News Release, Naval Sea Systems Command
Indian Head, Md. — Personnel from Naval Surface Warfare Center Indian Head Explosive Ordnance Disposal Technology Division’s (NSWC IHEODTD) Chemical, Biological, and Radiological Defense (CBR-D) Division, Virginia Tech, and Carilion Healthcare recently met at the school’s corporate research center to test a modification of the Stryker Flyte System used by medical professionals in the treatment of COVID-19 patients.
“Since the emergence of the COVID-19 crisis, personnel from the CBR-D Division have marshalled all available resources to work toward innovative solutions with our partners in academia, industry, and across the government,” said Danielle Zimmerman, CBR-D Acting Division Director. “Through historical collaborative relationships, such as the one we have with Virginia Tech and the newly formed relationship with Carilion Healthcare, the expertise we maintain to protect our Sailors is now being leveraged in the private sector to enhance the safety of civilian medical personnel.”
The Stryker Flyte System is a two-part protective ensemble consisting of a reusable helmet with a top-mounted fan paired with a single-use garment comprised of a breathable viral barrier and an integrated face shield known as a Toga.
The concept was to modify the system by adding one or more layers of a readily available sterilization wrap, commonly referred to as Halyard, to the top of the Toga to improve filter efficiency to that of an N-95: the Centers for Disease Control and Prevention’s recommended respirator for health care professionals. The modification consists of a PVC pipe ring mounted to the Stryker Flyte helmet, and a large O-ring to secure the Halyard; simple and inexpensive components found at any local hardware store.
Testing was conducted with the garment worn as it would be in a hospital setting. The modified system was tested against both ambient particles of unknown size as well as silicone dioxide nano-aerosol measuring .114 microns, the approximate size of the virus.
Initial ambient air testing yielded less than stellar results. By adding successive Halyard layers and adjustments to the PVC ring; however, the team saw a significant rise in the filter efficiency. In controlled testing, the particle generator was set to produce approximately 500,000 particles per cubic centimeter — highly unrealistic but used to create a wide margin of safety.
Final test results far exceeded the team’s initial requirements. With the particle generator placed directly on the surface of the modified Stryker System, the real time fit factor never dropped below 300, exceeding the requirement for an N95 by a factor of three.
“This command is finding unique ways to adapt our technology and resources to aid in the fight of the COVID-19 pandemic,” said NSWC IHEODTD Technical Director Ashley Johnson. “It’s critical that we continue utilizing these resources and relying on the expertise of our personnel as we continue to adapt to this challenge. I’m proud that we are continuing to think outside of the box in finding ways to support both the community and the fleet in this fight.”
NSWC IHEODTD — a field activity of the Naval Sea Systems Command and part of the Navy’s Science and Engineering Establishment — is the leader in ordnance, energetics, and EOD solutions. The Division focuses on energetics research, development, testing, evaluation, in-service support, and disposal; and provides warfighters solutions to detect, locate, access, identify, render safe, recover, exploit, and dispose of explosive ordnance threats.