Head positioning standardization method

Abstract

Limited precision of head standardization is a problem in the prior art.　In the present invention, positioning of a patient head is standardized using two cameras, namely, a first digital camera 11 and a second digital camera 12. In a profile positioning step, while a display on a first monitor 13 is viewed, the vertical position of the first digital camera 11 is adjusted, and instructions are given to the patient to adjust the forward-backward position of the head so that the point of intersection of a first vertical reference line VL1 and a first horizontal reference line HL1 corresponding to the camera optical axis of the first digital camera 11 is in the center of the ear canal of the patient. In a front positioning step, while a display on a second monitor 16 is viewed, the vertical position of the second digital camera 12 is adjusted so that a second horizontal reference line HL2 passes through the center of the left and right eyeballs of the patient, and instructions are given to the patient to adjust the left-right inclination of the head and face such that the heights of the left and right eyes are equal, and to adjust the left-right orientation of the head and face so that a second vertical reference line VL2 passes through the center of the left and right eyes of the patient.

Description

Head positioning standard method

[0001] The present invention relates to a head positioning method for performing cephalometric X-ray imaging.

[0002] In the medical field, X-ray image information of the craniofacial skeleton is essential for quantitative maxillofacial morphological diagnosis, i.e., accurate morphological evaluation before and after treatment, particularly in orthodontic treatment to harmonize the positional relationship between the dentition and the maxillofacial skeleton, surgical orthodontic treatment to surgically correct maxillofacial distortions and morphological abnormalities, cosmetic surgery, or plastic surgery.

[0003] Furthermore, in quantitative morphological diagnosis, which examines morphological characteristics and changes rather than qualitative diagnosis, which examines the presence or absence of lesions, the orientation of the maxillofacial surface to be measured and evaluated, i.e., the clinical basis and reproducibility of the diagnostic orientation, such as the standardized front and left and right sides, is so important that it influences the evaluation and diagnostic content.

[0004] The orientation and size of images taken with conventional X-ray equipment are not consistent with each capture. Therefore, even if images of the internal maxillofacial skeletal structure, which cannot be seen with the naked eye, are obtained, it is difficult to quantitatively evaluate the characteristics of the maxillofacial skeleton or changes over time, such as before and after treatment.

[0005] Around 1940, about 40 years after the invention of medical X-ray equipment, the standardized cephalography method, in which the head is standardized at a fixed distance and in a fixed orientation, and the standardized cephalography equipment for this purpose were devised. This method made it possible for the first time to quantitatively diagnose the morphology of the maxillofacial region, and has since been widely used as the main diagnostic material for maxillofacial cranial morphology.

[0006] The standard cephalograms (cephalograms) taken with this standard cephalometric X-ray device have the problem that the position and orientation from the irradiation port change slightly each time the image is taken due to standard errors in head position, which affects the shape of the projected image and distorts the size and shape of the image, making it inconsistent.

[0007] Conventional cephalometric X-ray devices insert ear rods (positioning devices) into the patient's left and right ear canals (external auditory canals) to position the patient's head and perform cephalometric radiography (see Non-Patent Document 1). Since its creation in 1940, all cephalometric X-ray devices have used this ear rod cephalometric method, and no other cephalometric X-ray devices have yet been developed.

[0008] "Standard Cephalometric X-ray Radiography" (http: / / rada.or.jp / database / home4 / normal / ht-docs / member / synopsis / 030084.html)

[0009] In current cephalometric X-ray imaging, head alignment is performed using only ear rods. Therefore, it is difficult to completely control play that occurs due to differences in size and shape between the ear rod and the ear canal, as well as vertical rotational displacement of the head position around the ear rod, and the limits of head alignment accuracy using ear rods are an issue.

[0010] Furthermore, standard lateral cephalometric radiographs are not only used to evaluate and diagnose the morphological characteristics and changes of the maxillofacial skeleton, but are also used to evaluate and diagnose the relationship between the morphological characteristics of the maxillofacial bones and the positional relationships between the airway, tongue position, and surrounding movable organs such as the cervical vertebrae around the maxillofacial skeleton. The shape of the airway and the position of the tongue that are displayed are also affected by the positional relationship between the patient's posture and head position during imaging, i.e., the relationship between the cervical vertebrae and head position. Therefore, a new positioning standardization method that takes into account not only head position but also head position and the entire body as a whole is required.

[0011] The present invention proposes a head positioning standardization method with improved clinical validity and reproducibility.

[0012] Another object of the present invention is to provide a standard method for positioning head position in a state where the positional relationship between head position and posture is maintained, that is, in a posture that is clinically justifiable and highly reproducible.

[0013] The main purpose of adopting the head positioning standardization method of the present invention is to improve the clinical usefulness of the cephalometric data obtained using subsequent X-ray imaging equipment (such as a cephalometric X-ray equipment or a cephalometric X-ray CT equipment) and to enhance the accuracy of maxillofacial morphological diagnosis and treatment.

[0014] The present invention has been made to achieve the above object, and the invention described in claim 1 is a head positioning method for cephalometric X-ray radiography, comprising: a side positioning step of capturing an image of the side of a patient's head using a first digital camera whose camera optical axis is aligned with an X-ray imaging axis for capturing an image of the side of the patient's head placed in an imaging space, and displaying on a first monitor a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera together with the captured image of the side of the patient's head; and a front positioning step of capturing an image of the patient's head and face using a second digital camera whose camera optical axis is at an angle of 90° in a plan view with the camera optical axis of the first digital camera and is directed horizontally toward the patient's head and face placed in the imaging space, and displaying on a second monitor a second horizontal reference line and a second vertical reference line determined by the camera optical axis of the second digital camera together with the captured image of the patient's head and face. In the side positioning step, the first horizontal reference line and the second vertical reference line corresponding to the camera optical axis of the first digital camera are positioned on the same line as the image displayed on the first monitor. and instructing the patient to adjust the front-to-back position of the head, while watching the display on the second monitor, adjusting the up-and-down position of the second digital camera so that the second horizontal reference line passes through the centers of the patient's left and right eyeballs, and instructing the patient to adjust the left-to-right tilt of the head and face to make the heights of the left and right eyes equal, and also instructing the patient to adjust the left-to-right orientation of the head and face so that the second vertical reference line passes through the center of the patient's left and right eyes. After the adjustments in the side positioning step and the front positioning step are completed and head positioning is complete, a recording step of releasing the shutters of the first and second digital cameras to record a side image of the head in relation to the first horizontal reference line and the first vertical reference line, and a head and face image in relation to the second horizontal reference line and the second vertical reference line, and recording the height positions of the first and second digital cameras.

[0015] The invention described in claim 2 is a method for standard cephalometric X-ray photography, characterized in that after completing the recording step described in claim 1, the first digital camera is retracted from the X-ray photography axis and X-rays are irradiated.

[0016] The invention of claim 3 is a head positioning standardization method for X-ray CT cephalography, comprising: a side positioning step of capturing an image of the side of a patient's head using a first digital camera having a horizontal camera optical axis directed toward the side of the patient's head placed in an imaging space, and displaying on a first monitor a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera together with the captured image of the side of the patient's head; and a front positioning step of displaying on a second monitor a second horizontal reference line and a second vertical reference line determined by the horizontal camera optical axis directed toward the face of the patient's head placed in the imaging space, which form an angle of 90° in a plan view with the camera optical axis of the first digital camera, together with the captured image of the patient's head face, wherein in the side positioning step, while viewing the display on the first monitor, the first digital camera is positioned up and down so that the intersection of the first horizontal reference line and the first vertical reference line corresponding to the camera optical axis of the first digital camera is at the center of the patient's ear canal. and instructing the patient to adjust the vertical position of the second digital camera so that the second horizontal reference line passes through the centers of the patient's left and right eyeballs while watching the display on the second monitor. The patient is also instructed to adjust the left and right tilt of the head and face to make the heights of the left and right eyes equal, and the patient is also instructed to adjust the left and right orientation of the head and face so that the second vertical reference line passes through the centers of the patient's left and right eyes. After the adjustments in the side positioning step and front positioning step are completed and head positioning is complete, the method includes a recording step of releasing the shutters of the first and second digital cameras to record side images of the head in relation to the first horizontal reference line and the first vertical reference line, and to record images of the head and face in relation to the second horizontal reference line and the second vertical reference line, and to record the height positions of the first and second digital cameras.

[0017] The invention of claim 4 is the head positioning standardization method of claim 1 or 3, wherein when head positioning is performed again for the same patient, the side positioning step sets the height of the first digital camera to the height position recorded in the previous positioning, displays on the first monitor the side image of the head of the patient captured by the first digital camera, the first horizontal reference line and the first vertical reference line, and reads out the previously recorded side image of the head, the first horizontal reference line and the first vertical reference line and displays them overlapping on the display of the first monitor, and instructs the patient to position the side image of the head, the first horizontal reference line and the first vertical reference line corresponding to the camera optical axis of the first digital camera, so that the intersection of the first horizontal reference line and the first vertical reference line is located in the patient's external auditory canal. and adjusting the front-to-back position of the head so that the image is centered and the outline of the head overlaps with the previous image. In the front positioning step, the height of the second digital camera is set to the height position recorded in the previous positioning, the patient's head and face image taken by the second digital camera and the second horizontal and second vertical reference lines are displayed on the second monitor, and the previously recorded head and face image, second horizontal and second vertical reference lines are read out and displayed overlapping on the display of the second monitor, and instructions are given to the patient to make the heights of the left and right eyes equal and adjust the left-to-right direction of the head and face, and adjust so that the outline of the head and face overlaps with the previous image.

[0018] The invention described in claim 5 is a head positioning standardization method described in claim 4, which includes a recording step of releasing the shutters of the first digital camera and the second digital camera after the adjustments in the side positioning step and the front positioning step have been completed and head positioning has been completed, correlating the head side image with the first horizontal reference line and the first vertical reference line, and recording the head facial image with the second horizontal reference line and the second vertical reference line, and recording the height positions of the first digital camera and the second digital camera.

[0019] According to the present invention, the patient's head position can be positioned and standardized with high precision using head position images obtained by two digital cameras with lens optical axes that are orthogonal in plan view and horizontal and vertical reference lines based on the lens optical axes.

[0020] FIG. 1 is a perspective view showing the general configuration of a head positioning standardization device according to one embodiment of the present invention incorporated into a cephalometric X-ray radiography apparatus. FIG. 2 is a front view showing the general configuration of a cephalometric X-ray radiography apparatus incorporating the head positioning standardization device shown in FIG. 1. FIG. 3 is a plan view showing the general configuration of a cephalometric X-ray radiography apparatus incorporating the head positioning standardization device shown in FIG. 1. FIG. 4 is a schematic diagram showing a configuration in which the first digital camera 11 is retracted from the X-ray imaging axis. FIG. 5 is a schematic diagram showing a configuration in which the second digital camera 12 is moved vertically up and down. FIGS. 6(A), 6(B), and 6(C) are illustrative diagrams showing a side positioning step. FIGS. 7(A), 7(B), and 7(C) are illustrative diagrams showing a front positioning step. FIG. 8 is a perspective view showing the general configuration of a head positioning standardization device according to another embodiment of the present invention incorporated into a cephalometric X-ray radiography apparatus. FIG. 9 is a front view showing the general configuration of a cephalometric X-ray radiography apparatus incorporating the head positioning standardization device shown in FIG. 8. FIG. 10 is a plan view showing the general configuration of a cephalometric X-ray standardization apparatus incorporating the head positioning standardization device shown in FIG. 8 . FIG. 11 is an example of an image of the foot position displayed on the fifth monitor 29. FIG. 12 is an example of an image displayed on the third monitor 27 after adjustment. FIG. 13 is an example of an image displayed on the fourth monitor 28 after adjustment. FIG. 14 is a perspective view showing the general configuration of a cone-beam X-ray CT cephalography apparatus incorporating a head positioning standardization device according to another embodiment of the present invention. FIG. 15 is a plan view showing the general configuration of a cone-beam X-ray CT cephalography apparatus incorporating the head positioning standardization device shown in FIG. 14 . FIG. 16 is a perspective view showing an example configuration of a one-way mirror 15 used in the head positioning apparatus according to an embodiment of the present invention. It is a schematic diagram explaining the operation of the one-way mirror 15.

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [First Embodiment] Fig. 1 is a perspective view showing the general configuration of a head positioning standardization device according to one embodiment of the present invention incorporated into a cephalometric X-ray radiography system. Fig. 2 is a front view showing the general configuration of the cephalometric X-ray radiography system incorporating the head positioning standardization device shown in Fig. 1, and Fig. 3 is a plan view showing the general configuration of the cephalometric X-ray radiography system incorporating the head positioning standardization device shown in Fig. 1. In the following, when describing directions in Figs. 1 to 3, the left-right direction will be referred to as the X-direction, the front-back direction will be referred to as the Y-direction, and the up-down direction will be referred to as the Z-direction.

[0022] 1 to 3, standard cephalometric X-ray imaging device 1 includes an X-ray irradiation unit 2 and an X-ray detection unit 3. The distance between X-ray irradiation unit 2 and X-ray detection unit 3 is set to 165 cm in the X direction, and the device is designed so that the center of the patient's head (the patient's median plane) is located 15 cm in front of X-ray detection unit 3 when viewed in the X direction from X-ray irradiation unit 2. This is a globally accepted standard for cephalometric X-ray imaging.

[0023] Conventionally, ear rods have been used to position the patient's head. The ear rods are fixtures for positioning the center of the patient's head at a position 15 cm in front of the X-ray detector 3 in the X-direction.

[0024] In conventional methods, the patient's three-dimensional head position is fixed and positioned using a three-dimensional device, using ear rods and the surgeon's visual observation. Specifically, the left and right ear rods are inserted into the left and right ear canals of the patient's head, clamped, and fixed toward the center of the ear rods. The head's vertical orientation is then determined around the clamped ear rods. Therefore, the face orientation is largely determined by the contact position and state within the left and right ear canals when the ear rods are clamped. The remaining vertical orientation (around the ear rods) is determined by the surgeon's visual observation. The surgeon's visual observation at this time is based on the surgeon's viewpoint, and the direction changes with each imaging session, making it inconsistent. Furthermore, the positional relationship between the inserted ear rods and the ear canals cannot be visually observed. Therefore, even if the X-ray imaging axis is standardized around the center of the ear rods, it is difficult to accurately position the ear rods at the center of the ear canals. Furthermore, visual positioning based on matching the face orientation to the imaging direction is also insufficient in accuracy. Therefore, the head positioning, standard, and reproduction errors that occur each time an image is taken are fundamental issues in improving the accuracy and reliability of maxillofacial morphological diagnosis.

[0025] Furthermore, because positioning using ear rods is based on the idea of ​​fixing the three-dimensional shape of a non-standardized human body structure into a single standard three-dimensional shape, it is natural that there will be three-dimensional play between them, and even if the left and right ear rods are tightly clamped, it would be fine if they were only on one side, but because they are tightened from both sides, they will be tightly clamped at the two points on the left and right that happen to come into contact, and will only cause pain and immobilization, and will not correct the difference in three-dimensional shape or play between the left and right ear rods and the ear canals, but will instead distort the position and posture of the head.It is rare for a structure such as the human face to be precisely symmetrical in position and shape, and furthermore, the inside of the ear canal is covered with soft tissue, which is elastic and sensitive to pain, so there are limits to the accuracy of positioning using ear rods.

[0026] In this way, when using ear rods to fix the head in three dimensions, there is a certain amount of play that cannot be accommodated between the contact fixation parts. There is also a limit to how much play can be corrected by visual inspection, which is unsteady on the part of the surgeon and can only be confirmed from one direction at a time.

[0027] In this embodiment, instead of ear rods, two digital cameras, a first digital camera 11 and a second digital camera 12, are used to determine the position of the patient's head.

[0028] The first digital camera 11 is disposed so that its camera optical axis is aligned with the X-ray imaging axis irradiated from the X-ray irradiation unit 2. Specifically, the first digital camera 11 is attached to the housing of the X-ray irradiation unit 2, and is disposed so that the optical axis of its lens extends in the same line as the X-ray imaging axis irradiated from the X-ray irradiation unit 2. The X-ray imaging axis is an axis extending horizontally in the X direction from the X-ray irradiation unit 2, passing through the center of the patient's external ear canal, to the X-ray detection unit 3. The first digital camera 11 is disposed so that the optical axis of its lens is aligned with this X-ray imaging axis. Furthermore, because the first digital camera 11 is attached to the housing of the X-ray irradiation unit 2, when the X-ray irradiation unit 2 is moved up and down vertically in the Z direction along the support column 5, the first digital camera 11 also moves up and down vertically in the Z direction. In other words, the X-ray imaging axis emitted from the X-ray irradiation unit 2 and the optical axis of the first digital camera 11 are always located on the same axis, regardless of the height positions of the X-ray irradiation unit 2 and the first digital camera 11.

[0029] However, when the X-ray irradiation unit 2 irradiates X-rays to perform standard X-ray imaging, the first digital camera 11 is retracted to a position that does not interfere with the X-ray irradiation. For example, as shown in Figures 4(A) and 4(B), the first digital camera 11 is provided so as to be slidable horizontally, for example, in the Y direction, relative to the housing of the X-ray irradiation unit 2. Therefore, when the first digital camera 11 is retracted as shown in Figure 4(B), the X-ray irradiation unit 2 can irradiate X-rays without any hindrance.

[0030] Alternatively, instead of arranging the optical axes of the first digital cameras in a straight line on the X-ray imaging axis, multiple first digital cameras may be arranged around the X-ray irradiation port (starting point of the X-ray imaging axis) in the X-ray irradiation unit 2. For example, two digital cameras may be arranged in front of and behind the y-axis passing through the center of the X-ray irradiation port (X-ray imaging axis), and two digital cameras may be arranged above and below the center on the z-axis passing through the center point of the X-ray imaging axis, with the optical axes of each camera parallel to the X-ray imaging axis. By correcting and displaying each image based on horizontal and vertical reference planes passing through the X-ray imaging axis, i.e., the intersection of these planes, i.e., the ear canal on the X-ray imaging axis, as the center, a lateral image centered on the ear canal can be obtained, similar to a camera image from the X-ray imaging direction. While not strictly identical to a camera image arranged on the X-ray imaging axis, the horizontal and vertical reference planes are precisely standardized to match the imaging axis, and therefore the effect on positioning accuracy based on each reference plane passing through the imaging axis is the same. Furthermore, by properly and consistently standardizing the positional relationship (arrangement) of each camera with the center of the X-ray imaging port, it is possible to always obtain the same state of the ear canal and side camera images, thereby achieving sufficient standardization accuracy and reproducibility. This method allows the same accuracy to be obtained without having to move the first digital camera to a position that does not interfere with X-ray imaging during X-ray imaging, which leads to reduced manufacturing costs for the imaging device and shorter time required to maintain head position during imaging.

[0031] A first monitor 13 for displaying an image captured by the first digital camera 11 is connected to the first digital camera 11. The first monitor 13 may be provided in an operator's room partitioned from the room in which the cephalometric X-ray apparatus 1 is placed. The first monitor 13 can display a first horizontal reference line HL1 and a first vertical reference line VL1 determined by the optical axis of the first digital camera 11. That is, since the viewing direction of the first digital camera 11 is the optical axis direction in the X direction, a horizontal reference line extends horizontally in the Y direction from the optical axis, and a vertical reference line extends vertically in the Z direction from the optical axis, so the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1 is the optical axis.

[0032] The first monitor 13 displays an image of the side of the patient's head taken by the first digital camera 11 as viewed in the optical axis direction in the X direction, together with a first horizontal reference line HL1 and a first vertical reference line VL1.

[0033] The second digital camera 12 is disposed at a position that forms an angle of 90° with the optical axis of the first digital camera 11 in a plan view. As an example, the second digital camera 12 is attached to a support 14 that is vertically erected on the base 6, and its height position can be adjusted by moving it up and down in the Z direction along the support 14, as shown in FIG. 5 . The support 14 is disposed at a position 15 cm away from the X-ray detection unit 3 in the X direction. Therefore, the optical axis of the second digital camera 12 extends horizontally in the Y direction at a position 15 cm away from the X-ray detection unit 3 in the X direction. Furthermore, since the optical axis of the second digital camera 12 extends in the Y direction and the optical axis of the first digital camera 11 extends in the X direction, the two optical axes form an angle of 90° in a plan view.

[0034] The second digital camera 12 is a camera for capturing an image of the patient's head and face, and its vertical position can be adjusted to match the patient's height. As will be described later, the optical axis of the second digital camera 12 is adjusted to be at the patient's eye height.

[0035] In addition, a magic mirror 15 may be provided in front of the lens of the second digital camera 12, so that the patient cannot directly see the lens of the second digital camera 12, but can see his or her own face reflected in the magic mirror 15.

[0036] That is, the patient is configured to see his or her own face reflected in the magic mirror 15, and furthermore, by marking a horizontal reference line and a median line on the magic mirror 15 in accordance with the camera position, the patient can easily adjust his or her head position by himself or herself or in response to the instructions of the photographer, by referring to the reference lines.

[0037] The magic mirror 15 may be fixedly held on the support 14, or may be configured to move up and down along with the second digital camera 12 when the second digital camera 12 moves up and down along the support 14.

[0038] A second monitor 16 for displaying the image captured by the second digital camera 12 is connected to the second digital camera 12. The second monitor 16 may also be provided in an operator's room partitioned from the room in which the cephalometric X-ray apparatus 1 is placed. The second monitor 16 can display a second horizontal reference line HL2 and a second vertical reference line VL2 determined by the optical axis of the second digital camera 12. That is, since the viewing direction of the second digital camera 12 is the optical axis direction in the Y direction, a horizontal reference line extends horizontally in the X direction centered on the optical axis, and a vertical reference line extends vertically in the Z direction centered on the optical axis, so the intersection of the second horizontal reference line HL2 and the second vertical reference line VL2 indicates the optical axis.

[0039] The second monitor 16 displays the patient's head and face as seen in the optical axis direction in the Y direction, captured by the second digital camera 12, together with the second horizontal reference line HL2 and the second vertical reference line VL2.

[0040] If the first monitor 13 and the second monitor 16 are installed side by side in the surgeon's room, for example, the surgeon can correctly position the patient's head prior to standard head X-ray imaging by looking at the first monitor 13 and the second monitor 16 simultaneously, based on the image of the side of the patient's head seen from the viewpoint of the first digital camera 11 and the image of the head and face seen from the viewpoint of the second digital camera 12, which is at a 90° angle to the first digital camera 11.

[0041] A specific example of a head positioning method will be described below.

[0042] (1) First, the operator instructs the patient to place his / her feet on the imaging position of the cephalometric X-ray apparatus 1 and stand in a natural posture with his / her back straight.

[0043] The cephalometric X-ray imaging device 1 has a horizontally arranged base 6, on which foot position indicators 7 are displayed indicating where the subject should stand based on the imaging direction and position, so that the patient stands naturally on the base 6 in accordance with these foot position indicators 7.

[0044] (2) A side positioning step is performed.

[0045] In the side positioning step, the surgeon adjusts the height of the first digital camera 11 while looking at the display on the first monitor 13 so that the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1, which correspond to the optical axis of the first digital camera 11, is at the same height as the center of the patient's ear canal.

[0046] For example, when the image displayed on the first monitor 13 is the image shown in Fig. 6(A), the X-ray irradiation unit 2 and X-ray detection unit 3 held by the arm 8 are displaced upward along the support column 5. Note that, because the support column 5 is erected vertically on the horizontal base 6, the X-ray irradiation unit 2 and X-ray detection unit 3 are displaced vertically upward. As described above, the first digital camera 11 is attached to (the housing of) the X-ray irradiation unit 2, and therefore, as the X-ray irradiation unit 2 is displaced upward, the first digital camera 11 also displaces upward, and its horizontal optical axis displaces upward while remaining horizontal.

[0047] 6B, the height position of first digital camera 11 is fixed and stored. Since the height position of first digital camera 11 at this time can be represented by the height position of arm 8 on support pole 5, this height position may be stored.

[0048] Even if the image displayed on the first monitor 13 becomes the image shown in Fig. 6B, the optical axis of the first digital camera 11 (the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1) is not at the center of the patient's ear canal, which means that the patient's head is slightly backward.

[0049] The surgeon then instructs the patient to move their head slightly forward, and while watching the image on the first monitor 13 captured by the first digital camera 11, when the patient's head reaches the position shown in Figure 6(C), instructs the patient to maintain the current position.

[0050] (3) Perform the front positioning step.

[0051] In the front positioning step, the surgeon instructs the patient to orient the patient's head and face so that they are facing straight ahead while viewing the image displayed on the second monitor 16. For example, if the patient's gaze tends to be downward, the surgeon instructs the patient to lift their face, and if the patient's face is facing upward, the surgeon instructs the patient to tuck their chin and look straight ahead. This instruction corrects the up-down tilt of the patient's head and face, so that they are facing straight ahead.

[0052] 7A, the height position of second digital camera 12 is slightly low, so the height position of second digital camera 12 is displaced vertically upward along support column 14. Then, when the image displayed on second monitor 16 becomes the image shown in FIG. 7B, the height position of second digital camera 12 is fixed and stored. Because support column 14 supporting second digital camera 12 is erected vertically on horizontal base 6, the height position of second digital camera 12 can be represented by the height position on support column 14, so this height position may be stored.

[0053] 7B, the patient's head and face are tilted slightly to the right. Therefore, the surgeon instructs the patient to tilt their head and face slightly to the left.

[0054] Furthermore, the second vertical reference line VL2 corresponds to the midline of the patient's head and face in the display on the second monitor 16. Therefore, the patient is instructed to adjust the left-right orientation of the head and face so that the patient's head and face are evenly aligned with respect to the second vertical reference line VL2, specifically so that the second vertical reference line VL2 is positioned between the left and right eyeballs or so that the second vertical reference line VL2 passes through the center of the nose.

[0055] In this case, by placing a magic marker 115 in front of the second digital camera, which marks the horizontal and midline reference lines passing through the optical axis of the second digital camera, the surgeon can easily confirm and reflect the direction and amount of movement of the instructions based on the positional relationship between the patient's face reflected in the magic mirror 15 and the reference lines. It also makes it easy to show the surgeon the front direction they want. This allows both the patient and the surgeon to confirm and achieve a common front direction that is acceptable to both. This is effective in confirming the treatment goals that both the patient and the surgeon are imagining, which leads to aiming for and achieving a treatment result that satisfies the patient, including symmetry based on the front direction in a common understanding, and thus leads to increased patient satisfaction with treatment.

[0056] Then, when the image displayed on the second monitor 16 becomes the image shown in FIG. 7(C), the patient is instructed to maintain the current position and state.

[0057] (4) Perform the recording step.

[0058] The recording step is performed after the patient's head has been positioned at a predetermined position in the side positioning step and the front positioning step described above. Before performing the recording step, the images displayed on the first monitor 13 and the second monitor 16 are checked, and if the images displayed are misaligned due to the patient moving or the like, the side positioning step or the front positioning step may be performed again to position the patient's head at a predetermined position.

[0059] In the recording step, the shutters of the first digital camera 11 and the second digital camera 12 are released, and the captured head side image and head face image are saved and recorded. The shutter operations of the first digital camera 11 and the second digital camera 12 may be performed simultaneously by remote operation.

[0060] The head side image captured by the first digital camera 11 may be recorded in association with the first horizontal reference line HL1 and the first vertical reference line VL1. Similarly, the head and face image captured by the second digital camera 12 may be recorded in association with the second horizontal reference line and the second vertical reference line.

[0061] In the recording step, the height positions of the first digital camera 11 and the second digital camera 12 are also recorded.

[0062] Although the schematic diagrams of the configuration of the head X-ray standard imaging device incorporating the head positioning standard device shown in Figures 1 to 3 do not show the personal computer and memory that perform the above-mentioned recording steps, the recording steps are performed by the personal computer and memory connected to the first digital camera 11, the second digital camera 12, and the first monitor 13 and the second monitor 16.

[0063] After the patient's head is positioned in the imaging space of cephalometric X-ray imaging device 1 through the above-described process, X-ray is irradiated from X-ray irradiator 2, and the X-ray that passes through the positioned head is detected by X-ray detector 3, thereby obtaining a so-called cephalometric X-ray photograph. As described above, when X-ray is irradiated from X-ray irradiator 2, first digital camera 11 is automatically retracted to a position that does not interfere with the X-ray irradiation.

[0064] The obtained cephalometric radiograph may be stored in association with the lateral head image and the facial head image recorded in the recording step.

[0065] Next, a method for positioning the head of a patient will be described, in order to perform cephalometric X-ray imaging again on the same patient after a certain period of time has elapsed.

[0066] (1) In the cephalometric X-ray imaging device 1, the patient stands naturally on the base 6 according to the foot position indicators 7. At this time, if there is an image from a fixed digital camera for the feet that captured the position of the patient's feet during the previous head positioning, that image may be used as a reference to have the patient stand in the same position on the base 6 as the previous time (the same position according to the foot position indicators 7).

[0067] (2) A side positioning step is performed.

[0068] In the side positioning step, the height position of the first digital camera 11 recorded in the previous positioning is read out, and the height of the first digital camera 11 is set to the read-out height. Specifically, the X-ray irradiation unit 2 and X-ray detection unit 3 held by the arm 8 are displaced along the support column, and the height positions of the X-ray irradiation unit 2, X-ray detection unit 3, and first digital camera 11 are set to the height positions used in the previous side positioning.

[0069] As a result, an image similar to the image shown in Fig. 6(B) or the image shown in Fig. 6(C), in which the first horizontal reference line HL1 passes through the center of the patient's ear canal, is displayed on the first monitor 13. In other words, it is displayed that the height of the first digital camera 11 has reached the desired height, but the position of the patient's head in the front-to-back direction does not match the desired position.

[0070] The surgeon then instructs the patient to move their head forward or backward, and when the patient's head is in the position shown in Figure 6 (C), that is, when the optical axis of the first digital camera 11 (the intersection of the first horizontal reference line HL1 and the first vertical reference line VL1) is at the center of the patient's ear canal, the surgeon instructs the patient to maintain their current position and state.

[0071] Furthermore, in the side positioning step, the head side image, the first horizontal reference line HL1, and the first vertical reference line VL1 recorded in the previous positioning may be read out and displayed so as to overlap with the display on the first monitor 13. The read-out first horizontal reference line HL1 and the first vertical reference line VL1 displayed on the first monitor 13 completely overlap with the first horizontal reference line HL1 and the first vertical reference line VL1 currently displayed. On the other hand, the read-out head side image usually does not completely overlap with the current image due to changes in the patient's hairstyle, facial expression, and other changes over time, but the center position of the ear canal does overlap. Therefore, the head position may be adjusted by searching for feature points in the previous image and adjusting them so that they overlap with the current image and so that the outlines of the head and the head are roughly overlapped.

[0072] (3) Perform the front positioning step.

[0073] In the front positioning step, the height position of the second digital camera 12 recorded in the previous positioning is read out, and the height of the second digital camera 12 is set to the read height.

[0074] Then, while looking at the display screen of the second monitor 16, the surgeon gives instructions to the patient so that the image shows the patient's head and face facing straight ahead. For example, if the patient's gaze tends to be downward, the surgeon instructs the patient to lift their face, and if the patient's face is facing up, the surgeon instructs the patient to tuck their chin and look straight ahead. With these instructions, the image of the patient's head and face displayed on the second monitor 16 will correct any tilt in the up and down direction and will show the patient facing straight ahead.

[0075] As a result, an image similar to that shown in Fig. 7B is displayed on the second monitor 16. That is, an image of the patient's head and face with the patient facing straight ahead.

[0076] If the image displayed on the second monitor 16 is similar to the image shown in Figure 7 (B), the left and right tilt of the patient's head and face has not been adjusted, and the left and right direction of the patient's head and face has not been adjusted.

[0077] Therefore, the surgeon instructs the patient to adjust the left and right tilt of the head and face so that the second horizontal reference line HL2 passes through the centers of the left and right eyeballs. The surgeon also adjusts the left and right orientation of the head and face so that the second vertical reference line VL2 passes vertically through the centers of the left and right eyes. Note that the left and right orientation of the head and face may be adjusted so that, when the second vertical reference line VL2 passes vertically through the centers of the left and right eyes, the second vertical reference line VL2 also passes vertically through the center of the nose and the center of the mouth.

[0078] Furthermore, in the front positioning step, the head and face image, the second horizontal reference line HL2, and the second vertical reference line VL2 recorded in the previous positioning may be read out and displayed so as to overlap with the display on the second monitor 16. The display on the second monitor 16 of the read out second horizontal reference line HL2 and second vertical reference line VL2 completely overlaps with the second horizontal reference line HL2 and second vertical reference line VL2 currently displayed.

[0079] On the other hand, the read-out head and face image usually does not completely overlap with the current image due to changes in the patient's hairstyle, facial expression, etc. over time, but they do overlap at the point where the second horizontal reference line HL2 passes through the centers of the left and right eyeballs. Therefore, facial feature points, etc. in the previous image may be searched for, and the position of the head and face may be adjusted so that they overlap with the current image and so that the facial contours are roughly overlapped.

[0080] Then, when the image displayed on the second monitor 16 becomes the image shown in FIG. 7(C), the patient is instructed to maintain the current position and state.

[0081] (4) Perform the recording step.

[0082] The contents of the recording step are the same as those of the recording step explained above, so a duplicated explanation will be omitted here.

[0083] Through the above processing, the patient's head is positioned in exactly the same position as in the previous cephalometric X-ray imaging in the imaging space of cephalometric X-ray imaging apparatus 1. After positioning, X-rays are irradiated from X-ray irradiation unit 2, and the X-rays that pass through the positioned head are detected by X-ray detection unit 3, resulting in a so-called cephalometric X-ray.

[0084] Both the cephalometric radiograph obtained in the previous cephalometric radiography and the cephalometric radiograph obtained in the current cephalometric radiography are X-ray images of the head positioned using the head positioning method according to an embodiment of the present invention. Therefore, the two cephalometric radiographs have high accuracy in measuring the frontal and lateral head positions and are X-ray images with consistent clinical evidence. Comparing and contrasting the contents of both images is useful for accurately diagnosing and treating a patient's maxillofacial morphology.

[0085] [Second embodiment] Fig. 8 is a perspective view showing the general configuration of a head positioning standardization device according to another embodiment of the present invention incorporated into a cephalometric X-ray radiography apparatus. Fig. 9 is a front view showing the general configuration of a cephalometric X-ray radiography apparatus incorporating the head positioning standardization device shown in Fig. 8, and Fig. 10 is a plan view showing the general configuration of a cephalometric X-ray radiography apparatus incorporating the head positioning standardization device shown in Fig. 8. In the following explanation of directions in Figs. 8 to 10, the left-right direction will be referred to as the X-direction, the front-back direction as the Y-direction, and the up-down direction as the Z-direction.

[0086] 8 to 10 , standard cephalometric X-ray imaging device 1 includes a base 6 with a horizontally-mounted top, a vertically extending support column 5 attached to the rear edge of base 6, and a pair of arms 8 (81, 82) attached to support column 5, extending horizontally on both sides in the X direction with their tips extending in the Y direction. An X-ray irradiation unit 2 is fixed to the tip of arm 81, and an X-ray detection unit 3 is provided at the tip of arm 82. The distance between X-ray irradiation unit 2 and X-ray detection unit 3 is set to 165 cm in the X direction, and the device is designed so that the center of the subject's head (the patient's median plane) is positioned 15 cm in front of X-ray detection unit 3 as viewed in the X direction from X-ray irradiation unit 2. This is a globally accepted standard for cephalometric X-ray imaging.

[0087] In this embodiment, two digital cameras, a first digital camera 11 and a second digital camera 12, are used to perform head positioning standardization in order to position the center of the subject's head (i.e., the median plane) 15 cm in front of the X-ray detection unit 3. This configuration is the same as the configuration in the first embodiment described above, so the same components are given the same reference numbers and symbols, and duplicate explanations will be omitted.

[0088] Another feature of this embodiment is that a third digital camera 21 and a fourth digital camera 22 are provided, and in addition to the head positioning standard, the patient's posture (body axis) during imaging can also be confirmed and positioned from two orthogonal directions using the viewpoints of the digital cameras, just like the head position. Furthermore, a fifth digital camera 23 is provided to capture the foot position.

[0089] More specifically, the third digital camera 21 is held by a support column 24 that extends vertically from the left edge of the base 6. In plan view, the support column 24 is located at the same position in the Y direction as the X-ray irradiation unit 2 and the first digital camera 11. As a result, the third digital camera 21 is set so that its lens optical axis is parallel to the lens optical axis of the first digital camera, and the vertical reference line is at the same position in the Y direction. In other words, the lens optical axis of the third digital camera 21 is designed to be positioned perpendicular to the lens optical axis of the first digital camera.

[0090] In addition, an auxiliary arm 25 is provided that hangs down perpendicularly from arm 82, and a fourth digital camera 22 is held by the auxiliary arm 25. The auxiliary arm 25 is provided at the same position as the support 14 in the X direction in a plan view or a front view. In other words, it is provided at a position 15 cm away from the X-ray detection unit 3 in the X direction. As a result, the fourth digital camera 22 is set so that its lens optical axis is parallel to the lens optical axis of the second digital camera and is on the same straight line in a plan view.

[0091] Furthermore, an auxiliary support 26 is erected vertically at the rear edge of the base 6, at a position 15 cm to the left of the X-ray detection unit 3 in the X direction in a plan view. A fifth digital camera 23 is held on the auxiliary support 26. The lens optical axis of the fifth digital camera 23 is directed in the Y direction and toward the foot position indicator 7.

[0092] The third digital camera 21, the fourth digital camera 22 and the fifth digital camera 23 are connected to a third monitor 27, a fourth monitor 28 and a fifth monitor 29, respectively, for displaying images captured by the digital cameras 21, 22 and 23.

[0093] The head positioning method in the cephalometric X-ray imaging device 1 incorporating the head positioning standard device shown in Figures 8 to 10 is similar to the head positioning method in the cephalometric X-ray imaging device 1 described with reference to Figures 1 to 3, and mainly includes a lateral positioning step for the side of the head viewed from the viewpoint of the first digital camera 11 and a front positioning step for the head face viewed from the viewpoint of the second digital camera 12, and further includes a body axis lateral positioning step for the posture viewed from the viewpoint of the third digital camera 21 and a body axis posterior positioning step for the posture viewed from the viewpoint of the fourth digital camera 22.

[0094] The method may also include a step of positioning the feet by looking in the direction of the viewpoint of the fifth digital camera 23 .

[0095] The purpose of posture is not to precisely position the body, but to capture the center of posture, i.e., the body axis. If the body axis is bent significantly, this may affect the positioning of the head, which is supported by the cervical vertebrae. Therefore, it is necessary for head positioning standards to maintain a constant morphological relationship between head position and posture.

[0096] Therefore, in this embodiment, when positioning the head, the body axis lateral positioning step and the body axis posterior positioning step are performed before the lateral positioning step for the head lateral side and the frontal positioning step for the head face, and the head is positioned in the standardized correct posture before being positioned.

[0097] Furthermore, when a patient stands naturally on the base 6 of the cephalometric X-ray imaging device 1 for standard cephalometric X-ray imaging, if the position of the patient's feet deviates from the center position of the imaging area or the imaging direction each time imaging is performed, or if they are different, this will affect the positioning and reproduction of the head.

[0098] Therefore, when photographing, first, a foot positioning step is performed in which the patient's foot positions are viewed from the viewpoint direction of the fifth digital camera 23 and determined to be fixed positions that match the head photographing position and direction.

[0099] A specific example of a head positioning method in the cephalometric X-ray imaging apparatus 1 incorporating the head positioning apparatus shown in FIGS. 8 to 10 will be described below.

[0100] (1) Perform a foot positioning step.

[0101] In the foot positioning step, the operator instructs the patient to place his / her feet on the imaging device of the cephalometric X-ray imaging apparatus 1 and stand in a natural posture with his / her back straight.

[0102] The cephalometric X-ray imaging device 1 has a horizontally placed base 6, and the base 6 has foot position indicators 7 on which the patient should stand, so the patient stands up naturally on the base 6 according to the foot position indicators 7.

[0103] At this time, if the patient's foot position is too close together or too far apart, for example, the surgeon will instruct the patient to correct the foot position. In this case, the patient's foot position is confirmed by the image captured from the viewpoint of the fifth digital camera 23 and displayed on the fifth monitor 29.

[0104] Once the patient's foot positions have been determined, the shutter of the fifth digital camera 23 is released and the image displayed on the fifth monitor 29 is recorded in memory. Figure 11 shows an example of the recorded image relating to the foot positions.

[0105] (2) A body axis lateral positioning step is performed.

[0106] In the body axis lateral positioning step, the surgeon adjusts the height of the third digital camera 21 while viewing the display on the third monitor 27 so that a third horizontal reference line HL3 extending horizontally from the optical axis of the third digital camera 21 is at, for example, the height of the patient's shoulders. The surgeon also instructs the patient to adjust their body position in the front-to-back direction so that a third vertical reference line VL3 extending vertically from the optical axis of the third digital camera 21 (this third vertical reference line VL3 is on the same straight line as the first vertical reference line VL1 of the first digital camera 11) passes through a position that divides the patient's body approximately equally in the front and back directions. Figure 12 shows an example of an image displayed on the third monitor 27 after adjustment. From Figure 12, it can be seen that the patient is standing naturally and that the center of their posture, i.e., their body axis, is aligned with the third vertical reference line VL3.

[0107] (3) A step of positioning the back of the body axis is performed.

[0108] In the body axis rear positioning step, the surgeon adjusts the height of the fourth digital camera 22 while looking at the display on the fourth monitor 28 so that the fourth horizontal reference line HL4 extending horizontally to the left and right from the optical axis of the fourth digital camera 22 is at the height of the patient's shoulders, for example.

[0109] Alternatively, the height of the fourth digital camera may be adjusted so that it is at the midpoint between the patient's shoulders or waist, or a camera at a desired position may be selected from multiple fourth digital cameras arranged on the same vertical reference line, and the image from that camera may be displayed on the monitor.

[0110] The patient is instructed to adjust the position of their body left and right so that a fourth vertical reference line VL4 extending vertically up and down from the optical axis of the fourth digital camera 22 (this fourth vertical reference line VL4 is on the same straight line as the second vertical reference line VL2 of the second digital camera 12) passes through a position that divides the patient's body approximately equally into left and right halves. If the patient's shoulders are at different heights relative to the fourth horizontal reference line HL4, the patient is instructed to adjust their posture left and right so that the heights of their left and right shoulders are equal.

[0111] An example of an image displayed on the fourth monitor 28 after adjustment is shown in Fig. 13. From Fig. 13, it can be seen that the patient's posture is not tilted to the left or right, and that the center of the posture, i.e., the body axis, is aligned with the fourth vertical reference line VL4.

[0112] (4) A side positioning step is performed.

[0113] (5) Perform the front positioning step.

[0114] The contents of the side positioning step and the front positioning step are exactly the same as those explained above, so a duplicate explanation will be omitted here.

[0115] (6) Perform the recording step.

[0116] The recording step is performed after the patient's body axis has been positioned in the above-mentioned body axis lateral positioning step and body axis posterior positioning step, and the position of the patient's head has been accurately determined in a predetermined position in the lateral positioning step and frontal positioning step.

[0117] Before performing the recording step, the images displayed on the first monitor 13, the second monitor 16, the third monitor 27, and the fourth monitor 28 are checked to ensure that the position has not shifted due to the patient moving, etc.

[0118] In the recording step, the shutters of the first digital camera 11, the second digital camera 12, the third digital camera 21, and the fourth digital camera 22 are released, and the captured images of the side of the head, the face of the head, the side of the body axis, and the back of the body axis are retained and recorded. The shutter operations of the first digital camera 11, the second digital camera 12, the third digital camera 21, and the fourth digital camera 22 may be performed simultaneously by remote operation.

[0119] The side image of the head captured by the first digital camera 11 may be recorded in association with the first horizontal reference line HL1 and the first vertical reference line VL1, the head and face image captured by the second digital camera 12 may be recorded in association with the second horizontal reference line HL2 and the second vertical reference line VL2, the side image of the body axis captured by the third digital camera 21 may be recorded in association with the third horizontal reference line HL3 and the third vertical reference line VL3, and the dorsal image of the body axis captured by the fourth digital camera 22 may be recorded in association with the fourth horizontal reference line HL4 and the fourth vertical reference line VL4.

[0120] In the recording step, the height positions of the first digital camera 11, the second digital camera 12, the third digital camera 21, and the fourth digital camera 22 are also recorded.

[0121] Through the above processing, the patient's feet are positioned, the body axis is positioned, and the head is then positioned in cephalometric X-ray imaging apparatus 1. After that, X-rays are irradiated from X-ray irradiation unit 2, and the X-rays that pass through the positioned head are detected by X-ray detection unit 3, thereby obtaining a so-called cephalometric X-ray photograph. When X-rays are irradiated from X-ray irradiation unit 2, first digital camera 11 is automatically retracted to a position that does not interfere with the X-ray irradiation.

[0122] [Third embodiment] Fig. 14 is a perspective view showing the general configuration of a head positioning standardization device according to another embodiment of the present invention incorporated into a cone-beam X-ray CT head imaging system, and Fig. 15 is a plan view showing the general configuration of the cone-beam X-ray CT head imaging system incorporating the head positioning standardization device shown in Fig. 14.

[0123] 14 and 15 , a CT head imaging device 30 includes a vertically erected support column 31 and a support frame 32 that extends horizontally from the upper end of the support column 31 and can move linearly up and down (in the Z direction in the CT coordinate system). A rotating arm 34 that can rotate within a horizontal plane around a support shaft 33 provided on the support frame 32 is provided below the tip of the support frame 32. An X-ray irradiation unit 35 is provided on one end of the rotating arm 34, and an X-ray detection unit 36 ​​is provided on the other end of the rotating arm 34. In a plan view, the X-ray irradiation unit 35 and the X-ray detection unit 36 ​​face each other with the support shaft 33 as the origin. The CT head imaging device 30 irradiates the patient's head, which is placed in an imaging space formed below the support shaft 33, with X-rays from the X-ray irradiation unit 35 in a range of 180° to 360° in a planar view while rotating the rotating arm 34 horizontally, and generates a tomographic X-ray image of the patient's head based on the X-rays detected by the X-ray detection unit 36.

[0124] The CT head imaging device 30 incorporates a head positioning standard device for accurately and reproducibly positioning the head of a patient placed in an imaging space at a predetermined position prior to X-ray CT imaging.

[0125] The first digital camera 11 can be adjusted in height in the vertical direction along the height of the support column 31 of the support frame 32 to match the patient's head position. The first digital camera 11 is also movable in the vertical and horizontal directions (y- and z-axes) from its initial position while maintaining the camera's optical axis parallel to the patient's head and face to be imaged. This allows the camera to be adjusted in the vertical and horizontal directions (y- and z-axes) to match the position of the ear canal at a head position where the patient's facial and head region (side) to be imaged is properly positioned within the CT imaging field of view (FOV). The adjusted position is recorded based on the initial position. (In CT, the imaging field is fixed, and for people with long faces, high or low external ears, etc., the camera position capturing the external ear must also be adjusted to match the head position. In the case of CT, moving the camera position does not change the magnification or display orientation of the image. Once the moved position is recorded, the same position coordinates can be used for subsequent imaging, ensuring high reproducibility. Therefore, the camera does not necessarily need to be in the same position.)

[0126] Alternatively, the first digital camera may be not just one, but multiple cameras, and a desired camera may be selected from the multiple camera images. This eliminates the need for movement adjustment, and even if movement adjustment is required, it can be kept to a minimum.

[0127] In addition, when viewed in a plane, when the first digital camera 11 is positioned at a horizontal 0° position (x-axis of the CT imaging coordinate system), the second digital camera 12 has a camera optical axis that forms an angle of 90° with the camera optical axis of the first digital camera 11 and is directed horizontally (y-axis of the CT imaging coordinate system) toward the head and face of the patient placed in the imaging space.

[0128] As an example, the second digital camera 12 is attached to a support frame 32 located at the top of the support column 31, facing the patient's face. The vertical position of the support frame 32 can be adjusted to match the patient's head position by vertically moving the support frame 32 along the height of the support column 31. The second digital camera 12 is also movable vertically (parallel to the z-axis) from its initial position to match the patient's left and right pupil positions, while maintaining its optical axis (parallel to the y-axis). The moved position is recorded based on the initial position. (Unlike X-ray imaging, the first digital camera position 11 can also be adjusted, so it is simpler to record and reproduce the first and second camera positions separately based on their initial positions, rather than adjusting the second camera position based on the first camera position. As a result, the face and head can always be photographed in the same orientation using the same coordinate system.)

[0129] Alternatively, by placing the second digital camera 12 on the midline with the same optical axis and selecting a camera at the desired position at the height of the pupil or the canthus of the eye, movement can be eliminated or movement adjustments can be minimized. Furthermore, the second digital camera 12 does not necessarily have to be located on the midline; similar effects can be achieved by placing two cameras symmetrically about the midline. In this case, the width of the left and right camera positions can be adjusted, and the center of the left and right camera positions can be moved and adjusted parallel to the midline in the left-right direction (y-axis direction). This allows for various front-facing positioning, such as in cases where the centers of the left and right eyes are not aligned with the midline of the face, or in cases where the left and right eyes are asymmetrical. Even in this case, by regularly placing multiple pairs of cameras symmetrically or vertically, vertical and horizontal movement adjustments can be eliminated or minimized depending on the camera selection.

[0130] In addition, by placing a pair of cameras on the midline and using them together, the camera on the midline can be used to identify midline feature points other than the eyes, aligning the midline of the face (left and right orientation), and by using a pair of cameras on the left and right to align the eye height, the up and down orientation of the face can be positioned separately from the optimal viewing direction.

[0131] Furthermore, a magic mirror 15 that reflects the patient's frontal head position is placed vertically in front of the second digital camera 12. A horizontal reference line and a midline based on the optical axis of the second digital camera 12 are displayed on the magic mirror, and as the position of the second digital camera 12 is moved up and down, the mirror moves in unison (it does not move horizontally). This makes it possible to align the operator's viewpoint with the patient's viewpoint, allowing both the operator and the patient to more accurately confirm instructions to the patient regarding head position and the details of those instructions, and to adjust the head position.

[0132] In this embodiment, at least two digital cameras, a first digital camera 11 and a second digital camera 12, which are arranged orthogonally, are used to accurately capture the front and side of the patient, and the patient's head is positioned with high precision in the imaging space of the CT head imaging device 30 in accordance with the imaging coordinate system.

[0133] When positioned, the first digital camera 11 is placed parallel to the x-axis of the CT imaging coordinate system, but not on the x-axis. It is placed at a position corresponding to the ear canal, tragus, etc., so that it does not overlap with the X-ray irradiation port. Therefore, if the first digital camera 11 does not interfere with X-ray imaging, it is placed parallel to the X-ray irradiation port on the X-ray irradiation unit 35. However, if the first digital camera 11 is placed in a position that interferes with X-ray imaging, the X-ray irradiation unit may be extended and the first digital camera may be placed at an angle θ, as shown in FIG. 15 . In this case, during camera imaging, the first digital camera 11 is placed parallel to the x-axis of the CT imaging coordinate system, and the second digital camera 12 is placed on the y-axis. During X-ray imaging, the arm may be rotated by the angle θ to move to a position where the X-ray imaging axis is the x-axis, and X-ray imaging may begin. Alternatively, X-ray imaging may be initiated from the camera imaging position, and the x- and y-axes corrected by the angle θ through calculation during image processing may be used as imaging coordinates.

[0134] The head positioning device may further include a third digital camera 21 and a fourth digital camera 22. In addition to the head positioning, the device may be configured to be able to check and position the patient's posture (body axis) during imaging from two orthogonal directions using the viewpoints of the digital cameras, just like the head position. It may also include a fifth digital camera 23 for capturing the foot position.

[0135] Specifically, the first digital camera 11 is provided with a mounting plate 39 that extends vertically downward, and the third digital camera 21 is disposed on this mounting plate 39 so as to be movable up and down. The lens optical axis of the third digital camera 21 is an optical axis that extends parallel to the lens optical axis of the first digital camera 11.

[0136] Alternatively, the third digital camera 21 may be mounted on a support 40 that extends vertically upward from a leg 38 that extends horizontally along the floor from the lower end of the support 31, with the camera lens optical axis parallel to the patient direction, which is parallel to the X-ray imaging axis, on a vertical reference plane that passes through the X-ray imaging axis.

[0137] The position where the patient stands is defined by legs 37 and 38 extending horizontally from the bottom end of the support column 31 along the floor. A support column 40 is erected vertically at the tip of the leg column 37, at an angle of -90° in a plan view. A fourth digital camera 22 is held on the upper part of the support column 40 so that it can be displaced up and down. The lens optical axis of the fourth digital camera 22 extends horizontally and toward the center (origin) in a plan view. Multiple third digital cameras 21 and 22 may be provided in the vertical direction. This allows the desired camera position to be selected, eliminating or minimizing the need for vertical movement adjustment.

[0138] Furthermore, a fifth digital camera 23 is attached to the lower part of the support 39. The lens optical axis of the fifth digital camera 23 faces diagonally downward and forward.

[0139] Although not shown in the figure, the third digital camera 21, the fourth digital camera 22, and the fifth digital camera 23 are connected to a third monitor 27, a fourth monitor 28, and a fifth monitor 29, respectively, for displaying the images captured by each digital camera 21, 22, and 23.

[0140] The head positioning method performed prior to CT imaging in the CT cephalography system 30 incorporating the head positioning device shown in Figures 14 and 15 is substantially the same as the head positioning method in the cephalography system 1 shown in Figures 8 to 10. The only difference is that the head positioning is performed with the rotation arm 34 positioned such that the first digital camera 11 is fixed at 0° in plan view.

[0141] Therefore, the specific steps of (1) performing the foot positioning step, (2) performing the body axis lateral positioning step, (3) performing the body axis posterior positioning step, (4) performing the lateral positioning step, (5) performing the frontal positioning step, and (6) performing the recording step are the same as those in the method described above, and therefore redundant explanations will be omitted.

[0142] FIG. 16 is a perspective view showing an example of the configuration of a magic mirror 15 (see FIGS. 1, 3, 8, 9, 10, 14, and 15) used in the head positioning standard device according to the embodiment of the present invention.

[0143] The magic mirror 15 may be formed of a transparent glass plate 150 having a vertically long rectangular shape when viewed from the front and a thickness of 3 mm to 5 mm. A thin silver plating layer 151, for example, is applied to the rear surface of the glass plate 150. In addition, a front horizontal reference line H ０ And the vertical reference line V extending vertically to the center in the left-right direction ０ Furthermore, on the rear surface of the glass plate 150, a rear horizontal reference line H extending horizontally in the center in the vertical direction is displayed. ０ ' and a back vertical reference line V extending vertically to the center in the left-right direction ０ ' is displayed.

[0144] In the case of the magic mirror 15, for example, when the reflectance is 50%, light incident from the front side enters the glass plate 150 from the front side of the glass plate 150, and for example, 50% is reflected by the silver plating layer 151 applied to the back surface of the glass plate 150, passes through the glass plate 150, and is emitted from the front side. In addition, for example, 50% of the light that enters the glass plate 150 is not reflected by the silver plating layer 151 applied to the back surface of the glass plate 150, but passes through the silver plating layer 151 and is emitted from the back side.

[0145] In the magic mirror 15, a front horizontal reference line H is displayed on the front surface of the glass plate 150. ０ , table vertical reference line V ０ and the rear horizontal reference line H indicated on the rear surface of the glass plate 150. ０ ', rear vertical reference line V ０ When viewed from the front of the magic mirror 15, ０ and H ０ ', V ０ and V ０ The horizontal and vertical reference lines H and V are designed to overlap completely, forming a single horizontal reference line H and a single vertical reference line (midline) V.

[0146] The patient faces the one-way mirror 15, which has a midline (vertical reference) line and a horizontal reference line drawn on it, and positions the patient in a frontal orientation that satisfies them. The surgeon checks the left-right symmetry of the patient's face as they face the one-way mirror 15 at the height of the horizontal reference line and from a fixed viewpoint from a camera positioned based on the midline (vertical reference) line, and guides the patient's head position from an anatomical and clinical perspective, and with the patient's confirmation, finally positions the patient in a frontal orientation that satisfies both the patient and the surgeon. The same head position can then be repeatedly positioned and reproduced from the positional relationship between the reference plane and the camera images of the orthogonal front and lateral maxillofacial region taken from a fixed viewpoint based on that reference plane.

[0147] The magic mirror 15 of the embodiment can improve the accuracy of the head orientation of the patient facing the magic mirror 15 in this frontal head position.

[0148] As shown in FIG. 17A, the patient is positioned at the horizontal reference line H ０ , H ０ When the horizontal reference line H ０ , H ０ However, if the patient's viewpoint shifts up or down, the horizontal reference line H ０ and H ０ It appears to be two lines (double).

[0149] 17B, ​​the patient is positioned on the vertical reference line V ０ , V ０ When the vertical reference line V ０ , V ０ However, if the patient's viewpoint shifts to the right or left, the vertical reference line V ０ and V ０ ' appears to be two (double).

[0150] The operator's viewpoint can be determined three-dimensionally by the camera, the front, and the side, orthogonal to each other, and by horizontal and vertical reference lines, allowing the patient's head position to be positioned. On the other hand, the patient can only see the front position reflected in the one-way mirror 15, so it can be said that the control of the direction viewed from the side is insufficient.

[0151] Therefore, by adjusting the height and direction of the patient's face so that the displayed horizon does not appear doubled, the patient can more accurately position the head direction from the side.The surgeon also adjusts the height of the magic mirror 15 equipped with a camera on the horizontal reference plane so that the patient does not appear doubled and has a natural posture and head position.From next time, by having the patient determine the front based on the height, the same front direction can be reproduced more accurately and in a shorter time.

[0152] Similarly, by displaying the vertical reference line (midline) three-dimensionally, it becomes possible to determine and reproduce the left-right orientation and position of the face based on how it appears.

[0153] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims.

[0154] This application corresponds to Japanese Patent Application No. 2020-151642 filed with the Japan Patent Office on September 9, 2020, the entire disclosure of which is incorporated herein by reference.

[0155] DESCRIPTION OF SYMBOLS 1 Cephalometric X-ray imaging device 2, 35 X-ray irradiation unit 3, 36 X-ray detection unit 5, 14, 24, 31, 40 Support 6 Base 7 Foot position display 8, 81, 82 Arm 11 First digital camera 12 Second digital camera 13 First monitor 15 Magic mirror 16 Second monitor 21 Third digital camera 22 Fourth digital camera 23 Fifth digital camera 25 Auxiliary arm 26 Auxiliary support 27 Third monitor 28 Fourth monitor 29 Fifth monitor 30 CT cephalography device 32 Support frame 33 Support shaft 34 Rotating arm 35 X-ray irradiation unit 36 ​​X-ray detection unit 37, 38 Legs 39 Mounting plate 150 Glass plate 151 Silver plating layer

Claims

1. A method for positioning the head of a patient placed in an imaging space in accordance with a certain standard, the method comprising: capturing an image of the side of the head of the patient with a first digital camera; capturing an image of the head and the face of the patient with a second digital camera; and performing head positioning based on the image of the side of the head and the face of the head, the method comprising: a one-way mirror that reflects a frontal head position of the patient is disposed in front of the second digital camera, and the one-way mirror is configured to move up and down integrally with the second digital camera as the second digital camera moves up and down; a horizontal reference line and a median line based on the optical axis of the second digital camera are displayed on the one-way mirror; a front display monitor that displays the patient's head and face image captured by the second digital camera together with a horizontal reference line and a midline based on the optical axis of the second digital camera; While looking at the display on the front display monitor, the photographer instructs the patient to adjust the left, right, and up and down directions of the patient's head and face so that the horizontal reference line passes through the center of the patient's left and right eyeballs and the midline passes through the center between the patient's left and right eyes. The patient is allowed to adjust the head position in accordance with the photographer's instructions while looking at his or her own face reflected in the one-way mirror and referring to the horizontal reference line and the midline displayed on the one-way mirror, When the patient's head position adjustment is completed, the shutter of the second digital camera is released to record an image of the patient's head and face, and the patient's frontal head position is determined based on the horizontal reference line and the midline.

2. The head positioning standard method according to claim 1 , wherein the optical axis of the first digital camera and the optical axis of the second digital camera form an angle of 90° in a plan view.

3. The head positioning is performed prior to X-ray photography for standard cephalometric X-ray photography, the first digital camera is disposed so that an optical axis of the first digital camera is aligned with an X-ray imaging axis for imaging a side of the head of a patient disposed in the imaging space; a side display monitor that displays a side image of the patient's head captured by the first digital camera together with a first horizontal reference line and a first vertical reference line based on an optical axis of the first digital camera; While viewing the display on the side display monitor, the photographer instructs the patient to adjust the front-back position of the patient's head so that the center of the patient's ear canal is at the intersection of the first horizontal reference line and the first vertical reference line; 3. The head positioning method according to claim 2, wherein, when the patient's head adjustment is completed, the shutter of the first digital camera is released to record a lateral image of the patient's head, and the patient's lateral head position is determined based on the first horizontal reference line and the first vertical reference line.

4. 4. The head positioning standard method according to claim 3, wherein the first digital camera is provided so as to retreat to a position away from the X-ray imaging axis so as not to obstruct X-ray irradiation during X-ray imaging.

5. The head positioning standard method according to claim 3, wherein the first digital camera is composed of a plurality of digital cameras that have a camera optical axis that is not collinear with the X-ray imaging axis but is parallel to the X-ray imaging axis, and that are positioned so as not to interfere with X-ray irradiation.

6. The head positioning is performed prior to X-ray CT head imaging, the first digital camera is arranged to have a horizontal camera optical axis directed toward a side of the head of a patient arranged in the imaging space; a side display monitor that displays a side image of the patient's head captured by the first digital camera together with a first horizontal reference line and a first vertical reference line based on a camera optical axis of the first digital camera; While viewing the display on the side display monitor, the photographer instructs the patient to adjust the front-back position of the patient's head so that the center of the patient's ear canal is at the intersection of the first horizontal reference line and the first vertical reference line; 3. The head positioning method according to claim 2, wherein, when the patient's head position adjustment is completed, the shutter of the first digital camera is released to record a lateral image of the patient's head, and the lateral head position of the patient is determined based on the first horizontal reference line and the first vertical reference line.

7. the one-way mirror has a front horizontal reference line and a front median line marked on the front surface of the one-way mirror, and a back horizontal reference line and a back median line marked on the back surface of the one-way mirror, 2. The head positioning standard method according to claim 1, wherein the patient adjusts the head position in a state in which the front horizontal reference line and the back horizontal reference line overlap and appear as a single line, and the front midline and the back midline overlap and appear as a single line.

8. When repositioning the head of the same patient, setting the heights of the first digital camera and the second digital camera to the height positions used in the previous positioning; Displaying the side image of the patient's head recorded at the previous positioning on the side display monitor; Displaying the patient's head and face image recorded in the previous positioning on the front display monitor; instructing the patient to adjust the front-back position of his / her head so that the side image of the patient's head captured by the first digital camera overlaps with the recorded side image of the patient's head on the side display monitor; 7. The head positioning method according to claim 3 or 6, characterized in that the patient is instructed to adjust his / her head so that the image of the patient's head and face captured by the second digital camera overlaps with the recorded image of the patient's head and face on the front display monitor.

9. A head positioning standardization method for head X-ray standardization, comprising: a side positioning slap that uses a first digital camera whose optical axis is aligned with an X-ray imaging axis for imaging the side of the patient's head placed in the imaging space, to capture an image of the side of the patient's head, and displays on a first monitor a first horizontal reference line and a first vertical reference line determined by the optical axis of the first digital camera together with the captured image of the side of the patient's head; a front positioning step of capturing an image of the patient's head and face using a second digital camera having a horizontal camera optical axis that forms an angle of 90° in a plan view with the camera optical axis of the first digital camera and is directed toward the patient's head and face arranged in the imaging space, and displaying a second horizontal reference line and a second vertical reference line determined by the camera optical axis of the second digital camera on a second monitor together with the captured image of the patient's head and face, In the side positioning step, while watching the display on the first monitor, the vertical position of the first digital camera is adjusted together with the X-ray imaging axis so that the intersection of a first horizontal reference line and a first vertical reference line corresponding to the camera optical axis of the first digital camera is at the center of the patient's ear canal, and the patient is instructed to adjust the front-to-back position of the head; In the front positioning step, while viewing the display on the second monitor, the vertical position of the second digital camera is adjusted so that the second horizontal reference line passes through the centers of the patient's left and right eyeballs, and instructions are given to the patient to adjust the left and right tilt of the head and face to make the heights of the left and right eyes equal, and instructions are given to the patient to adjust the left and right orientation of the head and face so that the second vertical reference line passes through the centers of the patient's left and right eyes, After the adjustments in the side positioning step and the front positioning step are completed and head positioning is completed, the head positioning standardization method includes a recording step of releasing the shutters of the first digital camera and the second digital camera to record the side image of the head in association with the first horizontal reference line and the first vertical reference line, and the head face image in association with the second horizontal reference line and the second vertical reference line, and recording the height positions of the first digital camera and the second digital camera.

10. A standard head X-ray imaging method, characterized in that after completing the recording step described in claim 9, the first digital camera is retracted from the X-ray imaging axis and X-ray irradiation is performed.

11. A head positioning standard method for X-ray CT head imaging, comprising: a side positioning step of capturing an image of the side of the patient's head using a first digital camera arranged in the imaging space and having a horizontal camera optical axis directed toward the side of the patient's head, and displaying on a first monitor a first horizontal reference line and a first vertical reference line determined by the camera optical axis of the first digital camera together with the captured image of the side of the patient's head; a front positioning step of displaying on a second monitor a second horizontal reference line and a second vertical reference line, the second horizontal reference line and the second vertical reference line being determined by a horizontal camera optical axis that forms an angle of 90° with the camera optical axis of the first digital camera in a plan view and is directed toward the head and face of a patient placed in an imaging space, together with the captured head and face image of the patient; In the side positioning step, while watching the display on the first monitor, the vertical position of the first digital camera is adjusted so that the intersection of the first horizontal reference line and the first vertical reference line corresponding to the camera optical axis of the first digital camera is at the center of the patient's ear canal, and the patient is instructed to adjust the front-to-back position of the head; In the front positioning step, while viewing the display on the second monitor, the vertical position of the second digital camera is adjusted so that the second horizontal reference line passes through the centers of the patient's left and right eyeballs, and instructions are given to the patient to adjust the left and right tilt of the head and face to make the heights of the left and right eyes equal, and instructions are given to the patient to adjust the left and right orientation of the head and face so that the second vertical reference line passes through the centers of the patient's left and right eyes, After the adjustments in the side positioning step and the front positioning step are completed and head positioning is completed, the head positioning standardization method includes a recording step of releasing the shutters of the first digital camera and the second digital camera to record the side image of the head in association with the first horizontal reference line and the first vertical reference line, and the head face image in association with the second horizontal reference line and the second vertical reference line, and recording the height positions of the first digital camera and the second digital camera.

12. A head positioning standard method according to claim 9 or 11, comprising: When repositioning the head of the same patient, In the side positioning step, Set the height of the first digital camera to the height position recorded in the previous positioning; a side image of the patient's head captured by the first digital camera and a first horizontal reference line and a first vertical reference line are displayed on a first monitor, and a previously recorded side image of the head, a first horizontal reference line and a first vertical reference line are read out and displayed in an overlapping manner on the display of the first monitor; instructing the patient to adjust the front-to-back position of the head so that the intersection of the first horizontal reference line and the first vertical reference line, which correspond to the camera optical axis of the first digital camera, is at the center of the patient's ear canal and so that the outline of the image overlaps with that of the previous image; In the front positioning step, Set the height of the second digital camera to the height position recorded in the previous positioning, displaying the patient's head and face image captured by the second digital camera and the second horizontal and second vertical reference lines on the second monitor, and reading out the previously recorded head and face image, second horizontal and second vertical reference lines and displaying them overlapping the display on the second monitor; A head positioning standardization method including instructing the patient to equalize the height of the left and right eyes, adjust the left and right direction of the head and face, and adjust so that the outline overlaps with the previous image.

13. A head positioning standard method as described in claim 12, which includes a recording step of releasing the shutters of the first digital camera and the second digital camera after the adjustments in the side positioning step and the front positioning step have been completed and head positioning has been completed, recording the side image of the head in association with the first horizontal reference line and the first vertical reference line, and recording the head facial image in association with the second horizontal reference line and the second vertical reference line, and recording the height positions of the first digital camera and the second digital camera.

Images