By Tiffany Holloway
A service member uses his prosthetic eyes to control a tracking reticle on the screen with a tactile (tongue-based) display. (Photo courtesy of USAMRMC.)
February is Low Vision Awareness Month, a campaign that was started to raise awareness for macular degeneration and other vision problems. Low vision affects a person’s entire life, interfering with the ability to perform daily activities. The term “low vision” means partial sight or visual impairment that is not correctable with contact lenses or eyeglasses. We often take our sight for granted, but tragedy can strike at any time, even more so on the battlefield.
“That’s why the U.S. Army Medical Research and Materiel Command [USAMRMC] has decided to aid injured Soldiers,” said COL Karl Friedl, Director of the Telemedicine and Advanced Technology Research Center (TATRC).
Through its vision portfolio, TATRC funded and investigated technologies for noninvasive vision sensory substitution and augmentation to allow wounded warriors to return to more normal social interactions. These outcomes range from being able to navigate without a cane to having improved visual acuity after a variety of injuries.
Over 18 months, the Florida Institute for Human and Machine Cognition developed a prototype called the Anthro-Centric Multisensory Interface for Vision Augmentation and/or Substitution (ACMI-VAS). This system has the potential to give the sense of vision, including peripheral vision. This information may help to improve a blind individual’s situational awareness, according to Robert C. Read, Program Manager for Vision, Diabetes, and Pain Research at TATRC.
One of the first experiments performed in the realm of sensory substitution involved pilots flying and executing aerobatics while blindfolded. The pilots were getting all of their veridical information from an early version of the Tactile Situation Awareness System (TSAS), developed by the U.S. Army Aeromedical Research Laboratory, a subcommand of USAMRMC. With TSAS, these pilots could perform maneuvers in the air successfully without visual input.
“They improved the user control interfaces and developed a method to allow tactual understanding of color. The final portion of this grant will focus on human research participant testing and evaluation, data analysis, drafting a publication detailing the results, and development of the final ACMI-VAS prototype design specification document,” said Dr. Anil Raj, a Research Scientist with the Florida Institute for Human and Machine Cognition.
The main systems used for these human-centered interfaces are auditory and tactile displays. One of the displays includes a TSAS. The other two tactical displays are the Videotact produced by ForeThought Development LLC and BrainPort electro-tactile tongue displays, produced by Wicab Inc.
The purpose of these technologies is to support vision and balance. Sounds are displayed tactually on the tongue or abdomen to allow individuals to recognize human speech. Speech recognition technology is used to increase the saliency of human speech components against a background of other sounds. In addition to augmenting auditory capabilities, Raj and his team are working to augment visual capabilities using methods such as incorporating three-dimensional models of the environment in real time.
“Even profoundly blind individuals may benefit from the modularity of the system, as they could choose to use specific displays for any given activity.”
The noninvasive nature of the ACMI approach ensures that wounded warriors can benefit from future upgrades as technologies improve, without the risks of further surgeries or infection that implantable devices can present. The proposed complementary interface displays can be tailored to suit individual needs.
“For example, an injury that spared the peripheral vision may only require the higher-resolution displays, whereas a condition like hemianopia [a loss of vision that affects half of the visual field of one eye or both eyes] might only require a low-resolution spatial awareness component,” Raj said.
This proposed technology development will result in a single integrated system prototype capable of providing an alternative mechanism for visual sensing of high-resolution central vision, low-resolution peripheral vision, and stabilization of the imagery despite perturbations of the head.
“Even profoundly blind individuals may benefit from the modularity of the system, as they could choose to use specific displays for any given activity,” said Read.
Raj added that use of the ACMI software framework ensures that integration of improvements in any of the major technologies, including sensing devices such as a camera and interfaces—potentially even implantable ones—will occur quickly, speeding up evaluation of incremental changes and their deployment to the users.
- TIFFANY HOLLOWAYis the Deputy Public Affairs Officer at the U.S. Army Medical Research and Materiel Command. She holds a B.A. in journalism from Auburn University Montgomery and an M.A. in public relations from Webster University.
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