The Challenges

Healthcare acquired infections (HAIs) place a significant economic and regulatory cost -estimated at $25B annually – on hospitals and there is an urgency to act now to reduce these infections. Some infections spread because pathogens become airborne. Thus, effective ventilation and purification measures can be useful to minimize HAIs.

Our Solution

We deployed a network of 6 Duet air quality sensors to determine the concentration of particles in the size range of 300 nm to 10 μm – consistent with most microbes of concern from a health perspective. Simultaneously we deployed Trio sensors that were used to capture biological particles on cassettes that were then analyzed for composition of these airborne particles.

Our Duet sensors measured real-time concentrations of particulate matter (PM), VOCs, CO2, temperature, and relative humidity, while the Trio sensors recorded all the real-time values as in the Duet and also captured airborne biological particles in an easily removable cassette for offline analysis. The mesh-networked Duet sensors provided an immediate overview of air quality in different areas of the hospital, including the emergency room, operating room, and medical/surgical rooms. The sensors were easy to deploy in multiple locations without having to connect to local Wi-Fi.

The sensor data showed the hospital which times and locations had the poorest air quality and also how it changed over time. When the concentrations of particles recorded by the Duets was below a threshold value, then airborne microbe concentration, as determined by Trios, was nearly zero. Above a threshold level, there was a linear relation between total particle concentration and the concentration of airborne microbes. This suggests that operating the ventilation system to ensure that the airborne particle concentration was below the threshold should ensure that pathogens released in a room were quickly evacuated from the space before it could cause an infection or be transported to the rest of the hospital.

The Results

The deployment of a sensor network allowed us to analyze the connections between air quality in the different spaces of the hospital. Our automated analysis determined that air quality in some spaces was linked to other spaces, and thus, any pathogens released in one of these spaces could spread to other spaces. Additionally, we determined that operating the ventilation system to maintain particle concentrations recorded by the Duet sensors to be below a threshold value, could result in safer operation of the facility.