The U.S. Army has awarded a three-year, $1.9 million grant to Worcester Polytechnic Institute (WPI) in Massachusetts to develop miniaturized wireless sensors that can detect early signs of blood loss on the battlefield and potentially save soldiers' lives.
The planned sensors will measure vital signs by shining infrared and visible light through the skin and measure how blood in the arteries absorb different frequencies of light, just like a pulse oximeter. Algorithms that will be developed as part of the same project will process signals from the sensors to measure seven different physiological signals, including what WPI calls "a novel way to detect bleeding." The sensors will include accelerometers to record body movement and posture.
One of the lead researchers, Ki Chon, head of the Biomedical Engineering Department at WPI, previously created an algorithm to detect early signs of blood loss. According to a WPI news story, Chon and co-project leader Yitzhak Mendelson, an associate professor of biomedical engineering at the Massachusetts school, believe that the same algorithm could pick up signs of dehydration in people who have not lost blood, and they will test that theory in this project.
The WPI team will be evaluating placement of the sensors on the body and working to minimize wireless signal distortion caused by body movement. "This is not a trivial matter, so we hope that our strategies will work to overcome this noise," Mendelson says in the WPI article. "Unless we can prove that the information is consistently accurate and reliable, medics and trauma physicians won’t trust or use the device."
Mendelson also will direct development of a smartphone app that will allow Army medics to use their phones as handheld diagnostic tools. The phone's video camera will provide the light source and measure reflections.
In the second and third year of the grant, WPI will collaborate with the University of Massachusetts Medical School and the affiliated UMass Memorial Medical Center to test prototype monitors in real-life trauma situations. Accident victims transported by UMass Memorial's Life-Flight helicopter will be given monitors, as will some trauma patients arriving at the emergency department by ambulance.
A clinical team at UMass Medical School will develop clinical decision support tools for smartphones to assist emergency medical technicians and, eventually, Army field medics. A planned study will follow monitoring of trauma patients in the field, through the ED and into surgery or intensive care.
WPI says the sensors and smartphone apps will not be used for medical decisions during this phase, but only to measure whether data collected matches each trauma team's findings. If the technology proves to be accurate, it could represent a breakthrough in life-saving early detection.
"The majority of trauma victims we see have a blunt-force injury, with no visible signs of bleeding," says UMass emergency physician Dr. Chad Darling. So we are always concerned about internal bleeding, and typically order a CT scan to see what's happening inside. An early-detection system for internal bleeding would be helpful, and certainly would be very important for first-responders in the field."