Type of Submission

Poster

Keywords

Prosthetic, myoelectric, electromyography, biomedical, microcontroller, engineering, biomechanics, 3D printing

Proposal

The project goal is to design a low cost prosthetic hand controlled by a PIC18F25K22 microcontroller that will allow the user to perform simple tasks that require a greater dexterity than what a mechanical prosthetic can deliver. The digits of the prosthetic will be contracted or relaxed using electromyographic signals measured by electrodes on a single muscle group. Grip settings, which define the open and closed position for each digit, are used for the control of the hand. This allows common actions, such as grabbing a door handle or pencil, to be accomplished with readings from one muscle group instead of requiring a muscle group for each digit. Additionally, the use of pressure sensors on the fingers provide feedback to the user, and prevent the system from damaging itself by forcing the digits into an impossible position.

Our design focuses on increasing the accessibility and affordability of a prosthetic hand, without significantly sacrificing its quality or usefulness. Apart from wires, screws, and such miscellany, all components are 3D printed. This significantly decreases the cost, as well as ensures that replacement parts are readily available, with access to the STLs and a FDM printer. The design utilizes an OLED display interface, showing the currently selected hand grip and allowing the user to cycle through settings and menus using four tactile buttons. Settings include adjusting contrast and calibrating the EMG threshold for the current user. The calibration stores the EMG values of the relaxed and flexed state of the muscle group, and calculates the ideal threshold, the value at which the system closes the grip of the hand.

Prosthetic hands on the market are either prohibitively expensive, or unwieldy and limited in their usefulness. Targeting the former issue by relying on 3D printed parts, greatly alleviates the financial burden of the hand. Likewise, defining finger/grip positions and using EMG signals to switch between open and closed positions allows finer control than a mechanical prosthetic without burdening the user with a significant learning curve for using their prosthetic.

Start Date

4-8-2020 1:00 PM

End Date

4-22-2020 6:00 PM

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Publication Date

April 2020

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Apr 8th, 1:00 PM Apr 22nd, 6:00 PM

Bionic Hand Team

The project goal is to design a low cost prosthetic hand controlled by a PIC18F25K22 microcontroller that will allow the user to perform simple tasks that require a greater dexterity than what a mechanical prosthetic can deliver. The digits of the prosthetic will be contracted or relaxed using electromyographic signals measured by electrodes on a single muscle group. Grip settings, which define the open and closed position for each digit, are used for the control of the hand. This allows common actions, such as grabbing a door handle or pencil, to be accomplished with readings from one muscle group instead of requiring a muscle group for each digit. Additionally, the use of pressure sensors on the fingers provide feedback to the user, and prevent the system from damaging itself by forcing the digits into an impossible position.

Our design focuses on increasing the accessibility and affordability of a prosthetic hand, without significantly sacrificing its quality or usefulness. Apart from wires, screws, and such miscellany, all components are 3D printed. This significantly decreases the cost, as well as ensures that replacement parts are readily available, with access to the STLs and a FDM printer. The design utilizes an OLED display interface, showing the currently selected hand grip and allowing the user to cycle through settings and menus using four tactile buttons. Settings include adjusting contrast and calibrating the EMG threshold for the current user. The calibration stores the EMG values of the relaxed and flexed state of the muscle group, and calculates the ideal threshold, the value at which the system closes the grip of the hand.

Prosthetic hands on the market are either prohibitively expensive, or unwieldy and limited in their usefulness. Targeting the former issue by relying on 3D printed parts, greatly alleviates the financial burden of the hand. Likewise, defining finger/grip positions and using EMG signals to switch between open and closed positions allows finer control than a mechanical prosthetic without burdening the user with a significant learning curve for using their prosthetic.

 

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