1. Infrared Camera from Wii System to Track Ultrasound Probe and Create 3-D Image
Vanderbilt University
Department of Biomedical Engineering
Van Gambrell
Laura Owen
Steven Walston
Jonathan Whitfield
Advisor Dr. Christopher Lee - Department of Neurology

2. Amyotrophic Lateral Sclerosis
ALS is a progressive neurodegenerative disease that causes atrophy of voluntary muscles through degradation of motor neurons
The size, shape, and structural makeup of muscles like the bicep can be good indicators of the severity of the disease

3. ALS in the United States
20-30 thousand people in the US have ALS
Doctors diagnose approximately 5,000 new cases every year.
Once diagnosed, a person with ALS is only expected to live 3-5 years.
Understanding the effects of the disease should help increase the life expectancy and in time hopefully cure it
Stephen Hawking

4. Dr. Christopher Lee
Vanderbilt University Medical Center, Neurology Department 
Dr. Lee specializes in evaluating muscle ultrasound in ALS patients
He uses this information to determine early clinical and electrodiagnostic features of critical illness polyneuropathy and myopathy

5. Imaging Muscles MRI Ultrasound MRI Great images
But expensive, time consuming, and immobile
Current standard
Ultrasound
Images comparable to MRI
Cheaper
Short imaging time
2D linear images acquired by free hand
Difficult to make a reproducible 3D image 
Ultrasound
With an MRI you get a perfect 360 view of slices so makes an accurate 3-d model
-However Ultrasound is less methodical and leaves room for gaps in measuring data.  which would prevent the 3-D model from being fully representative.

6. Imaging Machinery Ultrasound MRI Cost: Sonosite Titan: $16,500 Size:
Small laptop
8" LCD
Mobile:
Portable docking station
4 hour battery life
Cost:
Typical MRI Machine: $3 Million
Size:
490 Square Feet
Mobile:
Not Mobile
MRI machine 7 feet by 7 feet by 10 feet
MRI Cost : ~$3 million
Sonosite Titan: $16,500
Size of a small laptop
Comes with a portable docking station
small with an 8" LCD
has a 4 hour battery life
laura

7. Could 3-D Ultrasound be a good alternative to MRI
Can the location and position of the ultrasound probe be monitored?
Can a three dimensional image of muscle be generated using the signal from the probe and correlating it with the data of the orientation of the US probe?
Will an imaging system that fulfills these two questions be effective, portable, and cost efficient?
Will the monitoring of muscle volume be effective in researching treatments for ALS?
- Accurate
    -Free Hand Sensitivity
-Comparable to MRI
-If the machine cant fulfill these requirements then there is no need for the machine, because MRI will produce better results
laura
The main goal of this project is to create a way to monitor the muscle atrophy.  

8. Solution Design
Objective is to use 2 Wii-mote CCD's to track infrared LEDs
x and y position from each wii mote to calculate position in 3D
Using a triangulation algorithm to determine the position of the LED in 3 dimensional space using the 2 Wii-motes
Wii-mote can track up to four infrared emitters at one time
Placement of the LEDs will allow the tracking of the probe in  3-D space
Using the gyroscope from the Wii Motion Plus we will be able obtain the yaw, pitch, and roll information of the US probe
jon

9. Status and Results
Wiimote simultaneously tracks 4 infrared LEDs in 2D space 
Wrote a triangulation algorithm that computes 3D location from the 2 sets of data
Determined the camera calibration information, including focal length and other matrix information
Calculated a centroid to return one data set for 4 IR light sources
Ordered the WiiMotion Plus, Andruino, and adapter
Have Opensource code to return the Yaw, Pitch and Roll data from the WM+ and Andruino
Determined sampling rate to be 60 Hz
jon

10. Data Transfer Schematic
jon

11. Wii-Motion Plus and Arduino
Wii-Motion Plus has much more sensitive accelerometers than the wii mote that can provide 6 degrees of freedom to correctly establish the U.S. probe's orientation.
jon
Arduino is an open source prototyping platform that can interface with the Wii-Motion Plus and the computer to provide angular data from the U.S. probe

12. Physical Schematic
Determined the asymmetrical arrangements of infrared light to be placed on the US probe
Determined that one WiiMote Camera should have a field of view perpendicular to the typical orientation of the US probe
The backbone of the triangulation algorithm has been determined
The orientation of the two motes can be used in unison with the distance between the two returned data points.
This relation can determine the third z coordinate using simple trigonometry
Determined the camera calibration information, including focal length and other matrix information
Calculated a centroid to return one data set for 4 IF lights

13. Estimated Final Cost of Design
Wii Motes: $39.99 
X 2 = $79.98
Wii Motion Plus: $17.96
Adruino: $30.00
Adruino + Wii Motion Plus Adapter: $4.00
Circuit Electronics: $15
LEDs, Resistors, Battery, Wires
System Mount: ~$20.00
Arm Stabilizer: ~$18.00
Unforeseen Additions: ~$40.00
Final Cost: ~$225.00
laura

14. Known Problems
Infrared signals from external sources can interfere with LED signals
The IR LEDs emit signal in a conical area (limited view)
Potential accuracy problems
Incorrect centroid calculations due to blocked IR LED
steven

15. Wiimote Sensitivity 2 infrared LEDs 30.48cm apart
Error = -2.46mm ± 2.23 (mean ± std) 
steven

16. Current Work Plans Set up the Wii Motion Plus + Adruino
Use the Opensource Software to obtain working gyroscope data
Sync wiimote and ultrasound acquisition rates
Interface the system with the 3-D reconstruction software
steven

17. Future Work Plans By March 1st
Physically attach the WiiMotion+ device to US probe
Create a mounting system for the IR cameras
 Use the position data to tag Ultrasound images and create a 3 dimensional image
 Mid March
Begin taking samples for data analysis
April
Have completed data acquisition
Quality assessment
steven