title: Application of sonomicrometry and multidimensional scaling to cardiac catheter tracking.
abstract: This paper describes a technique for tracking the three-dimensional (3-D) position of a cardiac catheter using sonomicrometry and the mathematical method of multidimensional scaling (MDS). Sonomicrometry is used to measure the distances between ultrasonic transceivers. MDS is then used to calculate the 3-D coordinates of the ultrasonic transceiver locations, including the catheter tip, from the measured distances. Feasibility of catheter tracking was initially studied using simulated data from a geometric model in which the actual coordinates of all transceivers were known. The method was then shown to be feasible in vivo by tracking a catheter-mounted piezoelectric transducer using seven reference crystals sewn to the epicardial surface of a sheep heart. Simulation results indicate that a catheter can be tracked with a root-mean-square (rms) error of 1.51 +/- 0.05 mm and an average-distance error of e = 1.06 +/- 0.27 mm using 12 reference points. In vivo results showed acceptable stress values (G < 0.05) for 95% of the data samples with an average-distance error of e = 0.52 +/- 0.66 mm. These simulation and experimental results show that sonomicrometry and MDS can be used to accurately localize the 3-D position and track the motion of a catheter tip within the heart.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708-0281, USA. scott@eelmail.mc.duke.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Meyer
authors.forename: P D
authors.initials: PD
authors.lastname: Wolf
mesh_terms: D006328:Cardiac Catheterization / Q000379:methods*; D005240:Feasibility Studies; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008962:Models, Theoretical; D011187:Posture; D014159:Transducers; D014463:Ultrasonography / Q000379:methods*