1. Wave Consulting
Department of Mechanical Engineering
Box 870276
Tuscaloosa, AL 35487
August 1, 2014
Dr. Daniel Fonseca
Dr. Rick Houser
The University of Alabama
1022 NERC
Tuscaloosa, AL 35487
Dr. Fonseca and Dr. Houser:
This document contains information for an EEG measurement device designed by Wave
Consulting. The User’s Guide we spoke about earlier can be found in the appendix of this report.
Thank you both for allowing our senior design team to work with you on this project.
Sincerely,
David Tubbs
Team Communicator
detubbs@crimson.ua.edu
2. Wireless EEG Transmission Device
Submitted to: Dr. Daniel Fonseca and Dr. Rick Houser
Submitted by: Wave Consulting
Course: ME 490
Instructor: Dr. Marcus Ashford
Mechanical Engineering Department
The University of Alabama
Tuscaloosa, Alabama
August 1, 2014
3. By signing this page, each team member agrees with the contents of the proposal.
Ryne Hill
Technical Division/Finance/Safety Executive
Signature Date 08/01/2014
Taylor Jenkins
Project Executive/Technical Division
Signature Date 08/01/2014
Mykalah Sundquist
Evaluation Division/Technical
Signature Date 08/01/2014
David Tubbs
Public Relations/Technical Division
Signature Date 08/01/2014
Trevor Turnbough
Team Coordinator/Evaluation Division
Signature Date 08/01/2014
4. Executive Summary
An Electroencephalography test (EEG) involves the amplification of bioelectric
potentials, which are associated with neuronal activity of the brain. The EEG uses electrodes to
measure brain waves, which are measured in Hertz. The purpose of this project was to design
and develop a mobile device that employs an EEG 19 channel amplifier. Our design involves the
use of our client’s current Mitsar amplifier and WinEEG computer software. The helmet uses the
same electrodes and housing units that our client’s Bio-Medical helmet uses on a neoprene cap
with a chinstrap for durability and comfort. A wireless system is used to transfer the EEG data to
the client’s personal computer.
The team divided into roles to promote organization, efficiency, and accountability.
Taylor Jenkins was assigned the executive role; Trevor Turnbough was responsible for
coordination; the evaluation and safety roles were run by Ryne Hill; Mykalah Sundquist was
assigned the finance role; and David Tubbs headed the public role. Technical roles were divided
among the team with data transfer headed by Taylor Jenkins and Trevor Turnbough, controls and
instrumentation were headed by Mykalah Sundquist and Ryne Hill, and fabrication was led by
David Tubbs.
The University of Alabama had many of the manufacturing capabilities that we used for
the fabrication of this device including the 3D printing lab and Makers Space, both located in
Hardaway Hall. The University of Alabama has allowed the use of its facilities and staff during
this project.
The final project was delivered to the clients on July 31, 2014. Continued testing and
future work is set to be carried out by graduate students in the department of Mechanical
Engineering at The University of Alabama.
5. Table of Contents
Introduction and Background ......................................................................................................... 1
Desired End Product ....................................................................................................................... 2
Design Requirements...................................................................................................................... 3
Technical Approach........................................................................................................................ 4
Project Timetable............................................................................................................................ 6
Budget............................................................................................................................................. 7
Facilities and Resources.................................................................................................................. 7
Team Organization.......................................................................................................................... 8
References....................................................................................................................................... 9
Appendix....................................................................................................................................... 10
6. 1
Introduction and Background
Electroencephalography (EEG) is the recording of brain activity. It uses scalp mounted
electrodes to measure fluctuating voltages within the neurons of the brain. EEG can be used to
diagnose ailments such as epilepsy, comas, and sleep disorders. A typical EEG test involves
electrodes being placed on the patient’s head for a short period of time, usually 20 or 30 minutes.
Figure 1 illustrates the greatest problem with current EEG systems: Placing individual sensors on
the patients scalp.
Figure 1. EEG test
A drawback with most conventional EEG tests is that the patients are required to be in the
same room as the testing machine. While this doesn’t provide any severe discomfort to the
patient, it does make it difficult to diagnose some problems. For example, consider the use of an
EEG to help diagnose a sleeping disorder. The physician needs the patient to sleep naturally, an
7. 2
exceedingly difficult proposition for someone with a bundle of wires attached to their head. Even
smaller EEG systems consisting of a cap with several installed electrodes run via a ribbon cable
can still be a hassle.
A wireless EEG system with cap mounted electrodes would have many benefits for the
client and for the patient alike. A wireless set up is much easier to set up for both the person
administering the test and for the patient. Set up time for the test is decreased drastically, because
individual sensors don’t have to be placed one by one on the patients head, nor does the patient
need to be tethered directly to the computer. The wireless cap allows the test administrator to set
the cap up correctly on the individual much more quickly, and then simply go to his computer
and start administering the test. A benefit for the patient receiving the test is that they don’t have
to spend as much time at the testing facility or be restricted to the immediate vicinity of the
testing computer.
Desired End Product
The desired end product was a wireless EEG system that included EEG electrodes and a
wireless data transfer system. The desired end product was one that has already been tested and
proven reliable and safe.
This apparatus will be used with an existing testing device that is not mobile. Dr. Houser and
Dr. Fonseca were given the helmet with all of the sensors for the EEG, a document that outlines
how to use the product, and a tutorial presentation.
Deliverables:
Helmet with EEG sensors
Wireless data transfer system
8. 3
User’s Manual
Wireless protocol documentation
Spare parts for future testing
Design Requirements
The functional requirements of the EEG data transfer system that Wave Consulting was
tasked with designing is an impedance checking and monitoring device and an amplifier capable
of recording raw brain waves at 19 locations according to the “10-20” international EEG
standard.
Physical design specifications were based on a cap design based on a large adult sized
head (59 to 63 cm circumference). The cap and amplifier have wireless connection capability
with real time recording up to 30ft.
The main design constraint for the EEG data transfer system was mobility. The housing
for the electrodes allows for easy administration of gel into the electrode to insure adequate
impedance. Completion date was August 2014.
It was also important to our client that we deliver a product under budget while still
meeting the needs and functional requirements. Since the project related to human subject
testing, we had to be careful not to do anything that could put the department at risk of lawsuit or
punishment. Certain ethical constraints were also presented since the project involved human
subject testing. The safety, health, and welfare of the patients were held paramount in the
performance of all EEG testing. Members of Wave Consulting acted in professional matters for
the client and patient as faithful trustees.
9. 4
Technical Approach
Figure 2. Technical Approach Flow Chart
Figure 2 illustrates a general overview of the technical approach used to complete this
project. The details of each step are explained below.
The problem statement was obtained and discussed with the clients to better understand
the overall scope of the project. Once the problem was defined, a meeting with Dr. Houser and
Dr. Fonseca was arranged to better define specific goals and needs for the final project.
The helmet that was selected for this project had to meet several requirements set forth by
the client. Those requirements are discussed in detail in other sections of this report and include
patient comfort and durability. Rresearch was done to ensure that a proper helmet is selected.
Once a helmet was selected, EEG electrode sensor research began.
The Wave Consulting team gathered data on existing EEG sensors to begin design work
on the EEG portion of the project. Once initial research was done, the team decided on a sensor
Research Helmet
Designs
Concept
Selection
EEG Sensor
Research
Testing and
Feedback
Adjustments
Sensor
Selection
Finalization
Problem
Definition
System
Selection
Research Data
Transfer Systems System
selection
Assembly
10. 5
to use on the project. With a sensor selected, the team presented their work to the client for
approval.
When sensors were selected and a cap was constructed, wireless data transfer system
research began. Research was conducted on existing wireless data transfer systems to learn more
about how they work and to narrow the selection down. Once research was done on data transfer
systems, a system was selected by the team.
After all of the items were approved and purchased, the assembly of the system took
place. When the product was tested for a period of time to ensure it worked properly, the design
was finalized and submitted as a final product.
Throughout the entire process, several steps were completed simultaneously. As an
example, the EEG sensor selection and the wireless data transfer research were both going on at
the same time. Having steps that overlap encouraged the team to always be working on a
different aspect of the project.
Future work for this project is planned to be completed by Mechanical Engineering
graduate students. Plans for future work should involve signal testing with a low range function
generator. Details for a function generator that meets the needs of the project can be found in the
appendix of this report. Further human subject testing can begin once approval from The
University of Alabama IRB is gained by Dr. Houser and Dr. Fonseca.
11. 6
Project Timetable
Figure 3. Project Timetable
Figure 3 shows the timetable for our project over the summer. Based on the time frame,
the project concluded during the first week of August. The chart shows which tasks took up the
majority of the time. These included: testing the wireless system, the EEG sensor analysis, and
final assembly. While some tasks were done simultaneously, others were undertaken in a
sequential order.
4/7 4/17 4/27 5/7 5/17 5/27 6/6 6/16 6/26 7/6 7/16 7/26 8/5
Research Helmet Designs
Helmet Selection
Helmet Design Analysis
Finalization of Helmet Design
EEG Sensor Research
Sensor Selection
Analysis of EEG sensors
Assemble into Helmet
Research Data Transfer systems
Testing & Adjustments of cap
Testing of wireless systems
Carrying case design and build
Selected wireless systems
Final Assembly
Poster Fair
Final Presentation
12. 7
Budget
The cost to the client included a $2000 Design Clinic Fee for the use of Mechanical
Engineering resources. All hardware used to create the final project is listed below:
EEG Cap Prototype -$465
o Neoprene Cap x 2 - $40
o EEG Electrodes x 2 - $250
o Ear Electrodes - $30
o Electrode Mounts x 25 - $42
o Miscellaneous Cap items - $103
Wireless Data Transmission- $892
o RS232 Transceiver - $159
o USB kit with Transmitter & Receiver - $210
o Stream HD Wireless PC to TV - $147
o Wireless USB Docking Station - $50
o Battery Pack-$40
o Miscellaneous Wireless Data Transmission items - $286
Total Expenses - $1357
Budget Remaining - $643
Facilities and Resources
Throughout our design process, Wave Consulting met in various rooms around campus.
These sites included room 236 in the Biology building, the ideaLab located on the ground floor
in Hardaway Hall as well as the Hardaway Hall computer lab.
Wave consulting used Dr. Keith Williams, Dr. Fei Hu, and Dr. Hwan Sik-Yoon and
their knowledge to assist in data transfer system selection. Additional faculty members including
13. 8
Dr. Marcus Ashford, Dr. Daniel Fonseca, Dr. Rick Houser, and Dr. Steve Thoma were also
consulted.
Team Organization
The team was divided into technical and non-technical divisions. The six non-technical
divisions consisted of an executive division, coordination division, finance division, evaluation
division, public division, and a safety division. Taylor Jenkins was in charge of the executive
division. Taylor’s job was to supervise team activities and control the project focus as well as
maintain efficiency through time management. Trevor Turnbough was in charge of the
coordination division, his responsibilities included organizing and keeping records of group
meetings with the team, client, and/or professors and establishing coordination and
communication between team members. Ryne Hill headed the finance and safety divisions, he
performed economic analysis to ensure the project is within budget constraints and confirm
safety parameters for the product and ensure they are met. Mykalah Sundquist was in charge of
the evaluation division. Her job was to oversee that the product met the required level of quality
and the testing of the design, she also confirmed parameters for verifying the analysis and
presentation format. David Tubbs was head of the public division. David presented the proposal
and final product to the client and generated public interest in the project.
The technical division consists of three different sub-divisions; data transfer, controls and
instrumentation, and fabrication. Data transfer was led by Trevor Turnbough. This sub-division
consists statistical analysis of the wireless system for the 19 channel feedback design. Taylor
Jenkins and Ryne Hill were in charge of the controls and instrumentation. This sub-division
included the electrical setup and sensor calibration and will work in conjunction with data
14. 9
transfer to properly apply a wireless data transfer system. Fabrication was be led by Mykalah
Sundquist and David Tubbs. This sub-division consisted of building the helmet, sensor adapters,
wiring harness, and an ergonomic prototype.
References
Operation Manual (2012). Electroencephalographic System. Mitsar Co. Ltd.,
St. Petersburg, Russia. Copy in possession of author.
Operator’s Manual (2011). tDCS Model 1300A Low-Intensity Stimulator. Soterix
Medical Inc., New York, NY. Copy in possession of author.
User Manual (2012). StarStim. Neuroelectrics Barcelona SL, Barcelona, Spain. Copy in
possession of author.
Rizzoni, G. (2005). Principles and Applications of Electrical Engineering (5th
ed.).
New York: McGraw-Hill.
Wheeler, A.J., & Ganji, A.R. (2010). Introduction to Engineering Experimentation
(3rd
ed.). Upper Saddle River, NJ: Prentice-Hall.
16. 11
Introduction
The University of Alabama Mechanical Engineering student team of Ryne Hill, Taylor Jenkins,
Mykalah Sundquist, David Tubbs, and Trevor Turnbough worked to develop a wireless EEG
brain wave monitoring system. This document should be considered the User’s Guide for the
product. Future work is planned for graduate students in the Mechanical Engineering department
at The University of Alabama. Proper documentation has been passed along to them to continue
work.
Users Responsibility
It is assumed that the Mitsar EEG amplifier and WinEEG software will be used with this system.
As such, special care must be taken with these items. The literature provided with these systems
specifically states that the use of outside sources of data transfer (wireless USB) could damage
the systems. By using the wireless data transfer system on the existing amplifier, the user accepts
all responsibility for damages that may occur. The user should be aware that any future warranty
claims with Mitsar could be subject to scrutiny about proper usage of their products.
Safety Instructions
All safety protocols set forth by Mitsar should be followed in using this system. Please reference
the Mitsar Operation Manual to review safety instructions before use.
System Components
The system, as delivered by Wave Consulting in August 2014, contained the items listed below.
As stated before, an existing Mitsar amplifier and a WinEEG USB security key are required to
create a functioning system.
Component Name Qty.
EEG Cap with electrodes (Size: L) 1
6 ft. wiring loom (cap to amplifier) 1
3 ft. wiring loom (cap to amplifier) 1
Wireless USB transmitter 1
Wireless USB receiver 1
Ergonomic Pack 1
Battery Pack 1
Spares Qty.
Spare electrodes with housings 2
17. 12
System Usage
In setting up an EEG test, the following set of instructions should be followed. It is assumed that
steps succeeding these are identical to current EEG testing procedure and thus not listed.
1. Select a wiring loom to be used. Different length wiring looms are provided to tailor a fit
for patient comfort.
2. Plug loom into EEG cap and amplifier.
a. The red connectors indicate the correct orientation of the loom. Each connector is
labeled either cap side or amplifier side.
3. Plug Wireless USB receiver into an open USB port on the test computer
4. Plug the USB cord from the amplifier into the wireless USB transmitter
5. Power the battery pack by depressing the power button
a. Green lights on the battery pack should be illuminated
b. 2 lights should appear on the USB transmitter. The red light indicates power is
being delivered, the green light indicates the USB connection is established. This
power supply provides power to the amplifier and wireless data transfer system
6. Once the system is powered, green lights should be illuminated on the wireless USB icon
on the desktop.
a. The connection can be checked using the Warpia software
7. Based on testing set forth in the wireless protocol, the range of the system was found to
be 30 feet in a clear line of sight
a. Though wireless transmission through a single wall is possible, it should be
avoided if possible
Steps past step #7 should follow standard EEG test administration.
Troubleshooting for the wireless system and EEG cap can be found in this document.
The useable range for this device was determined by the testing protocol shown in Appendix B
below. The useable range was determined to be just under 30 feet with an open line of sight. The
device was also successfully tested with two 5 inch walls in between the transmitter and receiver.
This should allow testing to be done in an open classroom as originally requested by the client.
Troubleshooting
The following section provides troubleshooting guidelines for the EEG cap and wireless system.
Further troubleshooting advice, if required, can be found in literature provided with the Mitsar
amplifier.
Cap Troubleshooting
If an electrode is not reading properly
1. Verify wiring continuity in cap and loom
a. Continuity can be checked with a voltmeter
18. 13
2. Verify pin connection in 25 pin connector
3. Verify battery charge level
a. Battery should be charged after four tests
4. Reboot WinEEG software
5. Restart system by turning off battery pack
6. Replace sensor with a spare electrode. Note: See electrode installation instructions below.
If an electrode housing falls out of place
1. Spare electrode caps can be found in the spare parts provided
2. Locate electrode housing and cap in proper hole location. Take care that the electrode
housing and cap line up with each other. Note: The housing should be on the inside of the
EEG helmet and the white electrode housing cap should be on the outside of the EEG
helmet. Please refer to other electrodes for proper installation.
3. Place a drift punch over the white electrode cap. Verify that the working surface below
the cap is sturdy and flat. Swiftly impact the drift punch with a hammer several times to
depress cap into housing.
4. Verify proper installation by comparing to other electrodes and stretching the neoprene.
If upon stretching, the electrode stays in place, the electrode can be considered properly
installed.
Wireless System Troubleshooting
If wireless signal is lost
1. Verify power source is working
2. Check that lights are illuminated on Wireless USB receiver
3. Verify system stayed within useable range
a. If system is taken out of range, a reset of the power may be required
4. Confirm WinEEG software is operating correctly
a. If WinEEG is not responding: wait 10-20 seconds. If system does not regain
working status, a restart is required
19. 14
Appendix B- Wireless Testing Protocol
Wireless Testing Protocol
The following document explains the testing that will be completed once successful
wireless data transmission is achieved. The purpose of this testing is to determine the usable
range of the wireless device in both ideal and non-ideal conditions, which will be explained in
further detail below. The results of this testing will be used to accurately describe to our clients
the effective range of their new wireless EEG device.
The device being tested is a Warpia StreamHD wireless system. The system operates
using ultra wideband radio waves and claims to have an effective range of up to 30 ft. The USB
dongle operates on a point to point basis, where their maximum range is achieved when they are
in line of sight. The conditions that the device will be tested under are going to replicate how the
device will be used for our wireless EEG application.
To test, the wireless dongle (PC adapter) will be plugged into a personal computer. The
other wireless dongle (device adapter) will be plugged into the Mitsar EEG amplifier. The device
adapter and the amplifier will both be placed inside the ergonomic backpack that will be
included when we present the product to the clients.
Testing under Ideal Conditions:
To test under ideal conditions, the PC adapter will be plugged into the computer and the
device adapter plugged into the amplifier and inside the pack. Once the dongles are connected,
we will run the WinEEG software, which will work properly until we reach a distance where the
dongles become disconnected, or the data transfer rate becomes too slow. At either of these
instances, the WinEEG software will stop the test and display a message that tells us there was a
data transmission error involving the amplifier.
A team member will walk with the amplifier, away from the PC, in a direct line of sight
with the PC, until the system loses connectivity. When connectivity is lost, the team member will
stop walking, and the distance between them and the PC will be measured in feet. This will be
the effective distance, under ideal conditions, that the wireless device will transfer data. In order
to make this distance measurement as accurate as possible, this test will be performed four times,
in multiple directions, and the average distance of those tests will be found and recorded as the
effective range.
Testing under Non-Ideal Conditions:
To test under non-ideal conditions, the PC adapter will be plugged into the computer and
the device adapter plugged into the amplifier and inside the pack. Once the dongles are
connected, we will run the WinEEG software, which will work properly until we reach a
distance where the dongles become disconnected, or the data transfer rate becomes too slow. At
either of these instances, the WinEEG software will stop the test and display a message that tells
us there was a data transmission error involving the amplifier.
20. 15
A team member will walk away from the PC, similarly to what was done in the ideal test,
but this time will go around a wall and continue to walk until the error message appears. At the
point, the member will stop walking, and the distance will be recorded in feet. This test will also
be run five times in order to get a more accurate average.
Because the wireless system that is being used works on a line of sight basis, we do not
believe that it will successfully transmit data beyond one wall. But, a test will also be performed
with a member walking around one wall and then another. If the system displays an error
message before the second wall is reached or as the second wall is passed, we will state that the
product is not to be used beyond one wall.
There have been some concerns about Wi-Fi and cell phone usage causing interference.
Since the system is ultra wideband radio, it operates at a different range than Wi-Fi and cellular,
so no interference should be received. To be sure of this, we will run the same test as described
above, but while making phone calls and using the Wi-Fi. When performing these tests, the
average distances will be compared to the distances that were recorded earlier. If we find that
there is any interference, it will be noted in the user manual.
Test Results
All test results found during these testing periods will be recorded and inserted into the
user manual that will be provided to the clients. Any noticeable interference that we find will
also be inserted into the user manual.
21. 16
Appendix C- Document for future work
Continuation of Wireless EEG Project
This outline is a summary of our project, describing what we did and the resources that
we used as a team. We hope that the information provided will help with the continuation of this
wireless EEG project. The summary will be broken up into two categories, cap design and
fabrication, and wireless data transmission.
Cap Design
We started the project out with a bare 2.5mm swim cap. We then ordered EEG electrode
disks from electro-cap, along with the appropriate electrode disk holders. We used insulated
wiring from EEG electrodes that we already had, but this wiring can also be ordered from the
electro-cap website if you would like to duplicate our cap. We ran all of the wiring from the
electrodes to a 25-pin D-sub female crimp connector that was purchased from the local
RadioShack. The red ergonomic piece that the wires run through was made by one of our group
members in SolidWorks. He will stay on campus for the fall semester, so he can give you the file
if you would like, and we will include his information at the bottom of the document if you need
to contact him for any reason. Links for all of the items mentioned above can be found below:
2.5 mm Neosport cap: http://www.amazon.com/NeoSport-Wetsuits-Premium-Neoprene-2-
5mm/dp/B003554EFE
EEG electrode disks, holders, gel and wiring: http://www.electro-cap.com/index.cfm/supplies/
Note: The electro-cap link will take you to their supplies page, but you have to call them
to order the supplies that you need using the part numbers next to each product.
25 pin D-sub crimp female connector:
http://www.radioshack.com/product/index.jsp?productId=2102865
Wireless System Design:
We first ordered a Cables Unlimited wireless USB set that wasn’t compatible with
wireless mice and keyboards, so it gave us a lot of trouble. The second system we ordered was
the newer version of the Cables Unlimited system, which did support devices like mice and
keyboards. This system was also unsuccessful. The successful system that was used is a Warpia
wireless USB system. All of the paperwork and set up/installation guides that were included with
the wireless systems will be given to the client. Links for all of these devices are provided below:
Cables unlimited system 1 (no mouse support):
http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Delectronics&field-
22. 17
keywords=cables+unlimited+wireless+usb&rh=n%3A172282%2Ck%3Acables+unlimited+wirel
ess+usb
Cables unlimited system 2 (mouse support): http://www.amazon.com/Cables-Unlimited-
DisplayDock-Wireless-
Docking/dp/B003D1CBY6/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1405974142&sr=1-1-
catcorr&keywords=cables+unlimited+wireless+usb
Warpia StreamHD (successful system)
http://www.amazon.com/Warpia-StreamHD-Wireless-Full-1080P/dp/B004GTN0T4
Team Member Contact Information:
This is the information of the team member that will remain at school in the Fall. You
may contact him with any questions that you have about the project. Feel free to call, text or
email. He’ll be on campus Tuesdays and Thursdays.
-Ryne Hill
-rahill2@crimson.ua.edu
-678.447.6453
23. 18
Appendix D-Function Generator Information
The following function generator can be used to test the EEG cap. Wave Consulting was unable
to test due to time constraints of ordering this system.
http://www.mtiinstruments.com/products/precisionsignalsource.aspx
