Ahmet Atasoy

24 DOF EMG controlled hybrid actuated prosthetic hand

A complete mechanical design concept of an electromyogram (EMG) controlled hybrid prosthetic hand, with 24 degree of freedom (DOF) anthropomorphic structure is presented. Brushless DC motors along with Shape Memory Alloy (SMA) actuators are used to achieve dexterous functionality. An 8 channel EMG is used for detecting 7 basic hand gestures for control purposes. The prosthetic hand will be integrated with the Neural Network (NNE) based controller in the next phase of the study.

SMA actuated prosthetic finger design

The proposed work will cover a mechanical design that imitates natural shape and posture of anatomic finger and design of Shape Memory Alloy (SMA) actuators that mimics natural functions of a finger. The best mechanical finger design lies in imitating the complex structure (anatomy) of the human finger with all its bones, joints, muscles, tendons and their connections as close as possible. At this point shape memory alloys are good potential with its muscle like working principles, SMA actuators are placed on phalanges to provide finger movements.

Evaluation of Sensory Feedback from a Robotic Hand: A Preliminary Study

In this study, a robotic hand was equipped with force and bend sensors. Sensors were modified to fit the robotic hand and for more efficient utilization. A cylindrical grasping task was performed for three conditions, namely no object, soft object and hard object. Features were formed using the outputs of the sensors and their first and second derivatives. A multinomial logistic regression model was fitted to the data. Classification was done according to both object type (no object, soft object and hard object classes) and movement type (no movement, flexion, contact/release and extension classes). Results have shown that the information from the force sensors do not adequately contribute to the feature space because of poor coupling and this affects discrimination of soft object and contact/release classes. More sensors and a better actuation protocol need to be used in future work.

Finger design for anthropomorphic prosthetic hands

The prototype of a human hand can be has anthropomorphic features when considering the complex structure (anatomy) of the human hand with all its joints, muscles, tendons and their connection. In this study as a starting point an anthropomorphic approach is proposed for the mechanical design of the index finger. For this purpose the mechanical structures of the index finger are reproduced in both real and virtual environments. The results for the simulation and prototype are then compared with each other and the human index finger.