Insertion/removal supporting apparatus and insertion/removal supporting method

1. A supporting apparatus for supporting insertion of a flexible insertion member into a subject and removal thereof, the supporting apparatus comprising:

a controller comprising hardware, the controller being configured to:

determine a first attention point on the insertion member while within the subject at a first time based on a first calculated shape of the insertion member at the first time, the first attention point being a characteristic point determined based on the shape of the insertion member at the first time,

after a displacement of the insertion member within the subject, at a second time after the first time, determine a new first attention point based on a second calculated shape of the insertion member at the second time, the new first attention point being the characteristic point determined based on the shape of the insertion member at the second time;

determine a first displacement between the first attention point and the new first attention point;

determine a second displacement of at least one rear-side attention point fixed to the insertion member, the second displacement being from the first time to the second time, the second displacement being along a predetermined portion in a longitudinal direction of the insertion member;

calculate a relationship between the first displacement and the second displacement;

determine a state of the insertion member or the subject based on the calculated relationship; and

determines that a level of abnormality of the state of the insertion member or the subject increases as a ratio of the first displacement to the second displacement increases.

2. The supporting apparatus according to claim 1 , wherein the controller determines that the smaller the first displacement is, the more proper the insertion member is inserted along the subject.

3. The supporting apparatus according to claim 1 , wherein the first attention point and new first displacement are determined based on a bending portion of the insertion member.

4. The supporting apparatus according to claim 3 , wherein the first attention point and new first displacement are each turn-around points of the bending portion of the insertion member.

5. The supporting apparatus according to claim 1 , wherein the state to be determined includes a state representing whether or not the insertion member extends the subject at a position corresponding to the new first attention point.

6. The supporting apparatus according to claim 1 , wherein the state to be determined includes a state where the insertion member pushes or presses the subject.

7. The supporting apparatus according to claim 1 , further comprising:

a plurality of position sensors arranged in the insertion member,

wherein the controller calculates the shape of the insertion member at the first time and at the second time, based on detection results of the position sensors, and calculates the positions of the first attention point and the new first attention point, based on the calculated shape of the insertion member at the first time and at the second time and the detection results of the position sensors, and

determines the first displacement, based on the position corresponding to the new first attention point.

8. The supporting apparatus according to claim 1 , further comprising:

an insertion amount sensor configured to be arranged at an insertion port of the subject and to detect an insertion amount of the insertion member; and

a shape sensor which acquires information on the shape of the insertion member at the first time and at the second time,

wherein the controller calculates the shape of the insertion member at the first time and at the second time, based on a detection result of the shape sensor, and calculates positions of the first attention point and the new first attention point, based on the calculated shape of the insertion member at the first time and at the second time and the detection result of the insertion amount sensor, and

determines the first displacement, based on the position of the new first attention point.

9. The supporting apparatus according to claim 1 , further comprising:

a position sensor arranged at the insertion member; and

a shape sensor which acquires information on the shape of the insertion member at the first time and at the second time,

wherein the controller calculates the shape of the insertion member at the first time and at the second time, based on a detection result of the shape sensor, and calculates positions of the first attention point and the new first attention point, based on the calculated shape of the insertion member at the first time and at the second time and the detection result of the position sensor, and

determines the first displacement, based on the position of the new first attention point.

10. The supporting apparatus according to claim 1 , further comprising:

a position sensor arranged at the insertion member,

wherein the controller determines the second displacement, based on detection results of the position sensor.

11. The supporting apparatus according to claim 1 , further comprising:

an insertion amount sensor configured to be arranged at an insertion port of the subject and to detect an insertion amount of the insertion member; and

a shape sensor which acquires information on the shape of the insertion member at the first time and at the second time,

wherein the controller determines the second displacement, based on detection results of the insertion amount sensor and detection results of the shape sensor.

12. The supporting apparatus according to claim 1 , further comprising:

a position sensor arranged at the insertion member; and

a shape sensor which acquires information on the shape of the insertion member at the first time and at the second time,

wherein the controller determines the second displacement, based on detection results of the position sensor and detection results of the shape sensor.