Method and apparatus for three-dimensional translumenal ultrasonic imaging

An ultrasonic translumenal scanning system for providing multi-planar images of internal tissue and organs from a single lumenal location within the body of a subject, said ultrasonic translumenal scanning system comprising:

• (a) a magnetic field generator located outside the body of the subject, said magnetic field generator for supplying a magnetic field having three orthogonal field components that define a first coordinate system;
• (b) an ultrasonic endoscope for lumenal insertion in the body of the subject, said ultrasonic endoscope including an endoscopic shell, a probe mounted to the distal end of said endoscopic shell, and a control handle mounted to the proximate end of said endoscopic shell;
• said probe including a magnetic field sensor for detecting the magnetic field strength of each of said three orthogonal field components of said magnetic field supplied by said magnetic field generator, said magnetic field sensor for supplying a signal representative of said field strength of each of said three orthogonal field components supplied by said magnetic field generator, said magnetic field sensor being mounted at a fixed position within said probe;
• said probe further including transducer mounting means and an ultrasonic transducer for generating a two-dimensional ultrasonic scanning pattern, said ultrasonic transducer being mounted to said transducer mounting means with said transducer mounting means being positioned in said probe at a predetermined location relative to said magnetic field sensor, said transducer mounting means including means for rotating said ultrasonic transducer about two orthogonal axes of a second coordinate system in which the first of said two axes lies in the plane of said two-dimensional scanning pattern and the second of said two axes is substantially perpendicular to both said first coordinate axis and the axial center line of said probe;
• said control handle including first and second manually operable actuators interconnected with said transducer mounting means, said first manually operable actuator being operable for rotating said two-dimensional scanning pattern about said first axis of said second coordinate system, said second manually operable actuator being operable for rotating said two-dimensional scanning pattern about said second axis of said second coordinate system;
• said probe further including first and second rotational sensors mounted to said transducer mounting, said first rotational sensor for supplying a signal representative of the amount by which said two-dimensional scanning pattern is rotated about said first axis of said second coordinate system, said second rotational sensor for supplying a signal representative of the amount by which said two-dimensional scanning pattern is rotated about said second axis of said coordinate system;
• and
• (c) electrical conductors for coupling said signal supplied by said magnetic field sensor and said signals representative of said rotation about said first and second axes of said second coordinate system through said endoscopic shell to a location external of said ultrasonic endoscope, said electrical conductors including conductors also for supplying signals to said ultrasonic transducer for producing said two-dimensional scanning pattern and for supplying imaging signals generated by said ultrasonic transducer to a location external of said ultrasonic endoscope.