Ultrasonic diagnosis system in which periphery of magnetic sensor included in distal part of ultrasonic endoscope is made of non-conductive material

Abstract

An ultrasonic transducer for producing an ultrasonic tomographic image is included in a distal part of an ultrasonic endoscope to be inserted into an object of observation. The ultrasonic transducer is rotated. Echoes of ultrasonic waves produced by the ultrasonic transducer are detected in order to produce an ultrasonic tomographic image that is a two-dimensional image. A magnetic sensor for detecting a position is included in the distal part. A magnetic field generated by a magnetic field generator locked near the object of observation is sensed. The position and orientation of the distal part are detected, whereby information of a position and orientation relevant to the ultrasonic tomographic image is obtained. Based on the information of the position and orientation, a plurality of produced ultrasonic tomographic images is synthesized in order to produce an ultrasonic image that is a three-dimensional image. The periphery of the magnetic sensor in the distal part is made of a non-conductive material. An eddy current developing near the magnetic sensor is therefore limited. Consequently, the precision in position detection performed by the magnetic sensor improves. The precision in position relevant to each of the ultrasonic tomographic images constituting the ultrasonic image therefore improves. Thus, an ultrasonic image with high positional precision can be produced.