Enabling a Cerebral Palsy Patient to Use a PC with a Foot-Operated Device

Anand JoshiFahad KhanSuzy Lopez

Michael PowellCarlos Vallin

Presented at Roswell Nursing Home andRehabilitation Center

April 28th, 2009

Project Overview

• Continuation of a previous group’s project

• Designed and implemented a system to allow a cerebral palsy patient to access software applications on a desktop computer

• Created a customized solution that is cost-effective and addresses the patient’s needs

• Sponsored by Kiwanis International

Design Features

The design includes the following features

• Non-invasive

• Robust and lightweight

• Comfortable and easy-to-use

• Cost-effective

• Easy to set up and maintain

• User-friendly

• Automatic startup software procedure

Previous System – Starting Point

Problems With Previous System

• Head Tracking was inaccurate due to extraneous movements by the patient and lack of head control

• Difficult for patient to see screen when moving head for

tracking purposes

• Need for third party help to attach mouse to wheelchair

• Wireless mouse runs off of batteries that need to be

replaced periodically

• Wireless mouse was uncomfortable to patient

• Software interface non-intuitive

New System

• Nintendo Wiimote – Commercially available for easy replacement

• Foot Operated Device (FOD) - Scrolling

• Wiimote Nunchuk - Clicking

• Hardware/Software translator: GlovePIE

• New On-Screen Keyboard

– Text Editor

– Email Reader and Composer

– Web Browser

Pre-Experimentation Constraints

The following constraints were observed prior to the first phase of experimentation with the patient

• Wheelchair-bound• Motor skills• Speech• Living environment

Post-Experimentation Constraints

The following constraints were observed after the first phase of experimentation

• Fatigue with excessive use of the system

• Involuntary motion while operating the system

Project Goals

The system includes the following functionality to accommodate the aforementioned constraints

• Foot Operated Device and Wiimote mapped

patient’s foot movements to the on-screen

keyboard

• Thresholds established for maximum left and

right foot movements

• Horizontal on-screen keyboard with wrap around

function and enhanced key functionality

• Customized e-mail, browser and text application

Keyboard Navigation

The Wiimote tracks the following three foot movements:

• Center – Highlights the key• Right – Transforms the key to move right

Foot rotates to the right

and cursor scrolls to the right

Keyboard Navigation

The Wiimote tracks the following three foot movements:

• Center – Highlights the key• Right – Transforms the key to move right• Left – Transforms the key to move leftFoot

rotates to the left

and cursor scrolls to the left

Snapshot of FOD Interfaced with the Keyboard

Enhanced Keyboard Functionality

Main Menu Function gives access to the following applications:

•Text Editor

•Email Application (Read/Write)

•Web Browser

Text Editor

• Intuitive interface

• Scrollable

• Saves text to a .txt file

• Auto saves to avoid

losing data while

switching applications

Email Application (Reading Interface)

• “Get New” button

should be used for

downloading new

emails

• Reading Pane toggle

added for better patient

control

Email Application (Writing Interface)

• Easy to use and self

explanatory buttons such

as

“From”, “To”, “Subject”,

”Body”

• This eliminated repeated

toggling and resulted in

making the whole

processes faster and

more efficient.

Web Browser

• “Enter URL” button

should be used for

entering website

addresses

• ↑ is used for scrolling

up

• ↓ is used for scrolling

down

• → for scrolling across

the page

Scalability Measures

The design serves as a framework to develop further applications by taking advantage of the following

• Predictive text technology

• Develop software applications that take into

account the patient inputs

• Specialized gadgets

• Games(Patient prefers Bingo)

• Instant Messaging

• Twitter

Changes in Software

Proposed Features Additional Features

• Foot-controlled navigation

• Glove pie used as a translator

between HW/SW

• Text editor application

• Custom e-mail application

• Custom web browser

• Center cursor application

• Keyboard Wrap Around

Function

• Accelerated scrolling

• Text-to-speech

• Error-correction

• Stability control

• Configuration file

• Predictive text technology

Changes in Hardware

Device Proposed Final

Foot Operated Device

• LED cluster

• Reflective Tape

• IR LED used in conjunction with Wiimote

Clicking mechanism

• Mouse with 30’

range

• Attached to wheel chair

•One magnetic

sensor

• Nunchuk Wii device

• Attached to Desk not wheelchair

Cost of Parts and Equipment

The following costs include development expenses:

• Projected cost $2,000

• Actual cost $265

CPIO group made used “off the shelf” products to minimize cost and reduce replacement difficulty

Labor was provided by the CPIO Group from the Georgia Institute of Technology

Hardware Recommendations

The following improvements can be made to increase the accuracy of the input devices

• Mount the webcam on an adjustable stand

• Reduce the size of the mouse enclosure

• Obtain tighter finger glove and stronger magnet

• Identify additional methods of input

• Attach the armrest to a desk

• Design a wireless foot pedal

Software Recommendations

The following improvements can be made to make a more comprehensive user interface

• Automate software startup procedure

• Improve error-correction algorithms

• Enable user to navigate within text

• Enhance dictionary

• Extend web browser to handle all content

• Allow user to use horizontal and vertical motion

• Create easy-to-use configuration interface

Questions?