Depth adjustable fluid movement medical instrument using reflected light distance sensor and control method therefor

The present invention relates to a depth adjustable fluid movement medical instrument using a reflected light distance sensor capable of inserting a syringe needle to an accurate depth on the basis of information of a distance measured by light reflected from a limiting membrane of a biological body and a control method therefor. The depth adjustable fluid movement medical instrument comprises: a handpiece for injecting or collecting a fluid; a syringe needle fixed to the handpiece and having one side end thereof to be inserted into a biological body exposed; a distance sensor optical fiber, attached to the syringe needle at a fixed distance from an endmost portion of the syringe needle, for measuring an axial distance according to the insertion of the syringe needle; a fluid movement pressure part for adjusting the movement of the fluid and the inside of the biological body through the syringe needle; and a distance sensor measurement part for outputting a signal measuring a relative distance between the tip of the syringe needle located inside an outer limiting membrane and an inner limiting membrane of the biological body by using a tip of the optical fiber located outside the outer limiting membrane of the biological body through the distance sensor optical fiber.