Madushanka Takes Artificial Limbs to Next Level

Dr. Kanishka Madusanka
If only we could regrow limbs like in the magical world of Harry Potter.... The reality however is that we have to depend on the ingenuity of our scientists to build artificial limbs (prostheses), the next best thing to growing back lost limbs. Encouragingly, technology on prosthetics has come far. The capabilities of these technological advancements are famously put to test and displayed to the world at the likes of the Paralympics and the Invictus Games.             
Prof. Ruwan Gopura

Most prostheses use biological signals retrieved from the joint muscles to control movement. Electromyography (EMG) is often used to extract such biological signals. However, amputees are often left with only a stump, minus many muscles that a normal limb would have. This makes it difficult to extract EMG signals that can properly control a prosthesis. In such situations, scientists try to integrate other external sensors with EMG signals to create prosthesis which mimic their biological counterparts as closely as possible.


Kanishka Madusanka, our researcher from the Department of Mechanical Engineering, University of Moratuwa, has found motivation for his PhD research in combining vision sensors with EMG signals for controlling prostheses. Madusanka, explaining the difficulties faced by amputees said, “while we take natural motion for granted, they find it very difficult. My aim is to improve their quality of life”. He goes on to say that a simple task such as reaching for a glass of water needs enormous visual and physical coordination. Madusanka focused on amputees who have lost most of the arm with only a part above the elbow remaining (trans-humeral amputees). His technique attempts to recreate the lost link between the limb and the amputee's vision. 

Prof.George K. Mann

Simply speaking, EMG signals taken from the remaining muscles of the disabled arm, and visual signals from a camera are combined to change the elbow angle to extend the palm towards the object to be reached. Although this sounds like a simple action to us, the prosthesis needs complex instructions to carry this out. Madusanka has been able to combine the EMG and visual systems as a single controller, and a reach-to-grasp algorithm for its operation. The controller is able to make the artificial limb reach for and position it self to grasp an object correctly. Experimental evaluations were conducted in a simulated environment showing promising results and scope for improvement.

Dr. Madusanka who hails from Galle, began his education at Richmond College and later moved to Royal College, Colombo, where he completed his secondary education. He secured a place in the Department of Mechanical Engineering, University of Moratuwa and completed his Bachelors degree in 2014. He was then able to join the group of researchers led by Prof. Ruwan Gopura to work towards his PhD in Biomedical Engineering.

Prof. Gopura completed his Bachelors and Masters degrees from the University of Moratuwa. He then proceeded to pursue a PhD at Saga University, Japan. Upon completing a post-doctoral position at Saga, he returned to the University of Moratuwa to join the Department of Mechanical Engineering which he is currently heading. He is also the current Chairman of the IEEE Robotics and Automation Society of the Sri Lanka Chapter and is an accomplished researcher. His research on Robotic Prosthetic Devices received funding from the National Research Council (NRC) of Sri Lanka and the Senate Research Committee (SRC) of the University of Moratuwa.  His international links, particularly with Prof. Kazuo Kiguchi of Kyushu University, help him and his Bionics lab to be at the cutting-edge of robotics research.

Madusanka has travelled to Japan, China and the UK to present his research at prestigious conferences. Based on these credentials, he has secured a post-doctoral position with the Shenzhen Institute of Advanced Technology affiliated to the Chinese Academy of Science, to work with Rehabilitation Robots. He values the knowledge and the creative skills he gained during his candidature at the University of Moratuwa. He also mentioned with gratitude, his co-supervisors Prof. George Mann and Dr. Ranjith Amarasinghe for their guidance. 

Prof. George Mann is a Professor in Mechanical Engineering at the Memorial University of Newfoundland, Canada. He has a doctoral degree in Intelligent Control from the same University. His research is in the Intelligent Systems Laboratory (ISLAB) at Memorial University. His main research areas are, intelligent control, robotics and machine vision.

Dr. Ranjith Amarasinghe, a Senior Lecturer in Mechanical Engineering at the University of Moratuwa, is an expert in Mechatronics, Automation & Robotics Sensors and Nanotechnology. He has Dr.Eng. in Micro/Nano Electro Mechanical Systems from Ritsumeikan University, Japan. 


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