3d tracking of an interventional instrument in 2d ultrasound guided interventions

A tracking method for tracking an interventional instrument that has one or more ultrasound sensors disposed with the interventional instrument, the tracking method comprising:

• operating an ultrasound imaging device including an ultrasound probe to display a two-dimensional (2D) ultrasound image of a visualization plane;
• rotating the ultrasound probe about an axis to scan a plurality of planes spanning a range of plane angles (θ) that encompasses the plane angle of the visualization plane and, for each plane of the plurality of planes, operating the ultrasound imaging device to perform a 2D ultrasound sweep of the plane;
• during each 2D ultrasound sweep, detecting a signal emitted by each ultrasound sensor in response to the 2D ultrasound sweep;
• for each ultrasound sensor, identifying an optimal plane for which the signal emitted by the ultrasound sensor is highest and locating the ultrasound sensor in the optimal plane;
• determining the location of each ultrasound sensor in a three-dimensional (3D) reference space by transforming the location of the ultrasound sensor in its optimal plane to the 3D reference space using a transform parameterized by plane angle;
• determining spatial information (T, L) for the interventional instrument based on the locations of the one or more ultrasound sensors in the 3D reference space;
• and
• displaying a visual indicator of the determined spatial information for the interventional instrument on the displayed 2D ultrasound image of the visualization plane.

A tracking device for tracking an interventional instrument that has one or more ultrasound sensors disposed with the interventional instrument, the tracking device comprising:

• an ultrasound imaging device including an electronic processor and a display;
• and
• an ultrasound probe operatively connectable with the ultrasound imaging device and rotatable under control of the ultrasound imaging device to acquire a two-dimensional (2D) ultrasound image at a plane defined by a plane angle (θ);
• wherein the ultrasound imaging device is programmed to:
• acquire and display a 2D ultrasound image of a visualization plane defined by a visualization plane angle;
• perform 2D ultrasound sweeps for a range of plane angles encompassing the visualization plane angle and, for each 2D ultrasound sweep, storing its plane angle and a signal emitted by each ultrasound sensor in response to the 2D ultrasound sweep;
• identify an optimal plane for each ultrasound sensor based on its emitted signal strength over the range of plane angles and locating the ultrasound sensor in its optimal plane by analyzing the sensor signal as a function of the timing of the beams fired by the ultrasound probe during the 2D ultrasound sweep of the optimal plane;
• transform the locations of the ultrasound sensors in their respective optimal planes to a three-dimensional (3D) reference space using a 2D-to-3D transform parameterized by plane angle;
• and
• display, on the displayed 2D ultrasound image, a visual indicator of spatial information (T, L) for the interventional instrument generated from the locations of the one or more ultrasound sensors in the 3D reference space.