抄録
We developed a compact system for analyzing mandibular movements with the application of an infrared sensor, and examined factors which affected e its precision in order to determine the precision numerically.
The essential points were as follows;
(1) We were able to pick out the following three factors which affected the system.
(i) The distance between the LED and the infrared sensor (repressented as “L”)
(ii) The angle formed between the axis of the LED and the axis of the infrared sensor (called the angle of “deviation”; component of X axis:θx, component of Y axis:θy)
(iii) The rotation of the infrared sensor (termed the “rotation”:δ)
(2) According to the regression analysis, under the condition that L (=Lo+ΔL: Lo=100.0mm) was in the range (90.0≤L≤110.0), the maximum errors of the X and Y axes components were both 0.04mm when ΔL was neglected.
(3) Under the condition of the range (|θx|≤10° and |θy|≤10°), the standard error of the X axis component was 8.7 percent and that of the Y axis component was 9.7 percent.
We were then able to determine that δ was zero in the sagittal view.
(4)According to experiments involving trial and error, we could fulfill the requirements of 90.0≤L≤110.0mm, |θx|≤10°, |θy|≤10°, and δ=0°.
(5)Under the conditions indicated above, the precision of this system was estimated to be 0.15mm.
