JP4704969B2 - Forearm bone densitometer - Google Patents

Description

  The present invention relates to a bone density measuring device, and more particularly to a device for measuring the density of a forearm bone.

  Bone density measurement (measurement of mineral density in bone) is important data for diagnosing osteoporosis and observing treatment, and various types of bone density have been used to measure this bone density. A measuring device has been proposed. In addition, there are various methods for measuring the bone density, such as a method using radiation such as X-rays and a method using ultrasonic waves.

  A bone density measuring apparatus using X-rays or the like uses a rib or a rib as a measurement target part. When the ribs are the target, in the actual measurement, the forearm is placed on the mounting table and fixed, and X-rays are irradiated from the bottom of the mounting table to a predetermined area of the forearm, and are provided in the arm above the mounting table. X-rays that have passed through the forearm are detected by a detector, and data is acquired. In normal diagnosis, the position of 1/3 of the forearm length from the ulnar styloid process is used as the measurement position. The forearm length is the length from the ulnar styloid process to the elbow head, and it is necessary to measure the forearm length along with the acquisition of X-ray data.

  When the forearm is placed on the mounting table, for example, in Patent Document 1 below, the forearm is placed on the mounting table with the elbow placed on the elbow rest fixed on the mounting table, and the sliding grip is held by hand. Thereby, the forearm can be fixed at a stable position. The forearm length is obtained from the position of the elbow rest and the position of the ulnar styloid process determined visually from the outside.

  As described above, the bone density measurement position in the radius is closer to the distal forearm length. For this reason, when the elbow is applied to the elbow rest, that is, the position of the forearm is determined based on the elbow, the measurement position changes depending on the physique of the subject. In Patent Document 1, an adapter is attached to a fixed elbow pad to adjust the position of the elbow, thereby adjusting the bone density measurement position. Moreover, in patent document 2 below, the elbow rest can be inserted and removed at several places with respect to the mounting table, and the position of the elbow is adjusted according to the inserted position to adjust the measurement position.

JP 2004-16392 A Japanese Patent No. 2735507

  In the device of the above-mentioned patent document, the position of the elbow is adjusted so that the bone density measurement position does not change greatly, but the forearm is still positioned with reference to the elbow. Therefore, in order to adjust the measurement position, it is necessary to adjust the position of the elbow rest, and there is a problem that the work is complicated.

  The present invention facilitates adjustment of a bone density measuring position in a forearm bone density measuring apparatus.

  In the forearm bone density measuring apparatus of the present invention, the grip positioned at a predetermined position on the mounting table and the slide movement in the left-right direction so that the distance from the positioned grip changes, An elbow rest contacting the elbow. A grip is positioned at a predetermined position on the mounting table, and this grip is gripped by the hand of the forearm to be measured. Since the position of the hand is fixed, it is possible to suppress the bone density measurement position that is closer to the hand of the forearm from being changed due to the physique difference of the subject. The measurement of the forearm length is performed using the elbow rest applied to the elbow in a state where the grip is held and the forearm is positioned on the mounting table, and the position is obtained.

  The elbow rest can be supported by a support rod extending from a rod support portion fixed on the mounting table. By being supported by the support rod, it is not necessary to directly fix the elbow rest on the mounting table, and measurement is possible even if the elbow is not on the mounting table.

  Two elbow pads and two support rods for supporting each of them separately can be provided so as to correspond to the bone density measurement of both the left and right forearms. The two support rods can be supported by the rod support portion on the mounting table so as to be slidable in the left-right direction.

  The rod support portion can be provided with grip engaging elements for engaging the grip at two positions in the left-right direction. One engagement position can be a position when the right arm is measured, and the other engagement position is a position when the left arm is measured.

  Further, the grip may be provided with an elbow rest engaging element that engages with the elbow rest to integrate the elbow rest and the grip. The grip engaged with the elbow rest is supported by a support rod that fixes and supports the elbow rest. Further, the elbow rest and the supporting rod to be supported can be fixed by engaging the grip and the elbow rest positioned on the rod support portion by the grip engaging element with the elbow rest engaging element.

  Further, when two elbow pads are provided, the elbow pads can also be used as a grip. When one elbow rest is used as a grip, the other functions as an elbow rest.

  By grasping the grip positioned at a predetermined position of the mounting table with the hand of the forearm to be measured and positioning the forearm, it is possible to reduce the change in the bone density measurement position due to the physical difference of the subject.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1-3 is a figure which shows the external appearance of the bone density measuring apparatus 10 of this embodiment, FIG. 1 is a perspective view, FIG. 2 is a right view, FIG. 3 is a front view. The bone density measuring apparatus 10 includes a main body 12 in which a device for measuring bone density is housed, and a leg body 14 on which the main body 12 is placed and supported at a predetermined height and inclined at a predetermined angle. In the present embodiment, the inclination is 10 °. The leg 14 is provided with a caster 16 with a stop function so that the apparatus can be easily moved and fixed.

  The main body 12 is erected from the base 20, a base 20 whose upper surface is a mounting table 18 on which the forearm is placed, an arm 22 that is disposed above the base 20 so that the forearm is positioned between the base 20 and the base 20. And a wall portion 24 that supports the arm portion. A top plate 26 made of a material capable of transmitting X-rays is disposed at substantially the center of the mounting table 18. In addition, a grip 28 that is gripped by the hand of the forearm to be inspected when the subject measures is positioned next to the top plate 26. Further, an elbow pad 30 </ b> L that contacts the elbow of the forearm is supported by an elbow pad support rod 34 </ b> L that extends from a rod support part 32 that is fixed to the base 20. The grip 28 is positioned on the right side of the top plate 26 in FIGS. 1 to 3, but can be positioned on the left side.

  FIG. 4 is a plan view in which a part of the arm portion 22 is omitted so that the configuration on the mounting table 18 can be seen. On the left and right sides of the rod support portion 32, contact pads 36 are provided for contacting the forearm and positioning the forearm in the depth direction. In addition to the elbow pads 30L and elbow pad support rods 34L shown on the left side of the main body 12 in FIGS. 1 to 3, an elbow pad 30R located on the right side and an elbow pad support rod 34R for supporting the same. It is shown. In the rod support portion 32, an encoder or a potentiometer for detecting the movement amount of the support rods 34L and 34R is provided. The point that the position of the grip 28 can be changed and the point that the elbow rest and the elbow rest supporting rod are provided correspond to the measurement of the left and right forearms. I will explain it again.

  FIG. 5 is a block diagram showing an internal configuration of the main body 12, particularly a configuration related to measurement using X-rays. An X-ray generator 38 and a power supply 40 that supplies power to the X-ray generator 38 are accommodated in the base 20 of the main body 12. The X-ray generator 38 emits X-rays in the form of a fan beam, and the irradiated X-rays are detected by a detection unit 42 housed in the arm unit 22. The detection unit 42 includes a one-dimensional array of detection elements corresponding to the shape of the fan beam. The X-ray generator 38 and the detection unit 42 are coupled by a bracket 44 and move integrally in the main body 12. The moving direction is the left-right direction in FIG. The X-ray beam shape may be a pencil beam or a cone beam in addition to a fan beam. The direction in which the X-ray generator 38 can be moved is determined according to the beam shape.

  Two-dimensional X-ray data can be collected by irradiating fan beam-shaped X-rays with the X-ray generator 38 and moving them in the left-right direction while detecting them with the detection unit 42. This data is taken into the control unit 46, predetermined processing is executed, and bone density is calculated.

  FIG. 6 is a view showing a state in which the left forearm 48 is positioned on the mounting table 18. In this state, bone density measurement is performed. The bone of the left forearm is also shown for illustration. The inner side of the arm, that is, the lower bone in FIG. 6 is the radius 50, and the other is the ulna 52. The process near the distal end of the ulna 52 is the ulnar styloid process 54 and the proximal end is the elbow head 56.

  The left hand 48 is positioned on the mounting table 18 by grasping the grip 28 with the left hand and bringing the left hand and the forearm into contact with the two contact pads 36. As shown in the figure, since the grip 28 is positioned on the right side toward the top plate 26, the distal end sides of the radius 50 and the ulna 52 are positioned on the top plate 26 that is the X-ray irradiation range. Become. Further, the elbow rest support rod 34L is slid to bring the elbow rest 30L into contact with the elbow head 56. By detecting the amount of movement of the elbow rest support rod 34L, the position of the elbow head 56 is measured. If an X-ray image is acquired and the position of the ulnar styloid process 54 is specified from this image, the length of the forearm length can be calculated from this position and the position of the elbow rest. Further, since the ulnar pedicle-like protrusion 54 can be confirmed visually, the position of the ulnar pedicle-like protrusion 54 can be specified regardless of image processing of the X-ray image. For example, a laser marker generator that moves in the left-right direction is provided in the arm portion 22, and the generator is moved so that the laser marker is aligned with the position of the ulnar pedicle process 54. The position of the ulnar styloid process 54 can be determined from the position of the laser generator at this time.

  7 and 8 are views showing the grip 28, the elbow pads 30L and 30R, the elbow pad support rods 34L and 34R, and the rod support portion 32 extracted. FIG. 8 is a diagram showing the state of FIG. 7 upside down. The two elbow pad support rods 34L and 34R are arranged side by side so as to be overlapped on the near side and the far side, and can slide independently on the rod support portion 34, respectively. As shown in FIG. 8, a rack 58 is formed in the longitudinal direction on the lower surface of the elbow support rods 34L, 34R. ing. Therefore, the slide amount of the elbow rest support rod 34L can be detected by the rotary encoder 60L. Similarly, the slide amount of the elbow rest support rod 34R can also be detected by the rotary encoder 60R. The positions of the elbow pads 30L and 30R near the rod support portion 32, that is, near the top plate 26 are regulated by a stopper 62 provided on the rod support portion 32.

  The grip 28 has an engagement hole 64 (see FIG. 10) into which the elbow pads 30L and 30R can be inserted. FIG. 7 shows a state in which the elbow rest 30R is inserted into the engagement hole 64 of the grip 28 so that the grip and the elbow rest are integrated. The grip 28 can be extracted from the elbow pad 30R as shown in FIG. The grip 28 can be inserted into and removed from the elbow rest 30L.

  10-12 is explanatory drawing of the operation | movement which concerns on attachment or detachment of the grip 28, and fixation of the elbow rest support rods 34L and 34R. FIG. 10 shows a state where the grip 28 is removed. As described above, the grip 28 has the engagement holes 64 that engage with the elbow pads 30L and 30R. Further, two positioning projections 66L and 66R are provided on the left and right sides of the engagement hole 64 on the surface of the elbow pads 30L and 30R. The positioning protrusion 66L engages with a positioning hole 68L provided in the stopper 62 on the right side toward the rod support portion 32 (see FIG. 10). The other positioning projection 66R engages with a positioning hole 68R provided in the left stopper 62 as shown in FIG.

  As shown in FIG. 11, the grip 28 is inserted into the elbow rest 30R, these are integrated, and the positioning protrusion 66L is engaged with the positioning hole 68L. Thereby, the grip 28 is positioned with respect to the rod support portion 32. That is, it is positioned at a predetermined position on the mounting table 18. Further, the grip 28 is integrated with the elbow rest 30R and supported so as not to wobble the elbow rest supporting rod 34R. Further, the elbow rest 30R is fixed by being integrated with the grip 28 positioned with respect to the mounting table 18, and the elbow rest supporting rod 34R for supporting the elbow rest 30R is also fixed, and the sliding movement becomes impossible. While the grip 28 is positioned and fixed, the other elbow rest 30L is slidable in the left-right direction with respect to the grip 28.

  FIG. 12 shows a state where the grip 28 is positioned on the left side of the rod support portion 32, which is opposite to that in FIG. 11. The engagement hole 64 of the grip 28 is engaged with the elbow pad 30L, and the positioning projection 66R is engaged with the positioning hole 68R. Thereby, the grip 28 is positioned with respect to the mounting table 18, and the elbow rest 30L and the elbow rest supporting rod 34L are fixed. On the other hand, the elbow rest 30R can slide in the left-right direction with respect to the grip 28.

  The procedure at the time of measurement will be described. When measuring the left forearm 48, the elbow rest 30R is moved to the left until it abuts against the stopper 62, and the grip 28 is inserted into the elbow rest 30R. At the same time, the positioning protrusion 66L is also inserted into the positioning hole 68L. Thereby, the grip 28 is positioned with respect to the mounting table 18. If a sensor for detecting that the positioning projection 66L is inserted into the positioning hole 68L is provided, it can be determined that the left forearm is being measured.

  The subject sits facing the right in the front of the bone densitometer, that is, in FIG. Then, the left forearm 48 is inserted from the front side into the space surrounded by the U shape at the base 20, the wall 24, and the arm 22, and the grip 28 is gripped with the left hand, and the left and left forearms are applied to the contact pads. Make contact. At this time, since the mounting table 18 and the arm part 22 are inclined so that the front side becomes higher, it is difficult for the subject's upper arm and shoulder to hit the arm part 22 positioned so as to cover the mounting table 18 above. Therefore, the subject can place the forearm in a predetermined position with a natural posture. The inclination of the mounting table 18 and the arm portion 22 is 10 ° in the apparatus of the present embodiment, but a range of 5 to 15 ° is almost preferable. Further, the inclination angle may be changed. This can be achieved, for example, by changing the inclination of the surface on which the main body 12 of the leg 14 is placed.

  When the forearm is placed at a regular position, the grip 28 is positioned at a predetermined position. Therefore, the ulnar styloid projection 54 and the bone density measurement position are located in the X-ray irradiation range (the range where the top plate 26 is provided). Will fit.

  Next, the elbow rest 30L is moved and brought into contact with the elbow head 56. At this time, the position of the elbow rest 30L is captured by the control unit 46 from the rotary encoder 60L and used for calculating the forearm length. Since the elbow rest 30L is supported by the main body 12 via the elbow rest support rod 34 and the rod support portion 32, the elbow rest 30L can be brought into contact with the elbow head 56 at a position protruding from the mounting table 18. Thereby, the dimension of the left-right direction of the mounting base 18 can be made small, and size reduction of an apparatus can be achieved.

  X-rays are emitted and scanned in the left-right direction to obtain a two-dimensional X-ray image. From this image, the position of the ulnar pedicle 54 necessary for calculating the forearm length can be acquired. When the forearm length is calculated, the bone density data of this portion is calculated from the X-ray data at a position 1/3 of the forearm length from the ulnar styloid process 54. As a measurement position, 1/3 of the forearm length is most commonly used, but measurement at other positions is also possible.

  In measuring the right forearm, the elbow rest 30L is brought into contact with the stopper 62, the grip 28 is inserted therein, and the positioning projection 66R is inserted into the positioning hole 68R, thereby positioning the grip 28. As in the case of the left forearm, the right forearm is positioned by inserting the right forearm into a space surrounded by a U-shape, grasping the grip 28 with the right hand, and bringing the arm into contact with the contact pad 36. The position of the elbow head 56 is acquired by sliding the elbow pad 30 </ b> R into contact with the elbow head 56. Then, X-rays are irradiated, an X-ray image is acquired, the forearm length is obtained, and the bone density at the measurement position is calculated.

  In the bone density measuring apparatus 10 of this embodiment, the main body 12 and the leg body 14 are detachable. By removing the main body 12 from the leg body 14 and placing the U-shaped opening on the floor so as to face upward, the bone density of the ribs can also be measured.

  In the present embodiment, the grip 28 is attached to one of the elbow pads 30L and 30R, but the elbow pads 30L and 30R may also be configured to serve as a grip. In this case, a configuration (for example, a pin) for directly engaging the elbow rest with the stopper 62 is provided, and the elbow rest engaged with the stopper is used as a grip.

It is a perspective view which shows the external appearance of the bone density measuring apparatus of this embodiment. It is a right view which shows the external appearance of the bone density measuring apparatus of this embodiment. It is a front view which shows the external appearance of the bone density measuring apparatus of this embodiment. It is a top view of the bone density measuring apparatus of this embodiment, and is a figure which abbreviate | omitted a part of arm part especially. It is a block diagram which shows the structure which concerns on acquisition of the X-ray image of the bone density measuring apparatus of this embodiment. It is a top view of the bone density measuring apparatus of this embodiment, and is a figure which shows the state at the time of the measurement which mounted the left forearm. It is the figure which extracted and showed the structure concerning the operation | movement of a grip and an elbow rest. It is the figure which extracted and showed the structure which concerns on operation | movement of a grip and an elbow rest, and has shown the state which looked at FIG. 7 from the back side. It is the figure which extracted and showed the structure concerning the operation | movement of a grip and an elbow rest. It is operation | movement explanatory drawing of a grip and an elbow rest, and is a figure which shows the state before mounting | wearing a grip. It is operation | movement explanatory drawing of a grip and an elbow rest, and is a figure which shows the state which positioned the grip in the position for measuring the left forearm. It is operation | movement explanatory drawing of a grip and an elbow rest, and is a figure which shows the state which positioned the grip in the position for measuring a right forearm.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Bone density measuring device, 12 Main body, 14 Legs, 18 Mounting base, 22 Arm part, 28 Grip, 30L, 30R Elbow pad, 32 Rod support part, 34L, 34R Elbow pad support rod, 36 Contact pad, 48 Left Forearm, 50 radius, 52 ulna, 54 ulnar pedicle, 56 elbow head, 62 stopper, 64 engagement hole, 66L, 66R positioning protrusion, 68L, 68R positioning hole.

Claims (4)

A forearm bone density measuring device for measuring a bone density by performing a predetermined measurement on a subject's forearm,
A mounting table for mounting the forearm;
A grip that can be positioned at a predetermined position on the mounting table and is gripped by the hand of the forearm to be measured;
An elbow rest that is slidable in the left-right direction so that the distance from the positioned grip changes, and that contacts the elbow of the forearm to be measured;
An elbow head position acquisition unit that acquires an elbow head position based on the position of the elbow pad;
I have a,
The elbow rest is equipped with two of the first elbow rest and the second elbow rest,
A first support rod extending in the left-right direction and having a first elbow rest fixedly supported at the left end;
A second support rod extending in the left-right direction and having a second elbow rest fixedly supported at the right end;
A rod support fixed to the mounting table and supporting the first and second support rods so as to be slidable in the left-right direction;
A bone density measuring device for forearm, comprising: The bone density measuring device for forearm according to claim 1 , wherein grip engaging elements for engaging the grip and positioning the grip with respect to the mounting table at two predetermined left and right positions on the mounting table. A bone density measuring device for forearm. The bone density measuring device for forearm according to claim 2 ,
The grip has an elbow rest engaging element that engages the elbow rest and integrates the elbow rest and the grip;
The grip is supported by the support rod corresponding to this elbow rest by being integrated with the elbow rest by the elbow rest engaging element,
The elbow rest and the support rod that fixes and supports the elbow rest are fixed by engaging the grip and the elbow rest positioned on the mounting table by the grip engaging element with the elbow rest engaging element.
Bone density measuring device for forearm. The bone density measuring apparatus for forearm according to claim 1 , wherein the elbow rest also serves as a grip, and when one elbow rest is used as a grip, the other elbow rest functions as an elbow rest. Bone density measuring device.

Images