UC Davis

An algorithm for real–time venipuncture needle guidance is described, using an optical coherence tomography (OCT) probe that emits light pulses at fixed angular intervals along a cone, giving accurate distance measurements to points on the blood vessel. Using this data, a method is developed to visually display the blood vessel for needle guidance. A least–squares fit to a general quadric surface, specified by a symmetric matrix, is performed. For a cylindrical blood vessel, this provides an estimate for its orientation, from which its location and radius can be determined. The algorithm is compatible, in efficiency and robustness, with real–time implementation.