# US 12,004,709 B2 · Flexible tube insertion apparatus, insertion control apparatus, and flexible tube insertion method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,709 B2 - Document ID: US12004709B2 - Status: Granted - Kind: B2 - Application number: 17/027,224 - Filed: 2020-09-21 - Published: 2021-01-07 - Granted: 2024-06-11 - Earliest claimed: 2018-03-27 - Assignees: Olympus Corporation - Applicants: Olympus Corporation - Inventors: Ryo Tezuka; Ryo Tojo; Takeshi Takahashi - Web page: https://patentgrep.com/patent/US12004709B2 ## CPC - A61B 1/00078: {with stiffening means} - A61B 1/00006: {of control signals} - A61B 1/00009: {of image signals during a use of endoscope} - A61B 1/0002: {provided with data storages} - A61B 1/0051: {with controlled bending of insertion part} - A61B 1/0057: {Constructional details of force transmission elements, e.g. control wires} - A61B 5/065: {Determining position of the probe employing exclusively positioning means located on or in the probe, e.g. using position sensors arranged on the probe} - A61B 1/00045: {Display arrangement} - A61B 1/0058: {using shape-memory elements} - A61B 1/31: for the rectum, e.g. proctoscopes or sigmoidoscopes - A61B 2034/2051: {Electromagnetic tracking systems} - A61B 2034/2061: {using shape-sensors, e.g. fiber shape sensors with Bragg gratings} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A flexible tube insertion apparatus includes: a flexible tube; a stiffness control system configured to control a stiffness of the tube; a buckling detection system configured to detect occurrence of a buckling in the tube; a pulling operation detection system configured to detect that a pulling operation of the tube is performed, after detection of the occurrence of the buckling; and a storage configured to store position information of a stiffness-to-be-enhanced portion of the tube neighboring a buckling portion of the tube and located on a distal side of the buckling portion. The stiffness control system is configured to enhance a stiffness of the stiffness-to-be-enhanced portion, based on the position information, at detection of the pulling operation. ## Claims ### Claim 1 A flexible tube insertion apparatus comprising: a processor comprising hardware, the processor being configured to: control a stiffness of each of various portions of a flexible tube configured to be inserted into a tract of a target; detect occurrence of a buckling in the flexible tube; detect that a pulling operation of the flexible tube is performed, after detecting the occurrence of the buckling; store position information of a stiffness-to-be-enhanced portion including a portion of the flexible tube adjacent to a buckling portion of the flexible tube and located on a distal side of the buckling portion, and increase a stiffness of the stiffness-to-be-enhanced portion, based on the position information stored in the storage device, when the pulling operation is detected. ### Claim 2 (depends on 1) The flexible tube insertion apparatus of claim 1, wherein the processor is configured to: detect completion of the pulling operation, and increase the stiffness of the stiffness-to-be-enhanced portion when the completion of the pulling operation is detected. ### Claim 3 (depends on 1) The flexible tube insertion apparatus of claim 1, wherein the processor is configured not to increase the stiffness of the flexible tube during a period from when the occurrence of the buckling is detected to when the pulling operation is detected. ### Claim 4 (depends on 1) The flexible tube insertion apparatus of claim 1, further comprising stiffness changing devices, and the processor is configured to independently control the stiffness changing devices, the stiffness changing devices being provided on the flexible tube and arranged along a longitudinal axis of the flexible tube, and each stiffness changing device being configured to change a stiffness of a portion of the flexible tube in which the stiffness changing device is provided. ### Claim 5 (depends on 1) The flexible tube insertion apparatus of claim 1, wherein the processor is further configured to calculate a shape of the flexible tube, wherein the stiffness-to-be-enhanced portion is determined, based on information of the calculated shape of the flexible tube. ### Claim 6 (depends on 5) The flexible tube insertion apparatus of claim 5, further comprising a shape sensor configured to acquire shape information of each of various portions of the flexible tube, and the processor is configured to calculate a shape of an entirety of the flexible tube, based on the shape information of each of various portions of the flexible tube acquired by the shape sensor. ### Claim 7 (depends on 6) The flexible tube insertion apparatus of claim 6, wherein the shape sensor includes bend sensors arranged along a longitudinal axis of the flexible tube, each bend sensor being configured to detect a bend of a portion of the flexible tube on which the bend sensor is provided, and the processor is configured to calculate the shape of the flexible tube, based on information of a curvature of each of various portions of the flexible tube detected by the bend sensor. ### Claim 8 (depends on 6) The flexible tube insertion apparatus of claim 6, wherein the shape sensor includes position sensors arranged along a longitudinal axis of the flexible tube, each position sensor being configured to detect a bend of a portion of the flexible tube on which the position sensor is provided, and the processor is configured to calculate the shape of the flexible tube, based on information of a position of each of various portions of the flexible tube detected by the position sensor. ### Claim 9 (depends on 6) The flexible tube insertion apparatus of claim 6, wherein the processor is configured to calculate a curvature of each of various portions of the flexible tube, based on the shape information of each of various portions of the flexible tube acquired by the shape sensor, and configured to detect the occurrence of the buckling, based on the curvature. ### Claim 10 (depends on 9) The flexible tube insertion apparatus of claim 9, wherein the processor is configured to judge that the buckling occurs in the flexible tube, if the curvature of any one of the various portions of the flexible tube exceeds a threshold for buckling occurrence detection. ### Claim 11 (depends on 10) The flexible tube insertion apparatus of claim 10, wherein the processor is configured to determine that the stiffness-to-be-enhanced portion is a portion of the flexible tube that corresponds to a range in which the curvature exceeds a threshold for stiffness-to-be-enhanced portion determination that is lower than the threshold for buckling occurrence detection. ### Claim 12 (depends on 10) The flexible tube insertion apparatus of claim 10, wherein the processor is configured to judge that the pulling operation is performed, when the curvature of the buckling portion decreases below a threshold for buckling elimination detection that is lower than the threshold for buckling occurrence detection. ### Claim 13 (depends on 10) The flexible tube insertion apparatus of claim 10, wherein the processor is configured to set a buckling occurrence expectation area where the occurrence of the buckling is expected, and configured to determine that the stiffness-to-be-enhanced portion is a portion of the flexible tube that is located in the buckling occurrence expectation area in the flexible tube in which the buckling is eliminated. ### Claim 14 (depends on 9) The flexible tube insertion apparatus of claim 9, wherein the processor is configured to calculate a maximum point of a curvature of a bend portion that is located on a distal side of the buckling portion and is closest to the buckling portion, and configured to determine the stiffness-to-be-enhanced portion, based on the maximum point. ### Claim 15 (depends on 14) The flexible tube insertion apparatus of claim 14, wherein the processor is configured to determine that the stiffness-to-be-enhanced portion is a portion of the flexible tube that includes the maximum point and corresponds to a range including at least a part of the buckling portion. ### Claim 16 (depends on 9) The flexible tube insertion apparatus of claim 9, wherein the processor is configured to calculate an inflection point between the buckling portion and a bend portion that is located on a distal side of the buckling portion and is closest to the buckling portion, and configured to determine the stiffness-to-be-enhanced portion, based on the inflection point. ### Claim 17 (depends on 16) The flexible tube insertion apparatus of claim 16, wherein the processor is configured to determine that the stiffness-to-be-enhanced portion is a portion of the flexible tube that includes the inflection point and corresponds to a range including at least a part of the buckling portion. ### Claim 18 (depends on 6) The flexible tube insertion apparatus of claim 6, wherein the processor is configured to calculate a velocity of each of various portions of the flexible tube, based on the shape information of each of various portions of the flexible tube acquired by the shape sensor, configured to calculate a velocity ratio of two mutually distanced portions of the flexible tube, and configured to detect the occurrence of the buckling, based on the velocity ratio. ### Claim 19 (depends on 18) The flexible tube insertion apparatus of claim 18, wherein the processor is configured to judge that the buckling occurs in the flexible tube, when the velocity ratio of any one of sets of two portions of the flexible tube is lower than the threshold for buckling occurrence detection. ### Claim 20 (depends on 19) The flexible tube insertion apparatus of claim 19, wherein the processor is configured to determine that the stiffness-to-be-enhanced portion is a portion of the flexible tube that corresponds to a portion with the velocity ratio lower than a threshold for stiffness-to-be-enhanced portion determination that is higher than the threshold for buckling occurrence detection. ### Claim 21 (depends on 19) The flexible tube insertion apparatus of claim 19, wherein the processor is configured to judge that the pulling operation is performed, when the velocity ratios of all sets of two portions of the flexible tube exceed a threshold for buckling elimination detection that is greater than the threshold for buckling occurrence detection. ### Claim 22 (depends on 6) The flexible tube insertion apparatus of claim 6, wherein the processor is configured to calculate a crossing angle between a tangent line at an inflection point of two successive bend portions formed in the flexible tube, and a straight line passing through an axis of the flexible tube in a predetermined position of the tract, and configured to detect the occurrence of the buckling, based on the crossing angle. ### Claim 23 (depends on 22) The flexible tube insertion apparatus of claim 22, wherein the processor is configured to judge that the buckling occurs in the flexible tube, when a variation with time of the crossing angle is positive. ### Claim 24 (depends on 22) The flexible tube insertion apparatus of claim 22, wherein the processor is configured to judge that the buckling occurs in the flexible tube, when the crossing angle is greater than a threshold for buckling occurrence detection. ### Claim 25 (depends on 24) The flexible tube insertion apparatus of claim 24, wherein the processor is configured to judge that the puling operation is performed, when the crossing angle is less than a threshold for buckling elimination detection that is lower than the threshold for buckling occurrence detection. ### Claim 26 (depends on 6) The flexible tube insertion apparatus of claim 6, wherein the processor is configured to calculate a radius of curvature of a proximal-side bend portion of two successive bend portions formed in the flexible tube, and configured to detect the occurrence of the buckling, based on the radius of curvature. ### Claim 27 (depends on 26) The flexible tube insertion apparatus of claim 26, wherein the processor is configured to judge that the buckling occurs in the flexible tube, when a variation with time of the radius of curvature is negative. ### Claim 28 (depends on 1) The flexible tube insertion apparatus of claim 1, wherein the processor is configured to measure an insertion amount of the flexible tube and to detect a position of a predetermined portion of the flexible tube, and configured to detect the occurrence of the buckling, based on the insertion amount and the position. ### Claim 29 (depends on 1) The flexible tube insertion apparatus of claim 1, wherein the processor is configured to measure an insertion amount of the flexible tube, and configured to judge that the pulling operation is performed, when the insertion amount decreases by an amount greater than a threshold. ### Claim 30 (depends on 1) The flexible tube insertion apparatus of claim 1, wherein the stiffness-to-be-enhanced portion further includes a portion of the flexible tube that corresponds to the buckling portion. ### Claim 31 An insertion control apparatus comprising: a processor comprising hardware, the processor being configured to: control a stiffness of each of various portions of a flexible tube configured to be inserted into a tract of a target; detect occurrence of a buckling in the flexible tube; detect that a pulling operation of the flexible tube is performed, after detecting the occurrence of the buckling; store position information of a stiffness-to-be-enhanced portion including a portion of the flexible tube adjacent to a buckling portion of the flexible tube and located on a distal side of the buckling portion, and increase a stiffness of the stiffness-to-be-enhanced portion, based on the position information stored in the storage device, when the pulling operation is detected. ### Claim 32 A flexible tube insertion method comprising: controlling a stiffness of each of various portions of a flexible tube to be inserted into a tract of a target; detecting occurrence of a buckling in the flexible tube; detecting that a pulling operation of the flexible tube is performed, after detecting the occurrence of the buckling; storing position information of a stiffness-to-be-enhanced portion including a portion of the flexible tube adjacent to a buckling portion of the flexible tube and located on a distal side of the buckling portion; and increasing a stiffness of the stiffness-to-be-enhanced portion, based on the stored position information, when detecting the pulling operation. ### Claim 33 A flexible tube insertion method comprising: inserting a flexible tube into a tract of a target, the flexible tube including stiffness changing devices arranged along a longitudinal axis of the flexible tube; performing a pulling operation of the flexible tube after a buckling occurs in the flexible tube; and increasing a stiffness of a stiffness changing device that is located at a stiffness-to-be-enhanced portion including a portion of the flexible tube adjacent to a buckling portion of the flexible tube and located on a distal side of the buckling portion, after the pulling operation is performed.