An application of bioelectrical impedance for the detection of tissular bubbles in the diver: preliminary results

Symptoms that appear in the diver submitted to a fast decompression are known as decompression sickness. Rapid decompression causes bubbles of inert gases to form and grow within tissue or vascular space. Troubles only occur if bubbles are present in sufficient numbers. Ultrasonic Doppler techniques only permit the detection of great quantities of bubbles circulating in large vessels. A method using impedance measurement and the way to use it in hyperbaric fields are described. It allows the detection of tissular bubbles at an early stage by monitoring a muscular zone. The results obtained in the animal during traumatic decompressions and the initial results obtained in man during three experimental dives up to a simulated depth of 180 m of seawater shows a relationship between recorded impedance variations and the appearance of decompression sickness.