Adjustable marker reference device

An adjustable marker reference device, for use in identifying a surgical instrument, the adjustable marker reference device comprising:

• a base provided with a first groove;
• an upper cover disposed on the base, wherein the upper cover is provided with a second groove corresponding to the first groove;
• a set of connecting rods disposed between the base and the upper cover, wherein the set of connecting rods has two movable ends and a pivot point;
• a plurality of markers respectively disposed on the upper cover and the two movable ends;
• a fixing button extending through the first groove, the pivot point and the second groove, wherein, when the fixing button is pressed, the set of connecting rods is capable of freely bringing the pivot point to slide along the first groove and the second groove, and when the fixing button is not pressed and the pivot point is located and fixed at one of a plurality of default positions defined by the first groove and the second groove, the set of connecting rods is fixed;
• wherein, when the set of connecting rods is fixed, a plurality of virtual lines between any two of the plurality of markers meet the following conditions:
• lengths of the virtual lines are all greater than a first predetermined length;
• and
• a length difference between any two of the virtual lines is greater than a second predetermined length, or an angle between any two of the virtual lines is greater than a predetermined angle.