Finding Sciatic Function Index after nerve injury - PowerPoint PPT Presentation

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Finding Sciatic Function Index after nerve injury

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Finding Sciatic Function Index after nerve injury – PowerPoint PPT presentation

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Title: Finding Sciatic Function Index after nerve injury


1
Finding Sciatic Function Index after nerve injury
  • Group 33 Final Presentation
  • December 3rd, 2007
  • Presenter Kyle Mairose

2
Finding SFI after nerve injury
  • Group members
  • Kyle Mairose
  • Dave Working
  • Kenny Dike
  • Mentors
  • Matt Wood
  • Dr. Sakiyama-Elbert

3
Presentation Overview
  • SFI Background
  • Current Method
  • Our Method
  • Design Details
  • Apparatus
  • Software
  • Analytic efforts
  • Materials and manufacturing
  • Safety
  • Conclusions

4
Background
  • Nerve regeneration studies
  • Use gait to measure functional regeneration
  • What do we measure?
  • Sciatic crush injuries and toe spread

5
Sciatic Function Index
  • Quantitative measurement of functional recovery
  • Uses toe spreads and predetermined constants
  • Calculations
  • Toe spread factor (TSF) (ETS-NTS)/NTS
  • Intermediate TSF (ITSF) (EITS-NITS)/NITS
  • Print length factor (PLF) (EPL-NPL)/NPL
  • SFI (-38.3 x PLF) (109.5 x TSF) (13.3 x
    ITSF)

TS ITS
PL
6
Obtaining SFI
  • Current Method
  • Ink-paper
  • Paint Paws
  • Walk on recording paper
  • Scan Paper
  • Pick points in Matlab
  • Drawbacks
  • Time consuming
  • Messy
  • Inaccurate
  • Guessing for missing points
  • Smudging problem with wet paint

7
Our Solution
  • Pressure sensors were too expensive
  • Digital imaging showed most promise
  • No smudging
  • Complete prints
  • High speed camera vs. Digital camcorder
  • Stationary vs. translational

8
Requirements
  • Given Requirements
  • Avoid ink-paper method
  • Automated analysis
  • Transportable
  • Should be less than 30 lbs
  • Support lab rat (520g)
  • Budget 1,000-2,000
  • Further Design Requirements
  • 0.5mm resolution
  • Sampling rate of 30 fps

9
Design Overview
  • Apparatus
  • Stationary miniDV camcorder
  • Angled mirror under Plexiglas walkway
  • Minimizes apparatus size
  • Minimizes mechanical complexity
  • Easy for one person to use

10
Design Overview
  • Software
  • DVCapture from Epoch.com (free)
  • Easy conversion from camcorder to saved AVI files
  • Original Matlab program
  • Automatically finds frames of interest
  • Displays sets of prints for user to click points
  • Automatically calculated SFI values

11
Analytic Efforts
  • Adequate Resolution?
  • Panasonic GS320
  • effective pixel count of 1,920,000 pixels
  • 43 degree field of view
  • 0.5 mm resolution 0.25 mm2/pixel
  • (0.25mm2/pixel)x(1920000 pixels)480,000mm2
  • Sqrt(480000)692.8mm
  • 692.8/(2tan(21.5))879.4mm
  • If camera is within 879.4mm of the rat then the
    resolution will be adequate

12
Analytic Efforts
  • Adequate footprints per trial?
  • At brisk 36cm/s, rat stride is 15.7 cm
  • Take 800mm distance from rat to camera
  • 2(800)tan(43/2) 630.2 mm of walkway
  • (630.2mm)/(157mm) 4
  • At least 4 prints per trial will be recorded

13
Design Details Apparatus
  • Materials
  • Wooden Frame
  • Plexiglas Walkway
  • Acrylic Mirror
  • Tag-board Cover

14
Design Details Apparatus
6 in.
23 in.
36 in.
45 deg.
9 in.
15
Design Details Apparatus
  • Panasonic GS320 miniDV digital camera
  • Placed on wooden stand 33.8 inches from base
    using a detached wooden distance gauge
  • Experimenter will mark hind feet green with a
    10mm tip permanent marker, manually focus camera,
    and begin trials

16
Design Details Software
  • DV Capture
  • Free download
  • Video stream using Firewire
  • Saves camcorder data in AVI files

17
Design Details Software
  • Part One Choosing Frames
  • User loads AVI_Reader m-file
  • prompted to input .avi filename
  • Each frame saved in RGB 4-D array
  • Conversion to Lab color space
  • Closer approximation of human vision
  • L represents lightness (black to white)
  • a represents red-green value
  • b represents blue-yellow value

18
Design Details Software
  • Pixels are labeled green, white, or black
  • White and black are filtered out
  • Frames are converted to black and white
  • Morphological filters are used
  • (dilation, erosion, etc)

19
Design Details Software
  • Locations and areas of 2 largest groups (hind
    paws) are found
  • Paw images are cropped from original frames
  • Local maximum of areas determine frames of
    interest (paw is fully down)

20
Design Details Software
  • Part II Point-Picking
  • Cropped paw images displayed as experimental and
    normal
  • User prompted to click 6 points on each paw
  • Toe spread, Intermediate toe spread, Paw length
  • User is asked to confirm points
  • Subsequent sets of paws displayed
  • Part III SFI Calculation
  • Average and individual SFI values

21
Design Details Software
  • Color Calibration program
  • One time calibration step
  • Prompts user to select green, white, and black
    regions on frame from AVI file
  • 6 numbers will be output that should be
    hard-coded into the AVI_Reader program
  • Simple instructions are given

22
Design Details Safety
  • Design Safe 2.0
  • In general, our apparatus poses very low risk
  • Two situations pose moderate risk
  • Changing lights (if lamps are utilized) may
    result in electrocution if light is not unplugged
    first
  • Cleaning biological waste from rats may cause
    infection if gloves and disinfectants are not
    used

23
Required Parts
  • Plexiglas
  • Custom cut from Professional Plastics
  • Dimensions (2) 6x6 in. (1) 9x36 in. (2) 6x36
    in.
  • Cost 60.00
  • Acrylic Mirror
  • Custom cut, flat, unbreakable
  • Dimensions 8.48 x 36 inches
  • Reflection Products, Inc.
  • 26.51

24
Required Parts
  • Wood
  • Approximately 70
  • (2) 2x4, 6 in. length
  • (4) 1x1/2,16 in. length
  • (1) 2x9, 36 in. length, (1) 2x6, 36 inch.
  • Brackets (www.mcmaster.com)
  • 4 L-brackets (steel)
  • Length 1 59/64", 2  25/64, Width  2  3/8
  • no. 15275A63, 0.97 each
  • 9 Square brackets (steel)
  • 1 31/32" x 1 31/32 in, No 1030A15, 1.14 each

25
Required Parts
  • Panasonic GS320 3CCD miniDV digital camcorder
  • SD card Slot, Firewire, USB
  • Manual zoom
  • 1,920,000 effective pixel count
  • Available at Best Buy for 429.99
  • Firewire Cable
  • IEEE-1394, 6 prong to 4 prong, 6ft
  • 5.29 at www.cablewholesale.com

26
Required Parts
  • Wood Screws
  • Steel-Grade 2, Zinc Plated
  • Flat Head Phillips, 4 size, ¾ inch length
  • 1.73 at www.mscdirect.com, 87906038
  • General Purpose Silicone Caulking
  • Part GE22566 from www.nothingbuthardware.com
  • 2.29
  • Jumbo Permanent Marker
  • Green, 10mm tip
  • Part 43100, www.nextag.com
  • 2.15

27
Optional Parts
  • Desk Lamp
  • Flexible neck, 20 W
  • Need outlet
  • No. 001745499, Walmart
  • 12.95
  • Stanley MaxLife 369 Flashlight
  • Battery operated
  • No. 95-112N, Home Depot
  • 24.99

28
Construction
  • Step 1 base
  • Brackets and wood screws
  • Step 2 walkway
  • Silicon Cauking

29
Construction
  • Combine with caulking
  • Slide in mirror and secure
  • Screw on posts
  • Add tag-board with caulking

30
Construction
31
Optional Lighting
  • If lighting is inadequate
  • 2 adjustable neck lamps on sides of apparatus
  • Require electrical outlet
  • Offer adjustable lighting
  • 1 tripod flashlight placed behind camcorder
  • Easier to setup than lamps
  • Battery powered

32
Cost
33
Conclusions
  • No valuable IP
  • The project was a success
  • Unable to automate the point selection or
    eliminate the need for marking the feet
  • Faster, more accurate process than before
  • We learned
  • A LOT about image processing!
  • The importance of good communication
  • Future directions
  • Automate point selection
  • Focus on speed and efficiency
  • More robust image processing to eliminate marking
    feet

34
Acknowledgements
  • Matt Wood
  • Dr. Sakiyama-Elbert
  • Dr. Robert Pless
  • Dr. Morans Lab

35
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