Patients who have lost hand function because of injuries or nerve-related conditions such as stroke and muscular dystrophy could be able to restore movements using a new lightweight rehabilitation device called EsoGlove.
The device, developed by a research team from the National University of Singapore, is made of soft materials and builds on conventional robotic hand rehab devices, according to a news release. The EsoGlove has sensors to detect muscle signals and conforms to the natural movements of the human hand, reducing discomfort and risk of injury. It also is compact and portable, so patients who are recovering at home or are bedridden could complete rehab exercises with greater ease and comfort.
“For patients to restore their hand functions, they need to go through rehabilitation programs that involve repetitive tasks such as gripping and releasing objects,” Raye Yeow, PhD, assistant professor in the NUS Department of Biomedical Engineering, who specializes in soft wearable robotics, said in the release. “These exercises are often labor intensive and are confined to clinical settings. EsoGlove is designed to enable patients to carry out rehabilitation exercises in various settings – in the hospital wards, rehabilitation centers and even at home. Equipped with technology that can detect and interpret muscle signals, EsoGlove can also assist patients in daily activities, for instance by guiding the fingers to perform tasks such as holding a cup.”
The NUS team includes Yeow, his clinical collaborator Lim Jeong Hoon, MD, PhD, from the NUS Department of Medicine, and PhD candidate Yap Hong Kai and undergraduate student Benjamin Ang Wee Keong, both from the NUS Biomedical Engineering department.
Greater comfort and convenience
Conventional robotic devices for hand rehabilitation consist of rigid electromechanical components, which can be heavy and uncomfortable for patients.
“EsoGlove is unique as it is made entirely of soft components and does not require complicated mechanical setups,” Yeow said in the release. “The main body of the glove is made of fabric, with soft actuators embedded. It also has adjustable Velcro straps to cater to different hand sizes.”
EsoGlove is connected to a pump-valve control system that modulates the air pressure which directs the soft actuators. When the actuators are pressurized by air, they apply distributed forces along the length of the finger to promote finger movements, such as bending, extending and twisting, to support different hand motions. This novel method does not constrain the finger’s natural movements, unlike conventional devices that make use of rigid links and joints. Each actuator also functions independently, providing assistance to each finger separately.
The robotic glove can be applied in a tabletop version for patients who are in bed and a waist-belt version for patients who are mobile and recovering at home.
Smart control and assistance
EsoGlove’s intuitive control mechanism involves the coupling of electromyography and radio-frequency identification technologies. With this feature, the robotic glove can detect a patient’s intent to perform a hand action on a particular object, such as picking up a pen or holding a mug. By interpreting the muscle signals of the wearer, the robotic glove can help the patient move the fingers to accomplish the specific tasks involving objects of various shapes and sizes in an intuitive manner.
“With this unique approach, we can develop therapeutic tools using safe and wearable robotic technology,” Lim, who is also a senior consultant at the National University Hospital’s Division of Neurology, said in the release. “Patients can take the initiative in their own rehabilitative process, rather than being passive recipients of therapists’ intervention.”
“As the soft actuators in the EsoGlove are made from nonferromagnetic materials, they are suitable for use in functional magnetic resonance imaging studies,” Yap, also from the NUS Graduate School for Integrative Sciences and Engineering, said in the release. “We hope that the robotic glove can contribute towards investigating the brain’s activity in relation to motor performance during hand rehabilitation, and unravel the functional effects of soft rehabilitation robotics on brain stimulation.”
The researchers plan to start pilot clinical studies at the National University Hospital in February to validate the device’s performance, and to obtain patient and clinical feedback the team can use to refine the design of the device. The studies will take about six months and involve 30 patients.
The team has also filed a patent for EsoGlove, and will start a spin-off company to commercialize the device.