Galvanic Vestibular Stimulation Induces Spaceflight Effects in the Brain

Astronauts returning from space often have trouble keeping their balance and walking for a while. Researchers at the National Space Biomedical Research Institute have now developed a device that can simulate these effects without having to leave our planet’s surface. They created a Galvanic vestibular stimulation system that delivers electrical pulses through electrodes behind the ears, stimulating the vestibular nerve. Although the concept behind this has been known for quite a while, this is the first compact, mobile and comfortable to wear implementation.
From the press release:

"We know that GVS is a good model of how microgravity affects astronauts," Moore said. "What we didn’t know is how good of an operational analog GVS is for the effects of spaceflight. We now have a validated, ground-based analog for the effects of spaceflight on neurological function that is not just posture, balance and eye movement."
In order to determine the viability of using GVS as an analog, Moore tested 12 subjects in the Vertical Motion Simulator at NASA Ames Research Center at Moffett Field, Calif. Each subject flew 16 simulated shuttle landings, with the pilots experiencing the GVS analog during eight of the simulations. The subjects included a veteran shuttle commander, NASA test pilots and U.S. Air Force pilots. The results were compared to data collected from more than 100 shuttle landings.
According to Moore, one out of five shuttle landings have been outside the optimal performance range, such as touchdown speed and sink rate. He said the pilots using GVS during landing simulations experienced sensorimotor disturbances similar to the shuttle pilots.
For example, GVS generated a significant increase in touchdown speed consistent with that observed in actual shuttle landings. "Without GVS, they were right on the target – around 204 knots," Moore said. "With GVS, the average speed was pushed up to about 210 knots, which is at the upper limit of the target range."
The study subjects also experienced GVS-induced problems during a routine landing approach braking maneuver that required the pilots to bring the craft from a 20-degree glideslope angle to a 1.5-degree angle. This is a point during actual shuttle landing approaches at which pilots experienced sensorimotor issues and increased gravitational forces from acceleration.
"The GVS stimulation of the nerves is making the simulator pilots think the spacecraft is moving around. We are happy with that result," he said. "GVS induced similar decrements in simulator landings to those during actual shuttle landings."

The system is primarily meant for training of potential astronauts but might also find use in training aircraft pilots and in preparing people with vestibular disorders for the effects following surgery. And, in reference to our yesterday’s post, it could also be used for simulating Mars landings. Be sure to check out the video in the press release.
Press release: System uses electrical trickery on the brain to induce realistic spaceflight effects…