Gas Bubble Detection and Decompression Sickness Prevention by NoninvasiveBioelectrical Impedance Spectroscopy

摘要

Excessively rapid decompression causes bubble formation in the blood and tissueswhich can in turn cause Decompreesion SicKness (DcS) through a variety of mecheniams that inc1ude direct mechanical damage to tissue and perfusion impairment. Noninvasive computer-driven Electrical Impedance Spectroacopic (EIS) and Impedance Plethys-ographic (IPG) methods were developed and used to track such bubble formation and its attendant hemodynamic effects. Studies of bubble formation in gelatin confirmed theoretical indications that bubble formation and growth should cause systemic changes in the electrical impedance spectroacope the hot liquid through effects of soluble adsorption at the bubble gas liquid interface. Using these changes as indices for bubbLe formation in EIS technology was applied to detect bubble formation in the tails of rats decompressed to simulated altitudes. The tails were also monitored for bubble-induced hemodynamic changes using more conventional IrG techniques. Results were correleted with the incidence of DCS which was judged to have occurred with the exhibition of respiratory distress convulsions or death. Because the decompressions used in the animal experiments were 65% further work remains to determine whether ZIS and IPG monitoring can provide noninvasive objective and premonitory indices of DcS in humans.