Project Status: Ongoing
It is estimated that about 10 million people around the globe have some form of amputee out of which 30% are arm amputees. In recent years there has been a rise in development and availability of many anthropomorphic bionic hands. Due to higher degrees of freedom their grasp planning can be a challenging task. While these hands can be very dextrous, but they cost a fortune and are generally limited to research purposes.
My project on Neuro-Controlled Prosthesis under the guidance of Prof. M. Manjunatha, School of Medical Science and Technology focusses on two aspects of hand prosthetics –
1. Grasp planning of anthropomorphic prosthetic hands.
2. Development of a low-cost 3D printed underactuated prosthetic hand.
While the two research aspects are seemingly opposite, it really speaks volumes about the current needs – with low cost underactuated prosthetic hands, and what the future can look like – with dextrous human-like prosthetic hands.
Grasp Planning
Source- http://www.ieeexplore.ieee.org/document/8487795
For the grasp planning of anthropomorphic robotic hand, my idea was to develop a simple approach for power grasping. I used a simple geometrical approach where the fingers have been assumed to contact the surface of the object as tangential lines. Further, any object would be classified into either a cylindrical object or a spherical object based on its geometrical features and certain heuristics. Through this, the diameter could be extracted and accordingly the grasp can be planned. With further inputs from Miss. Rinku Roy, who is a Research Scholar under Prof. Manjunatha as well as my guide in this project, the planning approach was further generalized and made less dependent on the actual hand specifications. The geometrical relation between the joint angles and the object diameter was used as a fitness function and thus, the joint angles were determined using Particle Swarm Optimization – which is a very fast optimization algorithm and has good global search capabilities.
The research work has been published in the 7th IEEE International Conference on Biomedical Robotics and Biomechatronics – BioRob 2018. Here is a link to the paper:
Adaptive Grasping using an Interphalangeal Flexion Angle Model and Particle Swarm Optimization
Prosthetic Hand Design
The aim is to develop a low-cost 3D printed prosthetic hand so that it can be accessible to the masses and create real impact, especially in India where affording such advanced robotic hand can only be a luxury. Lower cost means fewer actuators and simpler design, which lead to the obvious choice for developing underactuated hands. The design nearly ready and it will be prototyped and tested with inputs as processed EEG or EMG signals.
Ankush Roy 