1. Sensor-based Human Motion Tracking Drew Walton CS525 Project Dr. Chow UCCS

2. Overview Describe the reason for evaluating different types of monitoring technologies Define requirements for consideration as a good choice for monitoring body movement Introduce four technologies that are capable of performing the required functions Compare the selected technologies

3. Reason for this project Interesting problem Remote monitoring of rehabilitative exercises! Curiosity What technologies are available? How are they being used for this application? Is there a problem to solve? Or am I too late?

4. The Present Situation Numerous technologies exist to monitor the movement of the human body Mechanical Sonic Magnetic Accelerometers and gyros Video Combinations

5. Requirements: minimum Track all types of motion Bending, twisting, circular, jumping Track through realistic velocities of motion Accomplished by adequate sample rates Track through all ranges of motion No motions should be out-of-bounds Tracking must be accurate Accuracy must be fine enough to capture subtle movements

6. Requirements: Nice to have Non-bulky Must not interfere with the exercise Easy to wear Not all patients will ave same range of motion, strength or dexterity Easy to use Not all patients will be technical Reasonable price Doctors will want to own many Don't want them to disappear Rugged Software to display the movement

7. Technology #1: Crossbow Mote Uses a combination of sonic and radio frequency transmissions Similar to counting the time between lightning and thunder Somewhat large circuit boards act as transmitters or receivers Currently best at tracking an entire person Multiple transmitter, single receiver approach

8. Technology #1: Crossbow Mote Limitations Not very accurate Suffers from multi-path issues Too large to wear comfortably Can't use at all on small body parts Not able to make rapid samples Too slow to track quicker movements No software available to display the body moving One hand-held, or serial port needed for each receiver

9. Technology #2: MIT Body Suit Uses ultrasonic transmissions, accelerometers and gyros Very accurate Uses 8 transmitters, 18 receivers all mounted on a body suit Must carry all equipment in a backpack Display software is available from somewhere

10. Technology #2: MIT Body Suit Limitations Heavy backpack Can't target single area to track Suit may be difficult for some to put on There is potential for accumulated errors to result in inaccurate displays

11. Technology #3: Moven Body Suit Very accurate Uses only inertial sensors, immune to noise Wireless transmission of data to base PC Body suit can be worn whole, or select upper or lower body Comes with display software

12. Technology #3: Moven Body Suit Limitations Still is a suit: some people may not be able to put on Cost is very high: $50,000

13. Technology #4: Vicon video The most accurate Uses 8 special video cameras all around the person being tracked No suit required! Patient wears small sensor dots for camera to pick up Display software is very nice Even has a language equivalent to Labanotation

14. Technology #4: Vicon video Limitations Price! As much as $194,000 A lot of equipment Cameras and mounting gear Receivers Computer A lot for a patient to set up

15. Comparison Accuracy: All have but crossbow, and MIT has cumulative error Bulkiness: Vicon is best, but Moven suit is very good Easy to wear: Vicon is dots placed using glue or velcro. Moven suit looks very good though Easy to use: Moven seems easiest. Cost: Crossbow is cheapest, but it doesn't really work. MIT is next, but isn't a product yet. Software: Vicon is best, Moven is good. MIT is from unknown source

16. References http://www.xbow.com (Crossbow Industries) http://www.xbow.com http://www.thinkartificial.org/artificial- intelligence/whole-body-computer-interfaces/ (MIT Motion capture suit) http://www.thinkartificial.org/artificial- intelligence/whole-body-computer-interfaces/ http://www.moven.com (Moven motion capture suit) http://www.moven.com http://www.vicon.com (Vicon video motion capture system) http://www.vicon.com http://www.motion-capture- system.com/resources/hardware.html (Listing of many companies and their motion capturing technologies) http://www.motion-capture- system.com/resources/hardware.html