High-Precision Displacement Measurement for Breast Biopsy Instrument Using Fiducial Markers

Sammanfattning

The use of automatic positioning systems for breast biopsy procedures requires high precision, making robust validation of positional accuracy important. This work investigates the use of fiducial markers as an alternative to traditional validation methods for such instruments. The evaluated instrument operates in discrete steps of approximately 0.1 mm along the x-, y-, and z-axes, requiring reliable sub-millimeter displacement estimation. The study further compares the performance of state-of-the-art fiducial markers for sub-millimeter displacement estimation along these axes. The three evaluated markers are ArUco, STag, and AprilTag. The results show that AprilTag achieves the best overall performance. Furthermore, the proposed method provides accurate displacement estimation along the horizontal and vertical axes but demonstrates limitations in depth estimation along the z-axis. The experimental setup is designed to be cost-effective, with the total hardware cost of the estimation system remaining below 2000 Swedish kronor.