Abstract:
A jointless glove based assistive prototype was designed to assist people with limited hand muscle strength associated with ageing and enhanced gripping abilities for daily activities. As an exploration into adaptive concepts in assistive technology, the prototype was developed with the benefits of both jointless and exoskeleton concepts. While jointless gloves provides a simple, compact and versatile base of which actuating mechanisms could act upon, the exoskeleton approach provided stability and more precise actuation. The proposed adapted jointless glove design allowed free and unhindered user motion when unassisted. It also provides instantaneous assistive forces to the fingertip when required, regardless of the hand positions. The prototype provides assistance for finger flexion and extension by a pulley system with side and dorsal routed cable on the finger. A dorsal palm mounted actuation unit provides linear motion and houses the electronics. The linear electrical actuator was designed to be connected to other moving parts via a disc clutching mechanism to provide isolated actuation to the fingertip while restricting rotation about the metacarpophalangeal joint. A crank slider mechanism limits the rotation by a semi-circular harness mounted on the proximal segment of the finger while the pulley system actuated the fingertip. The prototype was constructed by components made of laser-cut acrylics, 3D printed parts and commercially available electronics. Using an adapted jointless approach with exoskeletal harness, the prototype was lightweight, portable and versatile while being unrestrictive in user experience. The devised prototype was mathematically modelled and the results were compared for analyse. The end results validated the model and provided explanations to the partial variations observed in the results. The end results showed that the device was able to achieve a maximum fingertip force of 11N. However, the model suggested a higher resultant force where the inaccuracy of the manufactured parts and loss of forces caused by warping and friction contributed to the lowered result. The devised jointless glove prototype was able to strengthen the human hand where traditional factors such as wrist motions and restrictive user experience were minimized.