Burping Rainbows – Motion Sickness Part 8

chuck October 17, 2012 0

On the left, senator and astronaut Jake Garn.
On the right, the informal space sickness scale named after him.

Read Motion Sickness Part 7

 Not so long ago, in our very own galaxy …

(In which a novel method of suppressing space sickness is discovered.)

As the space age moved into the 1980s, space sickness continued to be a concern. By now there were several very effective anti-nausea drugs, but astronauts were reluctant to medicate themselves if they didn’t absolutely have to. “Space Adaptation Syndrome,” as it was politely called, could also come on with explosive suddenness, without the warning period of nausea that often precedes seasickness. In 1985 U.S. Senator Jake Garn flew on Space Shuttle Discovery’s mission STS-51-D as a congressional observer. Senator Garn left his mark on history when he threw up once, threw up again and then threw up some more. NASA’s Robert Stevenson, a former Scientific Liaison Officer with the Office of Naval Research said of Garn, “he represents the maximum level of space sickness that anyone can ever attain, and so the mark of being totally sick and incompetent [too incapacitated by sickness to do one's job] is ‘one Garn.’ Most guys will get to maybe a tenth Garn if that high. And within the Astronaut Corps, he forever will be remembered by that.”

In spite of the advances in anti-emetic drugs, research continued on new and different ways to reduce or even eliminate space sickness. Millard Reschke knew of experiments done in the 1970s by Canadian researcher Geoffrey Melvill Jones. Melvill Jones performed experiments on volunteers in which they wore glasses fitted with prisms to reverse the image they saw. If volunteers turned their heads to left, then the image would also track to the subject’s left instead of the to the right as it would normally. Not surprisingly, this sensory mismatch was a highly nauseogenic stimulus. While the VOR could eventually adapt itself, Melvill Jones discovered that if he flashed a strobe light during the adaptation period, the test subjects did not suffer from motion sickness. The hypothesis was that the strobing froze images on the retina, providing a sort of antidote to the nauseating effects of the sensory mismatch.

That’s right! Strap on a pair of these puppies, get yourself a strobe light  and you’ve got yourself a non-nauseogenic party.

In the late 1990s, Millard Reschke was on hand to test Astronaut X, who had just returned from a six month stint aboard the Russia’s MIR space station.  Before the mission, Reschke had measured different aspects of Astronaut X’s VOR, including his “saccadic square waves,” a pattern of tiny, involuntary and imperceptible jerks of the eyeball that all of us have. Reschke discovered that Astronaut X’s saccadic waves were twice those of a typical test subject. This was interesting but at the time, not particularly meaningful. Upon Astronaut X’s return from space however, his unusual saccadic wave readings took on a whole new significance.

“This person, after landing, wasn’t what we would typically call the norm,” says Reschke. “His balance was much better than you normally see in long duration [six months or more] crew members. The motion sickness was a lot less; he was sick, but it was a lot less than you’d normally see. Its duration was much shorter. ” The real shocker came when Reschke measured Astronaut X’s saccadic waves after flight – they were three times what someone on the bell curve might have displayed.

“I thought and thought and thought about it,” says Reschke. “I was the only person there on landing to do the testing and I had no one to talk with about it. Then in the middle of the night it sort of hit me that what was happening was that the person was strobing – these little square wave jerks were allowing this individual to freeze images on the retina.” This, in theory, would account for Astronaut  X’s superior balance and lower than normal vulnerability to the unpleasant effects of Space Adaptation Syndrome.

Reschke reasoned that if he could construct a device that strobed the environment at the right frequency, he might forestall the onset of motion sickness. Obviously it was impractical to suggest fitting spacecraft with strobe lights. It would be like throwing a rave in outer space. Reschke soon hit upon the idea of creating specially modified eye-glasses that would strobe the environment for the person wearing them. The problem was how.

If you’re going into space and are worried about space sickness, just get a pair of these babies and waggle them up and down in front of your eyes – or read on for a less taxing solution.

When Millard Reschke initially observed Astronaut X in the late 1990s, the technology to produce a pair of strobing eye-glasses simply didn’t exist, but as the nineties melted into the new millennium, LCD (liquid crystal display) technology grew by leaps and bounds. In 2003 Reschke collaborated with two junior NASA scientists, Jeff Somers and George Ford. The three of them set to work fabricating a pair of glasses with LCD lenses that could strobe four times a second (4HZ).

The experimental device they created looked like a pair of 3D movie glasses. The lenses flashed quickly between being opaque and being clear. Most of the time, the lenses were blacked out, but four times a second they would become clear for less than half a  millisecond, just enough time for an image to leave an impression on the retina. This strobing is very noticeable to the user and for the majority of the time, with the lenses blacked out, wearers of the glasses are not actually seeing anything. In activities like operating a space shuttle, where split second reaction times are important, vision impaired to this degree is obviously not practical. But in test conditions, the glasses do reduce motion sickness. They were tested in cars, boats and parabolic flights, all with very positive outcomes. According to Reschke, the military even did long-term testing with instrumentation crews in Black Hawk attack helicopters. Instrumentation crews are prone to motion sickness from reading their instrument panels as they bounce through the air in the windowless fuselage of the helicopters. Here again the glasses passed with flying colours.

For all the goggles’ success, Reschke stresses that technological limitations still hamper a more practical, faster strobing version of the lenses. He cautions that, “We could have strobed the LCD lenses as high as 10 to 18 Hertz, but that’s the frequency range that can produce epileptic seizures. We considered that there might be a higher, perhaps even imperceptible strobing frequency that would be just as effective, but current LCD technology that we can fit into a pair of glasses can’t go there yet. Also,” he adds, sounding the lament of scientists everywhere, “our funding got cut.”

NASA honored Reschke and his collaborators for their innovative work, but in the long run, anti-emetic drugs are a far more convenient solution to the problem. As NASA looks to the future of managing motion sickness, they have also had some success with biofeedback programs. Tiny, portable biofeedback machines alert astronauts when their bodies are beginning to show signs of motion sickness that they would otherwise be unaware of. Through simple exercises, the astronauts learn how to normalize metabolic functions that weightlessness might otherwise skew into the nausea zone. It’s anyone’s guess as to what future methods for managing space sickness may be, but if past and current solutions are anything to judge by, they’ll be novel and surprising.

Read Motion Sickness: Conclusion

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