Medical device guiding system, medical device guiding method, and method for creating look-up table to be used in medical device guiding system

A medical device guiding method for guiding and controlling a position or an orientation of a medical device having a built-in magnet and introduced into a body cavity, based on a result of detecting the position and the orientation of the medical device from a first magnetic field of a specific frequency, by using a position detecting device having a magnetic field generator and a magnetic field detector, one of the magnetic field generator and the magnetic field detector being incorporated in the medical device, the method comprising:

• generating a guiding magnetic field acting on the magnet by a guiding coil supplied with power from a drive unit to control the position or the orientation of the medical device;
• generating a first magnetic field of a specific frequency by the magnetic field generator;
• detecting a magnetic field including the first magnetic field generated at the magnetic-field generating step by the magnetic field detector;
• estimating, when the medical device is arranged at a plurality of specific positions in a plurality of specific orientations, a second magnetic field that is induced at a position of the magnetic field detector, by at least one of the guiding coil and the magnetic field generator, due to the action of the first magnetic field, wherein the estimating is carried out by referring, based on the position and the orientation of the medical device, to a look-up table, the look-up table storing a plurality of pieces of numerical information having a correlation with the second magnetic field;
• calculating corrected magnetic-field information obtained by subtracting the estimated second magnetic field from the detected magnetic field;
• and
• estimating the position and the orientation of the medical device based on the calculated corrected magnetic-field information.

A method for creating a look-up table to be used in a medical device guiding system, the system comprising:

• a medical device having a built-in magnet and introduced into a body cavity;
• a position detecting device incorporated in the medical device and having a magnetic field generator including an emission coil and an oscillation circuit to generate a first magnetic field of a specific frequency, and a magnetic field detector including a plurality of magnetic field sensors arranged at a position detection area to detect a position and an orientation of the medical device based on the first magnetic field;
• and a magnetic guiding device having a guiding coil that generates a guiding magnetic field for changing the position or the orientation of the medical device by acting on the magnet and a drive unit connected to the guiding coil to supply power for generating the guiding magnetic field, the method comprising:
• setting a plurality of discrete specific positions and a plurality of discrete specific orientations within the position detection area;
• calculating a magnetic flux penetrating a plurality of guiding coils arranged at known positions around the position detection area when the medical device is arranged at one specific position and in one specific orientation to generate the first magnetic field;
• calculating an induction current flowing in the guiding coils based on calculated magnetic flux;
• calculating numerical information having a correlation with a second magnetic field induced at the magnetic field sensors, when the calculated induction current flows in the guiding coils;
• storing the calculated numerical information having the correlation with the second magnetic field in association with the one specific position and the one specific orientation;
• and
• creating a table by repeating the calculating the magnetic flux, the calculating the induction current, the calculating the numerical information, and the storing for all the specific positions and the specific orientations, by sequentially changing the one specific position and the one specific orientation.

A method for creating a look-up table to be used in a medical device guiding system, the system comprising:

• a medical device having a built-in magnet and introduced into a body cavity;
• a position detecting device incorporated in the medical device and having a magnetic field generator including an emission coil and an oscillation circuit to generate a first magnetic field of a specific frequency and a magnetic field detector including a plurality of magnetic field sensors arranged at a position detection area to detect a position and an orientation of the medical device based on the first magnetic field;
• and a magnetic guiding device having a guiding coil that generates a guiding magnetic field for changing the position or the orientation of the medical device by acting on the magnet and a drive unit connected to the guiding coil to supply power for generating the guiding magnetic field, the method comprising:
• setting a plurality of discrete specific positions and a plurality of discrete specific orientations within the position detection area;
• calculating mutual inductance with a plurality of guiding coils arranged at known positions around the position detection area when the medical device is arranged at one specific position and in one specific orientation to generate the first magnetic field;
• calculating an induction current flowing in the respective guiding coils based on calculated mutual inductance;
• calculating numerical information having a correlation with a second magnetic field induced at the magnetic field sensors arranged the position detection area to detect the first magnetic field, when the calculated induction current flows in the guiding coils;
• storing the calculated numerical information having the correlation with the second magnetic field in association with the one specific position and the one specific orientation;
• and
• creating a table by repeating the calculating the induction current, the calculating the numerical information, and the storing for all the specific positions and specific orientations, by sequentially changing the one specific position and the one specific orientation.

A method for creating a look-up table to be used in a medical device guiding system, the system comprising:

• a medical device having a built-in magnet and introduced into a body cavity;
• a position detecting device that includes a magnetic field generator including a drive coil arranged at a position detection area to generate a magnetic field for position detection and a resonance circuit including an emission coil and a capacitor, incorporated in the medical device to resonate due to the magnetic field for position detection, thereby generating a first magnetic field of a specific frequency, and a magnetic field detector including a plurality of magnetic field sensors arranged at the position detection area to detect a position and an orientation of the medical device based on the first magnetic field;
• and a magnetic guiding device having a guiding coil that generates a guiding magnetic field for changing the position or the orientation of the medical device by acting on the magnet and a drive unit connected to the guiding coil to supply power for generating the guiding magnetic field, the method comprising:
• setting a plurality of discrete specific positions and a plurality of discrete specific orientations within the position detection area;
• calculating a magnetic flux penetrating a plurality of guiding coils arranged at known positions around the position detection area or the drive coil, when the medical device is arranged at one specific position and in one specific orientation to generate the first magnetic field;
• calculating an induction current flowing in the guiding coils or the drive coil based on the calculated magnetic flux;
• calculating numerical information having a correlation with a second magnetic field induced at positions of the magnetic field sensors, when the calculated induction current flows in the guiding coils or the drive coil;
• storing the calculated numerical information having the correlation with the second magnetic field in association with the one specific position and the one specific orientation;
• and
• creating a table by repeating the calculating the magnetic flux, the calculating the induction current, the calculating the numerical information, and the storing for all the specific positions and the specific orientations, by sequentially changing the one specific position and the one specific orientation.

A method for creating a look-up table to be used in a medical device guiding system, the system comprising:

• a medical device having a built-in magnet and introduced into a body cavity;
• a position detecting device that includes a magnetic field generator including a drive coil arranged at a position detection area to generate a magnetic field for position detection and a resonance circuit including an emission coil and a capacitor, incorporated in the medical device to resonate due to the magnetic field for position detection, thereby generating a first magnetic field of a specific frequency, and a magnetic field detector including a plurality of magnetic field sensors arranged at the position detection area to detect a position and an orientation of the medical device based on the first magnetic field;
• and a magnetic guiding device having a guiding coil that generates a guiding magnetic field for changing the position or the orientation of the medical device by acting on the magnet and a drive unit connected to the guiding coil to supply power for generating the guiding magnetic field, the method comprising:
• setting a plurality of discrete specific positions and a plurality of discrete specific orientations within the position detection area;
• calculating mutual inductance with a plurality of guiding coils arranged at known positions around the position detection area or the drive coil, when the medical device is arranged at one specific position and in one specific orientation to generate the first magnetic field;
• calculating an induction current flowing in the respective guiding coils or the drive coil based on the calculated mutual inductance;
• calculating numerical information having a correlation with a second magnetic field induced at positions of the magnetic field sensors arranged the position detection area to detect the first magnetic field, when the calculated induction current flows in the guiding coils or the drive coil;
• storing the calculated numerical information having the correlation with the second magnetic field in association with the one specific position and the one specific orientation;
• and
• creating a table by repeating the calculating the induction current, the calculating the numerical information, and the storing for all the specific positions and the specific orientations, by sequentially changing the one specific position and the one specific orientation.

A method for creating a look-up table to be used in a medical device guiding system, the system comprising:

• a medical device having a built-in magnet and introduced into a body cavity;
• a position detecting device having a magnetic field generator including a plurality of emission coils arranged at a position detection area to generate a first magnetic field of a specific frequency and a magnetic field detector including a magnetic field sensor incorporated in the medical device to detect the first magnetic field, thereby detecting a position and an orientation of the medical device based on the first magnetic field;
• and a magnetic guiding device having a guiding coil that generates a guiding magnetic field for changing the position or the orientation of the medical device by acting on the magnet and a drive unit connected to the guiding coil to supply power for generating the guiding magnetic field, the method comprising:
• setting a plurality of discrete specific positions and a plurality of discrete specific orientations within the position detection area;
• calculating an induction current flowing in the guiding coil or the emission coil arranged at a known position around the position detection area, when the medical device is arranged at one specific position and in one specific orientation to generate the first magnetic field of a specific frequency with respect to the position detection area by the emission coil;
• calculating numerical information having a correlation with a second magnetic field induced at a position of the magnetic field sensor, when the calculated induction current flows in the guiding coil or the emission coil;
• storing the calculated numerical information having the correlation with the second magnetic field in association with the one specific position and the one specific orientation;
• and
• creating a table by repeating the calculating the induction current, the calculating the numerical information, and the storing for all the specific positions and specific orientations, by sequentially changing the one specific position and the one specific orientation.