A catheter-based minimally invasive therapy requires real time information about the position and orientation of a catheter tip for safe operation. To decrease X-ray exposure and to provide 3D information for operators, a simple sensor system for detecting the position and orientation utilizing the earth's magnetic field and ac (10 kHz) magnetic field transmitted by a two-axis source coil is proposed. A 2 mm × 2 mm × 3 mm three-axis MI sensor (Magneto-Impedance effect sensor) fabricated on a polymer structure for measuring the earth's magnetic field and the ac magnetic field is mounted on the catheter tip. The advantages of this sensor are: (1) small size; (2) high sensitivity; (3) retaining of through hole. The position and orientation is calculated and the obtained information of the position and orientation of the catheter tip is superimposed on the 3D map of the blood vessel captured in advance. A measurement in a blood vessel model has been performed and the calculated position and orientation image has been superimposed on the 3D graphic image of the blood vessel. The sensor system obviously indicated where the catheter tip was in the "y" shape blood vessel model.
- MI sensor
- Position and orientation