A portable device for long-term monitoring of oxygen uptake without discomfort has been developed based on a flow-through principle. The oxygen content of the exhaust gas was kept constant by a servo-controlled blower, so that the flow rate was essentially proportional to the oxygen uptake. This system was evaluated by both a bench test and in exercising human subjects. The limiting current-type oxygen sensor used this portable device produced results which were in good agreement those obtained using a zirconia oxygen sensor (r= 0.999), and stable values were obtained for at least 15 h. The response time for a stepped oxygen change was 4 s. The air flow rate produced by the blower was proportional to the supplied voltage. The results using a time-of-flight flowmeter were highly correlated with those for a hot-wire anemometer (r=0, 999) . The oxygen uptake of exercising human subjects measured with this portable device showed good agreement with that obtained by a conventional oxygen monitor (r=0.973 for cycle ergometer, r=0, 932 for treadmill) . This portable device was able to measure oxygen uptake in subjects during daily activities, and also while driving a car, without disturbance.

A system for making prolonged measurements of oxygen uptake without the use of mask or mouthpiece is described. A subject wears a hood through which air is drawn by a exhaust pump located on the end of hoses. The flow rate of main stream is measured by a pulsed wire flowmeter located between flexible hose and rigid hose. The flow rate is essentially constant during a run. One sample pump bypasses small amount of mixed air from the main stream. The other pump draws the room air. Two sample pumps operate alternatively at 2 min interval. The sample gas is dried by passing through molecular sieve desiccant and is delivered to in-line oxygen analyzer. Both signals of flow rate and oxygen concentrations of room air and mixed air are converted to digital quantities and then stores in memory devices at 5 min interval. All measuring devices were assembled to small package which the subject carries on his back. The weight was about 7 kg. The memory chip is removed from the device after experiment and oxygen uptake is estimated by connecting the memory chip to a microcomputer. This measurement compared favorably with measurement with Douglas bag collection and gas analysis.

A simple exercise test with vertical jumping was developed for children. The vertical acceleration wave form of back was measured with strain gauge type transducer. After amplification and rectification, the signal of positive acceleration was converted to frequency with voltage-to-frequency converter (VFC) and VFC signals were decoded by a digital counter. The digital output was normalized by gravitational value and defined as physical activity rate. 10 young males and 24 schoolchildren jumped at several frequencies and oxygen uptake, physical activity rate and heart rate were measured. Also 28 children under school age jumped arbitrary and heart rate and physical activity rate were recorded. The results showed that the oxygen uptake per body weight had good correlation to the physical activity rate (r=0.95) . Although heart rate was significantly different with ages, physical activity rate which was defined as an index of exrecise test, was no significant difference with ages and weights (α<0.05) . The results indicated that this jumping test was helpful to make exercise stress test for younger children.

A photoplethysmograph (PPG) is a simple medical device for monitoring blood fl ow and transportation of substances in the blood. It consists of a light source and a photodetector for measuring transmitted and refl ected light signals. Clinically, PPGs are used to monitor the pulse rate, oxygen saturation, blood pressure, and blood vessel stiff ness. Wearable unobtrusive PPG monitors are commercially available. Here, we review the principle issues and clinical applications of PPG for monitoring oxygen saturation.
Blood Pressure ; Blood Vessels ; Heart Rate ; Oxygen ; Photoplethysmography ; Respiratory Rate ; Transportation

No abstract available.
Delivery of Health Care

The aim of this study is to evaluate the effects of agricultural activity on cognitive function, physical function, motivation, activity of daily living (ADL), self-efficacy and quality of life (QOL) of hospitalized elderly with dementia using multivariate statistical analysis. Elderly with dementia performed them for 2 months that replaced with agricultural activities once a week after they performed ordinary activities for 2 months. Ordinary and agricultural activities showed higher score than control condition. Two therapies are compared by principal component analysis (PCA), correlation analysis and multiple regression analysis (MRA). From the PCA analysis, motivation, muscular strength, walking ability, and mobility ability tended to improve during agricultural activities, but there was no significant difference in cognitive function, daily life, and behavioral disorders. In the correlation analysis, walking speed, walking time, timed up and go test (TUG), and grip strength showed a high score. MRA showed that improved physical function is improved during agricultural activities, but no significant improvement in cognitive function and ADL. Therefore, it was found that agricultural activities may be useful for improving physical functions. Long-term evaluation is needed for discussing the effects on cognitive functions and ADL.

Objective：The Japanese Orthopaedic Association Low Back Pain Evaluation Questionnaire (JOABPEQ) consists of 25 questions, which allows for the multifaceted evaluation of patients with low back pain. In this study, we aimed to investigate whether the JOABPEQ could be used to construct a regression model to quantify low back pain, lower limb symptoms, and hip range of motion (ROM) in patients with lumbar spinal stenosis.Methods：We evaluated 115 patients with lumbar spinal stenosis scheduled to undergo surgery at our hospital. We measured the degrees of low back pain, lower leg pain, and lower leg numbness using the visual analog scale before the surgery. In addition, we measured the ROM of the hip joint during flexion, external rotation, and internal rotation. All responses of the JOABPEQ and physical function data were subjected to a partial least-squares (PLS) regression analysis.Results：Low back pain, lower limb pain, lower limb numbness, and hip ROM during flexion could each be used for significant regression models with JOABPEQ items. However, the hip ROMs during external and internal rotation could not be used for regression models with the JOABPEQ.Conclusion：On the basis of the results of the PLS regression analysis in this study, the degree of pain symptoms in patients with lumbar spinal stenosis may be quantified with the JOABPEQ items. Furthermore, the flexion angle of the hip ROM was quantified using the JOABPEQ items. The results of this study may indicate an effective means for establishing treatment plans for physical therapy.