The human body is incredibly complex and amazing. For instance, consider the small, semi-circular canals just behind and below the ears that make up the vestibular system (VS). Those canals, and the fluid in them, keep humans upright and balanced when walking, running, driving and flying.
But there are many triggers that can “trick” the VS into sending false signals to the brain detecting movement when there isn’t any:
* Drinking alcohol can thin the fluid in the VS canals, making the drinker unsteady and more likely to fall down;
* Inner ear infections can cause disorientation and vertigo—even nausea or tinnitus;
* Some medications can affect vestibular imbalance and cause spatial disorientation (SD).
In fact, SD is the leading cause of Class A mishaps in Naval Aviation. Though SD is caused by many factors, including visual (flying “blind” through clouds or at night) and cognitive elements, the vestibular system is an important piece of SD that Navy pilots can understand and for which they can prepare.
A team from Naval Air Warfare Center Aircraft Division (NAWCAD) at Naval Air Station Patuxent River, Maryland, and Naval Air Warfare Center Training Systems Division (NAWCTSD), Orlando, Florida, is currently developing a new method to aid in that preparation by using a stimulation tool to send signals to the VS, which then provides false input to the brain.
The team is led by Lt. Cmdr. Amanda Lippert, a U.S. Naval Aerospace and Operational Physiologist and the Aeromedical Safety Officer (AMSO) for Naval Test Wing Atlantic. AMSOs are responsible for anything non-clinical that involves the human body in the flight/operational environment. AMSOs are also responsible for pilot safety and survival training.
Lippert’s team is developing a method to use Galvanic Vestibular Stimulation (GVS) to send signals to the brain during land-based training, allowing pilots to practice emergency procedures while disoriented.
“GVS can mimic how SD feels and allow pilots to practice their emergency training in an immersion-based simulation,” she said.
GVS is an electronic headband that would be worn during training to send small electrical impulses to the VS. Specific pulses cause sensations of banking left or right and can also simulate a long bank or false roll.
“Our pilots used to use a Multi-station Disorientation Demonstrator (MSDD),” Lippert said.
The MSDD is antiquated technology that has been inoperable for several years. It resembles a carnival ride where pilots would enter an enclosed capsule that would spin while the MSDD base would also rotate at different rates. There is also a visual component to the MSDD, in that moving objects are projected on the round screen that is viewable from the capsule. The demonstrator, affectionately called the “spin and puke,” created spatial disorientation accurately, but didn’t have a way to simulate emergency training, and is a one-time training event that initial flight students would experience prior to flying in Naval Aviation. Now, without even this outdated device, pilots are only receiving classroom briefings for the mandatory training.
“GVS will give us a practical and safe method of delivering improved training with a hands-on approach,” Lippert said. “And no one pukes with GVS—if they start feeling sick, we turn it off.”
“GVS has been around for a long time—mainly in the research realm,” she said. “We’re just trying to bring it into the training environment.”
GVS has been used by NASA and is already approved for risk considerations for a variety of research topics.
According to Lippert the first step in producing the training is easy and low-cost. AMSO’s would take the headband device to a flight simulator and run the tests during pilot training. A future, more robust trainer would involve integrating GVS into Virtual Reality goggles for a high fidelity training device. In either case, GVS provides vestibular input that can be coupled with a visual input, to create a sensory mismatch and replicate a variety of illusions experienced in the flight environment.
According to Lippert, there are already proposals for developing training curriculum.
“The Navy wants GVS, but acquisition takes time,” Lippert said. The GVS project was recently proposed for Naval Air Systems Command’s FY24 Naval Innovative Science & Engineering (NISE) funding. The process was competitive, and the GVS project was selected for funding. The Basic & Applied Training & Technologies for Learning & Evaluation (BATTLE) Lab, at NAWCTSD, is now purchasing a GVS device for their lab, and building the plan to develop training profiles for their FY24 project. Lippert is spearheading the collaborative efforts between the BATTLE Lab and GVS experts at NASA and Colorado University.
The GVS team from NAWCAD and NAWCTSD was recently recognized at the U.S. Naval Aeromedical Conference (USNAC) with two awards for their efforts with Galvanic Vestibular Stimulation as a training device for spatial disorientation in Naval Aviation. The team received the USNAC 2023 Theoretical Research Award and the USNAC 2023 Original Research Award.
Victoria Falcón is a strategic communications specialist with Naval Test Wing Atlantic. 