Next Tech Spotlight:
Physiological Closed-Loop Control of Mechanical Ventilation for the Future Battlefield
In conversation with Dr. Evan Ross, MD, Research Scientist, Katmai Diversified Services, U.S. Army Institute of Surgical Research (USAISR)
Dr. Evan Ross, Research Scientist at the U.S. Army Institute of Surgical Research (USAISR), is the Principal Investigator on several large research projects aiming to improve combat casualty care and surgical critical care. Dr. Ross recently spoke about why closed-loop ventilation is critical for optimizing combat casualty care, and how Thornhill Medical’s MOVES® SLC™, when configured for alternate control as a research tool, is allowing the USAISR team to make significant progress in closed-loop control algorithms for ventilation and oxygenation control.
What is the focus of your work at USAISR?
"My title is Research Scientist. I work for Katmai Diversified Services, a contract company that supports the USAISR mission of “Optimizing Combat Casualty Care.” At the USAISR, I serve as a principal investigator on multiple large research projects related to improving combat casualty care. My projects typically focus on surgical critical care, including severe burns and life-threatening hemorrhage. In addition to my core research projects, I also support research and development in the automation space."
What is closed-loop ventilation?
"Closed-loop control refers to a form of dynamic system control in which the output of the system is used to adjust the inputs to the system in order to drive the system in a desired direction. Classic examples of closed-loop control include the autopilot system of an aircraft or the thermostat in a house. When we apply this concept to medical devices, we call it “Physiological Closed Loop Control” or PCLC. Closed-loop ventilation is the application of PCLC principles to the control of mechanical ventilation."
What is the pressing problem that informs and guides your research on closed-loop ventilation?
"Future conflicts with peer and near-peer adversaries are anticipated to be characterized by an increase in both the number and severity of combat casualties, with a concomitant degradation of the ability to rapidly evacuate the wounded. Accordingly, medical providers in the future fight will be called upon to manage a higher number of very complex patients for longer periods than ever before – including patients experiencing respiratory failure and requiring mechanical ventilation."
What is the future benefit of this kind of technology for improving combat casualty care?
"We believe that these tools will help medical providers meet the complex needs of future combat casualty care by enabling them to safely and effectively care for a higher number of more difficult patients for longer than they would without these tools, thus saving lives and improving return to duty rates, thereby preserving the fighting force."
What is unique about your work on closed-loop ventilation?
"Where existing closed-loop ventilation systems are designed to function in isolation (i.e., without input beyond the ventilation data), we are developing our system to communicate with other closed loop controllers so that we can avoid runaway feedback loops."
How does MOVES® SLC™ contribute to this work? What is made possible by the technology partnership?
"When we began this project, the MOVES® SLC™ was the only ventilator on the market that we could identify that was configured for alternate control, meaning that the ventilator could be controlled from an input other than from the device itself. This is a critical component of our research because we must be able to take control of the ventilator away from the user’s inputs and instead hand control of the ventilator over to a piece of software. Without this alternate control configuration, we would not be able to develop, test, and refine closed loop control algorithms for ventilation and oxygenation control. In a very real sense, Thornhill Medical's partnership makes our entire research effort in this space possible. As a bonus, the MOVES® SLC™ is already heavily ruggedized for deployment into operational environments, which allows us to accelerate the timetable for getting our ventilator control systems onto the battlefield."