Atmospheric changes and physiological responses during a 6-day "disabled submarine" exercise.

Background: Survival time within a disabled submarine (SUBSUNK) is dependant on atmospheric composition and proper design and use of emergency atmospheric control systems. The objective of this study was to investigate atmospheric changes and physiological responses during a SUBSUNK trial.

Methods: There were 18 volunteers who were restrained within a 250 m3 front compartment of an Ula-class submarine submerged in 8 degrees C seawater for 6 d, 18 h.

Carbon dioxide scrubbing capabilities of two new nonpowered technologies.

Current guidance for survivors aboard a disabled submarine (DISSUB) recommends the use of the "stir-and-fan" method of carbon dioxide (CO2) scrubbing in which the contents of canisters of lithium hydroxide (LiOH) are dispersed onto horizontal surfaces. This technique is objectionable because it releases large quantities of fine, caustic LiOH dust and it utilizes LiOH inefficiently. This report presents the results of laboratory studies of the CO2 scrubbing capabilities of two new products that might improve on "stir-and-fan": the Battelle Curtain (BC) and the Micropore Reactive Plastic Curtain (RPC).

Patent foramen ovale: a review of associated conditions and the impact of physiological size.

Patent foramen ovale (PFO) is implicated in platypnea-orthodeoxia, stroke and decompression sickness (DCS) in divers and astronauts. However, PFO size in relation to clinical illness is largely unknown since few studies evaluate PFO, either functionally or anatomically. The autopsy incidence of PFO is approximately 27% and 6% for a large defect (0.

Immersed false vertical room. A new motion sickness model.

We evaluated a new model of motion sickness--an enclosure decorated with visual cues to upright which was immersed either inverted or "front"-wall down, in Johnson Space Center's Weightless Environment Training Facility (WETF) pool. This "WETF False Vertical Room" (WFVR) was tested with 19 male and 3 female SCUBA diver subjects, aged 23 to 57, who alternately set clocks mounted near the room's 8 corners and made exaggerated pitch head movements. We found that (1) the WFVR test runs produced motion sickness symptoms in 56% and 36% of subjects in the room-inverted and room-front-down positions, respectively.