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Biomedical subjects

A Påsche

Publications and source records attributed to A Påsche.

5 recordsLinked to original sources
PubMed1991

Effects of water temperature on performance: a practical evaluation of a neutral buoyancy facility.

Manual and cognitive performance of two female and four male divers was evaluated in "cold" and "warm" water in a Neutral Buoyancy Facility (NBF). A test battery of six manual and cognitive tests was applied in a fixed sequence in three separate, 3-h dives: Dive 1) Water temp.: 18-19 degrees C, wet suit 3-5 mm thick; Dive 2) Water temp.: 32-33 degrees C bathing suit and T-shirt; and Dive 3) Water temp.: 18-19 degrees C, tailor made wet suit 6.5 mm thick. No significant differences in performance between the three conditions were recorded. Mean rectal temperatures decreased by 1 degree C in all dive conditions, except in females in Dive 2. Ventilation was significantly higher in Dive 1 than in Dives 2 and 3. Thermal discomfort was reported only after 2 h in Dive 1. We suggest that support divers may work safely, comfortably and effectively for at least 2 h in water of 18-19 degrees C, if dressed in thermal protective wet suits.

Adult↗
PubMed1990

Pulmonary mechanical function and diffusion capacity after deep saturation dives.

To assess the effects of deep saturation dives on pulmonary function, static and dynamic lung volumes, transfer factor for carbon monoxide (T1CO), delta-N2, and closing volume (CV) were measured before and after eight saturation dives to pressures of 3.1-4.6 MPa. The atmospheres were helium-oxygen mixtures with partial pressures of oxygen of 40-60 kPa. The durations of the dives were 14-30 days. Mean rate of decompression was 10.5-13.5 kPa/hour. A total of 43 divers were examined, six of whom took part in two dives, the others in one only. Dynamic lung volumes did not change significantly but total lung capacity (TLC) increased significantly by 4.3% and residual volume (RV) by 14.8% (p less than 0.05). CV was increased by 16.7% (p less than 0.01). The T1CO was reduced from 13.0 +/- 1.6 to 11.8 +/- 1.7 mmol/min/kPa (p less than 0.01) when corrected to a haemoglobin concentration of 146 g/l. Effective alveolar volume was unchanged. The increase in TLC and decrease in T1CO were correlated (r = -0.574, p less than 0.02). A control examination of 38 of the divers four to six weeks after the dives showed a partial normalisation of the changes. The increase in TLC, RV, and CV, and the decrease in T1CO, could be explained by a loss of pulmonary elastic tissue caused by inflammatory reactions induced by oxygen toxicity or venous gas emboli.

Adult↗
PubMed1976

The effect of hypercapnia on respiratory characteristics and diving behaviour of freely diving seals.

Three trained young seals, one harp seal, Pagophilus groenlandicus, and two hooded seals, Cystophora cristata, have been used to study the effect of hypercapnia on respiratory characteristics and diving behaviour. The seals were allowed free movements within a circular pool, while diving and respiratory behaviour were recorded. During the experiments the alveolar CO2 tension was continually recorded. There was a significant decrease in duration of dives with increasing Paco2 for all animals. Ve increased significantly with increasing Paco2. This increase was caused by more frequent surfacing rather than by a higher respiratory frequency during the breathing periods. Tidal volume increased from 3 to 43% when inspired CO2 was increased from 0.03 to 9 vol%. The seals were all found to be less sensitive to CO2 than man. A decreased sensitivity to CO2 with age is suggested from the results.

Age Factors↗