By Ms Tiffany R Holloway (Army Medicine)January 30, 2012
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 for granted that we have our sight, or that we can smell, touch, hear, and taste. Tragedy can strike at any time, even more so when on the battlefield.
"That's why the U.S. Army Medical Research and Materiel Command has decided to aide injured Soldiers," said Col. Karl Friedl, director of the Telemedicine and Advanced Technology Research Center.
Under its vision portfolio, TATRC funded and investigated technologies for non-invasive vision sensory substitution and augmentation in order to allow wounded warriors to return to more normal social interactions. These efforts range from being able to navigate without a cane to having improved visual acuity throughout a range 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/Substitution system. This system has the potential to give the sense of vision to include 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, or TSAS (a U.S. Army Aeromedical Research Laboratory, a subcommand of MRMC, development). With the TSAS system, these pilots could still successfully perform maneuvers in the air 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, 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 (ForeThought Development, LLC, Blue Mounds, Wis.), and BrainPort® (Wicab, Inc., Middleton, Wis.) electro tactile tongue displays. The purpose of these technologies is to attempt to help vision and balance function.
Sounds are displayed tactually on the tongue or abdomen to allow individuals to recognize human speech. Speech recognition technology is used to increase saliency of human speech components against the background of other sounds in order to recognize words that would have been spoken. In addition to augmenting auditory capabilities, Dr. Raj and his team are working to augment visual capabilities by methods such as incorporating 3-dimensional models of the environment in real time.
The non-invasive nature of the ACMI approach ensures that wounded warriors could benefit from future upgrades as technologies improve without risks of further surgeries or infection associated with implantable devices. The proposed complementary interface displays can be tailored to suit the needs of an individual.
Raj said, "For example, an injury that spared the peripheral vision may only require the higher resolution displays, whereas a condition like hemianopsia might only require a low-resolution spatial awareness component."
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, the use of the ACMI software agent framework ensures that integration of improvements in any of the major technologies, including sensing devices like a camera and interfaces (potentially even implantable ones) will occur quickly, speeding up evaluation of incremental changes and their deployment to the users.
Collaborations like this give hope and a sense of encouragement to wounded warriors who may have lost their sight to make the most of remaining vision and realize that life does go on … with them.