IISc’s 3D printed gloves to help physiotherapy for stroke victims

In order to help stroke victims and patients with physical injuries, researchers in the Department of Physics at the Indian Institute of Science (IISc) have developed a soft, wearable device that exploits the fundamental properties of light to sense a patient’s limb or finger movements. The customisable, 3D printed gloves can be remotely controlled, opening up the possibility of teleconsultation physiotheraps.
Physiotherapy is one of the few treatments available for rehabilitating stroke victims and patients with physical injuries. However, it can take days to months, depending on the severity of the disability, making it challenging for patients as well as their attendants, the researchers said.
“We wanted to develop something affordable, and available to a person at all times at their convenience. The product should be easy to use and must provide feedback. Quantifiable feedback – for example, the units of pressure applied while squeezing a ball or the degree of bending of a leg with a knee injury – is crucial for doctors to monitor the patient, even remotely. Such feedback can also motivate patients to perform better in every consecutive session,” said Aveek Bid, associate professor at the Department of Physics, whose team has developed the device.
The researchers pointed out that the device has been tested for stability for over 10 months, and no loss of sensitivity or accuracy was found. Bid added that the device has been entirely designed and manufactured in India, and is expected to cost less than Rs 1,000. A patent has been filed for the device and the researchers hope to launch it in the market soon.
Physiotherapy often requires daily hospital visits. Home visits professionals or sophicated devices to monitor patients remotely, although ideal, are not readily available and are expensive. To address these challenges, the team has developed a mechanism which customisable wearables like hand gloves can be designed, 3D printed, and controlled remotely.
“The idea behind the device is that you wear something like a glove, the physiotherap controls the device from a remote location through the internet, and makes your hands and fingers move. The device can sense various hand and finger movements, and precisely detect parameters like pressure, bending angle and shape,” said Bid.
The approach can also be extended to applications like augmented reality and real-time monitoring of health parameters.
The technology that drives the device is based on the fundamental properties of light: refraction and reflection. A light source is placed at one end of a transparent rubbery material, and the other end has a light detector. Any movement in the finger or arm of the patient causes the flexible material to deform. The deformation alters the path of light, and there its properties. The device translates this change in light properties to a quantifiable unit. Since light travels across the entire length of the device, movement along any part of the patient’s finger or arm can be accurately measured, IISc stated.
The device is highly sensitive – enough to respond to the touch of a butterfly – said team member Abhijit Chandra Roy, DST-Inspire faculty at the Department of Physics and the brains behind the project. “In addition, while exing devices can only detect the bending of a finger, the new device can even measure the degree of bending at every joint of the finger,” he said.
The researchers used a silicon-based polymer material that is transparent (facilitating manipulation of light), soft (for comfort and repeated use), and most importantly, 3D printed; it can therefore be customised to fit each patient’s arm and fingers. The device can also capture and store data, and transmit it over the internet, facilitating remote monitoring clinicians or physiotheraps.