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Biomedical subjects

D Florentin

Publications and source records attributed to D Florentin.

3 recordsLinked to original sources

Assessing the discomfort of the whole-body multi-axis vibration: laboratory and field experiments.

Laboratory and field experiments were conducted to determine the best procedure for predicting the discomfort caused by multi-axis vibration. In the laboratory experiment, 11 seated subjects compared single-axis vibration in one axis to single-axis vibration in another axis, and compared dual-axis vibration to single-axis vibration. In the field experiment, 22 lorry drivers rated the discomfort of 16 different rides. The results show that the best procedure for predicting the discomfort is to combine the vibration inputs by taking the square root of the sum of squares of the weighted r.m.s. values of the vibration in each axis.

Adult

Refractoriness after hyperventilation-induced asthma.

It is still debated as to whether the bronchospasm induced by hyperpnoea in asthmatic subjects is followed by a period of refractoriness to a subsequent challenge. We studied, therefore, the effect of repeated challenges with eucapnic hyperpnoea in asthmatic subjects and compared it to that in normal subjects. Ten normal and 34 asthmatic subjects were challenged twice with a steady isocapnic hyperventilation (25 l X min-1 X m-2 BSA for 6 min) of dry air at room temperature. The interval between challenges was 30 min in the normal subjects and was 30-60 min in asthmatic subjects to allow for full recovery of FEV1 before the second challenge. In the normal subjects, neither the first nor the second challenge caused a detectable change in FEV1. In the asthmatic subjects, the fall in FEV1 was on average less marked at 5, 8 and 10 min after the second challenge than after the first one (p less than 0.05 by analysis of variance). Analysis of data from individuals showed partial to full refractoriness in 14 of the 34 subjects. In no instance was the fall in FEV1 significantly greater after the second challenge than after the first one. Thirteen other asthmatic subjects were challenged twice at a 30-60 min interval with stepwise increases in ventilation of dry air at room temperature until wheezing or chest tightness occurred or a ventilation of 50 l X min-1 X m-2 BSA was reached.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent