Multi-Adaptive, Pain-Management

Medical Chair

Roy D. McCord, Chirag Arya,

Raghav Chawla, Nathan Fu, Kevin Grebb, and David Odom

Georgia Institute of TechnologySchool of Electrical and Computer Engineering

Final Presentation and DemonstrationApril 23, 2009

Project Overview

• Wait times in dental offices, airports, and ERs have gotten longer; however, such waiting areas do little to ease the discomfort of incoming visitors.

• New design takes an existing chair and adds an on-board computer along with devices to aid in pain management.

• Anticipated parts cost is estimated at $830.00 per unit.

• Estimated retail price is $1000 per unit.

Organizational Structure

Fifteen Weeks Ago…

Today

Functional Design Layout

Defining the MarketPros and Cons

LocationEmergency

RoomDental Clinic

Airport (Other Non-Medical)

Market Size Large Small Large

Relevance of Peripherals

High High Medium

Risk of Damage

High Small High

Need of Additional Features

Low Low Medium

The Solution?

• We decided to account for all of these possibilities.

• Relay kit allows for easy switching of peripherals controlled by 5V power

Design AttributesBackground

• The human brain receives “electrical” signals and interprets them as brain waves

• A pain signal starts at the site of injury and travels toward the brain– If the brain does not interpret the signal as a pain

signal, no pain will be “felt”

• Goal is to distract the brain so that it does not interpret pain signals as pain

Pain-Masking Methods

• Acupuncture

• Acupressure

• Posterior Column Stimulation

• TENS Treatment

Our Choice: Acupressure

• Six USB-powered massagers were embedded in the chair

• Massager location based on research of “acupressure points”

• When specific pressure points are pressed, they release muscular tension and promote blood circulation

Technical ApproachPain-Mask Hardware – Additional Info

• Massagers operated depending on the area of the pain

• Manual/Automatic functionality

• Goal was for 70% of users to feel a reduction in pain

Design AttributesMind-Synchronization Generator

• Synchronize brain waves to states of relaxation by using visual and auditory stimulation

• Small enough to fit in user’s hand

• Easily built using simple analog components

Technical ApproachMind-Synchronization Generator

Courtesy of Bob Iannini

Resistances in ΩCapacitances in µF

Potential ImprovementsMind-Synchronization Generator (2.0)

• “No hands” operation– User does not have to know specifics to use– Automated frequency generation– One less piece of equipment that can be easily

damaged

• Implementation of binaural beats

• Different colored LEDs

Design AttributesMind-Synchronization Generator 2.0

• Microcontroller controls the pulse rate of light and sound separately– Easily reprogrammable

• Small enough to be hidden from user sight

• Different colored LEDs for user to choose

Technical ApproachMind-Synchronization Generator 2.0

• Atmel Butterfly Evaluation Board– ATmega169

– Low-power operation

– Small (1.77 in. x 2.64 in.)

– Programmed via RS232

• Interface board– Connects Butterfly with

CPU and relay for power

The DownsideMind Synchronizing

• Any series of flashing lights can, in certain cases, cause seizures.

• This implies a lot of legal red tape.

• Need to ensure that participants are fully aware of risks before use

Technical ApproachCPU Interface – EBOX 2300

• Target Device: EBOX 2300– X86 compatible 200Mhz

Vortex86 SoC– 128 MB System Memory– 256 MB Internal Flash Drive– Power consumption < 15W

• Runs Windows CE– Operating system tailored for

embedded systems– We use a custom build of CE

for the ER Chair

Technical ApproachCPU Interface – TouchScreen & Programming

• Touchscreen Interface– XENARC 705TSV™ – High brightness/contrast– 16x9 Aspect Ratio– Touch-sensitive

• Programming done with C#– Easily added as stand-alone

projects to custom CE build– Easy to assemble powerful

custom GUIs

CPU InterfaceFinished Product

CPU Interface Problem

• Phidgets 8/8/8 board will only drive small TTL chips, etc.

• Won’t supply enough current to massagers

• Created Phidgets “Black Box” to remedy this problem– Contains Phidgets 0/0/8 Relay

Board

• Required some hacking of the Phidgets Drivers subproject

Functional Layout Phidgets “Black Box”

Phidgets “Black Box”Looking inside…

Live Demonstration

Acceptance Testing• Ten random students were asked to test

the design and fill out a brief questionnaire.

• Questions covered physical aspects of the chair, as well as its functionality.

• Overall, responses were very positive.

Testing StatisticsThe Good

Does this hardware reduce pain?

Yes70%

No0%

Maybe30%

Yes

No

Maybe

• 70% felt that the massagers reduced pain.

• 100% found the chair comfortable.

• 100% found the CPU intuitive.

• 100% liked the touchscreen.

Testing StatisticsThe “Acceptable”

• 50% found the MSG “relaxing.”– An additional 30%

found it “sort of” relaxing

• 40% believed that the MSG would calm them “in a state of panic.”

Would the MSG Calm you in a State of Panic?

Yes40%

No40%

Maybe20%

Yes

No

Maybe

Acceptance TestingConclusions

• Overall, we believe these statistics prove a successful design.

• MSG is likely a bit “out there” for most users.

• CPU interface was the biggest success.

Project Issues• More specific market application

– Dental, ER, Airports, Family Practice?– We chose to allow for all of these possibilities.

• Integration of MSG 2.0 with CPU Interface– Need way to switch power without additional cost of

dozens of FETs

• Massagers require additional current to run.– Switched 8/8/8 board for a 0/0/8 relay kit

Possible Future Work

• Tailored headrest integrating touchscreen, mind-sync LEDs and audio speakers

• Custom overlay for integration of massaging hardware

• GPS tracking of chair locations

• Integration of MSG 2.0 into CPU Interface

• Improve durability of components– Reinforced touchscreen

Budget/Cost Analysis

Product Description

Quantity Unit Price Price

Chair 1 $200.00 $200.00

Xenarc 705TSV 7” touchscreen

1 $300.00 $300.00

EBOX 2300 1 $150.00 $150.00

USB Massage Ball

6 $10.00 $60.00

Phidgets 0/0/8 Interface Kit

1 $90.00 $90.00

Miscellaneous (cables, etc.)

-- -- $20.00

Total Parts Cost $830.00

According to the CDC, the average wait time in a common emergency room has grown to

over sixty minutes.