One-Minute N95 Decontamination

During COVID-19, hospitals are experiencing shortages of N95 masks – crucial for protecting healthcare workers. This led to hospitals re-using these masks. Although large hospital systems have the resources to operate enterprise-wide decontamination systems such as the Battelle CCDS hydrogen peroxide system, small and medium sized hospitals lack those capabilities and are instead re-using masks without decontamination between patients – endangering patients and healthcare workers alike. Our solution is an innovative point-of-care UV-C decontamination system that has been shown to meet FDA virus reduction guidelines in just 60 seconds, much faster than the 30-60 minutes required for the hydrogen peroxide systems. This quick cycle time empowers clinicians to decontaminate their own masks in the same time they are removing other PPE, eliminating the need for a centralized decontamination system and associated staffing. This device would help many hospitals around the globe.

In the US alone, the Department of Health and Human Services estimated that over 300 million N95 masks would be used in the month of March 2020 to fight the COVID-19 pandemic. Unfortunately, 3M and a half dozen smaller manufacturers were only producing around 50 million in January, and surge production has only been able to scale to about 100 million masks a month. These shortages led the CDC and the FDA to issue guidelines for re-using and decontaminating these masks, and even motivated the federal government to allocate $415M to deploy Battelle CCDS decontamination systems at 60 sites around the nation. Unfortunately, access to those systems is limited in practice to larger hospital systems that have the staffing and tracking experience to safely convey clean and dirty N95 masks to and from an individual clinician and a CCDS facility located in their state. This often leaves small and medium sized hospitals with no other option than to re-use contaminated masks, which represents a grave cross-contamination risk to patients and healthcare workers.

We developed a UV-C chamber to quickly decontaminate N95 masks. In healthcare settings, a clinician would exit an ICU room wearing presumed contaminated PPE, and walk towards one of these chambers in their unit – for example at the central nurse’s station. The door of the chamber is initially open, and the clinician removes their N95 mask and hangs it by the rubber strap on a transparent hook in the chamber. The clinician closes the door to start the machine. In the time it takes the clinician to then remove their gown, gloves, and other PPE followed by washing up, their N95 mask is decontaminated to FDA standards by eight high-output UV-C bulbs. When the cycle is finished, the door automatically swings open, and the clinician reaches into the chamber with their now-clean hands and takes their decontaminated N95 to their next assignment.

Our design process began by interviewing clinicians and infectious control personnel, as well as conducting an exhaustive literature review to really understand the problem of decontamination from both a technical and a user-centric viewpoint. The solution we ended up prototyping and validating is particularly advantageous for small and medium sized hospitals, which often have no other N95 decontamination system in place and are currently re-using contaminated N95 masks between patients. Through the interview process and the literature review we discovered several desired characteristics that we believe will lead to rapid adoption of the finished product. For example we ensured that the 1-minute cycle time was fast enough so that the clinician wouldn’t be waiting on the device after they finish doffing PPE and washing up. Also, we developed a novel single-door method of maintaining a sterile field, which improves upon the existing two-door pass-through designs that limit where the device can physically be placed in the hospital (i.e. our device may be placed against a wall or in a corner).

Our fast, low-cost N95 decontamination chamber addresses a critical shortage of N95 masks caused by the COVID-19 pandemic. Empowering hospitals with this device will directly improve health security for the current pandemic as well as for future crises as they arise.

There exists a large gap in commercially available decontamination systems. Large-scale N95 decontamination systems such as the Battelle CCDS hydrogen peroxide vapor chamber have an estimated 7-figure cost associated with them. Small scale hydrogen peroxide systems like the ones manufactured by Steris reduce the cost only to an estimated 6-figure asking price. These costs are beyond the reach of many small to medium sized hospitals, who also lack the staffing and institutional experience required to track N95 masks (which must be returned to the original clinician that used them) and ferry clean and dirty masks to a centralized location. That capability problem is so significant that even after the US government invested $415M to deploy 60 Battelle CCDS units available at no cost to small and medium-sized clinics, they are still not using them due to the aforementioned lack of staffing and experience. UV-C studies have shown promise for this technology to be used to decontaminate N95 masks, however no such device for N95 masks has reached the market. Our UV-C chamber, at an estimated 4-figure purchase price, is more affordable and being point-of-care (used by the clinicians themselves) it does not require any staffing or collection experience.

Our UV-C chamber utilizes a variety of patent-pending core technology. The primary decontamination agent in the device is UV-C light, and eight high-output bulbs were utilized to achieve over 2 Joules/cm2 of UV-C energy, far greater than existing UV-C chambers which were not designed to provide the high luminance required for N95 disinfection. The chamber itself is lined with an expanded Teflon (EPTFE) material that is 97% reflective in UV-C, far greater than the 73% reflectivity of typical Aluminum-lined chambers. The hook that holds the N95 mask is made from a fused quartz material that is UV-C transparent, to ensure that the portion of the mask strap that touches the hook is not shadowed from the UV-C germicidal light. Finally, the automatically-opening single-door mechanism represents an innovation above the two-door pass-through chambers commonly found on the market, because our single-door chamber may be placed against a wall or in a corner while commercially-available two-door chambers must be placed in specific locations that allow access to both the front and the rear of the device.

Although a body of research exists that guided us to an appropriate UV-C dosing goal for our chamber, the ultimate test is whether the device actually deactivates viruses at the level specified by the FDA for N95 decontamination. Preliminary viral reduction testing being conducted at a virology lab at the Louis Stokes Cleveland VA Medical Center indicates that a 60 second UV-C dose in our chamber surpasses the FDA’s required log 3 reduction (99.9% virus reduction) in the outer surface of the N95 mask.

Currently the team includes two primary investigators, in addition to nine students both at the undergraduate and graduate levels.

Our team is composed of two groups. One group, at Cleveland Clinic, contains medical doctors and graduate students immersed in life science research including prior UV-C germicidal irradiation work. The other group, at Case Western Reserve University, is composed of engineers working to design, build, and validate our prototype device. Both organizations contain experienced innovations and technology transfer teams well-versed in licensing this technology to manufacturers.

Our Cleveland Clinic team is partnering with a team of expert engineers at Case Western Reserve University. They are responsible for the construction and validation of our prototype.

In addition to funding further development of this project, the team is looking forward to accessing the mentoring and networking capabilities of Solve and MIT. 

We believe our device is ready to go to manufacture, and for us that means finding a company positioned to take this to market and licensing the technology to them. We are hopeful that Solve and MIT can help us find a corporate partner that would be a good fit for this technology.

During the current pandemic, we have been working tirelessly to develop not only effective therapies for COVID-19 but also new standards of practice and sanitation methods to make limited PPE supplies last longer in a safe way. Our team of investigators have a high level of expertise and the sophisticated infrastructure needed to facilitate success in creating our N95 decontamination chamber. For over 95 years, Cleveland Clinic physicians and researchers have made innovative breakthroughs that have changed the course of medicine. We believe that our patients deserve the best outcomes possible, and it is this mission that enables us to push the boundaries of discovery every day. As such, we are well-positioned to apply our expertise to the coronavirus pandemic and get the answers we need now.