography and forearm O2 consumption (VO2 forearm)
by the invasive method. There was a significant correlation between
the rate of increase in total-Hb during venous occlusion obtained
from NIR signals and BFforearm in each subject (r=
0.853[umlaut]u`0.981, p<0.001) . There was also a significant
correlation (r=0.854[umlaut]u`0.944, p<0.001) between the O2
consumption index estimated from NIR signals and VO2 forearm . The
mean values for O2 supply index in 5 subjects increased with exercise
intensity, while the O2 consumption index showed no further increase
above 25% of MVC. We found significant positive correlations between
those O2 supply index and BFforearm (r=0.986, p<0.001), and the
O2 consumption index and VO2 forearm (r=0.976, p<0.001) during
exercise at 5-30% of MVC. These results demonstrate that analysis of
NIR signals during venous occlusion provides an advantageous method
of estimation of O2 supply and consumption in working muscles during
exercise of varying intensity.
Received 16 December 1994; accepted in final form 27 November
1995.
APS Manuscript Number A1276-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 12 December 95