European Journal of Scientific Research - EuroJournals

869 N. A Abu Osman, S. Yahud and S. Y Goh
weight of the prosthetic hand could be reduced and skin could be added into the design to give more
humanlike impression.
Functional strength on each joint is depending on the tendon’s material. Terelyne string is used
as tendon and able to withstand a maximum functional weight of 45 kg. Therefore, the prosthetic hand
is capable of handling functional weight more than required by human hand [12]. The path of fingertip
trajectory for each prosthetic finger is similar to Guo’s trajectory [13]. Maximum flexion angles for
each joint are varied but approaching the value suggested by Thakor et. al [14]. The prosthetic hand is
able to pose the four desired tasks without reaching a maximum angle of each joint. The four tasks
focused in the study are basic functional activities commonly performed by human hand. The selection
of hand tasks can be observed in experiment to investigate functional strength of the hand by Chao et.
al [12].
The proposed BCI system is able to control the prosthetic hand, during online experiment.
Subject however has to be trained in order for him/her to control the prosthetic hand. Performance of
prosthetic hand in BCI environment is very much depending on factors such as subject’s EEG control
ability, system performance, feedback delay and 50 Hz interference. As far as the author is concern,
there is no experimental work done to demonstrate the actual performance of BCI controlling a
prosthetic hand.
5.0. Conclusion
The prototype of a prosthetic hand has fulfilled the objective of the study. A total 16 DOFs is
considered sufficient however it can be increase for better dexterity. Increasing the number of DOFs
could result in different and complicated mechanism. Thus it will add complexity to the design and
controller. The major contributor to the total weight of current prosthetic hand is DC motors. In future
build in actuators could be considered to replace DC motors. he prosthetic hand in this study was
developed specifically for BCI application. Application of BCI technology in controlling a prosthetic
hand is a promising method to restore communication of “locked-in” with external environment. To
date, experiment to test ability to control prosthetic hand was carried out on healthy subject. The
possibility of implementing the technology to “locked-in” patient is yet to be discovered.
Acknowledgement
I would like to thank the UM-BCI group for great teamwork and sharing knowledge in completing the
project. Thank you to all technicians in mechanical workshop, University of Malaya for their help and
advice during fabrication and machining processes.