Battle against the bends

Researchers at the University of Houston are developing a laser-based system that can diagnose decompression sickness in seconds.

The research, supported by a $400,000 grant from the US Navy, aims to produce the first optical non-invasive tool to test for the sickness caused by sudden, drastic changes in air or water pressure around a person. It can cause symptoms from joint pains (the bends), to seizures, strokes, comas or even in extreme cases death.

The device is used to find nitrogen gas, or microbubbles, which restrict blood flow and cause damage in blood vessels and tissues. It works in a similar way to ultrasound, reflecting laser light to give a high-resolution image. An early version of the tool has located microbubbles of six micrometers. Most are between five and 15 micrometers.

‘Most of the time, decompression sickness isn’t addressed until the person starts showing clinical symptoms,’ said Kirill Larin, assistant professor of biomedical engineering and mechanical engineering. ‘It would be better, of course, to treat the problem before the symptoms appear. That would allow individuals to take the appropriate medical actions to reduce the side effects of decompression sickness.’

Larin believes the US Navy could use the tool to screen divers and pilots when they return to the surface, giving a diagnosis in seconds thus allowing medical action to be taken straight away. The deivce could also be used on the International Space Station where astronauts moving between a ship and the station have previously suffered effects of decompression sickness.