Controlled image capturing method including position tracking and system used therein
Controlling an image capturing process by tracking the positions of the capsule endoscope is described. The images are taken only when there is either new position and/or new orientation change of the capsule endoscope. The method described effectively decreases the total amount of images that a doctor needs to review, and improves the power consumption of the capsule endoscope examination process.
1. An examination method using a capsule endoscope, comprising
introducing the capsule endoscope into a target area by swallowing,
wherein the capsule endoscope comprises a camera;
providing an external location system, capable of sensing and tracking a position and orientation the capsule endoscope;
moving the capsule endoscope from a previous position P i to a first position P c , wherein when capsule endoscope has a previous orientation O i at the previous position P i , and has a first orientation O c at the first position P c ;
calculating a distance D between P c and P i ; or/and
calculating a difference N between O c and O i ;
obtaining a total picture count n, wherein n is an integer greater than zero;
comparing distance D for each position between position P c to position P (n−m) with a threshold value D min , wherein 0<m<n; and
taking an image when D is greater than D min for all previous P n to P n−m positions and
not to taking an image but update the picture count n to n+1 and returning to the step of calculating a distance D between P c and P i ;
wherein i is an integer greater than 0 and c is an integer greater than 0.
2. The method of claim 1 , wherein moving the capsule endoscope to a first position further includes moving the capsule endoscope by peristalsis.
3. The method of claim 1 , wherein
m is an integer between 2-120.
4. The method of claim 1 , further comprises
calculating the difference N between O c and O i only when the distance D between P c and P i is less than or equal to D min .
5. The method of claim 4 , further comprises
taking an image if N is greater than N min .
6. The method of claim 5 , wherein N min is about 15-50 degrees.
7. The method of claim 1 , wherein
D min is 0.4-1.2 cm.
8. The method of claim 7 , wherein
D min is about 0.5-0.7 cm.
9. The method of claim 7 , wherein
D min is about 0.6-0.7 cm.
10. The method of claim 1 , further comprises
taking an image if N is greater than N min .
11. The method of claim 10 , wherein N min is about 15-50 degrees.
12. The method of claim 11 , wherein N min is about 25-30 degrees.
13. The method of claim 10 , wherein
N min is about 20-35 degrees.
14. The method of claim 1 , wherein the step of
determining if to take an image or not based on distance D or angle N, further comprises
taking an image when N is greater than N min for all previous P n −P n−m positions.
15. The method of claim 1 , further comprising
assigning P c =P n+1 , O c =O n+1 if an image has been taken or has been decided to be taken at P c .
16. The method of claim 1 , further comprising a step of
recording position information P c and orientation information O c when an image is taken and when an image is not taken.