JP4526326B2 - Medical panoramic X-ray imaging system - Google Patents

Description

  The present invention relates to a medical panoramic X-ray imaging apparatus.

As a medical panoramic X-ray imaging apparatus, for example, a dental panoramic X-ray imaging apparatus includes a mechanism for rotating a revolving frame including an X-ray source and an X-ray detection unit while linearly moving in a horizontal direction. Specifically, the X-ray imaging apparatus disclosed in Patent Document 1 relates to orthogonal panoramic imaging that irradiates X-rays perpendicularly to the dentition, and the rotation center of the swivel frame is relative to the axis of symmetry of the dental arch. A configuration that moves linearly in the vertical direction is adopted. Further, the X-ray imaging apparatus disclosed in Patent Document 2 uses a swing frame and a swing frame suspension shaft fixed to a swing end of the swing link on a fixed base that supports the swing frame. X-rays are irradiated in a substantially orthogonal state with respect to the dental arch and panoramic imaging of the teeth is performed so that the enlargement ratio is substantially constant. Further, the straight-turning mechanism described in Patent Document 3 uses a movable member having a linear or arc-shaped restriction groove and a mechanism for changing the eccentric amount of the restriction position with respect to the turning center of the turning frame, thereby providing a dental arch. An envelope according to the size of the X-ray can be arbitrarily selected, and panoramic imaging is performed at an X-ray incident angle optimum for dental diagnosis. The X-ray imaging apparatus described in Patent Document 4 is provided with an XY movement mechanism that moves the turning frame in the X direction and the Y direction perpendicular to the X frame, between the fixed frame and the turning frame, and drives two motors. Thus, the operation of the swivel frame can be arbitrarily controlled.
No. 1-17298 No. 1-17298 Japanese Utility Model Publication 2-18088 US Pat. No. 6,169,780 B1

  However, the X-ray imaging apparatus of Patent Document 1 has a problem that it is difficult to clearly distinguish each tooth from the image because the captured image includes many obstacle shadows of the lower jaw branch. Further, in the X-ray imaging apparatus of Patent Document 2, since X-rays are incident on the dental arch in a substantially orthogonal state, the captured image includes an obstruction shadow of the mandibular branch, and the state of the tooth is not always accurately determined. There is a problem that you can not. Furthermore, although the X-ray imaging apparatus of patent document 3 can image | photograph the panoramic image optimal for a dental diagnosis, since the amount of eccentricity must be changed according to the size of a dental arch, the amount of eccentricity is changed for every patient. Therefore, there is a problem that it takes time to start shooting. And although the X-ray imaging apparatus of patent document 4 can image | photograph the panoramic image optimal for a dental diagnosis, since two motors are required, an apparatus becomes large sized and the control of those becomes complicated. There is.

  Accordingly, an object of the present invention is to provide a medical panoramic X-ray imaging apparatus having a simple configuration capable of irradiating a dental row with an X-ray bundle with an optimal incident angle.

In order to achieve this object, the medical panoramic X-ray imaging apparatus of the present invention is supported so as to be linearly movable in a direction parallel to the horizontal axis along the fixed frame and the first guide portion fixed to the fixed frame. Provided on the movable frame, a swivel frame supported by the movable unit so as to be rotatable about a vertical axis and having an X-ray source and an X-ray detection unit opposed to each other across the vertical axis, and the fixed frame. A second guide portion extending symmetrically on both sides of the horizontal axis across the horizontal axis and extending in a curved shape, a polygonal line shape, or a combination thereof, the curvature of which gradually changes with distance from the horizontal axis, and the swivel frame And a guided portion that moves along the second guide portion as the turning frame turns, and a drive portion that turns the turning frame relative to the movable portion. To. Here, the second guide portion extends in a non-arc shape symmetrically on both sides in the horizontal direction across the horizontal axis along the first guide portion, and the non -arc shape as a whole is substantially “< It is preferable that both side portions of the substantially “<” shape have a slightly curved or arched shape toward the outside or the inside, or an arch shape .

  In this medical panoramic X-ray imaging apparatus, an X-ray bundle traveling from the X-ray source to the X-ray detection unit is configured to rotate and move the swivel frame. Is preferably determined so as to draw an envelope that does not pass through the mandibular branch.

In the medical panoramic X-ray imaging apparatus,
The drive unit is
A motor fixed to the swivel frame;
A rotating member that rotates with the rotation of the motor;
It is preferable to include a fixed reaction force portion that is fixed to the movable portion and applies a reaction force to the rotating member based on driving of the motor.

  According to the medical panoramic X-ray imaging apparatus configured as described above, the X-ray flux can be obtained with an optimal incident angle by appropriately setting the shape of the second guide portion according to the imaging method (for example, standard panoramic imaging). Can be used to shoot the optimal panoramic image.

  Embodiments of a medical standard panoramic X-ray imaging apparatus according to the present invention will be described below with reference to the accompanying drawings.

(1) Radiography equipment:
FIG. 1 shows a medical panoramic X-ray imaging apparatus 10 equipped with an operating device according to the present invention. As shown in the figure, the photographing apparatus 10 has a column 14 fixed to the floor 12. The column 14 supports a U-shaped lift 16 that rises and falls along the column 14. The elevating part 16 has a main body 18, an upper arm 20 and a lower arm 22 projecting forward from the upper and lower parts of the main body 18, and the upper arm 20 supports the swivel frame 24 below the lower arm 22. Supports a patient positioning mechanism 26 thereon. The swivel frame 24 includes a horizontal portion 28 and a pair of suspension portions 30 and 32 extending downward from both ends of the horizontal portion 28 so that the swivel frame 24 can swivel around a rotating shaft (not shown). In addition, an X-ray source 34 is provided in one suspension part 30, and an X-ray detection part 36 is provided in the other suspension part 32. According to the imaging device 10 configured as described above, the suspension portions 30 and 32 are swung around the patient positioned in the patient positioning mechanism 26 between the opposite suspension portions 30 and 32 and moved in the front-rear direction. imaging region of the patient (e.g., teeth) are X-ray from the X-ray source 34 with respect to the radiation, X-ray beam 38 that has passed through the imaging unit position is detected by the X-ray detector 36, in this X-ray detector 36 An X-ray image of the imaging region is created based on the detected X-ray.

(2) Linear motion turning mechanism:
In order for the revolving frame 24 to perform an operation in which revolving and linear movement in the front-rear direction are combined, the X-ray imaging apparatus 10 includes a linear motion revolving mechanism having the following configuration.

(2-1) Configuration of linear motion turning mechanism:
As shown in FIGS. 2 to 4, the upper arm 20 has a fixed frame 40. The fixed frame 40 has a first guide part 42. In the embodiment, the first guide portion 42 includes a pair of guide rails 44, and these pair of guide rails 44 are arranged in the horizontal direction (the arrow Y direction in FIG. 2) where the lifting body 18 faces the patient. They are arranged symmetrically and in parallel with respect to a horizontal axis (horizontal center line) 46. The fixed frame 40 also has a second guide 48. In the embodiment, the second guide portion 48 includes a guide plate 50 that is horizontally fixed between the pair of guide rails 44. The guide plate 50 is formed with arc-shaped guide slots (guide paths) 52 that extend symmetrically across the horizontal shaft 46 on both sides thereof. In the embodiment, the guide slot 52 has a substantially “<” shape extending symmetrically from the horizontal shaft 46 toward the rear (left side in FIG. 1) and substantially linearly on both sides of the horizontal shaft 46, or substantially the same. Both side portions of the “<” shape have a slightly curved or arched shape toward the outside or the inside, or an overall arched shape. At this time, it is preferable that the guide slot 52 has a shape in which the curvature of the curve or the arch gradually increases from the horizontal axis 46 toward both ends.

  The first guide portion 42 supports a linear motion frame (movable portion) 54 that moves in the arrow Y direction along the guide rail 44 via a pair of guide rails 44. In the embodiment, the linear motion frame 54 includes a space 56 penetrating in the vertical direction. The linear motion frame 54 includes support rollers 58 and lateral restriction rollers 60 at four positions, front, rear, left, and right. The movement in the arrow Y direction orthogonal to the Y direction (see FIG. 1) is restricted, and the movement in the arrow Y direction is possible based on the rotation of the support roller 58.

The linear motion frame 54 rotatably supports the revolving frame 24 via a bearing 64 centered on a vertical axis (rotary axis) 62 (see FIG. 3 ) orthogonal to the horizontal axis 46. In the embodiment, the bearing 64 includes an inner ring 66 formed on the linear motion frame 54, an outer ring 68 formed on the turning frame 24, and a large number of rolling elements disposed between the inner ring 66 and the outer ring 68 ( Ball) 70 and a rolling bearing.

  The linear motion frame 54 and the revolving frame 24 also include a drive unit 72 that rotates the revolving frame 24 with respect to the linear motion frame 54. The drive unit 72 includes a motor 74. In the embodiment, the motor 74 is fixed to the swing frame 24, for example, the suspension part 32 having the X-ray detection part 36, and a pulley 78 is attached to the rotation shaft 76. On the other hand, the linear motion frame 54 has a cylindrical support portion (fixed reaction force portion) 80 formed along the circumference centered on the vertical shaft 62, and a drive transmission belt ( Rotating member) 82 is suspended.

  The swivel frame 24 also has a vertical rod (guided portion) 84 extending in the vertical direction. The vertical rod 84 is disposed on a vertical plane including the X-ray bundle 38 emitted from the X-ray source 34 and detected by the X-ray detection unit 36, passes through the inner space 56 of the linear motion frame 54, and has an upper end portion. It is inserted into the guide slot 52 of the guide plate 50 disposed above. Further, as shown in the drawing, the vertical rod 84 is provided at a position eccentric from the vertical shaft 62 by a predetermined distance e (see FIG. 3).

(2-2) Basic operation of linear motion turning mechanism:
According to the linear motion turning mechanism having such a configuration, when the motor 74 of the drive unit 72 rotates, the rotation of the motor rotation shaft 76 is transmitted from the pulley 78 to the drive transmission belt 82. At this time, since the rotation of the linear motion frame 54 is restricted, the drive transmission belt 82 receives a reaction force based on the friction with the cylindrical support 80 of the linear motion frame 54, and the turning frame 24 based on the reaction force. Swivels about the vertical axis 62.

  When the revolving frame 24 rotates, the vertical rod 84 fixed to the revolving frame 24 moves along the guide slot 52. At this time, the vertical rod 84 receives a reaction force from the guide plate 50 in which the guide slot 52 is formed, and the linear motion frame 54 supporting the revolving frame 24 is guided by the guide plate 50 by the component in the arrow Y direction of the reaction force. And it moves in the arrow Y direction with respect to the fixed frame 40. As a result, the swivel frame 24 is provided with a motion (a straight motion swivel motion) in which the swivel around the vertical shaft 62 and the straight motion in the arrow Y direction are combined.

(2-3) Operation during X-ray imaging:
An operation when panoramic X-ray imaging is performed on a patient's teeth will be described. In this case, the turning frame 24 is set to the initial position shown in FIG. As shown in the figure, the swivel frame 24 in the initial position is oriented obliquely with respect to the horizontal axis 46, and the vertical rod 84 is located at a position away from one end (right end) of the guide slot 52 by an appropriate distance. The linear motion frame 54 is located in front of the guide rail 44 (lower side in FIG. 5).

  When the swivel frame 24 rotates in the clockwise direction in the drawing from the initial position and moves to a position substantially orthogonal to the horizontal axis 46 as shown in FIG. 6, the vertical rod 84 moves near one end (right end) of the guide slot 52. Based on the movement of the vertical rod 84 along the guide slot 52, the linear motion frame 54 moves rearward (upper side in FIG. 6) along the guide rail 44.

  Next, when the revolving frame 24 further rotates and moves to the position shown in FIG. 7, the vertical rod 84 moves along the guide slot 52 to the opposite side (from the right side to the left side in the drawing). Based on the movement of the vertical rod 84, the linear motion frame 54 moves further rearward (upper side in FIG. 7) along the guide rail 44.

  Next, when the swivel frame 24 further rotates and moves to the position shown in FIG. 8, the vertical rod 84 further moves in the same direction along the guide slot 52 (from the right side to the left side in the drawing). Based on the movement of the vertical rod 84 along, the linear motion frame 54 moves further rearward (upper side in FIG. 8) along the guide rail 44.

  Subsequently, when the revolving frame 24 is further rotated, although not shown in the drawing, an operation in which the state shown in FIGS. 7, 6, and 5 is reversed with respect to the horizontal axis 46 is performed.

  9 shows movements of the X-ray source 34, the X-ray detector 36, the X-ray bundle 38, the vertical shaft 62, and the vertical rod 84 that move in response to the operation of the swivel frame 24 described with reference to FIGS. Indicates. As shown in this figure, according to the X-ray imaging apparatus 10 according to the above-described embodiment, since the X-ray bundle 38 that passes through the mandibular branch 86 is relatively small, the X-ray imaging image in which the mandibular branch 86 has less obstacle shadows. Can be obtained. In other words, the shape of the guide slot 52 (guide path for guiding the vertical rod) is determined so that the X-ray bundle 38 draws an envelope 88 that does not pass through the lower jaw branch 86.

Other embodiments

  The above-described embodiment is one embodiment of the present invention, and the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the rotation belt is used as the rotation transmission unit of the drive unit 72 that rotates the rotation frame 24, but a gear or a chain may be used. Specifically, when gears are used, gears are provided on the rotating shaft of the motor 74 and teeth are continuously formed on the outer periphery of the cylindrical support 80, and another gear is provided between these gears and, if necessary, between them. The drive is connected through. When a chain is used, a sprocket wheel is provided on the rotating shaft of the motor 74 and sprocket teeth are continuously formed on the outer periphery of the cylindrical support 80, and the sprocket wheel and the sprocket teeth are driven and connected by the chain.

Further, the shape (guide path) of the guide slot 52 formed in the guide plate 50 is not limited to the above-described embodiment, and can be determined as appropriate so that optimum X-ray imaging can be obtained. The bulge direction of the curve drawn by the slot 52 may be forward or backward. Also, the guide plate 50 can be attached and detached, and the type of X-ray imaging (orthogonal panoramic imaging that obtains an image without overlapping teeth by irradiating X-rays perpendicularly to the tooth, and an image without obstruction shadows by the mandibular branch is obtained. It may be possible to replace the guide plate 50 with the guide slot 52 that can obtain the optimum X-ray imaging according to the jaw bone panoramic imaging.
Furthermore, panoramic imaging may be performed in a state where the patient is lying down with the rotation axis of the swivel arm in the horizontal direction as in a medical X-ray CT apparatus.

1 is a perspective view of a panoramic X-ray imaging apparatus according to the present invention. The top view which shows the structure of the linear motion turning mechanism mounted in the imaging device of FIG. The longitudinal cross-sectional view which shows the structure of the linear motion turning mechanism mounted in the imaging device of FIG. FIG. 2 is a cross-sectional view illustrating a configuration of a linear motion turning mechanism mounted on the photographing apparatus of FIG. 1. The top view explaining operation | movement of the straight path turning mechanism shown in FIGS. The top view explaining operation | movement of the straight path turning mechanism shown in FIGS. The top view explaining operation | movement of the straight path turning mechanism shown in FIGS. The top view explaining operation | movement of the straight path turning mechanism shown in FIGS. The figure which shows the locus | trajectory of an X-ray bundle, and its envelope.

Explanation of symbols

10: X-ray imaging apparatus, 12: floor, 14: support, 16: lifting part, 18: main body, 20: upper arm, 22: lower frame, 24: swivel frame, 26: patient positioning mechanism, 28: horizontal part, 30, 32: Suspension section, 34: X-ray source, 36: X-ray detection section, 38: X-ray bundle, 40: Fixed frame, 42: First guide section, 44: Guide rail, 46: Horizontal axis, 48: Second guide portion, 50: guide plate, 52: guide slot, 54: linear motion frame, 56: space, 58: support roller, 60: restriction roller, 62: vertical shaft, 64: bearing, 66: inner ring, 68 : Outer ring, 70: rolling element (ball), 72: drive unit, 74: motor, 76: rotating shaft, 78: pulley, 80: cylindrical support, 82: drive transmission belt, 84: vertical rod, 86: mandibular branch , 88: envelope.

Claims (3)

A fixed frame;
A movable part supported so as to be linearly movable in a direction parallel to the horizontal axis along the first guide part fixed to the fixed frame;
A swivel frame having an X-ray source and an X-ray detection unit that are supported by the movable unit so as to be rotatable about a vertical axis and are opposed to each other with the vertical axis interposed therebetween;
A second guide provided on the fixed frame and extending in a curved shape, a broken line shape or a combination thereof having a curvature that changes symmetrically on both sides of the horizontal axis across the horizontal axis and gradually away from the horizontal axis; And
A guided portion that is fixed to the swivel frame and moves along the second guide portion as the swivel frame turns;
A medical panoramic X-ray imaging apparatus, comprising: a drive unit that rotates the swing frame with respect to the movable unit. The second guide part is
Extending in a non-arc shape symmetrically on both sides in the horizontal direction across the horizontal axis along the first guide portion ,
The non-arc shape generally has a substantially “<” shape, a shape in which both side portions of the substantially “<” shape are slightly curved or arched toward the outside or the inside, or an arch shape. medical panoramic X-ray imaging apparatus according to claim 1, characterized in that forms. The drive unit is
A motor fixed to the swivel frame;
A rotating member that rotates with the rotation of the motor;
The medical panoramic X-ray imaging apparatus according to claim 1, further comprising a fixed reaction force portion that is fixed to the movable portion and applies a reaction force to the rotating member based on driving of the motor.

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