Systems and methods for registration of a medical device using a reduced search space

A medical system comprising:

• a flexible instrument including a sensor adapted to provide tracking data for a point on the instrument;
• a memory storing images of a patient anatomy;
• and
• a processor configured to:
• identify connected anatomical structures in the stored images of the patient anatomy;
• generate an anatomical centerline model from the identified connected anatomical structures;
• select a set of points disposed on a set of anatomical centerlines of the anatomical centerline model, each anatomical centerline of the set of anatomical centerlines connecting a plurality of center points of the connected anatomical structures;
• generate a first plurality of cylindrical linkage elements representing the connected anatomical structures, wherein each of the first plurality of cylindrical linkage elements is defined by two end points from the set of points, the two end points being disposed on a respective anatomical centerline of the set of anatomical centerlines, a linkage element centerline of each of the first plurality of cylindrical linkage elements spanning the shortest distance between the two end points, and wherein each of the first plurality of cylindrical linkage elements includes a radius from the linkage element centerline defining a cylindrical wall;
• receive the tracking data for the point on the instrument when the instrument is positioned within at least one of the connected anatomical structures;
• and
• match the point on the instrument to one of the first plurality of cylindrical linkage elements by:
• identifying a second plurality of cylindrical linkage elements of the first plurality of cylindrical linkage elements in a region of a point on the instrument wherein the identifying the second plurality of cylindrical linkage elements is based on the second plurality of cylindrical linkage elements being closer to the point on the instrument than one or more other cylindrical linkage elements of the first plurality of cylindrical linkage elements;
• and
• determining a distance between the point on the instrument and a respective anatomical centerline for each cylindrical linkage element in the second plurality of cylindrical linkage elements.