A method for measurement of the bubble formation threshold in biological liquids
Bjorno, L.; Kornum, L.O.; Krag, P.; Nielsen, C.H.; Paulev, P.E.
Undersea Biomedical Research 4(2): 97-102
1977
ISSN/ISBN: 0093-5387 PMID: 878073 Document Number: 116347
Liquid under pressure is saturated with a given gas, such as Ar, N or air, by circulation through a column of gas exchangers. A sample of the gas-saturated liquid was isolated in a test chamber, the volume of which was increased by means of a moving piston. The piston motion was cyclical with a variable frequency. Pressure in the test chamber was measured by means of a capacitive pressure pick-up. When the volume increase of the gas-saturated liquid in the test chamber was compensated for by the development of gas phase bubbles, the pressure decrease stopped; the recording device showed a pressure plateau or a dip in the pressure-time course, depending on the velocity of the growth of the bubbles. Bubble formation threshold was independent of the frequency of the piston movement within frequency limits from 1 Hz down to 10-3 Hz. Most experiments were carried out at a single frequency of 0.5 Hz. This new method have advantages over previous ones. [The mechanisms of bubble formation in blood of humans with decompressive sickness were discussed.].