Project

# Title Team Members TA Documents Sponsor
1 Prosthetic Hand for Typing
Rahul Krishnan
Rohil Hatalkar
Vaidotas Marcinkevicius
Dhruv Mathur design_document1.pdf
design_document2.pdf
design_document3.pdf
design_document4.pdf
final_paper1.pdf
proposal1.pdf
proposal2.pdf
Group Members:
Rahul Krishnan (rahulk3), Rohil Hatalkar (rah2)

Problem:
Currently, the field of prosthesis is making advances in bionic arm technology, however, these solutions are extremely expensive and not available to the public. In the modern age, the use of computers has become prevalent and people with disabilities (specifically those without one or both arms) may be at a significant disadvantage due to their lack of speed or inability to type.

Solution Overview:
We propose a simple solution to this problem by creating a prosthetic hand that can be used to type with a user's feet, primarily the two big toes. This device will have two main systems. The first system will have 5 buttons placed below the user's feet corresponding to the 5 fingers on a hand. The second system is a lightweight prosthetic hand that will support lateral finger movement. We will use bluetooth to communicate the correct binary response from the foot device to the prosthetic hand. Small motors on the joints of the fingers will move to extend the finger so the correct key can be pressed. The user is expected to be able to move their hand forward, backward, up, and down while hovering over the keyboard, so they can press any key on the keyboard with the use of their foot.

Solution Components: (We have provided links for specific parts we are considering.)

Foot System

Subsystem #1: 5 buttons will be placed on the top of the foot system corresponding to the fingers of the hand. When the user activates the button with their toe, the corresponding binary signal will be sent to the prosthetic hand that will complete the press on the keyboard. The diameter of the button should be about an inch as this would allow a toe to comfortably press the button. We will place the buttons approximately an inch apart to ensure the user does not press multiple buttons simultaneously.
https://www.digikey.com/product-detail/en/adafruit-industries-llc/3491/1528-2318-ND/7349497

Subsystem #2: An Arduino will be used, so we can get feedback from the buttons and send the binary response to the prosthetic hand system via bluetooth.
https://www.amazon.com/Arduino-A000066-ARDUINO-UNO-R3/dp/B008GRTSV6/ref=sxin_2_ac_d_pm?ac_md=2-1-QmV0d2VlbiAkMTUgYW5kICQyNQ%3D%3D-ac_d_pm&cv_ct_cx=arduino+uno&keywords=arduino+uno&pd_rd_i=B008GRTSV6&pd_rd_r=487e073d-9880-4882-9560-b91e97105dd7&pd_rd_w=ML2Hy&pd_rd_wg=Aj7jV&pf_rd_p=ef07af27-e48f-451d-ab63-8b6b216a0bc3&pf_rd_r=X3ZHPDV1X58A1MQV78CK&psc=1&qid=1580247656&s=electronics&sr=1-2-22d05c05-1231-4126-b7c4-3e7a9c0027d0

Subsystem #3: We are considering using a HC-05 Wireless BT Module as it is known to work with an Arduino. The bluetooth module will require a range of 1.5 meters as we consider that to be the maximum height of a table. This module ensures a quality connection at a maximum distance of 10 meters, which is sufficient for our project.
https://www.amazon.com/HiLetgo-Wireless-Bluetooth-Transceiver-Arduino/dp/B071YJG8DR

Subsystem #4: We plan on using a rechargeable battery that will power the pcb and Arduino. The battery will supply a voltage of at least 5V in order to minimize size and cost. Therefore, we will keep all of our sensors below that voltage range. The battery will be charged using a micro USB cable.
https://www.digikey.com/product-detail/en/jauch-quartz/LI18650PBF-2S1P-PCM-WIRE/1908-1346-ND/9560970

Prosthetic Hand System

Subsystem #1: We will have five motors that are attached to the joints of each finger. We are thinking of 3D printing the hand or getting it made from the shop with wood. When the bluetooth module receives the data packet from the foot device, the motor will rotate to extend the finger forward and push the key down.
https://www.digikey.com/product-detail/en/jinlong-machinery-electronics-inc/Z4TL2B124064X/1670-1016-ND/6009921

Subsystem #2: An Arduino will be used, so we can receive and handle responses from the bluetooth module inside the foot device. The Arduino Microcontroller will also be responsible for moving the motors correctly.
https://www.amazon.com/Arduino-A000066-ARDUINO-UNO-R3/dp/B008GRTSV6/ref=sxin_2_ac_d_pm?ac_md=2-1-QmV0d2VlbiAkMTUgYW5kICQyNQ%3D%3D-ac_d_pm&cv_ct_cx=arduino+uno&keywords=arduino+uno&pd_rd_i=B008GRTSV6&pd_rd_r=487e073d-9880-4882-9560-b91e97105dd7&pd_rd_w=ML2Hy&pd_rd_wg=Aj7jV&pf_rd_p=ef07af27-e48f-451d-ab63-8b6b216a0bc3&pf_rd_r=X3ZHPDV1X58A1MQV78CK&psc=1&qid=1580247656&s=electronics&sr=1-2-22d05c05-1231-4126-b7c4-3e7a9c0027d0

Subsystem #3: We are considering using a HC-05 Wireless BT Module as it is known to work with an Arduino. The bluetooth module will require a range of 1.5 meters as we consider that to be the maximum height of a table. This module ensures a quality connection at a maximum distance of 10 meters, which is sufficient for our project.
(https://www.amazon.com/HiLetgo-Wireless-Bluetooth-Transceiver-Arduino/dp/B071YJG8DR)

Subsystem #4: We plan on using a rechargeable battery that will power the pcb and Arduino. The battery will supply a voltage of at least 5V in order to minimize size and cost. Therefore, we will keep all of our motors below that voltage range. The battery will be charged using a micro USB cable.
https://www.digikey.com/product-detail/en/jauch-quartz/LI18650PBF-2S1P-PCM-WIRE/1908-1346-ND/9560970

Criterion of Success:
The goal of this project is for people with only one hand to be able to type with both hands. This typing system should allow the user to use their toes to press the buttons, which translate into key presses from the prosthetic hand. The foot system has to be easy to use with limited room for error such as pressing multiple buttons simultaneously. The prosthetic hand must be able to press the keys accurately when receiving the binary response from the foot system. The delay between pressing a button with a toe and the motor extending a finger to press the key should be short.

Low Cost Myoelectric Prosthetic Hand

Michael Fatina, Jonathan Pan-Doh, Edward Wu

Low Cost Myoelectric Prosthetic Hand

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According to the WHO, 80% of amputees are in developing nations, and less than 3% of that 80% have access to rehabilitative care. In a study by Heidi Witteveen, “the lack of sensory feedback was indicated as one of the major factors of prosthesis abandonment.” A low cost myoelectric prosthetic hand interfaced with a sensory substitution system returns functionality, increases the availability to amputees, and provides users with sensory feedback.

We will work with Aadeel Akhtar to develop a new iteration of his open source, low cost, myoelectric prosthetic hand. The current revision uses eight EMG channels, with sensors placed on the residual limb. A microcontroller communicates with an ADC, runs a classifier to determine the user’s type of grip, and controls motors in the hand achieving desired grips at predetermined velocities.

As requested by Aadeel, the socket and hand will operate independently using separate microcontrollers and interface with each other, providing modularity and customizability. The microcontroller in the socket will interface with the ADC and run the grip classifier, which will be expanded so finger velocities correspond to the amplitude of the user’s muscle activity. The hand microcontroller controls the motors and receives grip and velocity commands. Contact reflexes will be added via pressure sensors in fingertips, adjusting grip strength and velocity. The hand microcontroller will interface with existing sensory substitution systems using the pressure sensors. A PCB with a custom motor controller will fit inside the palm of the hand, and interface with the hand microcontroller.

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