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News Archive Space 2010

Lying in bed to serve science

5 March 2010

By Manuela Braun

 Drinking while lying down – no simple matter for Tim Hilchner
zum Bild Drinking while lying down – no simple matter for Tim Hilchner

Five hundred and four hours. Tim Hilchner has taken the trouble to calculate exactly how many hours he will spend in bed at one go. Five hundred and four hours during which his head will be lower than his legs and he will not be permitted to leave his bed in the DLR Institute of Aerospace Medicine  (Institut für Luft- und Raumfahrtmedizin) in Cologne for even a single second. On a small table at the head of the bed are several items within easy reach that will help the 27-year old kill time in the windowless room: his gaming console, a stack of computer games, a newspaper, a Rubik's cube from the eighties and a laptop computer with an email connection to the outside world. "Right now, it's almost as if I’m still at home," he says. Mind you, this student is only two hours into this long stint of bed rest in the service of science. "I do not know how the time will pass a few days from now."

Muscle and bone loss similar to astronauts

Tim Hilchner is one of the subjects in a study that will provide some insight, in the course of the next three weeks, into how astronauts cope with weightlessness. Their bodies respond to extended periods of lying down and to the six-degree incline of the bed with migration of body fluids and with loss of bone mass and muscular tissue. The dietary supplement potassium bicarbonate may be able to prevent or at least mitigate the impact on bone and muscular metabolism. This is why nutritionist Dr Petra Frings-Meuthen is distributing soluble potassium bicarbonate tablets to some of the trial subjects, while others are only being given water to drink at mealtimes. After three weeks of continuous bed rest, they will receive a medical examination to establish the extent to which their bones and muscles have altered during the study.

 Project leader Petra Frings-Meuthen
zum Bild Project leader Petra Frings-Meuthen

It was not easy to find suitable participants. Although notices at universities and newspaper advertisements attracted 300 interested candidates, many failed the comprehensive range of medical tests. "We had many criteria," states Dr Frings-Meuthen. Even a poor cholesterol result was sufficient grounds for rejection. After these tests, the candidates were interviewed to assess their psychological suitability. "You see, we need to know if someone will be able to cope with such a long period in a cellar." And some candidates were very naive in their assessment of the task. Only 20 candidates were found to be suitable for the study; eight of them were finally selected to take part.

Strict rules for bed rest

The daily routine is quite strict. As soon as the digital clock in the anteroom reaches 06:30, all test subjects are woken up. Breakfast, lunch, bathing – everything occurs at predetermined times so all participants adhere to a regular rhythm. At 23:15, it is time to sleep, and sleeping during the day is not permitted. A video camera is installed in each of the small rooms, recording the movements of the subject's torso. This enables the scientists to follow what took place during bed rest when they investigate unexplained scientific results. Bathing times are fixed, and every test candidate gets washed in a prone position. Anyone needing to use the toilet uses bedpan and urine bottle. "You certainly sacrifice your privacy," says Joachim Rawert, a 25-year old medical student, who takes it all in good humour.

 All food for the test candidates is weighed precisely
zum Bild All food for the test candidates is weighed precisely

The test subjects eat food that is freshly prepared in the kitchen, because for every candidate the amount of energy they will use was calculated precisely in advance. No one should gain or lose weight during this study. Nor can anyone leave anything uneaten on his or her plate. Second helpings are also banned. Today, it's rice, vegetables and chicken. "The quantities are weighed accurately – to the digit beyond the decimal point," says Dr Frings-Meuthen. Nothing is left to chance. Even the elimination of daylight helps the scientist to maintain a level playing field for her experiments. In response to ultraviolet radiation, the body produces vitamin D and that, in turn, raises the level of calcium absorption – with implications for bone growth. To ensure that all participants have the same quantity of vitamin D in their systems, each one receives a tablet with a uniform amount, rather than being exposed to sunlight. Almost 40 employees are at work around the clock, examining, testing and catering to the needs of the test candidates. "Experiment staff, night services, kitchen personnel, a team of doctors," are all on the list itemised by Dr Frings-Meuthen.

Pastimes over the next three weeks: reading and knitting

 Joachim Rawert knits to pass the time
zum Bild Joachim Rawert knits to pass the time

"I find a regulated daily routine really exciting," says Joachim Rawert. He also wants to structure the next few days for himself. He points to his big travel bag. "It contains course books, non-fiction and novels." In the morning, he wants to read course books, and then in the evening, he intends to reward himself with lighter fare. That is when he produces knitting needles and wool. The 25-year old has taken the trouble to teach himself to knit, and while lying down, he intends to make himself a scarf. "I've certainly got enough time." He can cite many reasons for taking part in this study. He is really looking forward to the experiment. “On one occasion, I taped my eyes shut for six days to find out what it is like to be blind." He also had his health checked thoroughly and now knows that he is fit. Last but not the least, every participant will receive the sum of 7000 euro. In the summer, however, the test candidates will be required to subject themselves to the same procedure once again, to double-check the results.

After three weeks, unsteady on the legs

Things will get really interesting in three weeks' time, when the participants have to stand up once again for the first time. "They're certainly going to be pretty unsteady on their feet," is the professional view of Dr Frings-Meuthen. "However, things will improve quickly after that, within a couple of hours." A full team of doctors will tend to the test candidates for a whole week, measuring bone density, testing muscular strength, analysing their gait and testing balance. These results will then be compared to the figures obtained from the tests conducted one week before the period of enforced bed rest. "Probably, in three weeks from now we'll all look like matchstick men," suggests Joachim Rawert with a grin. He has no concerns about his bones and muscles suffering in the process. Neither does sports student Tim Hilchner: "Anything I lose now, I can always build up again afterwards."

Manuela Braun
Deutsches Zentrum für Luft- und Raumfahrt (DLR) - German Aerospace Center

Corporate Communications

Tel.: +49 2203 601-3882

Fax: +49 2203 601-3249

Petra Frings-Meuthen
German Aerospace Center

Institute of Aerospace Medicine
, Muscle and Bone Metabolism
Tel.: +49 2203 601 3034

Fax: +49 2203 61159

Last update: 16/03/2010 11:25:16
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