title: One-step needle pose estimation for ultrasound guided biopsies.
abstract: A pose estimation method is proposed for measuring the position and orientation of a needle. The technique is to be used as a touchless needle guide system for guidance of percutaneous procedures with 4D ultrasound. A pair of uncalibrated, light-weight USB cameras is used as inputs. A database is prepared offline, from the needle line estimated from camera-captured images and from the true needle line recorded from an independent tracking device. A non-parametric learning algorithm determines the best fit model from the database. This model can then be used in real-time to estimate the true position of the needle with inputs from only the camera images. Simulation results confirm the feasibility of the method and show how a small, accurately made database can provide satisfactory results. In a series of tests with cameras, we achieved an average error of 2.4mm in position and 2.61 degrees in orientation. A study of the results shows that the overall accuracy of the method is affected by the system designed to make the database.
authors.affiliation: Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, V6T 1Z4. sarak@ece.ubc.ca
authors.forename: Sara
authors.initials: S
authors.lastname: Khosravi
authors.forename: Robert
authors.initials: R
authors.lastname: Rohling
authors.forename: Peter
authors.initials: P
authors.lastname: Lawrence
mesh_terms: D000465:Algorithms; D001706:Biopsy / Q000295:instrumentation / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods; D009339:Needles; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods*