the bio-inspired robotic sock
Photo courtesy of the National
University of Singapore
Researchers have invented a robotic sock that may be able to prevent deep vein thrombosis (DVT), although it has not yet been tested in clinical trials.
Equipped with soft actuators that mimic the tentacle movements of corals, the robotic sock emulates natural lower leg muscle contractions in the wearer’s leg, thereby promoting blood circulation throughout the body.
The device also allows the patient’s lower leg movements to be monitored to improve therapy outcomes.
The sock was created by Lim Jeong Hoon, MD, PhD, Raye Yeow Chen Hua, PhD, and Low Fanzhe (a PhD student), all from the National University of Singapore.
While exploring a way to prevent DVT, Dr Lim was inspired by the natural role of the human ankle muscles in facilitating venous blood flow back to the heart. He worked with Dr Yeow and Low to identify a way to perform this function for patients who are bedridden or unable to move their legs.
The team turned to nature for inspiration. They found similarities in the structural design of the coral tentacle, which can extend to grab food and contract to bring the food closer for consumption, and invented soft actuators that mimic this push-and-pull mechanism.
By integrating the actuators with a sock and the use of a programmable pneumatic pump-valve control system, the invention can create the desired robot-assisted ankle joint motions to facilitate blood flow in the leg.
“We chose to use only soft components and actuators to increase patient comfort during use, hence minimizing the risk of injury from excessive mechanical forces,” Low said. “Compression stockings are currently used in the hospital wards, so it makes sense to use a similar sock-based approach to provide comfort and minimize bulk on the ankle and foot.”
The researchers noted that the sock complements conventional ankle therapy exercises that therapists perform on patients, thereby optimizing therapy time and productivity.
In addition, the sock can be worn for prolonged periods to provide robot-assisted therapy, on top of the therapist-assisted sessions. The sock is also embedded with sensors to track the ankle joint angle, allowing the patient’s ankle motion to be monitored for better treatment.
“Given its compact size, modular design, and ease of use, the soft robotic sock can be adopted in hospital wards and rehabilitation centers for on-bed applications to prevent DVT among stroke patients or even at home for bedridden patients,” Dr Yeow said. “By reducing the risk of DVT using this device, we hope to improve survival rates of these patients.”
To investigate the effectiveness of the robotic sock, the researchers will be conducting pilot clinical trials with about 30 patients at the National University Hospital over 6 months, starting in March.
They hope the pilot trials will help them obtain patient and clinical feedback to further improve the design and capabilities of the device. The team intends to conduct trials across different local hospitals for better evaluation, and they also hope to commercialize the device in the future.
