1. Automatic Tracing of Vocal Fold Motion in High Speed Laryngeal Video Erik Bieging

2. Vocal Fold Imaging  Human vocal folds oscillate at 100 to 400 Hz during normal phonation  High-speed digital imaging (4000 frames/sec) is used to study the motion of the vocal folds  Automated methods are needed to extract edge of glottis and glottal area Vocal Folds Glottis

3. Current Methods Histogram method  Threshold is applied to separate glottis and vocal fold tissue  Threshold is determined from each frame’s histogram Thresh

4. Current Methods Region Growing  Seeds are started at darkest points in image  Regions are grown based on similarity between region pixels and surrounding pixels Active Contour  Initial region is defined using thresholding  Edge is iteratively moved based on image gradient and several parameters

5. New Differentiation Based Method  Each column of the image is passed through a smoothing differentiating filter  Max and min of derivative are taken to be glottal edges  Binary image created  Canny edge detection applied to binary image to smooth the edge

6. Comparison of Methods (a) (b) (c) (d) (e) High Quality Data: Lower Quality Data: (a)Original Image (b)Histogram (c)Region Growing (d)Active Contour (e)New Method

7. Comparison of Methods

8. Results  100 frames from 10 videos were analyzed with each method  Deviation from manually detected glottal area calculated VideoHistogram Region Growin g Active Cont ourOur Method 1110.66%197.55%62.98%15.53% 218.89%26.58%38.73%5.71% 33.93%5.50%40.38%1.85% 445.64%16.31%44.95%4.02% 530.80%21.58%43.85%18.72% 610.22%7.31%57.54%14.02% 730.69%18.21%34.11%3.05% 86.23%4.42%41.13%4.75% 947.13%47.29%38.92%12.97% 1010.75%10.73%39.77%10.60% Average31.49%35.55%44.24%9.12%

9. Computaion Time  Average time to analyze 100 frames:  Histogram: 2.09 min.  Region Growing: 40.98 min.  Active Contour: 67.69 min.  New method: 1.21 min