- Blood gases,
- Oxygen in the body,
- Space suits -- Testing,
- Life support systems (Space environment) -- Design and construction,
- Pressure suits -- Testing
Pacific Spaceflight's first proof-of concept pressure garment, the Mark I (model Gagarin), was worn by a test subject in a pressure chamber to test stable maintenance of blood oxygenation, body temperature and suit pressure. While breathing normal air at a simulated altitude of 4,000m (c.13,000ft) the test subject's blood oxygenation was 90%, a figure expected for an altitude of 2,590m (8,500ft). The test subject's blood oxygenation climbed back to normal (96%-95%) as the hypobaric chamber was repressurized to sea level figures. The garment successfully maintained the test subject in the first half of the Blood Oxygenation Disassociation Range of 'Minimal Sensory Impairment' rather than in the first quarter of the range of 'Minimal Mental Impairment' (expected had the pressure garment not functioned). Additionally, the test subject experienced no temperature discomfort, indicating that the cooling system functioned sufficiently, and experienced no perception of C02 poisoning. Medical staff observing the test observed no elevated heart rate, flushed appearance or other symptoms of hypercapnia (C02 poisoning) during the 35- minute test.