A Flexible Wearable Supernumerary Robotic Limb for Chronic Stroke Patients

Our research focuses on developing supernumerary robotic limbs to help hemiplegic patients with grasping movements. By employing flexible sensors, we aim to interpret patient intentions and enable robots to perform virus grasping tasks, ultimately enhancing patient's quality of life. This study introduces a novel, flexible, wearable robotic limb for chronic stroke patients.

It aids finger rehabilitation and gripping, featuring Linus, safety, compliance, waterproofing, and an impressive output to weight or pressure ratio. It offers envelope and fingertip grasping modes, maintains portability, and ensures user-friendly interaction. In our upcoming research, we will primarily concentrate on the domain of human machine interaction control, specifically in the context of grasping intent among individuals affected by hemiplegia.

Additionally, a concrete research goal involves refining mechanical design to enhance grasping performance. To begin, assemble the pre-designed mold, then use hot melt glue to secure the glass fibers at the designated positions in the mold. Weigh an appropriate amount of component A and B of the silicone elastomer and mix them in the specified ratio.

Use a vacuum mixing and degassing machine with a variable centrifugal force to mix and degas the elastomer mixture. Promptly inject the mixture into the assembled mold and let it sit for approximately 30 seconds. Then place the mold in a vacuum dryer for about one minute to enable any tiny air bubbles in the silicone rubber to escape.

Remove the mold from the dryer and place it in a thermostatic chamber set at 30 degrees Celsius for 12 hours. Position the demolded rubber body into the mold filled with silicone rubber. Place the entire assembly in a thermostatic chamber set at 30 degrees Celsius for 12 hours to allow the silicone rubber to cure.

Remove the cured silicone rubber body from the mold and trim any excess silicone rubber. To begin, take the designed pneumatic gripper and secure it with 3D printed parts. Using adhesive tape, attach it to the appropriate position on the glove.

Embed three flexible bending sensors into the glove. Instruct the participants to flex and extend their fingers. Use a data acquisition card to record sensor signals.

Amplify the sensor signals and route them to an Arduino. Now, collect data on the range and pattern of sensor changes during finger movements. Instruct participants to move their fingers freely within their range of ability.

After determining the threshold, determine the appropriate time to stop inflating the air and cease further finger bending. Set the maximum air pressure for the pneumatic gripper to 100 kilopascals. Solicit feedback from the wearers regarding their experience.

The survey of six patients showed a consensus among most participants regarding the comfort and user-friendliness of the designed wearable system. Participant five provides a less favorable evaluation and raises significant concerns about the device.