Dr. Ashish Dutta

Indian Institute of Technology

Dr. Ashish Dutta
Professor, Dept. of Mechanical Engineering
Office: Faculty Building Room 338
Phone:91-512-2597562 (Off.), 2598710 (Res)
Affiliated Center(s):
 Centre for Mechatronics

Design of an optimal
finger exoskeleton based on human motion data




Objective : understanding synergy between: hand kinematics - muscles - brain.


§ Human finger motion biomechanics.


§ Optimal design of a hand exoskeleton.


§ Hybrid control (EEG+EMG+Dynamics)


Finger biomechanics:


•How do humans perform simple object manipulation (rotation + translation) ?



Simple task of moving a coin and its motion analysis(NAIST Japan):


- 30 subjects performed this task.



Axes notation for each joint:


Manipulability calculation based on joint positions:

Ellipsoid calculations:


•Activity of each finger :

•Ellipsoid volume

•Direction of major axis of ellipsoid

•Ratio of axes

Rotations and 3D motion:



Design of finger exoskeleton:


•Three finger exoskeleton (index-middle-thumb).

•Grasping and simple manipulation ability.

•Control using EMG / EEG, Inverse kinematics.

•Use in stroke rehabilitation, assistive robot, physical therapy.


Thumb and middle finger:

Links made by rapid prototyping and actuated by ultrasonic motors:



Fabrication of the exoskeleton: Rapid prototyping:



Three finger exoskeleton for exact finger motion emulation:


- 10 DOF actuated by ultrasonic motors.

- Both translations and rotations are possible.

- Control : NN and Inverse Kinematics



New 4 DOF Two finger exoskeleton for Stroke Rehabilitation



Hybrid control:



Augment EMG with EEG for Control


Flow chart of the control strategy: EMG + EEG signal recording - Feature extraction and classification - control of joint motors.