Talha Shahid

Many exoskeleton systems use a cable-pulley mechanism for actuation for complex hand grips. This paper discusses a trajectory control of a finger using a mathematical model. The soft glove is designed based on the conceptual framework of a natural skeletal finger. A two-link mechanism forms the kinematic model of the finger joints and soft actuators. The design has a natural claw-like position for distal and middle phalanges during flexion. The cable passes through specially designed pulleys and anchors. An experiment is conducted to validate the controller model in predicting the finger position. A flex sensor measures the actual joint angle during flexion. The results indicate that the model is accurate in attaining the desired angular displacement. The controller is more accurate for lower joint angles of the finger. The model demonstrates potential in Continuous Passive Movement (CPM), task training exercises, and rehabilitation applications.

Soft hand exoskeleton is one of the technological alternatives for patients with hand paralysis. Several designs had been proposed to assist these patients to improve their quality of life. However, some of them are heavy and bulky and are not suitable for daily use. This work proposes a lightweight soft hand exoskeleton that can be activated using Electrooculogram (EOG). It has an under-actuated mechanism and 3D printed parts with cable routed around the glove and weighs 110 g. A control strategy was developed so that the wearer can blink their eyes to flex and extend the fingers. A series of experiments was conducted to evaluate its efficacy in performing basic gripping and grasping. The exoskeleton has the ability to grip and grasp objects with different shapes and sizes. It is hoped that the integration of EOG and soft hand exoskeleton can provide a new and unique way of rehabilitating the patient's hand and assisting him/her in various activities of daily living (ADL).

Soft robotics is a branch of robotics that deals with mechatronics and electromechanical systems primarily made of soft materials. This paper presents a summary of a chronicle study of various soft robotic hand exoskeletons, with different electroencephalography (EEG)- and electromyography (EMG)-based instrumentations and controls, for rehabilitation and assistance in activities of daily living. A total of 45 soft robotic hand exoskeletons are reviewed. The study follows two methodological frameworks: a systematic review and a chronological review of the exoskeletons. The first approach summarizes the designs of different soft robotic hand exoskeletons based on their mechanical, electrical and functional attributes, including the degree of freedom, number of fingers, force transmission, actuation mode and control strategy. The second approach discusses the technological trend of soft robotic hand exoskeletons in the past decade. The timeline analysis demonstrates the transformation of the exoskeletons from rigid ferrous materials to soft elastomeric materials. It uncovers recent research, development and integration of their mechanical and electrical components. It also approximates the future of the soft robotic hand exoskeletons and some of their crucial design attributes.

This paper proposes an optimal defect shape to increase the sensitivity of a MEMS cantilever based piezo resistive sensor. This work describes the sensitivity improvement using Stress concentration region (SCR) introduced in the cantilever beam. The SCR improves the surface stress on the cantilever beam and enhances the sensitivity of the sensor. A particular defect (sigma star) is introduced which is designed and place in a way that increases the sensitivity by about 20%.

The primary objective of designing the hand exoskeleton is to include a controllable degree of freedom (D.O.F) of the finger joints with minimum number of actuation modes. This paper describes the design and development of a multi D.O.F. hand-exoskeleton based on the rehabilitation criteria of an amputee to achieve different hand gestures on the passive amputee hand. The design contains 3 D.O.F finger links along with a separate flexion and extension of the wrist joint. The feedback sensors allow the exoskeleton to achieve perfect gripping as well as different hand gestures defined as classes in the library.