The first 30 minutes after a battlefield injury are dire: that’s when nearly 86 percent of battlefield deaths occur. Before attending to the wounded, frontline physicians have to quickly locate the casualty and extract him from the battlefield, often under heavy fire. This can take up costly minutes, as well as expose medics themselves as possible targets.
Now researchers at Carnegie Mellon University (CMU) are developing technology to give battlefield medics a helping hand–literally. Howie Choset, an associate professor of robotics at CMU, has engineered a snakelike robotic arm equipped with various sensors that can monitor a soldier’s condition. The robot can be wirelessly controlled via a joystick, so that a doctor at a remote clinic may move the robot to any point on a soldier’s body to assess his injuries as he’s being carried to a safe location. The robot’s serpentine flexibility allows it to maneuver within tight confines, so that, in case a casualty can’t be extracted from the battlefield immediately, the robot can perform an initial medical assessment in the field.
Choset and his colleagues have been building “snakebots” for over 10 years, improving range of motion and flexibility, as well as minimizing the overall size in multiple prototypes. In the past, the group has designed robots for urban search-and-rescue missions, and has worked with Ford Motor Company to build snake robots for precise auto-body painting. The team recently formed a startup company to commercialize one of its latest technologies, a robot that can potentially perform heart surgery.
Currently, the team is collaborating with the U.S. Army’s Telemedicine and Advanced Technology Research Center (TATRC) to integrate the robotic arm within the military’s high-tech stretcher, called the Life Support for Trauma and Transport system (LSTAT). This stretcher is essentially a portable intensive-care unit, with a ventilator, defibrillator, and other physiological monitors, and it’s currently being used in areas of Iraq and Afghanistan. Medics can quickly load a casualty onto the stretcher and attend to injuries with the equipment onboard.
“It has all these sensors onboard so we can perform preliminary diagnostics and maybe therapeutics to save the guy’s life,” says Choset. “The problem is, these sensors are attached to the LSTAT, and you would have to move them by hand, and if someone’s shot and you go over and help them, you’re an easy target. So we want to automate this whole system, and robotically move the sensors onto the patient while he’s being dragged off the battlefield.”
Choset and his students have engineered a highly articulated robotic arm that consists of multiple actuated joints, which give the robot a snakelike flexibility. Each joint has two degrees of freedom that, working together, allow the robot to flex, retract, and twist into different configurations, much like a live snake.
Because it’s impossible for a person to simultaneously control all the joints on the snake, the team developed software to enable precise control of the robot’s movements via a joystick. In lab tests, researchers could successfully guide the arm, mounted with a camera, up and down a skeleton’s body using the joystick and watch the resulting pictures on a laptop.
Choset has affixed various physiological sensors to the robotic arm, including a detector for carbon dioxide and oxygen to test whether a person is breathing. He says that the robot can also sport an oxygen mask and, if connected to the stretcher’s onboard ventilator, can potentially maneuver over a soldier’s mouth and deliver oxygen, without the help of a medic.
In the future, Choset hopes to add an ultrasound component to the robot, so that it can quickly scan a soldier for signs of internal bleeding. His team is collaborating with researchers at Georgetown University to develop an ultrasound probe for the robotic arm. To perform ultrasound, Choset says that the robot would require a certain amount of strength and delicacy so that it can determine how much force to apply to gently press a probe against the skin. He and his students plan to explore this robotic challenge in the future, along with other applications for the snake robot.
Sylvain Cardin, a senior medical robotics scientist at TATRC, suggests that there may be other military applications for the robotic arm. “It could be on a small vehicle you could send into the field, and the medic could attend the patient in a remote location,” says Cardin. “So you could be under fire, and could send this little vehicle out with the snake arm, and be able to attend the casualty without showing everyone we’re attending the casualty.”