Endoscope system and the method of controlling the endoscope

A method of controlling an endoscope system comprising:

• an endoscope comprising:
• an image sensor configured to take an image of an imaging target;
• a field-of-view adjustment mechanism configured to vary an orientation of the image sensor;
• and
• a driver configured to drive the field-of-view adjustment mechanism to vary the orientation of the image sensor;
• an endoscopic position sensor configured to detect a position of the endoscope in a body cavity;
• and
• a distance sensor configured to measure a distance from a distal end of the endoscope to the imaging target,
• wherein the method comprises:
• computing positions of the distal end of the endoscope and the imaging target on the basis of the position of the endoscope in the body cavity detected by the endoscopic position sensor and the distance from the distal end of the endoscope to the imaging target measured by the distance sensor;
• controlling one or more storages to store a position of the imaging target computed;
• computing a first driving amount by which the field-of-view adjustment mechanism is driven by the driver to vary the orientation of the image sensor based on the position of the imaging target computed stored in the one or more storages and the position of the distal end of the endoscope computed;
• controlling the one or more storages to store the image of the imaging target taken by the image sensor;
• performing a comparison of the image of the imaging target stored in the one or more storages with a newly taken image of the imaging target to determine a degree of similarity between the image of the imaging target stored in the one or more storages and the newly taken image of the imaging target;
• computing a second driving amount by which the field-of-view adjustment mechanism is driven by the driver to vary the orientation of the image sensor based on a result of comparison;
• and
• selecting one of the first driving amount and the second driving amount by which the field-of-view adjustment mechanism is driven by the driver to vary the orientation of the image sensor based on the degree of similarity determined,
• wherein the method comprises:
• in response to determining that the degree of similarity is lower than a first predetermined value, determining whether a change with time in the degree of similarity is less than a second predetermined value;
• and
• in response to determining that the change with time in the degree of similarity is less than the second predetermined value, controlling the one or more storages to store the newly taken image of the imaging target as the image of the imaging target,
• wherein the method comprises:
• correcting a position of the endoscope in the body cavity detected by the endoscopic position sensor;
• comparing the first driving amount and the second driving amount to acquire a detection error for the endoscopic position sensor;
• and
• updating a correction parameter by which the position of the endoscope in the body cavity detected by the endoscopic position sensor is corrected, and
• wherein the method comprises:
• when the degree of similarity is lower than the first predetermined value, driving the driver according to the first driving amount;
• and
• when the degree of similarity is higher than the first predetermined value, driving the driver according to the second driving amount.

An endoscope system comprising:

• an endoscope comprising:
• an image sensor configured to take an image of an imaging target;
• a field-of-view adjustment mechanism configured to vary an orientation of the image sensor;
• and
• a driver configured to drive the field-of-view adjustment mechanism to vary the orientation of the image sensor;
• an endoscopic position sensor configured to detect a position of the endoscope in a body cavity;
• a distance sensor configured to measure a distance from a distal end of the endoscope to the imaging target;
• and
• a processor comprising hardware, wherein the processor is configured to:
• compute positions of the distal end of the endoscope and the imaging target on the basis of the position of the endoscope in the body cavity detected by the endoscopic position sensor and the distance from the distal end of the endoscope to the imaging target measured by the distance sensor;
• control one or more storages to store a position of the imaging target computed;
• compute a first driving amount by which the field-of-view adjustment mechanism is driven by the driver to vary the orientation of the image sensor based on the position of the imaging target computed stored in the one or more storages and the position of the distal end of the endoscope computed;
• control the one or more storages to store the image of the imaging target taken by the image sensor;
• perform a comparison of the image of the imaging target stored in the one or more storages with a newly taken image of the imaging target to determine a degree of similarity between the image of the imaging target stored in the one or more storages and the newly taken image of the imaging target;
• compute a second driving amount by which the field-of-view adjustment mechanism is driven by the driver to vary the orientation of the image sensor based on a result of comparison;
• and
• select one of the first driving amount and the second driving amount by which the field-of-view adjustment mechanism is driven by the driver to vary the orientation of the image sensor based on the degree of similarity determined,
• wherein the processor is configured to:
• in response to determining the degree of similarity based on a first predetermined value, determine whether a change with time in the degree of similarity is less than a second predetermined value;
• and
• in response to determining that the change with time in the degree of similarity is less than the second predetermined value, control the one or more storages to store the newly taken image of the imaging target as the image of the imaging target,
• wherein the processor is configured to:
• correct a position of the endoscope in the body cavity detected by the endoscopic position sensor;
• compare the first driving amount and the second driving amount to acquire a detection error for the endoscopic position sensor;
• and
• update a correction parameter by which the position of the endoscope in the body cavity detected by the endoscopic position sensor is corrected,
• wherein when the degree of similarity is lower than the first predetermined value, the processor is configured to drive the driver according to the first driving amount, and
• wherein when the degree of similarity is higher than the first predetermined value, the processor is configured to drive the driver according to the second driving amount.