In-Vivo embol detector (I-VED)
Goals / Objectives:
The well known problems of decompression sickness suffered by divers, caused by e.g. rapid surfacing, can also affect astronauts in space, e.g. after extravehicular activity. The bubbles thus formed in the body tissue can cause permanent disability or even death. The objective of this project is to develop technologies facilitating in-vivo non-invasive detection of bubbles in the human blood stream.
Decompression sickness (DCS) is a clinical syndrome caused by rapid reduction of environmental pressure in the body that results in formation of bubbles within body tissues. Bubble formation in the organism may create DCS symptoms that range from joint pain to permanent deficits or even death. Hyperbaric DCS can occur from rapid decompression in pressurized tunnels or caissons, in hyperbaric chambers and in diving whereas hypobaric DCS from decompression during a flight, from attitude chamber exposure or in space (during extravehicular activity (EVA). In current space programs there is a risk of DCS during EVAs because in that case crewmembers go from a cabin pressure of 14.7 psia inside the space shuttle or international space station (ISS) to the space suit pressure of 4.3 psia.
EVA preparation protocols are designed in order to prevent serious DCS symptoms, and are based on statistical evaluation of previous decompression experiments. Although up to now no serious DCS symptoms have occurred, these preparation protocols cannot assure the safety of crewmembers performing EVAs due to the big variation of individual and day-by-day susceptibility but also due to the multiple factors affecting DCS occurrence. Furthermore, it is not known if these protocols can be efficient for populations on which little data exist such as women, previously injured people, etc. The long time needed for EVA preparations makes it almost impossible for astronauts to use it in emergency situations. All the above together with the increasing need for EVAs in the following years, underline the importance of developing an in-vivo non-intrusive technique for the detection of bubbles in the body of astronauts in their space suits (bubbles are precursors of DCS. On-line, in-vivo bubble detection would also help further investigation of EVA preparation protocols and possibly lead to greater flexibility and time saving that would improve the work efficiency in these activities.
The objective of the I-VED project is to test a demonstrator of the technologies that are necessary to develop the in-vivo, non-invasive bubble detector to measure instantaneously the conditions of bubble formation and the presence of bubbles in the human blood stream.
If positive results are obtained, the requirements for the I-VED technology demonstrator will be defined and assessments conducted on laboratory models.
Main contractor: Aristotle University of Thessaloniki, Department of inorganic chemistry.
Last update: 29 January 2008