Patent TW-I687198-B (TW)
Title: Dynamic reference deviation detecting method and system thereof
Inventor: KAO KUO TUNG
IPC: A61B34/20
Filed: 2018-05-25
Granted: 2020-03-11
Abstract: A dynamic reference deviation detecting method and a system thereof are proposed. The dynamic reference deviation detecting method is used for detecting a deviation of a dynamic reference coordinate system. The dynamic reference deviation detecting method provides a coordinate detecting step, a first coordinate 
variation calculating step, a second coordinate variation calculating step, a relative coordinate variation calculating step and a dynamic reference deviation detecting step. The coordinate detecting step is for driving an optical tracker to detect and record a first initial coordinate of a first optical sensing element and a second initial coordinate of a second optical sensing element. The first initial coordinate and the second initial coordinate are determined according to the dynamic reference coordinate system. The first coordinate variation calculating step is for driving the optical tracker to continuously detect a first instantaneous coordinate of the first optical sensing element. The first instantaneous coordinate is determined according to the dynamic reference coordinate system. Then, the first coordinate variation calculating step is for driving a processor to calculate a difference between the first instantaneous coordinate and the first initial coordinate to obtain a first difference value. The second coordinate variation calculating step is for driving the optical tracker to continuously detect a second instantaneous coordinate of the second optical sensing element. The second instantaneous coordinate is determined according to the 
dynamic reference coordinate system. Then, the second coordinate variation calculating step is for driving the processor to calculate a difference between the second instantaneous coordinate and the second initial coordinate to obtain a second difference value. The relative coordinate variation calculating step is for driving the processor to calculate a difference between the first instantaneous coordinate and the second instantaneous coordinate to obtain a relative instantaneous difference value. The relative coordinate variation calculating step is for driving the processor to calculate a difference between the first initial coordinate and the second initial coordinate to obtain a relative initial difference value. The relative coordinate variation calculating step is for driving the processor to calculate a difference between the relative instantaneous difference value and the relative initial difference value to obtain a relative difference value. The dynamic reference deviation detecting step is for driving the processor to determine whether the dynamic reference coordinate system is deviated according to the first difference value, the second difference value and the relative difference value. Therefore, the proposed dynamic reference deviation detecting method and the 
system thereof of the present disclosure may instantaneously determine whether the dynamic reference coordinate system is deviated so as to improve the reliability and accuracy of navigation.