PROJECT: AIRSPAR INFLATABLE FIELD HOSPITAL CONTACT: JESSE WALSH POULIN (firstname.lastname@example.org)
Hi I’m Jesse Walsh Poulin, my team and I are here to present our submission for a Negative Pressure Tent System. In this process we’ve managed to gather a diverse group of active participants and advisors (listed at the end of the document).
PROBLEM The twin problems we are currently facing are the treatment of a surge of critically ill patients with very limited existing ICU capacity, and to simultaneously contain the Airborne Contagion to prevent infection of other wards. In response, we propose a fully contained, self-standing, modular and scalable, inflatable field hospital.
SOLUTION A Typical Field Hospital installation would include a Ward and Anterooms. The Anterooms are connected to the Ward via waterproof zippers, to keep the spaces pneumatically connected. The entire tent is made of various types of fabric, all sourced in the USA.
The Base layer of the Outer Shell is a welded PVC floor tub which rises 10” above the ground to provide a durable and weatherproof base. The Walls and Roof of the Outer Shell may be composed of Heavy Acrylic Marine Canvas or Teflon-Coated Fiberglass, undercoated with aerogel insulation.
Beneath the Outer Shell is an inflatable Spaceframe – We’ve been developing a family of inflatable structures for a few years now and have created various structures which, when inflated to only 2-3 psi, become structurally rigid, withstanding winds over 50 knots. For this design, we intend to use this same manufacturing technique with heavier materials. The inflatable Spaceframe is freestanding and requires no stakes. The Base Perimeter tubes can be filled with water for ballast.
Once inflated, standard floor tiles are laid out. Everblock makes great tiles which accommodate the routing of electrical circuits throughout the structure. These tiles are also non-skid and easy to clean and work well over asphalt. The floor sits on top of the welded PVC floor tub, inside the field hospital. Clean and dry.
Next the HVAC system is installed. Active HEPA filtration units are contained within the anterooms to evacuate and scrub the air from within the Ward and exhaust it above roof level. The negative pressure created by this active exhaust will pull fresh air through the Hepa fabric on the side vents passively. On the advice of Shelly Miller PHD @ CU Boulder, our negative pressure target within the structure is -30 Pa which equates to approximately .004 psi. We are also targeting an air replacement rate of 12 times per hour.
Equipment and Patient beds may then be installed throughout the field hospital. We are targeting a capacity of 20 critical patients and intend to outfit the space to operate effectively as an ICU. Power may be supplied by the attendant hospital’s power system or by generator or other. The benefactors of this solution are myriad. If we could create effective and hypermobile temporary negative pressure ICUs to contain and treat outbreaks like COVID, now and into the future, we can help to solve the shortage in treatment space around the country and the world, reduce contagion rates, help to keep our health care workers safe, and contribute to an acceleration in our collective healing.
TEAM MEMBERS Nate Gust - Mechanical Engineer, M.S. Adam Gossett - Electrical Engineer Shelly Miller - PHD and Professor at University of Colorado, Boulder. Co-author of “Implementing a Negative-Pressure Isolation Ward for a Surge in Airborne-Infectious Patients” Nicholas Clements – PHD, co-author of paper listed above Michael Mccarten - former Deputy Director of Navy Medicine Plans, Policy and Logistics at the Pentagon. Though he is retired now, he was able to weigh in on some very important ‘boots on the ground’ aspects of our design. Clare King – President at Propel LLC