Modifications of Physiological Processes Concerning Extravehicular Activity in Microgravity 941334
The incidence of DCS in null gravity appears to be considerably less than predicted by 1-g experiments. In NASA studies in 1-g, 83% of the incidents of DCS occur in the legs. We report first on a study with a crossover design that indicated a considerable reduction in the decompression Doppler bubble grade in the lower extremities in subjects in simulated microgravity (bed rest) as compared to themselves when ambulatory in unit gravity.
Second we describe the results of a cardiovascular deconditioning study using a tail-suspended rat model. Since there may be a reduction in bubble production in 0-g, this would reduce the possibility of acquiring neurological DCS, especially by arterial gas embolism. Further, cardiovascular deconditioning appears to reduce the pulmonary artery hypertension (secondary to gas embolization) necessary to effect arterialization of bubbles.
Citation: Powell, M., Norfleet, W., Waligora, J., Kumar, K. et al., "Modifications of Physiological Processes Concerning Extravehicular Activity in Microgravity," SAE Technical Paper 941334, 1994, https://doi.org/10.4271/941334. Download Citation
Michael Powell, William Norfleet, Jim Waligora, K. V. Kumar, Ron Robinson, Bruce Butler
NASA Johnson Space Center, University of Texas Health Sciences Center
International Conference On Environmental Systems
SAE 1994 Transactions: Journal of Aerospace-V103-1