Exo Glove for stroke patients

Sensorimotor impairment of limbs is a major consequence of Spinal cord injury and strokes. To aid increasing amount of patients suffering from these neurological diseases, a lightweight, wearable and 3D printable exoskeletal glove has been developed. Unlike previously developed metal or fabric-based

Project Title

Exo Glove for stroke patients

Project Area of Specialization

Biomedical Engineering

Project Summary

Sensorimotor impairment of limbs is a major consequence of Spinal cord injury and strokes. To aid increasing amount of patients suffering from these neurological diseases, a lightweight, wearable and 3D printable exoskeletal glove has been developed. Unlike previously developed metal or fabric-based exoskeletons, our project presents the development of soft exoskeletal glove made of Thermoplastic Polyurethane (TPU). The drive mechanism consists of a single motor with tendons to perform extension and flexion of middle or index finger. A tendonbased differential drive mechanism is incorporated to allow for grasping irregular shaped objects. The design features easy 3d-Printability with TPU without a need for supports, a diamond structure to allow for ventilation and to maximize stretch-ability. Teflon tubes are embedded within the design to minimize the friction in tendon pathways.

Project Objectives

• Weight of the whole system should be less than 800g, otherwise it would cause fatigue for the user and will be less effective for rehabilitation.

• The device must have safety features to prevent hyperextension and hyperflexion and emergency power off switch in case anything goes wrong.

• Device should be comfortable to wear and should not cause any skin damage when flexing or extending the fingers

• The material used for the device should be biocompatible.

Project Implementation Method

The project is divided into 3 main parts:

1. Design of Soft-Exoglove

• The system was designed in such a way that it helps stroke patients to maximize the tactile sensitivity by removing material from the parts where finger interact with the object it holds.

• Glove features embedded pathways for tendon cables. External cables can get stuck in any object causing self-damage.

           2. Differential Mechanism

• A high torque geared DC Servo Motor MG996R that is the main actuator.

• A battery – Lipo 2s 800mAh battery that is able to power the device for more than 2 hours of continuous use.

        3: EMG Sensor

An emg sensor placed on the forearm is used for the actuation of geared motor using arduino uno.

Benefits of the Project

•    Affordable and time saving device for stroke patients
•    To eliminate the need of labor-intensive task of       physiotherapist
•    Compact and light weight assistive device

Technical Details of Final Deliverable

Soft-Exo Glove

• The glove features Rhombus shaped pattern which increases the compliance of the glove and its easier for the glove to aid the hand in its natural motion.

• Rhombus structure was chosen because it offers 1 Degree of Freedom in longitudinal direction. This decreases the structural rigidity and hence offers more compliance in longitudinal direction. So, we can do not require removal of material to increase compliance, unlike in case of circular or any other structure.

• The glove was designed in such a way that it is easily 3D-Printable with Thermoplastic Poly Urethane (TPU) which is one of the hardest material to 3D Print with.

• All the angles in the thimbles were set to less than 60 degrees at unbridged areas

• The tendon pathways for flexion of fingers feature a novel arrangement through which under-actuation of the fingers is achieved.

• TEFLON tubes were also embedded in the thimbles for reduced friction when underactuation is required.

Differential Mechanism

The actuation unit is an enclosure 3D Printed with PLA and it contains the following components:

• A high torque geared DC Servo Motor MG996R that is the main actuator.

• A dual track pulley that houses two antagonistic tendons. One for extension and one for flexion. When the motor turn clockwise, the tendon for flexion gets wounded on the pulley while the tendon for extension unwounds and slacks and vice versa. This way, extension and flexion of the fingers is achieved with a single motor

• A battery – Lipo 2s 800mAh battery that is able to power the device for more than 2 hours of continuous use.

EMG Sensor

Sensor placed on the forearm using high quality electrodes to capture the slightest of muscle activity. It produces a signal that is send to the arduino for processing. The sensor itself filters the signal. A threshold value is used for actuation of servo. If the signal value is greater than threshold then it moves in clockwise direction thus causing flexion and if it is lower than threshold value it moves in anti-clockwise direction causing extension.

Final Deliverable of the Project

HW/SW integrated system

Core Industry

Medical

Other Industries

Health

Core Technology

Robotics

Other Technologies

3D/4D Printing, Wearables and Implantables

Sustainable Development Goals

Good Health and Well-Being for People, Reduced Inequality

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com