JPH0131900B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an upright bed device used, for example, in an X-ray diagnostic apparatus. The height of the tilting bed used in X-ray diagnostic equipment must be as low as possible in the horizontal position, and the X-ray tube must be positioned as high as possible in the standing position. In order to meet this demand, a bed device based on the "rise-up" method is being used. An example of a bed apparatus using this "uphill" method will be described with reference to FIGS. 1 and 2A. This bed device includes a bed main body b having an arcuate surface rotatably supported on a support part a that houses a drive source, and a top plate c placed on the main body b so as to be movable in the longitudinal direction. An X-ray tube e and a spotting device f are arranged opposite to each other so as to sandwich a subject d placed on a top plate c, and are fixed to the bed main body b. When changing from the horizontal state shown in Fig. 1 to the standing state shown in Fig. 2 A, the bed body b is rotated by a drive source provided in the support part a (at this time, the center of gravity G is ). At this time, the top plate c is also moved upward at the same time so that the lower end of the top plate c does not interfere with the floor surface. In this way, subject d is placed in a horizontal position.
Diagnosis can be performed by setting the device in a standing position or an inverted position. However, in the bed device having the above configuration, the position of the center of gravity G changes from the horizontal position to the upright position through the state shown in FIG. Since the (overhang amount) changes from r1 to r2, there is a problem that the load fluctuation becomes large and the driving force of the driving source cannot be effectively utilized. Furthermore, when the amount of overhang is at its maximum as shown in FIG. 2B, the entire device becomes extremely unstable and vibration phenomena are likely to occur. Furthermore, if the top plate is moved to prevent interference, the perspective position will shift, necessitating repositioning. The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to provide a tilting bed device that can prevent fluctuations in the amount of overhang by substantially matching the positions of the pivot point and the center of gravity. This is the purpose. The present invention will be specifically explained below using Examples. FIG. 3 is a schematic diagram showing an embodiment of the tilting bed device of the present invention. In the figure, reference numeral 1 denotes a subject placed on a top plate 2. The top plate 2 is connected to a support frame 3 provided behind it, and a spotting device 4 and an X-ray tube 5 are attached to the support frame 3, which are arranged opposite to each other so as to sandwich the subject 1 therebetween. This support frame 3 is connected to an up/down shaft 7 that projects forward from a pedestal section 6 disposed behind it. Here, the raising/lowering axis 7 is located approximately at the center of gravity G of the raising/lowering section (a portion including the subject 1, the top plate 2, the support frame 3, the spot device 4, and the X-ray tube 5). Further, this raising/lowering shaft 7 is rotatable in the direction of arrow A in the figure and in the direction of arrow B (vertical direction) by a drive mechanism built in the pedestal section 6 and the details of which will be described later.
It is configured to be movable. FIG. 5 is a configuration diagram showing one embodiment of the drive mechanism. In the figure, a worm wheel 8 fixed to a lifting shaft 7 is driven by a worm gear 9 disposed below it.
The worm wheel 8 is rotatably supported and housed in a box-shaped guide member 11 by means of a bearing 10.
The guide member 11 is mounted so as to be movable up and down in the direction of arrow B in the figure on guides (not shown) provided on both side walls of the pedestal section 6. A sprocket 12 is fixed to both ends of the shaft portion of the worm gear 9, and this sprocket 12 is connected to a sprocket 14 fixed to both ends of each of two drive shafts 14 and 15 arranged above via a chain 13.
a, 15a. This chain 13
A weight 16 of an appropriate weight is attached at a suitable location to balance the weight of the guide member 11 when it "climbs up." A sprocket 18 is rotatably attached below the sprocket 12 via a connecting member 17, and this sprocket 18 connects to two rotating shafts 19 and 20 disposed at the lower end of the device via a chain 13. It is connected to sprockets 19a and 20a fixed to both ends. The chain 13 is therefore tensioned by each sprocket 12, 18, 14a, 15a, 19a, 20a. Further, the drive shafts 14 and 15 are provided with first power transmission members (for example, a sprocket and a chain) 21 and 2, respectively.
2, reducer 23, 24, second power transmission member 2
The drive shafts 14 and 15 are connected to motors 27 and 28, which are drive sources, through motors 5 and 26, and the rotation of the motors 27 and 28 rotates the drive shafts 14 and 15, thereby causing the sprockets 14 at both ends of the drive shafts 14 and 15 to rotate.
a, 15a rotate in the direction of arrow C in the figure. Incidentally, the rotating shaft portions of the motors 27 and 28, the shaft portion of the worm wheel 8, or the guide member 1
An appropriate position detection mechanism is installed between the guide 1 and the guide, so that the amount of movement or the movement position of each member can be detected. Next, the operation of the mechanism will be explained. Here, for convenience of explanation, the rotational speed in the direction of arrow A is set as V1, the vertical movement speed in the direction of arrow B is set as V2, and the rotational linear speed of the drive shaft 14a in the direction of arrow C is set as V1.
14. The rotational linear velocity of the drive shaft 15a in the direction of arrow D is expressed as V15, and the linear rotational velocity of the sprocket 12 in the direction of arrow E is expressed as V12. Further, the rotation of the sprocket 12 and the rotation in the direction of the arrow A are reduced by the worm gear 9 and the worm wheel 8, and if the reduction ratio is k, then the rotation in the direction of the arrow A is reduced.
rotational speed V1 in the direction and rotational linear velocity V in the direction of arrow E
There is a relationship between 12 and 12 that can be expressed by the following equation. V1=k・V12...(1) Also, the rotational linear velocity V of the drive shaft 14a in the direction of arrow C
14, the rotational linear velocity V15 of the drive shaft 15a in the direction of arrow D, and the rotational linear velocity V12 of the sprocket 12 in the direction of arrow D, the following two relational expressions hold true. V2=V15-V14...(2) V12=1/2(V14+V15)...(3) When 14a and 15a are rotated in the forward and reverse directions at arbitrary speeds X, rotation in the A direction and movement in the B direction The speed is obtained as shown in Table-1.

[Table] For example, if you drive in the C direction at a speed of -X and in the D direction at a speed of X as in the example (g), it will move in the B direction at a speed of 2X and will not rotate at all in the A direction. Further, if the motor is driven in the same direction in the C direction and the D direction at a speed of X as in the example (a), it rotates in the A direction at a speed of kX, but does not move in the B direction at all. On the other hand (a),
As in the examples (d), (e), and (f), it can be driven to move simultaneously in the A direction and the B direction. Above (a),
When solving for V14 and V15 using equations (a) and (c), the following equation is obtained. V14=1/KV1-1/2V2...(4) V15=1/KV1+1/2V2...(5) Once the raising/lowering rotation speed V1 and the rising speed V2 are determined, drive the drive shafts 14a and 15a that should be driven. The rotation speed can be arbitrarily selected and driven using equations (4) and (5). By using such a drive mechanism, movement in the directions of arrows A and B in FIG. 3 can be easily performed. That is, by rotating the raising/lowering shaft 7 in the direction of arrow A and moving it in the direction of arrow B (particularly upward), the horizontal position shown in FIG. 3 can be changed to the standing position shown in FIG. 4. Can be done. In this case, by appropriately setting the values of each member, the center of gravity G and the rotation fulcrum can always be made to coincide, so that the amount of overhang does not change. or,
By designing each member of the drive mechanism, the height L1 of the top plate in the horizontal position and the height L2 of the X-ray tube in the upright position can be set arbitrarily, and ideal values can be maintained. According to the device of the present invention described in detail above, it is possible to eliminate fluctuations in the amount of overhang by nearly matching the rotation fulcrum and the center of gravity, so there is no load fluctuation during movement, so the drive source can be used effectively. be able to. Furthermore, since the maximum overhang value is close to 0, the device is very stable and vibration phenomena are unlikely to occur. Furthermore, by moving the top plate up and down while rotating it with the tilting shaft, the subject can be moved from a horizontal position to an upright position without changing the positional relationship between the top plate and the X-ray generating and detecting parts. Since it is possible to smoothly change the position, there is no problem of the perspective position shifting during movement, and it is possible to provide an extremely useful elevating bed device that causes less discomfort to the patient. The present invention is not limited to the embodiments described above, and various modifications can be made without changing the gist thereof. For example, the drive mechanism for "climbing" the raising/lowering shaft is not limited to the combination of a chain and sprocket as in the above embodiment, but may also be constructed from a combination of a belt and a pulley, or a combination of a gear train, etc. It's okay. Alternatively, the motor serving as the driving source may be a single variable speed motor, and the power thereof may be selectively transmitted to two drive shafts via a clutch gear.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic diagrams showing an example of a conventional up/down bed device, FIGS. 3 and 4 are schematic diagrams showing an embodiment of the device of the present invention, and FIG. FIG. 2 is a schematic diagram showing an example of an inverted shaft drive mechanism. 1... Subject, 2... Top plate, 3... Support frame, 4
...Subbot device, 5...X-ray tube, 6... Frame section, 7...
Raising/lowering shaft, 8... Worm wheel, 9... Worm gear, 11... Guide member, 12, 14a, 15a, 1
8, 19a, 20a... Sprocket, 14, 15
...Drive shaft, 16... Weight, 27, 28... Motor.

Claims (1)

[Claims] 1. An X-ray generation section 5 that irradiates X-rays toward the subject 1; an X-ray detection section 4 that detects the X-rays emitted from the X-ray generation section 5 and transmitted through the subject 1;
A support frame 3 in which the X-ray detection section 4 and the X-ray generation section 5 are disposed facing each other so as to sandwich the subject 1; A shaft 7, a worm wheel 8 fixed to the raising and lowering shaft 7, a guide member 11 that rotatably supports the worm wheel 8 and is movable in the vertical direction, and a worm gear 9 that drives the worm wheel 8. , this worm gear 9
A pair of first sprockets 12 are fixed to both ends of the shaft portion of the sprocket, a chain 13 is strung on the first sprocket 12, and the first sprocket is disposed above the first sprocket 12 via the chain 13.
A pair of second sprockets 14a and a pair of third sprockets 15a that suspend the sprocket 12
and the first drive shaft 14 and the second drive shaft 15 whose both ends are fixed to the second sprocket 14a and the third sprocket 15a, respectively, and the first drive shaft 14 and the second drive shaft 15, respectively, as described above. A first drive source 2 that drives the raising/lowering shaft 7 in an arbitrary rotational direction and rotational speed so that it can rotate while moving up and down.
7 and a second drive source 28, and the second sprocket 14 disposed below the first sprocket 12.
A pair of fourth sprockets 19a and a pair of fifth sprockets 20a are respectively suspended from the chain 13 by the third sprocket 15a.
, a third drive shaft 19 and a fourth drive shaft 20 whose both ends are fixed to the fourth sprocket 19a and the fifth sprocket 20a, respectively;
Sprocket 19a and fifth sprocket 20a
A raising/tilting bed device comprising a pair of sixth sprockets 18 which are suspended via the chain 13 and are rotatably attached below the first sprocket 12 via a connecting member 17.