Frontiers In Space Medicine

Researchers Announce Advances In Medical Models And Tools For Space Exploration

By Ben Raker

While many researchers have been studying the possibility of life on Mars this past year after evidence suggesting the one-time presence of water was uncovered, another group of scientists has been busy exploring methods of preserving life on Mars once humans get there.

Both areas of research, along with a wide variety of others related to space exploration, were included in the program of the 55th Annual International Astronautical Congress (IAC), held Oct. 4-8, 2004, in Vancouver, BC.

Presenting at the conference were biomedical researchers from the University of Washington (UW), who led a symposium on modeling human biological functions in order to better predict and prepare for the effects that space will have on the bodies of astronauts.

The research presented was part of larger efforts funded by NASA's National Space Biomedical Research Institute (NSBRI) and other government bodies to create comprehensive, integrated models of human body functions–known as the Digital Astronaut project–and to develop advanced tools for medicine in space.

The first half of the session focused on recent successes in the area of modeling human physiological functions.

"It dealt mostly with cardiac and skeletal muscle because that's where there's been a lot of successes,” says Martin Kushmerick, a UW professor of radiology, bioengineering, and physiology and biophysics, and an organizer of the symposium. Kushmerick says that while the end goal of a model that integrates all functions within the body is probably decades off, he was encouraged by the research presented in the sessions. He says that researchers are beginning now to model the better-understood systems, like the energy use of muscular systems, that they will eventually link to the larger whole-body models.

The modeling might eventually help predict the effects of changes in the space environment–such as low gravity or radiation–on the typical human.

Kushmerick notes that the presentations at the meeting represented a new direction that had not been highlighted in previous years. Traditional space medicine has focused more on analyzing observed effects rather than modeling.

"It was new in the sense that the biology and the medicine that has been discussed at this meeting has been much more observational and empirical,” he says. "This was the first time that there was conscious effort to say, ‘Look, this might be made rational, algorithmic, predictable, mathematical.'”

Kushmerick's own presentation focused on models of how muscle cells create and use chemical energy, and how they interact with other cells to extend and contract the muscle.

Another presentation described models of how much blood a heart can pump based on knowledge of how the heart is constructed and how cells within the heart interact to cause contraction.

Paolo Vicini, a UW bioengineering professor, spoke about mathematical and computational tools available for modeling complex biological systems where data are limited. "It struck me as something that investigators in space medicine may find useful because the data gathered during space flight are probably the most expensive on or outside of the planet,” he says.

The long-term vision for the Digital Astronaut program is to create an integrated model that accounts for how various parts of the body work together–from the cellular level to organs to the whole body. Such a generalized model or set of models might one day be available online and is associated with the effort to create a "digital human” model for Earth-based study and medicine.

Efforts are also being made so the models account for variation in response among individuals–essentially modeling the typical responses and then calculating the uncertainty of that response occurring.

Predictions of effects on astronauts could also assist with deciding which medical tools to bring on deep space travels. Still, it will be hard to plan for everything. "We can't send some hybrid mix of University of Washington, Johns Hopkins, and Boston hospitals up into space,” says Kushmerick. "You have to send one person with two or three tools. So how are you going to do that?”

Advanced medical tools were the subject of the second half of the symposium.

"We're trying to develop autonomous medical systems that would allow a reasonably intelligent, reasonably trained person to solve a medical problem that came up that wasn't anticipated,” says Larry Crum, director of the Center for Industrial and Medical Ultrasound at the UW.

One of the medical tools reported on is a device to stop bleeding during surgery. This device improves upon existing cauterizing technology by using focused ultrasound beams. "They don't just coagulate the blood but they block the blood vessels supplying the bleeding,” says Crum.

Other devices in development include those that might be used to detect and break up a kidney stone or ablate a tumor.

The researchers stress that the results of new efforts in both developing new space-ready tools and modeling human functions will almost certainly help medicine on Earth as well as in space.

"Hopefully it'll be able to help more people than just a single astronaut going to Mars,” says Crum. "It will help lots of other people.”