The U. S. Army Corps of Engineers (USACE) met the challenge to provide additional hospital rooms for COVID-19 patients by inventing portable medical units created at the Engineer Research and Development Center (ERDC).
Relieving overcrowded hospital facilities, these prefabricated containers were modified as medical isolation rooms and received U. S. Patent 11103406, titled "Airborne infectious disease isolation units and method of making using prefabricated containers." The patent was issued in August 2021 for the six-member invention team at ERDC’s Installation Operations Command’s (IOC) Installation Support Division.
Led by Vicksburg's IOC Director Michael Channell, the quickly-assembled team developed the units with the expertise of Vicksburg residents David Rogillio and Mickey Blackmon, along with Brian Roden of Madison, Alabama; Bryan Merry of Huntsville, Alabama; and David Braidich of Manassas, Virginia.
“Our invention is for a quick and low-cost method of building airborne infectious isolation rooms using existing commercially available intermodal (ISO) container units,” Rogillio explained, adding that in most cities, commercial companies deliver ISO containers for residential storage (e.g., PODS), and thousands of these containers can be delivered for conversion to medical units for patients with infectious diseases. “Preferably, the present invention is assembled in a covered interior space, such as a large warehouse or sporting facility, that could be converted to house such isolation container units using existing utilities.”.
“Rather than having the entire building be considered ‘dirty’ or infected with airborne viruses floating around freely in open spaces, our current invention primarily confines airborne diseases within those units,” Rogillio said. This allows medical personnel the freedom to be without personal protective equipment throughout the building, requiring its use only within the containment units.
The production challenges issued by USACE focused on quick fabrication and evaluation of the units; nationwide availabilities of all materials, labor skill-sets and procurement options; use of fire-resistant materials; compliance with Life, Health and Safety codes; and the important medical requirements of negative pressure, direct line-of-sight patient visibility, clean and disinfect access and hookups for emergency/back-up power.
Remarkable invention turn-around
With non-stop intensity, the ERDC invention team fabricated a unit that met USACE requirements in less than 24 hours, using locally purchased materials within the required budget of $11,000-$14,000 per unit. The team then provided USACE with a detailed design document, including general cost estimates on how to construct these units and transition the technology nationwide.
The team conquered the USACE mission to build or repurpose COVID-19 facilities, fulfilling the urgency of patients in U.S. hotspots in need of more hospital space. For the pilot project, the inventors provided on-site supervisory and technical support.
Recognizing the team’s industrious work, Rogillio acknowledged the efforts of the craftsmen and heating, ventilation and air condition (HVAC) technicians.
“Their help was invaluable in getting this done,” Rogillio said. “The project was completed at the early stages of the pandemic, shortly after everyone was sent home. These guys all agreed to come back to work not knowing the effects of the virus.”
ERDC engineers and craftsmen also determined that the time to construct each unit would be shortened with assembly line practices, prefabricated doorways and on-site build experience.
The unit build team requires the journeymen positions of electricians, carpenters and HVAC personnel. No structural engineer or design services are required under the current design, though unique local conditions will drive the need for other skillsets and adaptations, Rogillio said. Some changes were made for efficiency and to meet governing requirements. ERDC provided rapid proof of concept, evaluation and technology transfer to the USACE COVID-19 overflow facility mission for the nation.
Medical container unit details
As noted in the patent application, the prefabricated container has a width of about eight feet, a height of about eight feet and a length of about 12-16 feet with a clear front door and an intake louver and exhaust vent about 12 inches below the roof’s ceiling. The room has washable wall interiors and floor coverings, allowing for easy cleaning and decontamination.
The exhaust fan and the adjustable damper at the intake louver are controlled to produce a negative air pressure in the isolation space of at least minus 0.01 inch of water gage (approximately 2.5 pascals) and a displacement ventilation exhaust flow rate through the exhaust vent of at least about 100 cubic feet per minute (cfm) greater than an intake flow rate through the intake louver.
In some embodiments, the exhaust fan and the adjustable damper of the intake louver are controlled to produce an exhaust air change rate of at least 12 air changes per hour for the medical isolation room.
Some units include access ramps in front of clear doors. Designs allow for the isolation units to be placed side-to-side facing the same direction, allowing direct line-of-sight for healthcare providers.
The team will be honored in 2022 at a recognition ceremony presenting each inventor a patent award plaque by leaders of the Office of Research and Technology Transfer, which processes patents for the center. They will also be honored on the Wall of Inventors’ area at ERDC’s headquarters in Vicksburg.