WO2019150746A1

WO2019150746A1 - Bone density measuring apparatus

Info

Publication number: WO2019150746A1
Application number: PCT/JP2018/044246
Authority: WO
Inventors: 宮本　高敬; 敏行仙田
Original assignee: 株式会社日立製作所
Priority date: 2018-01-30
Filing date: 2018-11-30
Publication date: 2019-08-08
Also published as: JP2019129959A; CN111432728B; JP6920228B2; CN111432728A

Abstract

A bone density measuring apparatus that holds a movable arm at an angle selected from among a first angle (θ1), a second angle (θ2), and a third angle (θ3). When the third angle is selected, the movable arm is in a standing posture and the space above a mounting table is opened. An X-ray detector, etc. for X-ray examinations can be arranged in this upper space. The movable arm has provided therein an upper release button and a lower release button that are for releasing the hold state of the movable arm.

Description

Bone density measuring device

The present invention relates to a bone density measuring apparatus, and more particularly, to a bone density measuring apparatus having a movable arm that moves in an inclined manner.

The bone density measuring device (bone density density measuring means apparatus) measures the bone density of the lumbar, femur (foreground bone) (radius, ulna), etc. in the subject. It is a device to do. Bone density is also called bone mineral content. As a bone density measuring device, there are known an integrated bone density measuring device in which a bed is integrated and a separate type bone density measuring device in which a bed is separated (see Patent Documents 1 to 3 for the latter). reference). Hereinafter, a separate-type bone density measuring apparatus will be described.

A separate-type bone density measurement and acquisition device generally includes a lower part provided on the lower side of the bed, an upper part provided on the upper side of the bed, and a connecting part that connects the lower part and the upper part. For example, an X-ray generator is provided in the lower part, and an X-ray detector is provided in the upper part. In order to prevent the head of the subject from colliding with the upper part when getting on and off the bed, a movable arm that tilts is provided as the upper part. Specifically, a horizontal rotation shaft is provided at the upper end of the connecting portion, and the movable arm rotates (tilts) around the horizontal rotation shaft. When the subject gets on the bed or when the subject gets off the bed, the movable arm is flipped upward, and the movable arm is inclined.

When performing X-ray imaging (X-ray imaging), the bone density measuring device is separated from the bed. Thereafter, an X-ray generator is disposed immediately above the bed (see FIG. 1 of Patent Document 1). In this state, the subject is irradiated with X-rays. On the back side of the top plate in the bed, a film that is sensitive to X-rays or a plate that detects X-rays and holds detection data is provided. When it is desired to perform bone density measurement after X-ray imaging, the X-ray generator is retracted from directly above the bed, and the bone density measuring device is assembled to the bed.

In FIG. 4 of Patent Document 2, a plurality of inclination angles that can be taken by the movable arm are shown. Of these, only one holding angle of the movable arm is shown.

JP 2003-325497 A JP 2014-188034 A JP2015-85115A

In a separate bone density measuring device, when the movable arm is in an inclined state, the movable arm crosses the upper space of the bed diagonally. In that case, if the X-ray generator is disposed immediately above the bed, the X-ray generator and the movable arm collide. When the movable arm is in a horizontal state, the movable arm horizontally crosses the space above the bed. In that case, even if the X-ray generator can be arranged right above the bed, the X-ray imaging cannot be performed because the movable arm is in the way. In any case, conventionally, it is necessary to sufficiently separate the bone density measuring device from the bed during X-ray imaging. The bone densitometer is quite heavy and requires considerable effort to move it. The same problem as described above also occurs when devices other than the X-ray generator are disposed above the bed, and when the devices are disposed above the bed in the bone density measuring apparatus in which the bed is integrated. obtain.

The present invention is to enable an apparatus to be arranged above a bed without separating the bone density measuring device from the bed.

The bone density measuring device disclosed in the present application includes one of an X-ray generator and an X-ray detector, a lower part provided below a bed on which a subject is placed, the X-ray generator, A movable arm provided on the upper side of the subject on the bed at the time of bone density measurement, the other end of the X-ray detector; provided on the back side of the bed; And a rotating mechanism that rotates the movable arm around a horizontal rotation axis provided at the upper end of the connecting body. The mechanism includes a first angle selected during the bone density measurement, a second angle selected when the subject gets on and off the bed, which is larger than the first angle, and the An angle larger than the second angle and the space above the bed In a third angle that is selected when releasing, it holds the movable arms, it is characterized in.

It is a figure which shows the side surface of the bone density measuring apparatus which concerns on embodiment. It is a figure which shows three attitude | positions which a movable arm can take. It is a perspective view which shows the upper surface of a movable arm. It is a perspective view which shows the lower surface of a movable arm. It is a schematic diagram which shows the modification of a lower side release button. It is the schematic which shows a rotation mechanism. It is a schematic diagram for demonstrating latch release. It is a figure for demonstrating the operation method of a movable arm.

Hereinafter, embodiments will be described with reference to the drawings.

(1) Outline of Embodiment A bone density measuring device according to an embodiment includes a lower part, a movable arm, a connecting part, and a rotating mechanism. The lower part includes one of an X-ray generator and an X-ray detector, and is provided below the bed on which the subject is placed. The movable arm includes the other of the X-ray generator and the X-ray detector, and is provided on the upper side of the bed when measuring the bone density. The connecting portion is a structure that is provided on the back side of the movable arm and the bed and has a function of connecting the back-side end portion of the lower portion and the back-side end portion of the movable arm. The rotation mechanism is a mechanism that rotates the movable arm around a horizontal rotation axis provided at the upper end of the connection portion. The rotation mechanism is a first angle for bone density measurement, an angle larger than the first angle, a second angle for the subject to get on and off the bed, and an angle larger than the second angle. The movable arm is held at an angle selected by the user from among the third angles for opening the space above the bed.

According to the above configuration, when the third angle is selected, the upper space of the bed is opened, and thus an apparatus such as an X-ray generator (an apparatus other than the bone density measuring device) is disposed in the upper space. It becomes possible to do. Therefore, it is not necessary to separate the bone density measuring device from the bed when using the device. As long as necessary equipment can be disposed in the upper space of the bed, a part of the movable arm held at the third angle may protrude from the bed as viewed from above.

In the embodiment, when the device arranged in the upper space is an X-ray generator for X-ray imaging, the movable arm does not collide with the X-ray generator and the three-dimensional X-ray irradiation formed by the X-ray generator The third angle and the shape of the movable arm are determined so that the movable arm does not enter the region. In the embodiment, the holding of the movable arm at the second angle and the third angle by the rotation mechanism regulates at least the downward movement of the movable arm. In general, even if movement of the movable arm is allowed, the posture of the movable arm is stabilized at each selected angle by the load of the movable arm itself. In the embodiment, the holding of the movable arm at the first angle by the rotation mechanism restricts both the downward movement and the upward movement of the movable arm. This prevents inadvertent movement of the movable arm during bone density measurement.

In the embodiment, the bone density measuring device releases the first releaser operated when releasing the holding of the movable arm at the first angle, and releases the holding of the movable arm at the second angle and the third angle. And a second release device operated by. According to this configuration, the first releaser and the second releaser can be arranged at convenient positions. Since the second releaser exhibits two release actions, the number of parts can be reduced accordingly. In the embodiment, the first releaser releases the restriction of the upward movement of the movable arm, and the second releaser releases the restriction of the downward movement of the movable arm.

In the embodiment, the first releaser is an upper release button provided on the upper side of the front end of the movable arm, and the second releaser is a lower release provided on the lower side of the front end of the movable arm. Button. In general, when the movable arm is in a horizontal posture (or when the first angle is selected), the upper surface of the movable arm is lower than the head of a standing user (usually an examiner). In such a positional relationship, the upper release button can be easily recognized and operated. On the other hand, generally, when the movable arm is in an inclined posture (or when the second angle or the third angle is selected), the upper surface of the movable arm becomes difficult or invisible when viewed from a standing user. Therefore, if a second releaser is provided below the front end of the movable arm, the visibility and operability can be improved.

In the embodiment, on the lower side of the front end portion of the movable arm, a slope that faces obliquely downward on the front side when the movable arm is held at the first angle is formed, and the lower release button is on the slope. Is provided. According to this configuration, the visibility and operability of the lower release button can be improved when the movable arm is tilted. In addition, in a state where the movable arm is held at the third angle, a portion where the movable arm protrudes immediately above the bed can be reduced or eliminated as viewed from above. In addition, in the state where the movable arm is held at the first angle, the field of view can be expanded when the examiner observes the subject. By forming the slope, the width of the front end of the movable arm in the vertical direction is reduced, so that it can be easily held. It is only necessary that a lower release button is provided in the outer edge of the slope. For example, a recess may be formed on the slope, and the lower release button may be provided there.

In the embodiment, the rotation mechanism includes an electromagnetic latch mechanism that holds the movable arm at the first angle, and a mechanical latch mechanism that holds the movable arm at the second angle and the third angle, and the first releaser and the electromagnetic latch The mechanism is electrically connected by a signal line, and the second releaser and the mechanical latch mechanism are mechanically connected by a wire. According to this configuration, each holding state can be formed by using both the electrical latch and the mechanical latch, and each holding state can be released. According to the electric latch, even if the first releaser is operated during the bone density measurement or the movement of the X-ray generator or the like, it is possible to control to invalidate the first releaser. According to the mechanical latch, the latch state can be easily formed with a simple configuration.

(2) Details of Embodiment FIG. 1 shows a side surface of a bone density measuring apparatus according to an embodiment. The illustrated bone density measuring device 10 is a medical device that measures the bone density of a subject's lumbar vertebrae, femur, forearm bone (radius, ulna), and other bones. The bone density measuring device 10 includes a lower part 12 provided below the top plate 18A of the imaging table 18, a movable arm 14 as an upper part provided above the imaging table 18, and a lower part 12 provided on the back side of the imaging table 18. A connecting portion 16 connected to the back end portion of the movable arm 14 and the back end portion of the movable arm 14, and a rotating mechanism 25 described in detail later.

The imaging table 18 functions as a bed on which the subject 20 is placed. The imaging table 18 is separated from the bone density measuring device 10. That is, the imaging table 18 and the bone density measuring device 10 are provided in a state where they can be physically separated from each other. The imaging table 18 is also used for X-ray imaging (X-ray imaging). In other words, the imaging table 18 for X-ray imaging is used as it is for bone density measurement. In order to optimize and maintain the spatial relationship between the imaging table 18 and the bone density measuring device 10, both may be mechanically coupled.

An X-ray generator is provided inside the lower part 12. The X-ray generator is for generating X-rays 23. The X-ray 23 is a fan beam that expands in a fan shape in the embodiment. The spreading direction is the x direction and the z direction. Here, the x direction is the longitudinal direction of the imaging table, which is also the body axis direction of the subject 20. The y direction is the short direction of the imaging table, which is the left-right direction of the subject 20. The z direction is the vertical direction (up and down direction). In FIG. 1, the y direction and the z direction are clearly shown. The X-ray 23 is scanned in the y direction (see S). Thereby, a two-dimensional irradiation area is formed. The X-ray 23 may be further scanned in the x direction. Instead of the fan beam, a pencil beam or a cone beam may be used.

An X-ray detector 24 is provided inside the movable arm 14. The X-ray detector 24 includes a plurality of X-ray sensors arranged in the x direction. X-ray detector 24 is mechanically scanned in the y direction along with X-ray generator 22. The movable arm 14 has a front side end portion 14A and a back side end portion 14B. Here, the near side is a near side (front side) when viewed from an inspector (user, not shown) approaching the imaging table 18, and the far side is a far side when viewed from the inspector. In FIG. 1, the y direction is the depth direction.

The rear end of the movable arm 14 is rotatably supported by the upper end of the connecting portion 16. Specifically, the rotation mechanism 25 is constructed across the movable arm 14 and the connecting portion 16. The rotating arm 25 causes the movable arm 14 to rotate (tilt or tilt) about the horizontal rotation shaft 26 as a rotation center. The rotation mechanism 25 includes two damper units, a stay snit, an electromagnetic latch mechanism, and a mechanical latch mechanism, which will be described later.

The rotation mechanism 25 has a function of holding the movable arm 14 at the first angle (θ1), the second angle (θ2), and the third angle (θ3). Depending on the situation, the angle of the movable arm is selected. Here, θ1 is 0 degree as a horizontal angle. θ2 is set within a range of 40 to 60 degrees in order to avoid contact between the subject and the movable arm when the subject gets on and off the imaging table 18, and to ensure operability and mobility. Is desirable. For example, θ2 is 50 degrees. θ3 is preferably set within a range of 65 to 90 degrees in order to secure a space for installing the device in a space above the mounting table (a space immediately above). For example, θ3 is 70 degrees. However, each numerical value described in this specification is an example.

When measuring the bone density, the inclination angle of the movable arm 14 is θ1. It is the lowest value of the range of angles that can be moved, and the movable arm 14 is held at that angle. That is, the upward movement of the movable arm 14 is restricted. When θ1 is selected, the movable arm 14 is in a horizontal posture, and the movable arm crosses horizontally above the imaging table 18.

When the subject 20 gets on and off the imaging table 18, the inclination angle of the movable arm 14 is θ2. The movable arm 14 is held at that angle. That is, the downward movement of the movable arm 14 is restricted. In this state, the upward movement of the movable arm 14 is allowed. It may be further regulated. When θ2 is selected, the movable arm 14 is in an intermediate inclined posture, and the movable arm crosses obliquely above the imaging table 18.

In the case of X-ray imaging, the inclination angle of the movable arm 14 is θ3. The movable arm is held at that angle. That is, the downward movement of the movable arm 14 is restricted. In this state, a slight movement of the movable arm 14 is allowed. It may be further regulated. The maximum value of the movable angular range of the movable arm 14 is an angle slightly larger than θ3. When θ3 is selected, the movable arm 14 is in a substantially upright posture (a steeply inclined posture, hereinafter referred to as “standing posture”), and most of the space above the imaging table 18 is opened.

The lower side of the front side portion (front side portion) 14A of the movable arm 14 is partially cut off obliquely to form a slope 14E. In a state where the movable arm 14 is in the horizontal posture, the inclined surface 14E faces obliquely forward on the front side. The inclination angle of the inclined surface 14E with respect to the y direction is φ1. φ1 is set within a range of 20 to 40 degrees, for example. According to the slope 14E, in the horizontal posture of the movable arm 14, the field of view of the examiner standing on the near side of the bone density measuring device 10 can be enlarged. That is, the subject 20 can be observed without lowering the head much. When the bone density of the forearm bone is measured on the observation table of the subject's forearm, the subject's upper arm and shoulder are less likely to contact the movable arm 14. There is also an advantage that the vertical width of the end portion of the front side portion 14A of the movable arm 14 is reduced and it becomes easy to have it. Further, according to the slope 14E, the visibility and operability of the components provided on the slope 14E can be enhanced in the intermediate tilt posture of the movable arm 14. The possibility of the subject's head contacting the movable arm 14 when getting on and off the imaging table 18 can also be reduced. Furthermore, according to the inclined surface 14E, when the movable arm is in the standing posture, a portion hidden by the movable arm 14 in the photographing table 18 can be reduced or eliminated when viewed from above. . The bone density measuring apparatus 10 has a box 30 that houses a calibration member.

FIG. 2 shows three postures that the movable arm 14 can take. At the time of bone density measurement, the movable arm 14 is in a horizontal posture as shown in FIG. At this time, the angle at which the movable arm 14 is held is θ1, and specifically, θ1 is 0 degree. At the time of bone density measurement, for example, the subject 20 lies on his / her back on the imaging table 18. In the horizontal posture of the movable arm 14, the examiner's head is generally at a higher position than the movable arm 14. Since a part of the movable arm 14 is cut off by the formation of the inclined surface 14E, it is possible to widen the field of view of the examiner as indicated by reference numeral 32. Moreover, a feeling of pressure can be reduced in the subject 20.

When the subject gets on and off the imaging table 18 (see reference numeral 34), as shown in (B), the movable arm 14 is flipped up by the inspector, and the movable arm 14 is set to the intermediate inclined posture. At this time, the angle at which the movable arm 14 is held is θ2, and the movable arm 14 crosses the upper side of the imaging table 18 obliquely. The slope 14E of the movable arm 14 faces the inspector, and if a part is arranged there, the visibility and operability of the part can be improved. According to the intermediate inclined posture, the space between the movable arm 14 and the imaging stand 18 is widened, and therefore, as described above, the subject's head becomes difficult to contact or contact the movable arm 14 when getting on and off. Disappear.

At the time of X-ray imaging, as shown in (C), the movable arm 14 is further lifted, and the movable arm 14 is brought into a substantially standing posture. As seen from above, a part of the movable arm 14 protrudes slightly from the photographic stand 18, but most of the space immediately above the photographic stand 18 is open. In the space immediately above, for example, an X-ray generator 36 for X-ray imaging is arranged. The X-ray generator 36 is supported by a rail or an arm so as to be horizontally movable and vertically movable. The X-ray generator 36 is normally disposed immediately above the center of the imaging area on the imaging table 18 (see reference numeral 37). The center of the imaging area is generally the center in the longitudinal direction and the center in the lateral direction of the imaging table 18. At the time of X-ray imaging, the examination site of the subject 20 is positioned within the imaging area by the X-ray generator 36. When the movable arm 14 is in the standing posture, the slope of the movable arm 14 is directed toward the front side, or is directed slightly toward the front side. At least the inclination angle of the movable arm 14 (so that the movable arm 14 does not enter the three-dimensional irradiation area formed by the X-ray generator 36 so that the movable arm 14 does not collide with the X-ray generator 36). It is desirable to determine θ3) and the angle of the slope. However, if the inclination angle of the movable arm 14 is too large, it becomes difficult to operate a component arranged on the inclined surface (because it is difficult for an inspector to reach the component). It is desirable to determine the inclination angle.

FIG. 3 shows the upper surface of the front end portion 14A of the movable arm 14. There is provided an upper release button 40 as a first releaser. When the movable arm 14 is changed from the horizontal posture to the tilted state, it is an electrical switch operated to release the electromagnetic latch that maintains the horizontal posture (regulating the upward movement). An emergency stop button, an irradiating indicator, and a power lamp are provided in the vicinity of the front end portion 14A.

FIG. 4 shows the lower side of the movable arm 14. The slope 14E is provided with a lower release button 42 as a second releaser. It is a mechanical switch that is operated when releasing the holding (control of upward movement) of the movable arm 14 in the intermediate inclined posture and the standing posture. A wire is provided between the lower release button 42 and a mechanical latch mechanism, which will be described later, and, for example, the push of the lower release button 42 pulls the wire to the lower release button 42 side. As a result, the mechanical latch mechanism is turned off.

The movable arm 14 has two side surfaces 14F, and two

dents

50 and 52 as a dent pair are provided in the lower part thereof (a corner portion straddling the two side surfaces 14F and the lower surface of the movable arm 14). ing. Two

depressions

50 and 52 are provided side by side on one side surface 14F, and two

depressions

50 and 52 are provided on the other side surface 14F side. These

depressions

50 and 52 serve as a guide when positioning both feet of the subject. When the body axis center is aligned with the center position in the X-ray scanning direction, the position of the subject is adjusted on the imaging table so that the two knees are aligned with the

depressions

50 and 52. The reason why the pair of depressions are provided on both sides of the movable arm 14 is that the position of the head and the position of both feet may be reversed on the imaging table. It is possible to replace each of the

recesses

50 and 52 with a marker. However, if they are formed into recesses, the possibility of contact with the knee can be reduced, or the collision force at the time of contact can be reduced. The above-described inclined surface and indented pair can be applied to a bone density measuring apparatus that does not have the rotating mechanism.

FIG. 4 shows a cover 45 that moves up and down together with the movable arm 14. The cover 45 is a decorative board that hides the internal mechanism. A reference marker 44 is provided at the upper end of the connecting portion. The cover 45 is provided with a first marker 46, and a second marker 48 is provided below the first marker 46. If the movable arm 14 is desired to be in an intermediate tilt position, the mechanical latch mechanism is activated when the movable arm 14 is lifted and the first marker 46 reaches or exceeds the reference marker 44. Thereafter, when the movable arm 14 is slightly lowered, the angle of the movable arm 14 is maintained. The holding angle at that time is the above θ2. If the movable arm 14 is to be raised, the mechanical latch mechanism is activated when the movable arm 14 is further lifted and the second marker 48 reaches or exceeds the reference marker 44. Thereafter, when the movable arm 14 is slightly lowered, the angle of the movable arm 14 is maintained. The holding angle at that time is the above θ3. Thus, by providing the movable marker and the fixed marker that move relative to each other, it is possible to provide an indication of the height when the movable arm 14 is pulled up.

In the example shown in FIG. 4, the lower release button 42 is provided on the slope 14E at a position close to the edge 14D. However, as shown in FIG. 5, the lower release button 42 is located on the back side of the slope 14E. 42A may be provided. According to such a configuration, when the movable arm 14 is in a substantially standing posture, even an inspector with a short height can easily reach the lower release button 42A. Alternatively, a plurality of

lower release buttons

42B and 42C having the same function may be provided on the slope 14E. Alternatively, two release operation buttons may be provided on the two side surfaces of the movable arm 14.

FIG. 6 schematically shows a configuration example of the rotation mechanism 25. The rotating mechanism 25 has a horizontal rotating shaft 26, and the movable arm 14 rotates around the horizontal rotating shaft 26. The connecting portion 16 has a frame 54, and the movable arm 14 has a frame 56. Two

damper units

58 and 60 and a stay unit 62 are provided across the frame 54 and the frame 56, and an electromagnetic latch mechanism described later is further provided. Each of them constitutes an element of the rotation mechanism 25. The two

damper units

58 and 60 give a constant upward urging force (levitation force) to the movable arm 14.

The stay unit 62 includes a fixed member and a movable member that slides relative to the fixed member, and further includes a mechanical latch mechanism 64. The mechanical latch mechanism 64 includes, for example, a movable piece that enters a plurality of openings formed in the movable member. A latching state is formed when a movable piece enters one of the openings. In the latched state, the downward movement of the movable arm 14 is restricted. However, in the latched state, the upward movement of the movable arm is allowed. However, the upward movement of the movable arm is limited when the rotation angle of the movable arm becomes maximum. The operation force of the lower release button is transmitted to the mechanical latch mechanism 64 through the wire, and thereby the latch state of the mechanical latch mechanism 64 is released. Thus, the mechanical latch mechanism 64 is a mechanism that holds the movable arm at the second angle θ2 and the third angle θ3. A mechanical latch mechanism 64 may be provided on the movable member, and a plurality of openings may be provided on the fixed member.

FIG. 7 shows a mechanical latch mechanism 64 and an electromagnetic latch mechanism 68. The mechanical latch mechanism 64 is provided in the stay unit 62 as already described. The mechanical latch mechanism 64 is mechanically connected to the lower release button 42 via a wire 66. The lower release button 42 is operated when releasing the latched state, that is, the holding state, in the intermediate tilted posture and the substantially upright posture of the movable arm.

The electromagnetic latch mechanism 68 is a mechanism that maintains the horizontal posture of the movable arm. The electromagnetic latch mechanism 68 includes an actuator 72, a latching (locking) pin 70, and a member 73 in which a pin hole is formed. The member 73 is fixed to the frame of the movable arm, and the member 73 has a hole for receiving the pin 70. When the pin 70 enters the hole, a latched state (locked state) is formed. The actuator 72 is fixed to the frame of the connecting portion. A signal line 74 is provided between the upper release button 40 and the actuator 72. When the upper release button 40 is operated in a state where the movable arm has a horizontal posture, a signal is output to the actuator 72 via the signal line 74, and the actuator 72 pulls the pin 70. As a result, the pin 70 is detached from the hole formed in the member 73, and the latched state is released. Thereby, it becomes possible to lift the movable arm in a horizontal posture upward. When the movable arm returns to the horizontal posture, a latched state is automatically formed. Even if the upper release button 40 is operated during bone density measurement or movement of the X-ray generator, the operation is invalidated. Since an electric latch is used, such control can be easily performed.

For example, when only the upper release button 40 is provided and all the latch release operations are performed on the upper release button 40, the upper release button 40 is hidden behind the movable arm when the movable arm is in the intermediate inclined posture and the standing posture. The operation becomes very difficult. On the other hand, if only the lower release button 42 is provided and all the latch release operations are performed on the lower release button 42, the lower release button 42 becomes invisible when the movable arm is in a horizontal posture, and the operation becomes difficult. In the embodiment, since both the upper release button 40 and the lower release button 42 are provided, the above-described problems can be avoided and the usability is very good.

(3) Arrangement of operation method of movable arm In FIG. 8, the operation and operation method of the movable arm are arranged. In the state indicated by reference numeral 100, the electromagnetic latch mechanism operates and a holding state is formed. That is, the horizontal posture of the movable arm is maintained. In that state, the mechanical latch mechanism is substantially inoperative. However, it is possible to cause it to perform a latch operation. As indicated by reference numeral 102, when it is desired to change the movable arm from the horizontal posture to the inclined posture, the upper release button is turned on, whereby the electromagnetic latch mechanism is unlocked (non-latched state). As indicated by reference numeral 104, when the angle of the movable arm reaches θ2, the mechanical latch mechanism automatically operates and enters a locked state (latched state). As indicated by reference numeral 106, when the angle of the movable arm is changed from θ2 to θ1, the lower release button is turned on, and the mechanical latch mechanism is unlocked. Actually, the lower release button can be turned on with the movable arm slightly lifted. When the angle of the movable arm reaches θ1, the electromagnetic latch mechanism automatically operates and the locked state is formed again. On the other hand, as indicated by reference numeral 108, when the angle of the movable arm is to be changed from θ2 to θ3, it is not necessary to operate the lower release button. As indicated by reference numeral 110, when the angle of the movable arm reaches θ3, the mechanical latch mechanism automatically operates and a locked state is formed. As indicated by reference numeral 112, when it is desired to change the angle of the movable arm from θ3 to θ2 or θ1, the lower release button is turned on, whereby the mechanical latch mechanism is unlocked. Actually, the lower release button can be turned on with the movable arm slightly lifted. When the angle of the movable arm reaches θ1, the electromagnetic latch mechanism automatically operates and the locked state is formed again.

According to the embodiment, since the movable arm can be in a substantially upright posture, it is possible to arrange an X-ray imaging device directly above the imaging table without separating the bone density measuring device from the imaging table. is there. Since the upper release button and the lower release button are provided on the movable arm, even if the posture of the movable arm changes, the visibility and operability of the buttons necessary for the operation can be improved. In the above embodiment, the X-ray generator is provided on the lower side and the X-ray detector is provided on the upper side. However, the arrangement thereof may be reversed. Even when the bone density measuring apparatus and the imaging stand are integrated, the above-described configuration can be adopted.

Claims

A lower part provided on the lower side of the bed on which the subject is placed, including one of the X-ray generator and the X-ray detector;
A movable arm provided with the other of the X-ray generator and the X-ray detector, and provided on the upper side of the bed during bone density measurement;
A connecting portion that is provided on the back side of the bed and connects the back side end of the lower part and the back side end of the movable arm;
A rotation mechanism for rotating the movable arm around a horizontal rotation axis provided at the upper end of the connecting portion;
Including
The rotation mechanism is a first angle selected when measuring the bone density, a second angle selected when the subject gets on and off the bed, and is larger than the first angle, and Holding the movable arm at a third angle selected when opening the upper space of the bed that is larger than the second angle;
A bone density measuring device characterized by the above.
The bone density measuring device according to claim 1,
A first releaser operated when releasing the holding of the movable arm at the first angle;
A second releaser operated when releasing the holding of the movable arm at the second angle and the third angle;
A bone density measuring apparatus comprising:
The bone density measuring device according to claim 2,
The first releaser is an upper release button provided on the upper side of the front end of the movable arm,
The second releaser is a lower release button provided on the lower side of the front end of the movable arm,
A bone density measuring device characterized by the above.
The bone density measuring device according to claim 3,
On the lower side of the front end portion of the movable arm, a slope that faces obliquely downward on the front side when the movable arm is held at the first angle is formed,
The lower release button is provided on the slope,
A bone density measuring device characterized by the above.
The bone density measuring device according to claim 2,
The rotation mechanism is
An electromagnetic latch mechanism for holding the movable arm at the first angle;
A mechanical latch mechanism for holding the movable arm at the second angle and the third angle;
Including
The first releaser and the electromagnetic latch mechanism are electrically connected by a signal line;
The second releaser and the mechanical latch mechanism are mechanically connected by a wire;
A bone density measuring device characterized by the above.
The bone density measuring device according to claim 1,
The bed is an imaging table used for both bone density measurement and X-ray imaging,
The third angle is an angle at which physical interference between the X-ray generator and the movable arm can be avoided when an X-ray generator is disposed above the imaging table during the X-ray imaging.
A bone density measuring device characterized by the above.
The bone density measuring device according to claim 1,
The first angle is 0 degree which is a horizontal angle;
The second angle is in the range of 40-60 degrees;
The third angle is in the range of 65 to 90 degrees;
A bone density measuring device characterized by the above.