How CFD could reduce the spread of infections and improve safety in ambulances
Computational fluid dynamics could help assess and control contamination on ambulance surfaces
Written by Megan Wells, Firerescue1 Contributor
Exposure to infectious disease is an occupational hazard for EMS providers. Even with proper maintenance and sanitization of an ambulance, the risk of lingering infections is still present. This issue is especially timely after a Nevada woman died early January 2017 from an incurable infection resistant to all 26 antibiotics available in the United States. Transmitting infections should be top of mind for all EMS providers.
Not only are infections a safety hazard to all occupants in an ambulance, studies have indicated that infections acquired from ambulances cause a significant financial burden, which is most likely due to the presence of contaminated devices within the ambulances.
A regional study examined the levels of bacterial contamination in Welsh ambulances each month over a 12-month period. The results showed that almost two-thirds (61 percent) of the 82 sites examined were contaminated before cleaning. After cleaning, more than a third (35 percent) were still contaminated or had been newly contaminated.
These results show that cleaning protocols in ambulances aren’t enough when it comes to eliminating germs and preventing infections from spreading.
Engineers might have an answer
Computational fluid dynamics (CFD) may be a solution. CFD uses math to solve and analyze problems that involve fluid flows.
Computers are used to perform the calculations required to simulate the interaction of liquids and gasses with surfaces defined by boundary conditions.
All findings from the analysis are put together to reveal the overall flow path of the liquid or gas. This flow can be visualized to show the velocity and spread of distribution for infections.
The information allows designers to understand how an area could be contaminated based on airflow, which allows them to proactively (and strategically) place air vents to funnel containments outside of a sensitive area and place equipment in areas outside of contaminated spaces.
How does CFD relate to the medical world?
The principles of CFD have been adapted in operating rooms for over 20 years. To improve operating room cleanliness, CFD has been used to direct laminar airflow down and away from sensitive areas like the operating table.
CFD has helped provide barriers to infection transmission within facilities and from external sources by:
- Reducing opportunities for infection transmission.
- Minimizing the risk of transmission for staff.
- Minimizing the opportunities to harbor infectious organisms in the operating room.
This success could be replicated in ambulances.
Airflows and CFD in ambulances
CFD has been used in the development of ambulances to make them more aerodynamic, but CFD has not yet been used for airflow control.
Michael Plishka, president of ZenStorming, a design and innovation consultancy, explains how CFD can be applied in ambulances.
“CFD could be used to optimize airflows for temperature, sound control and airborne pathogen control, specifically minimizing the influx of pathogens into the patient space,” he said.
The findings could enable designers to locate the best areas for air vents and equipment placement, and the airflows could work to keep any pathogens a patient may have from being spread to other occupants of the ambulance and during patient hand-off to the emergency room.
The future of CFD in EMS
Plishka predicts the use of CFD for ambulances will continue to grow. CFD already plays an important role in medical device development. Things like artificial hearts, various venous procedures, breathing, pumps, dialysis and catheters all use CFD principles but could be taken a step further for emergency care.
“I could see utilizing CFD for various types of robotic arms for holding patients, light sources or perhaps even injecting fluids, all under the control of the folks at the hospital or at a central unit,” Plishka said.
Minimizing human touch and interaction would complement the goal of infection reduction. By using robotic arms and strategic airflow, CFD can limit the spread or contraction of infections in an ambulance, thereby decreasing potential contagions and the risk of becoming infected.