JP6677470B2 - External force detection device, external force detection method, and program - Google Patents

Description

  An embodiment of the present invention relates to an external force detection device, an external force detection method, and a program.

  2. Description of the Related Art An apparatus for imaging a subject such as a patient with X-rays is known. An image obtained by imaging is used for diagnosing a joint such as a knee joint and estimating a three-dimensional positional relationship of the joint (for example, see Patent Document 1). Further, an auxiliary tool for applying a load similar to that in a standing state to a subject is disclosed (for example, see Patent Document 2). Attempts have been made to take an image of the subject with X-rays in a state where the auxiliary tool is attached to the subject, and to diagnose a joint using the obtained image.

  Here, when a load is applied to the subject, an external force is applied to the joint. In consideration of this external force, diagnosis of the joint and estimation of the positional relationship of the joint may be performed. Here, muscle tension generated by muscles and the like attached to the bone is applied to the bone of the actual human body. Therefore, the value of the external force applied to the joint of the subject to which the load is applied may not match the value of the load. However, conventionally, it has not been possible to accurately detect the external force applied to the joint.

JP 2006-263241 A JP 2006-296647 A

  An object of the present invention is to provide an external force detection device, an external force detection method, and a program that can accurately calculate an external force applied to a joint of a subject.

According to an embodiment, an external force detection device includes a displacement member, an addition unit, a first acquisition unit, and a first calculation unit. The displacement member is displaced according to the bending of the joint of the subject. The adding unit applies a load to the subject. The first acquisition unit acquires a displacement amount of the displacement member when a load is applied to the subject. The first calculator calculates an external force acting on the joint when a load is applied from the displacement amount. The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of a bone part continuous with the joint part, and the first acquisition unit applies the load to the subject. The displacement amount is obtained from the displacement of the mark of the displacement member when the displacement is performed.

FIG. 2 is a schematic diagram of an external force detection device. The schematic diagram which shows an example of a displacement member. The schematic diagram which shows an example of a displacement member. FIG. 2 is a block diagram showing a functional configuration of the external force detection device. FIG. 3 is a schematic diagram illustrating an example of an external force image. 9 is a flowchart illustrating an example of a procedure of an external force detection process. The schematic diagram which shows an example of an external force detection apparatus. FIG. 2 is a block diagram showing a functional configuration of the external force detection device. 9 is a flowchart illustrating an example of a procedure of an external force detection process. The schematic diagram which shows an example of another form of an addition part. The schematic diagram which shows an example of another form of an addition part. The schematic diagram which shows an example of another form of an addition part. FIG. 2 is a schematic diagram of an external force detection device. FIG. 3 is a functional block diagram of the external force detection device. The schematic diagram which shows an example of a dynamic model. The figure which shows an example of an analysis image. 9 is a flowchart illustrating an example of a procedure of an external force detection process. FIG. 2 is a block diagram illustrating an example of a hardware configuration of the external force detection device.

(First Embodiment)
Hereinafter, an external force detection device, an external force detection method, and a program according to an embodiment will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram of an external force detection device 10 according to the present embodiment. The external force detection device 10 is a device that detects an external force acting on the joint 24 when a load is applied to the subject H. Note that the external force indicates a force acting on the joint 24 from the outside when a load is applied to the subject H.

  In the present embodiment, a case where the joint 24 to be detected by the external force detection device 10 is the knee joint of the subject H will be described as an example. However, the joint 24 to be detected by the external force detection device 10 may be any joint of the subject H, and is not limited to the knee joint.

  The external force detecting device 10 includes a control unit 12, a UI (user interface) unit 14, a driving unit 61, a support base 62, a guide member 63, an additional unit 64, a load sensor 65, and a fixing member 66. , A displacement member 70, and a detection unit 72.

  The control unit 12 controls the external force detection device 10. The control unit 12 is connected to the UI unit 14, the detection unit 72, the driving unit 61, and the load sensor 65 so that data and signals can be transmitted and received.

  The support table 62 is a table that supports the subject H. In the present embodiment, the subject H is supported by the support 62 while lying on the support 62.

  The support member 62 is provided with a guide member 63 that is long along the longitudinal direction of the support member 62 (see the arrow X direction). The guide member 63 is provided with a driving unit 61, a fixing member 66, an additional unit 64, and a load sensor 65.

  The fixing member 66 is a member for fixing a part of the body of the subject H to the support 62. The fixing member 66 is fixed to the support 62. In the present embodiment, the fixing member 66 is arranged at a position where the waist of the subject H lying on the support base 62 can be fixed. The position of the fixing member 66 is not limited to the position shown in FIG.

  The adding unit 64 applies a load to the subject H. The additional portion 64 is provided movably along the longitudinal direction of the guide member 63 (see the arrow X direction). The driving section 61 reciprocates the adding section 64 in the longitudinal direction of the guide member 63 (see the arrow XA direction and the arrow XB direction).

  In the present embodiment, the adding unit 64 is arranged at a position where a load can be applied to the subject H from the sole side to the head side of the subject H lying on the support base 62.

  For example, assume that the subject H lies on the support 62. Then, the waist of the subject H is fixed by the fixing member 66. In this state, under the control of the control unit 12, the adding unit 64 is moved in a direction (arrow XA direction) approaching the fixing member 66. Then, a load is applied to the subject H.

  Further, under the control of the control unit 12, the adding unit 64 is moved in a direction (arrow XB direction) away from the fixing member 66. Then, the subject H is released from the state where the load is applied.

  The load sensor 65 is disposed on a surface of the additional portion 64 on the side of the fixing member 66. The load sensor 65 detects a load applied to the subject H. The load sensor 65 is a known sensor capable of detecting a load.

  In the present embodiment, the sole of the subject H contacts the load sensor 65. For this reason, when a load is applied to the subject H by moving the adding unit 64 toward the fixing member 66 (see the arrow XA direction), pressure is applied to the load sensor 65 by the sole of the subject H. Thus, the load sensor 65 detects a load.

  The UI unit 14 includes an input unit 14A and a display unit 14B. The input unit 14A accepts input of various instructions and information from the user. The input unit 14A is, for example, a keyboard, a mouse, a switch, a microphone, and the like.

  The display unit 14B displays an image. The display unit 14B is, for example, a CRT (Cathode Ray Tube) display, a liquid crystal display, an organic EL (Electro Luminescence) display, a plasma display, or the like.

  Note that the UI unit 14 may be a touch panel in which the input unit 14A and the display unit 14B are integrally configured.

  The displacement member 70 is a member that is displaced in accordance with the bending of the joint 24 of the subject H. The displacement member 70 is, for example, a sheet-shaped member that covers a region including the joint 24 to be detected in the subject H, or a member that covers a part of a pair of bones connected to the joint 24 to be detected from the outside. It is.

  FIG. 2 is a schematic diagram illustrating an example of the displacement member 70. In the present embodiment, a case where the displacement member 70 is a tubular, sheet-shaped member that covers from the waist to the toes of the subject H from the outside will be described as an example.

  That is, in the present embodiment, the subject H mounts the displacement member 70 by inserting the lower limb inside the cylindrical displacement member 70. Accordingly, the displacement member 70 is in a state of covering the joint 24 of the subject H and a pair of bones connected to the joint 24 from the outside.

  The displacement member 70 may have any shape and size that covers the joint 24 to be detected by the subject H. For this reason, the displacement member 70 only needs to have a shape and size that cover at least the joint 24 of the subject H and the bones above and below the joint 24, and is not limited to a shape that continuously covers from the waist to the toes. .

  The material of the displacement member 70 is preferably a material that does not easily adversely affect the image obtained by X-rays or nuclear magnetic resonance signals, such as deterioration of sharpness. The material of the displacement member 70 is preferably, for example, a nonmetal.

  In the present embodiment, a mark M is provided on the outer peripheral surface of the displacement member 70. The mark M is arranged at least along a crossing direction (arrow C direction) of the bone continuous to the detection target joint 24 with respect to the long direction (see the arrow L direction in FIG. 2). (See mark M1).

  The mark M only needs to be detectable by the detection unit 72 described later. More specifically, the color, the material, the shape, and the size of the mark M, and the arrangement position on the displacement member 70 may be detected by the detection unit 72. Further, the color, material, shape, size of the mark M, and the position of the mark M on the displacement member 70 should be such that the image obtained by X-rays or nuclear magnetic resonance signals is not adversely affected such as sharpness deterioration. Is preferred.

  FIG. 2 shows a case where the shape of the mark M is linear. Further, in the example shown in FIG. 2, a linear mark M1 along the cross direction (direction of arrow C) and a linear mark M along the long direction (direction of arrow L) are formed on the outer peripheral surface of the displacement member 70. Are arranged in a grid pattern.

  Note that the shape of the mark M may be a point. FIG. 3 shows a case where the shape of the mark M is a point. Further, in the example shown in FIG. 3, on the outer peripheral surface of the displacement member 70, a point mark M along the crossing direction (the direction of arrow C) and a line point along the long direction (the direction of arrow L) are provided. , And a plurality of marks M are arranged at an interval from each other.

  The material of the mark M is not limited. The material of the mark M is, for example, a metal such as gold.

  Returning to FIG. 1, the detection unit 72 detects a parameter (hereinafter, referred to as a displacement parameter) used for calculating a displacement amount of the displacement member 70. That is, the detection unit 72 detects a displacement parameter of a displacement amount of the displacement member 70 when a load is applied to the displacement member 70 before the load is applied. In the present embodiment, the detection unit 72 detects a displacement parameter by detecting a change in the length of the displacement member 70 when a load is applied.

  In addition, the length of the displacement member 70 refers to a longitudinal direction (see an arrow L direction in FIG. 2) of the displacement member 70 that is continuous with the joint 24, and an intersecting direction intersecting the longitudinal direction. (In the direction of arrow C in FIG. 2). In the present embodiment, the long direction of the bone part continuous to the joint part 24 (see the arrow L direction in FIG. 2), the long direction of the support 62 (the arrow X direction in FIG. 1), Are described as being identical.

  The detection unit 72 is a digital camera that photographs the displacement member 70 or a known detector that can detect the position of the mark M on the displacement member 70. In the present embodiment, as an example, a case where the detection unit 72 is a digital camera will be described.

  The detection unit 72 is arranged at a position where an area between the fixing member 66 and the addition unit 64 can be photographed. For this reason, the detection unit 72 photographs the displacement member 70 by photographing the subject H to which the displacement member 70 is attached. Then, the captured image of the displacement member 70 is output to the control unit 12 as a displacement parameter.

  Next, a functional configuration of the external force detection device 10 will be described. FIG. 4 is a block diagram illustrating a functional configuration of the external force detection device 10.

  The external force detection device 10 includes a detection unit 72, a load sensor 65, a drive unit 61, a UI unit 14, a storage unit 16, and a control unit 12. The control unit 12 is connected to the detection unit 72, the load sensor 65, the drive unit 61, the UI unit 14, and the storage unit 16 so that data and signals can be exchanged.

  The storage unit 16 is various storage media such as a hard disk device. The storage unit 16 stores various data and images.

  The control unit 12 controls the external force detection device 10. In the present embodiment, the control unit 12 includes a first reception unit 12A, a first acquisition unit 12B, a first calculation unit 12C, a second calculation unit 12D, a drive control unit 12E, and a second reception unit 12F. , A generation unit 12G, and a display control unit 12H.

  Part or all of first receiving unit 12A, first obtaining unit 12B, first calculating unit 12C, second calculating unit 12D, drive control unit 12E, second receiving unit 12F, generating unit 12G, and display control unit 12H. For example, the program may be realized by causing a processing device such as a CPU (Central Processing Unit) to execute a program, that is, realized by software, may be realized by hardware such as an IC (Integrated Circuit), or may be realized by software. And hardware may be used together.

  The first receiving unit 12A receives a detection result from the detecting unit 72. In the present embodiment, control unit 12 receives a captured image of displacement member 70 from detection unit 72. Further, the detection result of the load applied to the subject H is received from the load sensor 65.

  The first acquisition unit 12B acquires a displacement amount of the displacement member 70 when a load is applied to the subject H. “When a load is applied to the subject H” means when a load indicated by the detection result received from the load sensor 65 is applied to the subject H.

  The displacement amount of the displacement member 70 indicates a change amount of the length of the displacement member 70 before a load is applied.

  In the present embodiment, a case will be described where the first acquisition unit 12B acquires the displacement distribution of the displacement member 70 as the displacement amount of the displacement member 70. The displacement distribution of the displacement member 70 indicates the amount of displacement at each position of each of the divided regions of the displacement member 70 before the load is applied.

  For example, the first acquisition unit 12B analyzes a captured image of the displacement member 70 received from the detection unit 72, and calculates the amount of change in the length of the displacement member 70. Specifically, the first acquisition unit 12B includes a photographed image of the displacement member 70 photographed by the detection unit 72 before the load is applied, and a photographed image of the displacement member 70 photographed by the detection unit 72 when the load is applied. And get each of

  Then, the first acquisition unit 12B is configured to determine the displacement member 70 before the load is applied, and the displacement member 70 when the load is applied, in the long direction (arrow X direction, FIG. ) Is calculated. In addition, the first acquisition unit 12B is configured to intersect the displacement member 70 before the load is applied with the displacement member 70 when the load is applied in the cross direction (the direction of the arrow C in FIG. 2) that intersects the long direction. ) Calculate the amount of change in length. It should be noted that a known image analysis technique may be used to calculate these amounts of change.

  Note that a captured image of the displacement member 70 captured by the detection unit 72 before applying a load may be stored in the storage unit 16 in advance. In the present embodiment, a description will be given assuming that a captured image of the displacement member 70 captured by the detection unit 72 before applying a load is stored in the storage unit 16 in advance.

  Then, the first obtaining unit 12B calculates the amount of change in the length of the displacement member 70 for each of the regions obtained by dividing the displacement member 70 into a plurality of regions.

  Then, the first acquisition unit 12B uses the amount of change as the amount of displacement of the displacement member 70. Thereby, the first acquisition unit 12B acquires the displacement distribution of the displacement member 70.

  Note that the first acquisition unit 12B includes a photographed image of the displacement member 70 photographed by the detection unit 72 before the addition unit 64 applies the load, and a photograph of the displacement member 70 photographed by the detection unit 72 when the load is added. The displacement distribution of the displacement member 70 may be acquired by using the image.

  Further, the first acquisition unit 12B may acquire the displacement distribution of the displacement member 70 from the displacement of the mark M provided on the displacement member 70.

  For example, the first acquisition unit 12B includes a captured image of the displacement member 70 captured by the detection unit 72 before the load is applied, and a captured image of the displacement member 70 captured by the detection unit 72 when the load is applied. Get each. Then, the first acquisition unit 12B analyzes each position of the mark M of the displacement member 70 included in these captured images. Then, the first acquisition unit 12B calculates the displacement amount for each of the marks M of the displacement member 70 included in these captured images, for each mark M at a position corresponding to each other (the position on the displacement member 70 is the same). I do. Thereby, the first acquisition unit 12B may acquire the displacement distribution of the displacement member 70.

  The first acquisition unit 12B may acquire the displacement distribution of the displacement member 70 by analyzing the mark M included in an image captured by an external device such as a CT device or an MRI device. In this case, the external force detection device 10 can be configured to not include the detection unit 72.

  The first calculation unit 12C calculates an external force acting on the joint 24 of the subject H when a load is applied from the displacement distribution acquired by the first acquisition unit 12B.

  For example, the first calculation unit 12C stores a first table indicating the correspondence between the displacement amount and the external force in the storage unit 16 in advance. Then, the first calculation unit 12C reads, from each of the regions obtained by dividing the displacement member 70 into a plurality of regions, the external force corresponding to the displacement amount from the first table. Thus, the first calculation unit 12C calculates the external force for each of the regions obtained by dividing the displacement member 70 into a plurality of regions.

  The second calculation unit 12D calculates the joint angle of the joint unit 24 from the displacement amount acquired by the first acquisition unit 12B.

  For example, the second calculation unit 12D stores a second table indicating the correspondence between the displacement amount and the joint angle in the storage unit 16 in advance. Note that the second table may indicate the correspondence between the displacement distribution and the joint angle.

  Then, the second calculation unit 12D reads the joint angle corresponding to the displacement amount (or the displacement distribution) acquired by the first acquisition unit 12B from the second table. Thereby, the second calculating unit 12D calculates the joint angle of the joint unit 24 when a load is applied.

  The drive control unit 12E controls driving of the drive unit 61 and detection (photographing in the present embodiment) by the detection unit 72. The second receiving unit 12F receives various operation instructions from the user from the UI unit 14.

  The generation unit 12G generates an external force image indicating an external force acting on the joint unit 24. The external force image is an image in which the external force acting on the joint 24 of the subject H is indicated by a color density corresponding to the strength of the external force. In the present embodiment, the color density indicates at least one of the color and the density.

  In the present embodiment, the generation unit 12G displays an external force region on which an external force acts on a schematic image schematically showing the joint 24 to be detected of the subject H and a bone connected to the joint 24, by adding the external force area. An external force image represented by a color density corresponding to the image is generated.

  The display control unit 12H displays various images on the storage unit 16. In the present embodiment, the display control unit 12H displays the external force image generated by the generation unit 12G on the display unit 14B.

  FIG. 5 is a schematic diagram illustrating an example of the external force image 17. For example, the external force image 17 is an image in which, in the image H1 of the subject H schematically showing the lower limb, an external force region P1 where an external force acts is indicated by a color density according to the intensity of the external force. The external force image 17 may further include character information P2 indicating a value of the external force.

  The image H1 included in the external force image 17 may be an image schematically showing the lower limb bent at an angle that matches the joint angle calculated by the second calculator 12D. Further, the external force image 17 may further include character information indicating the joint angle calculated by the second calculating unit 12D. Further, the external force image 17 may include a gauge indicating a color density corresponding to the strength of the external force.

  Next, a procedure of an external force detection process executed by the external force detection device 10 according to the present embodiment will be described.

  FIG. 6 is a flowchart illustrating an example of a procedure of an external force detection process performed by the external force detection device 10 according to the present embodiment.

  First, it is determined whether or not the second receiving unit 12F has received an external force detection instruction from the input unit 14A (Step S100). For example, the user instructs external force detection by operating the input unit 14A. Then, the input unit 14A outputs a signal indicating external force detection to the control unit 12. When receiving a signal indicating external force detection from input unit 14A, first receiving unit 12A determines that an external force detection instruction has been received (step S100: Yes).

  If an affirmative determination is made in step S100 (step S100: Yes), the process proceeds to step S102. In step S102, the drive control unit 12E controls the drive unit 61 so as to apply a load to the subject H (step S102).

  More specifically, the drive control unit 12E controls the drive unit 61 to move the additional unit 64 along the guide member 63 in a direction approaching the fixed member 66 (the arrow XA direction in FIG. 1). Then, the drive control unit 12E moves the adding unit 64 toward the fixing member 66 until the load sensor 65 detects a predetermined desired load. The desired load is, for example, a load applied to the subject H in the standing state.

  Next, the first receiving unit 12A receives a captured image of the displacement member 70 from the detecting unit 72 (Step S104). Further, the first receiving unit 12 </ b> A receives, from the load sensor 65, a detection result of the load applied to the subject H.

  Next, the first acquisition unit 12B acquires the displacement amount of the displacement member 70 when a load is applied to the subject H (Step S106). In the present embodiment, as described above, the first acquisition unit 12B acquires the displacement distribution of the displacement member 70.

  Next, the first calculation unit 12C calculates an external force acting on the joint 24 of the subject H when a load is applied, from the displacement amount acquired by the first acquisition unit 12B in step S106 (step S108).

  Next, the second calculation unit 12D calculates the joint angle of the joint unit 24 when a load is applied from the displacement amount acquired by the first acquisition unit 12B in step S106 (step S110).

  Next, the generation unit 12G generates the external force image 17 indicating the external force calculated in Step S108 (Step S112).

  Next, the generation unit 12G stores the generated external force image 17 in the storage unit 16 in association with the identification information of the subject H to be detected (step S114).

  This identification information may include the date and time when the external force image 17 was generated.

  In addition, the generation unit 12G associates the captured image of the displacement member 70 received in step S104, the detection result of the load received from the load sensor 65, the displacement amount acquired in step S106, At least one of the external force calculated in S108 and the joint angle calculated in step S110 may be further stored in the storage unit 16. Then, this routine ends.

  On the other hand, if a negative determination is made in step S100 (step S100: No), the process proceeds to step S116. In step S116, the second receiving unit 12F determines whether a signal indicating an external force image display instruction has been received from the input unit 14A (step S116).

  If a negative determination is made in step S116 (step S116: No), this routine ends. If an affirmative determination is made in step S116 (step S116: Yes), the process proceeds to step S118.

  In step S118, the display control unit 12H reads the external force image 17 stored in the storage unit 16 (step S118). Then, the display control unit 12H displays the read external force image 17 on the display unit 14B (Step S120). Then, this routine ends.

  In the process of step S118, the display control unit 12H determines at least one of the list of the external force images 17 stored in the storage unit 16 and the list of the identification information of the subject H corresponding to the external force image 17. The information may be read and displayed on the display unit 14B. Then, by operating the input unit 14A, the user selects the external force image 17 to be displayed or the identification information of the subject H to be displayed. When the second receiving unit 12F receives the external force image 17 to be displayed or a signal indicating the identification information of the subject H from the input unit 14A, the display control unit 15H outputs a signal indicating the received external force image 17, or The external force image 17 corresponding to the signal indicating the received identification information may be read from the storage unit 16 and displayed on the display unit 14B.

  As described above, the external force detection device 10 according to the present embodiment includes the displacement member 70, the addition unit 64, the first acquisition unit 12B, and the first calculation unit 12C. The displacement member 70 is displaced in accordance with the bending of the joint 24 of the subject H. The adding unit 64 applies a load to the subject H. The first acquisition unit 12B acquires a displacement amount of the displacement member 70 when a load is applied to the subject H. The first calculation unit 12C calculates an external force acting on the joint 24 when a load is applied, from the amount of displacement.

  As described above, the external force detection device 10 of the present embodiment calculates the external force acting on the joint 24 from the displacement amount of the displacement member 70. Therefore, the external force can be calculated with higher accuracy than when the external force is calculated from the load applied to the subject H, the X-ray image of the subject H, and the like.

  Therefore, the external force detection device 10H of the present embodiment can accurately calculate the external force applied to the joint of the subject H when a load is applied to the subject H.

  Further, the displacement member 70 is preferably made of non-metal. When the displacement member 70 is made of a non-metallic material, even when the external force detection device 10 is applied to a CT (Computed Tomography) device or an MRI (magnetic resonance imaging) device, the accuracy of images obtained by these devices can be improved. The influence of the displacement member 70 can be suppressed.

  In addition, the displacement member 70 is disposed along a cross direction (arrow C direction, see FIG. 2) that intersects a long direction (arrow L direction, see FIG. 2) of the bone portion that is continuous with the joint 24. It is preferable to have the mark M. It is preferable that the first acquisition unit 12B acquires the displacement amount of the displacement member 70 from the displacement of the mark M of the displacement member 70 when a load is applied to the subject H.

  By acquiring the displacement amount of the displacement member 70 from the displacement of the mark M, the first acquisition unit 12B can acquire the displacement amount of the displacement member 70 with higher accuracy. The mark M is linear or dotted.

  The external force detection device 10 according to the present embodiment may include a second calculation unit 12D. The second calculator 12D calculates the joint angle of the joint 24 from the displacement amount. By calculating the joint angle of the joint section 24 from the displacement amount, the joint angle can be calculated more accurately and easily than when the joint angle is calculated from a captured image of the subject H or the like.

  For this reason, the external force detection device 10 of the present embodiment can accurately detect the external force applied to the joint 24 and can accurately and easily detect the joint angle of the joint 24.

  Further, the external force detection device 10 of the present embodiment includes a first acquisition unit 12B, a first calculation unit 12C, and a display control unit 12H. The first acquisition unit 12B acquires the displacement amount of the displacement member 70 that is displaced in accordance with the bending of the joint 24 of the subject H when a load is applied to the subject H. The first calculation unit 12C calculates an external force acting on the joint 24 when a load is applied, from the amount of displacement. The display control unit 12H displays an external force image indicating the external force on the display unit 14B.

  For this reason, in addition to the above-described effects, the external force detection device 10 according to the present embodiment can easily apply the external force acting on the joint 24 of the subject H to the user when a load is applied to the subject H. Can be provided.

  The external force detection device 10 according to the present embodiment can be applied to, for example, a CT device or an MRI device. For example, the external force detection device 10 is mounted on a CT device or an MRI device. Thus, the subject H can be imaged with the load applied, and the external force and the joint angle detected by the external force detection device 10 can be used for various information calculated by the CT device or the MRI device. For this reason, it is possible for the CT apparatus and the MRI apparatus to calculate information that can perform a highly accurate diagnosis.

(Second embodiment)
In the present embodiment, an embodiment in which the displacement member 70 includes a plurality of members will be described.

  FIG. 7 is a schematic diagram of an external force detection device 10B according to the present embodiment. The external force detection device 10B includes a control unit 13, a UI unit 14, a driving unit 61, a support base 62, a guide member 63, an addition unit 64, a load sensor 65, a fixing member 66, a displacement member 71, , A detection unit 67 and a fixing member 69. The control unit 13 is connected to the drive unit 61, the load sensor 65, the detection unit 67, and the UI unit 14 so that data and signals can be exchanged.

  The UI unit 14, the drive unit 61, the support 62, the guide member 63, the additional unit 64, the load sensor 65, and the fixing member 66 are the same as those in the first embodiment.

  The external force detection device 10B according to the present embodiment includes a displacement member 71 instead of the displacement member 70 according to the first embodiment.

  The displacement member 71 is a member that is displaced in accordance with the bending of the joint 24 of the subject H, similarly to the displacement member 70 of the first embodiment. The displacement member 71 is preferably made of a non-metal.

  The displacement member 71 includes a plurality of members. In the present embodiment, the displacement member 71 includes a first displacement member 71A, a second displacement member 71B, and a connecting member 71C. Note that the displacement member 71 may be composed of two or four or more members.

  The first displacement member 71 </ b> A and the second displacement member 71 </ b> B are arranged at intervals with the joint 24 to be detected interposed therebetween. In the present embodiment, the first displacement member 71A is mounted on the subject H lying on the support base 62 on the toe side (in the direction of the arrow XB) from the joint 24. The second displacement member 71B is mounted on the subject H lying on the support table 62 on the head side (the arrow XA direction side) of the joint 24.

  The first displacement member 71A and the second displacement member 71B have a shape that can be attached to the body of the subject H. That is, it is preferable that the first displacement member 71A and the second displacement member 71B have shapes conforming to the shape of the subject H outside the body.

  In the present embodiment, a case where the first displacement member 71A and the second displacement member 71B are cylindrical members will be described. Note that the shapes of the first displacement member 71A and the second displacement member 71B are not limited to cylindrical shapes.

  The connecting member 71C connects the first displacement member 71A and the second displacement member 71B. The connecting member 71C connects the first displacement member 71A and the second displacement member 71B so that each of the first displacement member 71A and the second displacement member 71B can be displaced from each other.

  Therefore, when the displacement member 71 is mounted on the lower leg of the subject H, the positions of the first displacement member 71A and the second displacement member 71B are displaced in accordance with the bending of the joint 24 of the lower leg.

  The detecting section 67 is provided on the connecting member 71C. The detection unit 67 detects a displacement parameter used for calculating a displacement amount of the displacement member 71. That is, the detection unit 67 detects a displacement parameter of a displacement amount of the displacement member 71 when the load is applied to the displacement member 71 before the load is applied.

  In the present embodiment, the detection unit 67 detects the amount of contraction of the relative distance between the first displacement member 71A and the second displacement member 71B as a displacement parameter. Then, the detection unit 67 outputs the contraction amount of the displacement member 71 to the control unit 13.

  The detection unit 67 is a known sensor that can detect a relative distance between the first displacement member 71A and the second displacement member 71B.

  Further, the detection unit 67 may be configured to have an angle detection function. In the present embodiment, the detecting section 67 detects the inclination of each of the first displacement member 71A and the second displacement member 71B with respect to the connecting member 71C. Then, the detector 67 outputs the angle detection result to the controller 13. In this case, the detection unit 67 may have a configuration having a function corresponding to a known angle detection sensor.

  The control unit 13 controls the external force detection device 10B.

  Next, a functional configuration of the external force detection device 10B will be described. FIG. 8 is a block diagram illustrating a functional configuration of the external force detection device 10B.

  The external force detection device 10B includes a detection unit 67, a load sensor 65, a drive unit 61, a UI unit 14, a storage unit 16, and a control unit 13. The control unit 13 is connected to the detection unit 67, the load sensor 65, the drive unit 61, the UI unit 14, and the storage unit 16 so as to be able to exchange data and signals.

  The control unit 13 controls the external force detection device 10B. In the present embodiment, the control unit 13 includes a first reception unit 13A, a first acquisition unit 13B, a first calculation unit 12C, a second calculation unit 13D, a drive control unit 12E, and a second reception unit 12F. , A generation unit 12G, and a display control unit 12H.

  Part or all of first reception unit 13A, first acquisition unit 13B, first calculation unit 12C, second calculation unit 13D, drive control unit 12E, second reception unit 12F, generation unit 12G, and display control unit 12H. For example, it is possible to make a processing device such as a CPU execute a program, that is, it may be realized by software, may be realized by hardware such as an IC, or may be realized by using software and hardware together. You may.

  The first receiving unit 13A receives a detection result from the detecting unit 67. In the present embodiment, first receiving unit 13 </ b> A receives a contraction amount of displacement member 71 from detecting unit 67. Further, the first receiving unit 13A receives, from the detecting unit 67, a detection result of the inclination of each of the first displacement member 71A and the second displacement member 71B with respect to the connecting member 71C. Further, the first receiving unit 13 </ b> A receives a load detection result from the load sensor 65.

  The first acquisition unit 13B acquires a displacement amount of the displacement member 71 when a load is applied to the subject H.

  In the present embodiment, the first acquisition unit 13B acquires the contraction amount of the displacement member 71 received from the detection unit 67 as the displacement amount of the displacement member 71.

  The first calculation unit 12C is configured to perform the first operation except that the first calculation unit 12C calculates the external force acting on the joint unit 24 using the displacement amount acquired by the first acquisition unit 13B instead of the displacement amount acquired by the first acquisition unit 12B. This is the same as the embodiment.

  The second calculator 13D calculates the joint angle of the joint 24 from the displacement acquired by the first acquirer 13B. The second calculator 13D may calculate the joint angle of the joint 24 in the same manner as the second calculator 12D of the first embodiment.

  The second calculating unit 13D calculates the joint angle of the joint unit 24 using the detection result of the inclination of each of the first displacement member 71A and the second displacement member 71B with respect to the connecting member 71C received from the detection unit 67. It may be calculated.

  For example, the second calculating unit 13D stores in advance a third table in which the inclination of each of the first displacement member 71A and the second displacement member 71B with respect to the connecting member 71C and the joint angle of the joint unit 24 are associated. 16 is stored. Then, the second calculation unit 13D reads, from the third table, the joint angle corresponding to the inclination of each of the first displacement member 71A and the second displacement member 71B with respect to the connecting member 71C, received from the detection unit 67. Thereby, the second calculator 13D calculates the joint angle of the joint 24.

  Next, a procedure of an external force detection process executed by the external force detection device 10B of the present embodiment will be described.

  FIG. 9 is a flowchart illustrating an example of a procedure of an external force detection process performed by the external force detection device 10B according to the present embodiment.

  First, the control unit 13 executes the processing of steps S200 to S202 in the same manner as steps S100 to S102 in the first embodiment. That is, first, it is determined whether or not the second receiving unit 12F has received an external force detection instruction from the input unit 14A (Step S200).

  If an affirmative determination is made in step S200 (step S200: Yes), the process proceeds to step S202. In step S202, the drive control unit 12E controls the drive unit 61 so as to apply a load to the subject H (step S202).

  Next, the first receiving unit 13A receives the detection result (Step S204). In step S204, the first receiving unit 13A receives the amount of contraction of the displacement member 71 from the detecting unit 67. Further, the first receiving unit 13A receives, from the detecting unit 67, a detection result of the inclination of each of the first displacement member 71A and the second displacement member 71B with respect to the connecting member 71C. The first receiving unit 13 </ b> A receives a load detection result from the detecting unit 67.

  Next, the first acquisition unit 13B acquires the displacement amount of the displacement member 70 from the contraction amount of the displacement member 71 received in Step S204 (Step S206).

  Next, the first calculation unit 12C calculates an external force acting on the joint 24 of the subject H from the displacement acquired by the first acquisition unit 12B in step S206 (step S208).

  Next, the second calculator 13D calculates the joint angle of the joint 24 (Step S210). Next, the generation unit 12G generates the external force image 17 indicating the external force calculated in Step S108 (Step S212). Next, the generation unit 12G stores the generated external force image 17 in the storage unit 16 in association with the identification information of the corresponding subject H to be detected (Step S214).

  Steps S208 to S214 are the same as steps S108 to S114 of the first embodiment (see FIG. 6). Then, this routine ends.

  On the other hand, if a negative determination is made in step S200 (step S200: No), the process proceeds to step S216. Then, the control unit 13 performs the processes of steps S216 to S220 in the same manner as steps S116 to 120 (see FIG. 6) in the first embodiment. Then, this routine ends.

  As described above, the external force detection device 10B according to the present embodiment includes the displacement member 71 instead of the displacement member 70 according to the first embodiment. Also in the case where the displacement member 71 including a plurality of members is provided, similarly to the first embodiment, the external force acting on the joint portion 24 when a load is applied is calculated from the displacement amount of the displacement member 71. I do.

  Therefore, similarly to the first embodiment, the external force detection device 10B of the present embodiment can accurately calculate the external force applied to the joint of the subject H when a load is applied to the subject H. it can.

<Modification>
In the above-described embodiment, the form in which the load is added to the subject H by moving the adding unit 64 along the guide member 63 has been described.

  However, the addition section 64 may be any configuration as long as it can apply a load to the subject H, and is not limited to the form described in the above embodiment. For example, the addition section 64 may adopt any of a pedal type, a cylinder type, and a lever type.

  FIGS. 10, 11, and 12 are schematic diagrams illustrating another example of the additional unit 64. FIG.

  FIG. 10 is a schematic diagram illustrating an example of the adding unit 644. The addition section 644 has a pedal-type structure. More specifically, the addition section 644 includes a first plate-shaped member 644A, a spring member 644C, and a second plate-shaped member 644B.

  The first plate member 644A is a plate member. The first plate-shaped member 644A has a plate surface in contact with the support member 642. That is, the first plate-shaped member 644A is supported by the support member 642. The support member 642 is fixed to the support 62.

  The second plate member 644B is a plate member. The second plate-shaped member 644B is disposed so as to face the fixing member 66. The fixing member 66 is the same as in the first embodiment. A load sensor 65 is provided on a surface of the second plate-shaped member 644B on the fixing member 66 side. The load sensor 65 is the same as in the first embodiment.

  The first plate-shaped member 644A and the second plate-shaped member 644B are connected by a spring member 644C. The spring member 644C is a long spring. The elongate direction of the spring member 644C coincides with a direction orthogonal to the elongate direction of the support table 62 on the mounting surface of the support table 62 on which the subject H is mounted.

  The second plate-shaped member 644B uses the spring member 644C as a rotation axis, in a direction in which it contacts the first plate-shaped member 644A (arrow YB direction), or in a direction away from the first plate-shaped member 644A (arrow arrow YA direction). It is provided rotatably. Also, the spring member 644C applies a restoring force to the second plate-shaped member 644B in the direction of the arrow YA.

  For this reason, a load (load in the direction of the arrow XA) from the second plate-shaped member 644B toward the fixed member 66 is applied to the subject H lying on the support base 62 by the restoring force of the spring member 644C.

  The material of the additional portion 644 is not limited. The material of the additional portion 644 is preferably, for example, a synthetic resin such as ABS. When the material of the addition unit 644 is a synthetic resin, when the external force detection device 10 is applied to a CT device or an MRI device, it is possible to suppress the addition unit 644 from affecting the accuracy of an image obtained by these devices. be able to.

  FIG. 11 is a schematic diagram illustrating an example of the cylinder-type addition section 646.

  The addition section 646 includes a first plate-shaped member 646A, a support member 646B, a cylinder 646D, a tubular member 646E, a control valve 646F, a tubular member 646G, and a compressor 646H.

  The first plate member 646A is a plate member. A load sensor 65 is provided on a surface of the first plate-shaped member 646A on the side of the fixing member 66. On the support base 62, a support member 642 and a support member 646B are stacked in this order. The support member 646B supports the first plate-shaped member 646A. The support member 642 supports the support member 646B movably along the long direction of the support table 62 (the direction of the arrow X). For this reason, the first plate-shaped member 646A is supported so as to be movable in the longitudinal direction (the direction of the arrow X) of the support member 642.

  A cylinder 646D is provided on a surface of the first plate member 646A opposite to the fixing member 66. The surface of the first plate-shaped member 646A opposite to the fixing member 66 is connected to the rod 646C of the cylinder 646D. The internal space of the cylinder 646D is connected to the compressor 646H via the tubular member 646E, the control valve 646F, and the tubular member 646G.

  The compressor 646H generates compressed air. The compressed air is sent to the cylinder 646D via the tubular member 646G, the control valve 646F, and the tubular member 646E. The rod 646C pushes the first plate-like member 646A in a direction (arrow XA direction) approaching the fixing member 66 by the compressed air sent to the internal space of the cylinder 646D. Therefore, a load is applied to the subject H by the first plate-shaped member 646A.

  It is preferable to adjust the length (length in the direction of arrow X) of the tubular member 646E and the tubular member 646G according to the configuration of the device to which the external force detection device 10 is applied.

  FIG. 12 is a schematic diagram illustrating an example of the lever-type adding unit 648. The lever type is a configuration using the principle of leverage.

  The addition portion 648 includes a first plate-shaped member 648A, a support member 648B, a support member 648C, a rotation shaft 648D, a shaft member 648E, and a weight 648F.

  The first plate member 648A is a plate member. A load sensor 65 is provided on a surface of the first plate-shaped member 648A on the side of the fixing member 66. On the support base 62, a support member 642 and a support member 648B are stacked in this order. The support member 648B rotatably supports the first plate-shaped member 648A and the support member 648C. The support member 642 is fixed on the support member 642.

  The surface of the first plate-shaped member 646A opposite to the fixing member 66 is connected to the shaft member 648E. The shaft member 648E is a rod-shaped member that is long in the longitudinal direction (the direction of the arrow X) of the support base 62. One end surface of the shaft member 648E in the long direction (the direction of the arrow X) is connected to the first plate-shaped member 648A. A weight 648F is provided on the other end side of the shaft member 648E in the long direction (the direction of the arrow X).

  Further, the shaft member 648E is rotatably supported by the rotation shaft 648D about the rotation shaft 648D (see the arrow Z1 direction and the arrow Z2 direction).

  For this reason, the shaft member 648E functions as a "lever" using the rotation shaft 648D as a fulcrum, the weight 648F as a point of action, and a connecting portion with the first plate-shaped member 648A as a power point.

  That is, at the point of action of the shaft member 648E where the weight 648F is provided, a force acts in the vertical direction (the direction of the arrow Z1), thereby causing the subject H to pass through the first plate-shaped member 648A in the direction of the arrow XA. A heading load can be added.

  By using the lever-type adding portion 648, a load greater than the weight of the weight 648F can be applied to the subject H even with a small weight 648F.

(Third embodiment)
In the present embodiment, a mode will be described in which the stress acting on the joint 24 is calculated using the external force detected by the external force detecting device 10 or the external force detecting device 10B of the above embodiment.

  The stress acting on the joint 24 in the present embodiment is obtained by adding the acting force acting on the joint 24 by a muscle to the external force.

  In the present embodiment, as an example, a form in which the stress acting on the stress region 42 is calculated using the external force detected by the external force detection device 10 of the first embodiment will be described. The external force detected by the external force detection device 10B of the second embodiment may be used.

  FIG. 13 is a schematic diagram of an external force detection device 10C according to the present embodiment.

  The external force detection device 10C includes a control unit 15, a UI unit 14, a driving unit 61, a support base 62, a guide member 63, an addition unit 64, a load sensor 65, a fixing member 66, a displacement member 70, , A detection unit 72, and the external device 18.

  The control unit 15 controls the external force detection device 10C. The control unit 15 is connected to the UI unit 14, the detection unit 72, the drive unit 61, the load sensor 65, and the external device 18 so as to be able to exchange data and signals.

  The UI unit 14, the driving unit 61, the support 62, the guide member 63, the adding unit 64, the load sensor 65, the fixing member 66, the displacement member 70, and the detecting unit 72 are the same as those in the first embodiment.

  The external device 18 is a device that acquires an image to be analyzed. The image to be analyzed is an image related to the joint 24 of the subject H and a bone connected to the joint. Specifically, the image to be analyzed includes the joint 24 of the subject H, a bone continuous with the joint 24, and a muscle. The muscle includes a muscle.

  The external device 18 obtains a time-series CT image of the subject H and a time-series MRI image of the subject H by scanning the subject H using, for example, X-rays or magnetism. Note that the external force detection device 10C and the external device 18 may be configured separately. Further, the external force detecting device 10C and the external device 18 may be integrally configured.

  Hereinafter, a case where the image to be analyzed handled in the present embodiment is a CT image will be described. However, the image to be analyzed is not limited to a CT image. For example, the image to be analyzed may be an MRI image or an ultrasonic echo image.

  The CT image is slice data expressing a two-dimensional spatial distribution of CT values, or volume data expressing a three-dimensional spatial distribution of CT values. Hereinafter, the CT image is assumed to be volume data. The external device 18 outputs a time-series CT image to the control unit 15.

  The control unit 15 may acquire a CT image to be analyzed from another device or an external storage unit. The image to be analyzed is not limited to a time-series image. In the following, an image to be analyzed will be described simply as an image or a CT image.

  In the present embodiment, the external force detecting device 10C detects the load by the load sensor 65 by the detecting unit 72 (photographing) while the load is added by the adding unit 64 to the subject H lying on the support base 62. , An external device 18 captures a CT image. Therefore, the CT image captured by the external device 18 is an image of the subject H in a state where the load detected by the load sensor 65 is added by the adding unit 64.

  FIG. 14 is an example of a functional block diagram of the external force detection device 10C. The external force detection device 10C includes a detection unit 72, a load sensor 65, a drive unit 61, an external device 18, the UI unit 14, the storage unit 16, and the control unit 15. The detection unit 72, the load sensor 65, the drive unit 61, the external device 18, the UI unit 14, and the storage unit 16 are connected to the control unit 15 so that data and signals can be exchanged.

  The control unit 15 controls the external force detection device 10C. The external force detection device 10C includes a first reception unit 12A, a first acquisition unit 12B, a first calculation unit 12C, a second calculation unit 12D, a drive control unit 12E, a second reception unit 12F, and a generation unit 15G. , A display control unit 15H, a second acquisition unit 15I, a construction unit 15J, a third calculation unit 15K, a fourth calculation unit 15L, and a fifth calculation unit 15M.

  The first reception unit 12A, the first acquisition unit 12B, the first calculation unit 12C, the second calculation unit 12D, the drive control unit 12E, the second reception unit 12F, the generation unit 15G, the display control unit 15H, the second acquisition unit 15I, A part or all of the construction unit 15J, the third calculation unit 15K, the fourth calculation unit 15L, and the fifth calculation unit 15M are, for example, realized by causing a processing device such as a CPU to execute a program, that is, realized by software. It may be realized by hardware such as an IC, or by using both software and hardware.

  The first reception unit 12A, the first acquisition unit 12B, the first calculation unit 12C, the second calculation unit 12D, the drive control unit 12E, and the second reception unit 12F are the same as in the first embodiment.

  The second acquisition unit 15I acquires an image related to the joint 24 of the subject H and a bone connected to the joint 24. In the present embodiment, the second obtaining unit 15I obtains a CT image from the external device 18 to obtain a CT image of the joint 24 of the subject H and a bone connected to the joint 24. Note that the CT image of the subject H may be stored in the storage unit 16 in advance. In this case, the second acquisition unit 15I may acquire the CT image by reading the CT image of the subject H to be analyzed from the storage unit 16.

  The second acquisition unit 15I outputs the acquired CT image to the third calculation unit 15K and the construction unit 15J.

  The constructing unit 15J constructs, from the CT images acquired by the second acquiring unit 15I, the three-dimensional shapes of the bones and the joints 24 and the characteristics of the load and deformation of each of the bones and the joints 24. .

  In the present embodiment, as an example, a description will be given of a case where the construction unit 15J constructs a dynamic model that indicates at least the three-dimensional shapes of the bones and the joints 24 and the relationship characteristics between the load and the deformation. The dynamic model is data obtained by adding a relation characteristic between the load and deformation of each of the bone and the joint to a bone and joint shape model indicating the three-dimensional shape of the bone and the joint 24. The relationship characteristic between the load and the deformation indicates the relationship between the load and the deformation. The relation characteristic between the load and the deformation indicates, for example, hardness.

  In the following, in order to simplify the description, the relationship between the load and the deformation may be simply referred to as “hardness”. However, the “hardness” referred to in the present embodiment is an example of the relationship between the load and the deformation as described above, and the relationship is not limited to the hardness.

  Specifically, the construction unit 15J extracts a bone region from the CT image acquired by the second acquisition unit 15I. For example, when the image to be analyzed is a CT image, the CT value of hard bone is about 1000 HU, and the CT value of soft tissue, which is connective tissue excluding bones such as tendons, ligaments, and muscles, is about 0 to 100 HU. For this reason, the construction unit 15J sets a threshold of a CT value for distinguishing a bone part from a soft tissue in advance. Note that the threshold may be adjustable by a user's operation of the input unit 14A or the like.

  Then, the construction unit 15J extracts the joint region and the bone region by extracting the region where the CT value is equal to or more than the threshold from the CT image acquired by the second acquisition unit 15I, and extracts the tertiary joint and the bone region. A bone joint shape model indicating the original shape is generated.

  For example, in the external force detection device 10C, when performing a structural analysis of the joint 24 by a numerical analysis using a finite element method (FEM), the constructing unit 15J converts the three-dimensional finite element model into a joint. And a bone joint shape model of the bone part. The finite element method is a method of dividing an analysis target area into mesh-like areas (called elements) surrounded by nodes and solving deformation approximately.

  Further, the constructing unit 15J generates a dynamic model in which a relation characteristic between the load and the deformation of each of the bone part and the joint part 24 is added to the bone joint shape model. Here, the CT value differs depending on the physical properties. For this reason, the construction unit 15J calculates, for each element, a relation characteristic between the load and the deformation, such as the hardness of the bone part and the joint part 24, in accordance with the CT value, and calculates each corresponding position of the bone joint shape model. A dynamic model is generated by adding to the element. Further, the obtained shape model may be subjected to a filtering process for removing discontinuous portions.

  Here, the displacement in the relation characteristic includes a displacement due to a rigid body displacement and a displacement due to a material deformation of each part. For this reason, the construction unit 15J may separate the displacement due to the rigid body displacement and the displacement due to the material deformation of each unit, and calculate the relationship characteristic between each load and the deformation for each element.

  Specifically, the constructing unit 15J is a biological tissue other than the bone and the joint, and is unlikely to be deformed by a factor other than the load, and is capable of extracting the deformation due to the load. May be further constructed. The factors other than the load are, specifically, factors other than the load, such as the degree of blood filling in the muscle fibers and the sliding motion of the filaments constituting the muscle fibers. Such living tissues are, for example, tendons, ligaments, and cartilage.

  In this case, the constructing unit 15J determines the relationship between the load and the deformation of the tendon, the ligament, and the cartilage included in the CT image with respect to the tendon, the ligament, and the cartilage by using the image analysis and the tracking technique (No. 2) may be calculated for each element.

  Then, the construction unit 15J adds, to each element at the corresponding position of the bone joint shape model, the relational characteristics of each of the bones and the joints 24 and the second relational characteristics of the living tissue such as tendons, ligaments and cartilage. By adding, a dynamic model may be constructed.

  FIG. 15 is a diagram schematically illustrating an example of the dynamic model 20. The mechanical model 20 includes a bone joint shape model showing the three-dimensional shape of each of the joint 24 and the bones 22A and 22B as the bones 22 connected to the joint 24. This is data to which a relation characteristic between the load and the deformation of the bone portion 22 is added.

  Referring back to FIG. 14, in the present embodiment, the structuring unit 15J calculates the relationship characteristics between the load and the deformation, such as the hardness of the bone unit 22 and the joint unit 24, according to the CT value, and generates the bone joint shape model. A dynamic model is generated by adding to each element at the corresponding position of.

  Here, an example of a method of calculating a relation characteristic between load and deformation for each element, which is calculated by the construction unit 15J, will be described.

  The construction unit 15J applies a load condition to the tendon and the end of the bone for the bone 22 and the joint 24 (which may include the above-described living tissue such as tendons, ligaments, and cartilage). Further, the construction unit 15J gives a displacement boundary condition to the bone end (the end of the bone) and the joint. In addition, the construction unit 15J gives a material composition formula to each living tissue. Then, the constructing unit 15J performs a large deformation / stress analysis based on continuum mechanics (Reference: "First Course in Continuum Mechanics (3rd Edition)", YC Fung).

  Large deformation / stress analysis means, for example, that after discretizing the equation of continuum mechanics by the finite element method, the physical quantities such as stress, strain, pressure, and deformation of each part, and their temporal changes are calculated by numerical calculation. Show. The large deformation / stress analysis is not limited to elastic analysis of isotropic deformation, but may be analysis by homogenization method considering anisotropic deformation characteristics of bones. Non-linear analysis in consideration of characteristics may be used, and static analysis or dynamic analysis may be used.

  Then, the constructing unit 15J calculates, from the CT image acquired by the second acquiring unit 15I, the relationship between the load and the deformation of each element in the bone 22 and the joint 24 by the large deformation / stress analysis. In addition, the construction unit 15J is a soft tissue (tendon, cartilage) that is a living tissue other than the bone part 22 and the joint part 24 and is hardly deformed by a factor other than the load and can extract the deformation due to the load. , Ligaments, etc.), image analysis and tracking techniques are used to further construct (calculate) a second relationship characteristic between load and deformation (displacement of soft tissue thickness or soft tissue).

  That is, the construction unit 15J constructs a relational characteristic (second relational characteristic) based on the thickness change of the soft tissue inside the joint 24 or the distortion of the soft tissue.

  Then, the construction unit 15J generates a dynamic model by adding the calculated relation characteristic and the second relation characteristic to each element at the corresponding position in the bone joint shape model.

  The construction unit 15J may construct a dynamic model in which the relation characteristics are added to each element at the corresponding position in the bone joint shape model (that is, the dynamic model does not include the second relation characteristics). However, it is preferable to construct a dynamic model including the second relation characteristic from the viewpoint of improving the accuracy of calculating the first stress described later.

  Returning to FIG. 14, the third calculation unit 15K calculates the positional relationship of the bone part 22 that is continuous with the joint part 24 using the CT image received from the second acquisition unit 15I.

  The positional relationship between the bones 22 continuing to the joint 24 includes an angle (joint angle) about the joint 24 between the bones 22 continuing to the joint 24, a center coordinate system of the bones, a moment of inertia, Includes bone mass, muscle Jacobian, etc.

  In the present embodiment, the third calculation unit 15K calculates a positional relationship using the CT image received from the second acquisition unit 15I, and generates a musculoskeletal model.

  The musculoskeletal model is obtained by arranging the three-dimensional shape of the muscle portion on a bone joint shape model showing the three-dimensional shape of the joint portion 24 and the bone portion 22 and adding the above positional relationship. Note that the musculoskeletal model may be a model in which three-dimensional shapes of ligaments and tendons are further arranged. The muscle portion in the present embodiment means a muscle that is connected with one of the two bone portions 22 connected to the joint portion 24 as a starting portion and the other as a stopping portion.

  Therefore, the musculoskeletal model indicates at least the positional relationship between the joint part 24 and the bone part 22 continuous with the joint part 24. Note that the musculoskeletal model may further include the hardness, weight, and the like of each of the bones 22, the joints 24, and the muscles connected to the bones 22.

  For example, the third calculating unit 15K generates a musculoskeletal model from the CT image using the following method.

  Specifically, similarly to the construction unit 15J, the third calculation unit 15K extracts, from the CT image acquired by the second acquisition unit 15I, an area where the CT value is equal to or larger than the threshold value, thereby obtaining the joint area area and the bone area. A partial region is extracted, and a bone joint shape model indicating a three-dimensional shape of the joint portion 24 and the bone portion 22 is generated. The third calculating unit 15K extracts a muscle region from the CT image by extracting a region of a CT value indicating a soft tissue (muscle), and arranges the three-dimensional shape of the muscle in the bone joint shape model. I do.

  Further, the third calculating unit 15K calculates the joint angle, the central coordinate system of the bone, the moment of inertia, and the bone as the positional relationship between the joint 24 and the bone 22 continuous with the joint 24 from the CT image. Calculate the mass and muscle Jacobian.

  For example, the third calculating unit 15K extracts, from the generated bone joint shape model, several points having characteristic shapes for each of the bone part 22 and the joint part 24. Then, the third calculating unit 15K calculates a coordinate system centered on the position of the center of gravity as a central coordinate system of each of the bones 22 and the joints 24.

  In addition, the third calculating unit 15K calculates the moment of inertia I for each of the bones 22 and the joints 24 around the respective axes of the calculated central coordinate system using the following equation (1).

I = Σmiri ² (1)

  In the formula (1), I indicates a moment of inertia, mi indicates the mass of an element when the bone part 22 and the joint part 24 are subdivided into a mesh, and ri indicates a distance to a coordinate axis. The mass of the element may be calculated from the previously stored standard density and the volume of the element. Also, ri may be calculated from the bone joint shape model.

Further, the third calculating unit 15K calculates the joint angle by performing coordinate transformation on the coordinate system of two adjacent bone parts 22 that are continuous with the joint part. For example, if the trunk near the side of the bone coordinate system (homogeneous transformation matrix) and T _a, the homogeneous transformation matrix representing the coordinate system of the distal bone and T _b, the relationship of the following formula (2) Holds. These coordinate systems may be calculated from the bone joint shape model.

T = T _b T _a ^-1 ... Equation (2)

  The third calculating unit 15K compares the matrix obtained when the matrix is rotated by α, β, and γ around the x-axis, the y-axis, and the z-axis with T using Equation (2), and Calculate the angles α, β, γ (Definition of Euler angles).

  Further, the third calculating unit 15K calculates the muscle Jacobian using the following equation (3).

  L = dl / dθ Expression (3)

  In the equation (3), L indicates muscular Jacobian, dl indicates a minute change in muscle length, and dθ indicates a minute change in joint angle. dl and dθ may use predetermined values or may be calculated from the geometric relationship between the muscle extracted from the CT image and the joint center.

  Note that the control unit 12 may calculate standard values of the moment of inertia, the mass of the bone unit 22 and the joint unit 24, and the muscle Jacobian in advance, and may store the standard values in the storage unit 16 in advance as a standard positional relationship. The third calculation unit 15K may use the moment of inertia, the masses of the bones 22 and the joints 24, and the muscle Jacobian stored in the storage unit 16. Further, when the third calculating unit 15K newly calculates at least one of the moment of inertia, the mass of the bone part 22, the mass of the joint part 24, and the muscular Jacobian, the value after the calculation is set as a new value. The storage unit 16 may be updated by storing it in the storage unit 16.

  Then, the third calculating unit 15K arranges the three-dimensional shape of the muscle in a bone joint shape model indicating the three-dimensional shape of the joint 24 and the bone 22, and calculates the calculated positional relationship (the joint angle, the joint angle of the bone 22). A musculoskeletal model is generated by adding a central coordinate system, a moment of inertia, masses of the bones 22 and the joints 24, muscle Jacobian, and the like.

  The third calculating unit 15K generates a time-series musculoskeletal model by generating a musculoskeletal model from each of the time-series CT images. That is, the third calculation unit 15K generates a time-series musculoskeletal model, and obtains the change in the joint angle and the length of the muscle from the time change of the position of the bone 22 extracted from the CT images acquired in time series. The change can also be calculated.

  The third calculating unit 15K may calculate the joint angle by acquiring the joint angle calculated from the displacement amount from the second calculating unit 12D. That is, the third calculating unit 15K may calculate the joint angle of the joint unit 24 calculated from the displacement amount of the displacement member 70 as the positional relationship.

  The fourth calculating unit 15L performs the inverse dynamics calculation using the positional relationship, the external force, and the load added by the adding unit 64, calculated by the third calculating unit 15K. By the inverse dynamics calculation, the fourth calculating unit 15L calculates the acting force acting on the joint unit 24 by the muscle.

  The acting force includes, for example, at least one of a muscle tension of a muscle connected between the bone portions 22 connected to the joint portion 24 and a torque acting on the joint portion 24. The muscle connected between the bones 22 connected to the joint 24 is defined as one of the two bones 22 connected to the joint 24 as a starting part and the other bone 22 as a stop. The muscles connected to these bones 22 are shown.

  The inverse dynamics calculation requires the joint angle, the central coordinate system of the bone, the moment of inertia, the mass of the bone, and the muscle Jacobian as the positional relationship between the joint 24 and the bone 22 connected to the joint 24. is there. In the inverse dynamics calculation, the external force calculated by the first calculating unit 12C (that is, the external force acting on the joint 24 when a load is applied to the subject H) and the load applied to the subject H Is used.

  The fourth calculator 15L acquires the joint angle, the central coordinate system of the bone, the moment of inertia, the mass of the bone, and the muscle Jacobian from the musculoskeletal model calculated by the third calculator 15K.

  In addition, the fourth calculation unit 15L acquires the external force from the first calculation unit 12C. Further, the fourth calculating unit 15L acquires the joint angle from the second calculating unit 12D. In addition, the fourth calculation unit 15L acquires a load detection result from the first reception unit 12A.

  The fourth calculating unit 15L may obtain the joint angle from the musculoskeletal model, or may obtain the joint angle from the second calculating unit 12D.

  The fourth calculating unit 15L calculates the following equation (using the joint angle, the central coordinate system of the bone, the moment of inertia, the mass of the bone, the muscle Jacobian, the external force, and the load (the load received from the load sensor 65)). 4) -Equation (6) calculates the acting force acting on the joint portion 24 by the muscle by performing the inverse dynamics calculation. The following equation (4) is an equation for calculating the torque acting on the joint 24.

  The equation of motion at each joint is represented by equation (4).

τ = Md ² θ / dt ² + Ddθ / dt + G (θ) + τe Expression (4)

In Expression (4), τ indicates a torque acting on a joint, θ indicates a joint angle, and dθ / dt indicates a joint angular velocity. Further, d ² θ / dt ² indicates a joint angular acceleration, M indicates a moment of inertia, D indicates a viscous resistance, and G (θ) indicates a gravitational term (changes depending on posture). Further, τe indicates the external force calculated by the first calculation unit 12C. In other words, τe is an external force acting on the joint 24 of the subject H to which a load has been applied at the time of capturing a CT image.

  That is, the fourth calculating unit 15L applies the external force calculated by the first calculating unit 12C to τe in Expression (4).

The fourth calculating unit 15L calculates the joint angular velocity (dθ / dt) by calculating the joint angular velocity using the time-series musculoskeletal model calculated by the third calculating unit 15K. Good. The fourth calculating unit 15L calculates the angular velocity of the joint angle using the time-series musculoskeletal model calculated by the third calculating unit 15K for the joint angular acceleration (d ² θ / dt ² ). Can be obtained by: The viscosity resistance (D) may be measured in advance and stored in the storage unit 16. The gravity term (G (θ)) may be calculated from the mass of the bone and the position of the center of gravity.

  When the CT image acquired by the second acquiring unit 15I is not a time-series image (that is, a one-shot CT image), it is not possible to obtain an item relating to time change in Expression (4). Therefore, in this case, the fourth calculating unit 15L may proceed with the process as τ = G (θ).

  The fourth calculating unit 15L calculates the muscle tension of the muscle connected between the bones connected to the joint by performing the inverse dynamics calculation.

  Here, when the load F is acting on the joint, the following equation (5) holds according to the principle of virtual work.

^{J T F + τ = L T} m ··· formula (5)
^{m = (L T) -1 (} J T F + τ) ··· (6)

In Expressions (5) and (6), J indicates a joint angle Jacobian (differential relationship between position and joint angle), L indicates a muscular Jacobian (differential relationship between joint angle and muscle length), and m indicates Indicates muscle tension. In the above formula (5), by multiplying the inverse matrix of ^{L T} to the left side (see equation (6)), a fourth calculating unit 15L calculates muscle tension m. F indicates a load, and is a detection result of the load received from the load sensor 65. In other words, F is the load applied to the subject H at the time of imaging of the CT image captured by the external device 18.

  For this reason, the fourth calculation unit 15L applies the load received from the load sensor 65 (that is, the load added to the subject H at the time of capturing the CT image) to F in Expressions (5) and (6). .

  The fourth calculating unit 15L may obtain the joint angle Jacobian (J) in Expressions (5) and (6) by partially differentiating the additional load (vector) with the joint angle (vector). .

  By the above processing, the fourth calculating unit 15L calculates the positional relationship (musculoskeletal model) calculated by the third calculating unit 15K, the load applied to the subject H at the time of capturing the CT image, and the object to which the load has been added. By performing inverse dynamics calculation using the external force acting on the joint 24 of the sample H, the acting force (muscle tension and torque acting on the joint) acting on the joint 24 by muscle is calculated. calculate.

  The fourth calculating unit 15L may calculate the acting force by assuming, as a muscle physical model, a viscoelastic model that simulates an actual muscle.

  Next, the fifth calculating unit 15M will be described.

  The fifth calculating unit 15M calculates the stress acting on the joint unit 24 based on the three-dimensional shape constructed by the constructing unit 15J, the relationship characteristics, and the acting force calculated by the fourth calculating unit 15L. In the present embodiment, the fifth calculating unit 15M calculates the stress acting on the joint unit 24 based on the dynamic model built by the building unit 15J and the acting force calculated by the fourth calculating unit 15L. Will be described.

  That is, the fifth calculating unit 15M calculates the stress for each element (each element in the FEM) on the contact surface between the bone unit 22 and the joint unit 24.

  Specifically, the fifth calculation unit 15M gives the muscle tension and the torque acting on the joint 24, which are calculated by the inverse dynamics calculation by the fourth calculation unit 15L, as boundary conditions of the external load on the dynamic model. Accordingly, the fifth calculating unit 15M analyzes the structure of the joint 24 and calculates the stress acting on the cartilage, which is the contact surface between the bone 22 and the joint 24. For the calculation of the stress, a numerical analysis using a known finite element method (FEM) may be used.

  The fifth calculating unit 15M calculates the stress of each element on the contact surface between the bone part 22 and the joint part 24, and thereby calculates the stress on the joint part 24 (that is, the contact surface between the bone part 22 and the joint part 24). The distribution of the acting stress is calculated.

  The generation unit 15G generates the external force image 17 (see FIG. 5) in the same manner as the UI unit 14 according to the first embodiment.

  Further, the generation unit 15G generates an analysis image including a stress image calculated by the fifth calculation unit 15M and indicating the stress acting on the joint unit 24. The stress image is an image in which a stress area where a stress acts on a contact surface between the bone portion 22 and the joint portion 24 of the subject H is indicated by a color density corresponding to the intensity of the stress. In the present embodiment, the color density indicates at least one of the color and the density.

  In the present embodiment, the generation unit 15G generates a stress area where a stress acts on the contact surface between the bone part 22 and the joint part 24 in the bone part image showing the three-dimensional shape of the bone part 22 by using the stress intensity. Is generated as a stress image.

  The second receiving unit 12F receives various operation instructions from the user from the input unit 14A.

  The display control unit 15H displays various images on the display unit 14B.

  In the present embodiment, the display control unit 15H displays the external force image 17 and the analysis image on the display unit 14B. The analysis image includes the stress image generated by the generation unit 15G.

  FIG. 16 is a diagram illustrating an example of the analysis image 34. For example, the analysis image 34 includes the dynamic model image 32 and the stress image 30. Note that the analysis image 34 may be an image including at least the stress image 30. When the analysis image 34 includes the dynamic model image 32, the generation unit 15G may generate the dynamic model image 32 and generate the analysis image 34 including the dynamic model image 32 and the stress image 30.

  The stress image 30 is a stress image in which the bone region image 40 and the stress region 42 on which the stress acts on the contact surface between the bone portion 22 and the joint portion 24 are represented by a color density corresponding to the intensity of the acting stress. .

In the example shown in FIG. 16, at the contact surface between the bone portion 22 and the joint 24, stress region 42 ₁ it is shown in a color density 36 ₁ showing the stress "8 × 10 ^-1". Further, the stress area 42 _5, are indicated by color density 36 ₅ showing the stress "5.333 × ^{10 -1".} Further, the stress region 42 ₈ is indicated by the color density 36 ₈ showing the stress "4.0 × ^{10 -1",} the outermost stress region _{42 14} is indicated by the color density _{36 14} showing the stress "0" ing.

  The stress image 30 may further include a gauge 36 indicating a color density corresponding to the strength of the stress.

  The gauge 36 displays, for example, a list of color densities corresponding to the intensity of the stress and the values of the stress corresponding to each color density in association with each other.

  The analysis image 34 may further include the dynamic model image 32 indicating the dynamic model. The dynamic model image 32 includes a shape model image 44 and a gauge 38.

  The shape model image 44 is obtained when the distribution and intensity of the stress acting on the contact surface between the bone portion 22 and the joint portion 24 are the distribution and intensity of the stress shown in the stress image 30 included in the same analysis image 34. 5 is an image showing the positional relationship between the bone part 22 and the joint part 24 in a three-dimensional shape.

  The gauge 38 is an image in which a list of color densities corresponding to the strength of the relation characteristic between the load and the deformation is associated with the value of the relation characteristic corresponding to each color density. The shape model image 44 is provided with a color density corresponding to the value of the relationship characteristic between load and deformation.

  When the generation unit 15G generates the analysis image 34 including the stress image 30, for example, the analysis image 34 illustrated in FIG. 16 is displayed on the display unit 14B. For this reason, the external force detection device 10C can display the stress image 30 in which the stress region 42 where the stress acts on the contact surface between the bone portion 22 and the joint portion 24 is displayed with a color density corresponding to the strength of the stress. it can. Therefore, the external force detection device 10C can easily provide the user with the position and range where the stress of each strength acts on the contact surface between the bone portion 22 and the joint portion 24.

  In addition, the generation unit 15G generates the analysis image 34 including the stress image 30 and the dynamic model image 32, so that, for example, the analysis image 34 illustrated in FIG. 16 is displayed on the display unit 14B. Therefore, the external force detection device 10C can easily provide the positional relationship such as the joint angle between the joint portion 24 and the bone portion 22 when the stress indicated by the stress image 30 is acting.

  Next, a procedure of an external force detection process executed by the external force detection device 10C will be described. FIG. 17 is a flowchart illustrating an example of a procedure of an external force detection process performed by the external force detection device 10C.

  First, the control unit 15 executes the processes of steps S300 to S320 in the same manner as steps S100 to S120 of the first embodiment.

  If a negative determination is made in step S316 (step S316: No), the process proceeds to step S322.

  In step S322, it is determined whether second receiving unit 12F has received an analysis instruction from input unit 14A (step S322). For example, the user instructs image analysis by operating the input unit 14A. When receiving the signal indicating the image analysis from the input unit 14A, the second receiving unit 12F determines that the analysis instruction has been received (Step S322: Yes).

  When an affirmative determination is made in step S322 (step S322: Yes), the second acquisition unit 15I acquires a CT image (step S324). Note that the CT image acquired in step S324 is a CT image of the subject H to which a load has been added by the drive control in step S302.

  Next, the construction unit 15J constructs a dynamic model from the CT image acquired in step S324 (step S326).

  Next, the third calculating unit 15K calculates the positional relationship of the bone part 22 continuing to the joint part 24 (step S328).

  Next, the fourth calculating unit 15L performs an inverse dynamics calculation to calculate the acting force acting on the joint 32 by the muscle (step S330).

  Next, the fifth calculating unit 15M calculates the stress acting on the joint unit 24 based on the dynamic model constructed by the construction unit 15J in step S326 and the acting force computed by the fourth computing unit 15L in step S330. It is calculated (step S332).

  Next, the generation unit 15G generates a stress image indicating the stress calculated in step S332 (step S334). In the present embodiment, as described above, the generation unit 15G generates an analysis image including a stress image.

  Next, the generation unit 15G stores the analysis image generated in Step S334 in the storage unit 16 (Step S336). Then, this routine ends. In step S336, the generation unit 15G preferably stores the analysis image generated in step S334 in the storage unit 16 in association with the identification information for identifying the analysis image. The identification information includes, for example, at least the subject ID of the subject H of the CT image acquired in step S324, the date and time of capturing the CT image, the date and time of generation of the analysis image, and the joint angle of the joint included in the CT image. It is preferred to include one.

  In this case, for example, the second acquisition unit 15I may acquire the subject ID of the subject H of the CT image and the date and time of capturing the CT image together with the CT image. Then, the generation unit 15G may use the subject ID and the imaging date and time as identification information. The generation unit 15G only needs to receive the joint angle of the joint included in the stress image included in the analysis image from the fourth calculation unit 15L. Then, the generation unit 15G may use the received joint angle as identification information.

  On the other hand, if the second receiving unit 12F makes a negative determination in step S322 (step S322: No), the process proceeds to step S338. For example, when receiving the signal indicating the display of the analysis image from the input unit 14A, the second receiving unit 12F makes a negative determination in step S338.

  In step S338, it is determined whether second reception unit 12F has received an instruction to display a stress image. For example, the second receiving unit 12F determines whether a display instruction of a stress image has been received from the input unit 14A. If an affirmative determination is made in step S338 (step S338: Yes), the process proceeds to step S340. On the other hand, if a negative determination is made in step S338 (step S338: No), this routine ends.

  Next, the display control unit 15H reads the analysis image stored in the storage unit 16 (Step S340). Then, the display control unit 15H displays the read analysis image on the display unit 14B (Step S342). Then, this routine ends.

  As described above, the external force detection device 10C according to the present embodiment includes the displacement member 70, the addition unit 64, the first acquisition unit 12B, the first calculation unit 12C, the second acquisition unit 15I, and the construction unit. 15J, a third calculator 15K, a fourth calculator 15L, and a fifth calculator 15M.

  The displacement member 70, the adding unit 64, the first obtaining unit 12B, and the first calculating unit 12C are the same as those in the first embodiment.

  The second acquisition unit 15I acquires image information (CT image) on the joint 24 of the subject H and the bone 22 continuous with the joint 24. The constructing unit 15J constructs, from the image information (CT image), the three-dimensional shapes of the bones 22 and the joints 24 and the characteristics of the loads and deformations on the bones 22 and the joints 24. The third calculating unit 15K calculates the positional relationship of the bone 22 that is continuous with the joint 24. The fourth calculating unit 15L performs an inverse dynamics calculation using the positional relationship, the external force, and the load added by the adding unit 64, and calculates the acting force acting on the joint unit 24 by the muscle. The fifth calculating unit 15M calculates the stress acting on the joint 24 based on the three-dimensional shape, the relation characteristics, and the acting force.

  As described above, the external force detection device 10C of the present embodiment performs the inverse dynamics calculation using the external force calculated from the displacement amount calculated by the first calculation unit 12C, and thereby the joint portion 24 is connected to the muscle by the muscle. Calculate the acting force. Then, the stress acting on the joint 24 is calculated using the acting force.

  That is, the external force detection device 10C according to the present embodiment calculates the stress based on the displacement calculated by the first calculation unit 12C. Therefore, in addition to the effects of the first embodiment, the external force detection device 10C of the present embodiment can accurately calculate the stress acting on the joint 24.

  Next, a hardware configuration of the external force detection devices 10, 10B, and 10C according to the above embodiment will be described. FIG. 18 is a block diagram illustrating a hardware configuration example of the external force detection devices 10, 10B, and 10C of the above embodiment.

  The external force detection devices 10, 10B, and 10C of the above embodiment include a CPU 800, a ROM (Read Only Memory) 820, a RAM (Random Access Memory) 840, a HDD (Hard Disk Drive) (not shown), and a communication I / F (not shown). Interface) 860. The CPU 800, the ROM 820, the RAM 840, the HDD (not shown), and the communication I / F 860 are interconnected by a bus, and have a hardware configuration using a normal computer.

  A program for executing the external force detection processing executed by the external force detection devices 10, 10B, and 10C according to the above-described embodiment is provided by being incorporated in the ROM 820 or the like in advance.

  Note that the program for executing the external force detection processing executed by the external force detection devices 10, 10B, and 10C of the above embodiment is a file that can be installed or executed in these devices in a CD-ROM, You may comprise so that it may be recorded and provided on computer-readable recording media, such as a floppy (trademark) disk (FD), CD-R, DVD (Digital Versatile Disk).

  Further, a program for executing the external force detection processing executed by the external force detection devices 10, 10B, and 10C of the above-described embodiments is stored on a computer connected to a network such as the Internet, and is downloaded via the network. May be provided. Further, a program for executing the external force detection process executed by the external force detection devices 10, 10B, and 10C of the above embodiments may be provided or distributed via a network such as the Internet.

  The program for executing the external force detection processing executed by the external force detection devices 10, 10B, and 10C of the above embodiment has a module configuration including the above-described respective functional units. As actual hardware, the CPU 800 reads out each program from a storage medium such as the ROM 820 and executes the programs to load the respective functional units on the main storage device and generate the functional units on the main storage device.

  The external force detection devices 10, 10B, and 10C of the above embodiments can be applied to any type of device equipped with an imaging mechanism for imaging the subject H. The external force detectors 10, 10 B, and 10 C of the above embodiments are, for example, an X-ray computed tomography apparatus (X-ray CT apparatus), a magnetic resonance diagnostic apparatus, an ultrasonic diagnostic apparatus, a SPECT (Single Photon Emission CT) apparatus, and a PET. (Position Emission Tomography) device, radiotherapy device, and the like.

  In the above-described embodiment, the description has been given on the assumption that the subject H is a human body. However, the subject H may be an object other than a human body. For example, the subject H may be a skeleton model.

  That is, the external force detection devices 10, 10B, and 10C of the above-described embodiments are applicable even when an object other than a human body is used as the subject H.

  Although the embodiments have been described above, the embodiments and the modified examples are presented as examples, and are not intended to limit the scope of the invention. These new embodiments and modifications can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10, 10B, 10C External force detection device 12B, 13B First acquisition unit 12C First calculation unit 12D, 13D Second calculation unit 12G, 15G Generation unit 12H, 15H Display control unit 15I Second acquisition unit 15J Construction unit 15K Third calculation Unit 15L Fourth calculation unit 15M Fifth calculation unit 64, 644, 646, 648 Addition unit 70, 71 Displacement member

Claims (14)

A displacement member that is displaced in accordance with bending of the joint of the subject,
An adding unit that applies a load to the subject,
A first acquisition unit that acquires a displacement amount of the displacement member when the load is applied to the subject;
A first calculator configured to calculate an external force acting on the joint when the load is applied, from the displacement amount;
With
The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of the bone portion that is continuous with the joint portion,
The first acquisition unit acquires the displacement amount from the displacement of the mark of the displacement member when the load is applied to the subject.
External force detector.   The external force detection device according to claim 1, wherein the displacement member is non-metal.   The external force detection device according to claim 1, wherein the mark is linear or point-like.   The external force detection device according to claim 1, further comprising a second calculation unit configured to calculate a joint angle of the joint from the displacement amount. A displacement member that is displaced in accordance with bending of the joint of the subject,
An adding unit that applies a load to the subject,
A first acquisition unit that acquires a displacement amount of the displacement member when the load is applied to the subject;
A first calculator configured to calculate an external force acting on the joint when the load is applied, from the displacement amount;
A second acquisition unit that acquires an image of the joint part of the subject and a bone part continuous with the joint part;
From the image, a construction unit that constructs a three-dimensional shape of the bone and the joint, and a relation characteristic between a load and deformation in the bone and the joint,
A third calculating unit that calculates a positional relationship between the bones continuing to the joint,
A fourth calculating unit that performs an inverse dynamics calculation using the positional relationship, the external force, and the load added by the adding unit, and calculates an acting force acting on a muscle on the joint unit;
A fifth calculation unit that calculates a stress acting on the joint based on the three-dimensional shape, the relationship characteristic, and the acting force;
External force detection device provided with. The third calculator calculates a joint angle of the joint calculated from the displacement as the positional relationship,
The external force detection device according to claim 5.   The external force detection device according to claim 5, wherein the construction unit constructs the relation characteristic based on a thickness change of a soft tissue inside the joint or a strain of the soft tissue. Obtaining a displacement amount of a displacement member that is displaced in accordance with bending of the joint of the subject when a load is applied to the subject by the adding unit;
Calculating the external force acting on the joint when the load is applied from the displacement amount;
Acquiring an image related to the joints and the bones connected to the joints of the subject,
From the image, constructing a three-dimensional shape of the bone and the joint, and the relationship characteristics of the load and deformation in the bone and the joint,
Calculating the positional relationship of the bone part continuous with the joint part;
A step of performing an inverse dynamics calculation using the positional relationship, the external force, and the load added by the addition unit, and calculating an acting force acting on a muscle on the joint;
Calculating the stress acting on the joint based on the three-dimensional shape, the relationship characteristic, and the acting force;
And an external force detection method. Obtaining a displacement amount of a displacement member that is displaced in accordance with bending of the joint of the subject when a load is applied to the subject by the adding unit;
Calculating the external force acting on the joint when the load is applied from the displacement amount;
Acquiring an image related to the joints and the bones connected to the joints of the subject,
From the image, constructing a three-dimensional shape of the bone and the joint, and the relationship characteristics of the load and deformation in the bone and the joint,
Calculating the positional relationship of the bone part continuous with the joint part;
A step of performing an inverse dynamics calculation using the positional relationship, the external force, and the load added by the addition unit, and calculating an acting force acting on a muscle on the joint;
Calculating the stress acting on the joint based on the three-dimensional shape, the relationship characteristic, and the acting force;
A program for causing a computer to execute. A first acquisition step of acquiring a displacement amount of a displacement member that is displaced in accordance with bending of a joint of the subject when a load is applied to the subject by the adding unit;
A first calculation step of calculating an external force acting on the joint when the load is applied, from the displacement amount;
Including
The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of the bone portion that is continuous with the joint portion,
The first obtaining step obtains the displacement amount from the displacement of the mark of the displacement member when the load is applied to the subject.
External force detection method. A first acquisition step of acquiring a displacement amount of a displacement member that is displaced in accordance with bending of a joint of the subject when a load is applied to the subject by the adding unit;
A first calculation step of calculating an external force acting on the joint when the load is applied, from the displacement amount;
Is a program for causing a computer to execute
The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of the bone portion that is continuous with the joint portion,
The first obtaining step obtains the displacement amount from the displacement of the mark of the displacement member when the load is applied to the subject.
program. A first obtaining unit configured to obtain a displacement amount of a displacement member that is displaced in accordance with bending of a joint of the subject when a load is applied to the subject;
A first calculator configured to calculate an external force acting on the joint when the load is applied, from the displacement amount;
A display control unit that displays an external force image indicating the external force on a display unit,
Equipped with a,
The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of the bone portion that is continuous with the joint portion,
The first acquisition unit acquires the displacement amount from the displacement of the mark of the displacement member when the load is applied to the subject.
External force detector. A first acquisition step of acquiring a displacement amount of a displacement member that is displaced in accordance with bending of a joint of the subject when a load is applied to the subject;
From the displacement amount, a calculation step of calculating an external force acting on the joint when the load is applied,
A display step of displaying an external force image indicating the external force on a display unit,
Only including,
The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of the bone portion that is continuous with the joint portion,
The first obtaining step obtains the displacement amount from the displacement of the mark of the displacement member when the load is applied to the subject.
External force detection method. A first acquisition step of acquiring a displacement amount of a displacement member that is displaced in accordance with bending of a joint of the subject when a load is applied to the subject;
From the displacement amount, a calculation step of calculating an external force acting on the joint when the load is applied,
A display step of displaying an external force image indicating the external force on a display unit,
A program for causing a computer to execute the,
The displacement member has a mark arranged along an intersecting direction that intersects a longitudinal direction of the bone portion that is continuous with the joint portion,
The first obtaining step obtains the displacement amount from the displacement of the mark of the displacement member when the load is applied to the subject.
Program .

Images