JPS6327703Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of the aperture device installed in the front of the tube in an X-ray fluoroscopic imaging device, which reduces the radiation dose to the patient and the operator, and also reduces the irradiation field and sharpens the image. be.

Conventionally, diaphragm devices used in X-ray fluoroscopy/imaging devices generally have a round slit for fluoroscopy, and a square or rectangular fixed slit for imaging. In the movable diaphragm device used in the apparatus, the opening degree of the rectangular diaphragm is automatically adjusted in response to changes in the distance between the focal point of the X-ray tube and the image receiving surface of the image tube. However, as shown in FIG.
The so-called surgical or circulatory system X has an image tube 3 at one end and an X-ray generator 4 at the other end.
In the X-ray television system, the electric movable diaphragm device 5 in front of the X-ray generator not only adjusts the opening of the square or rectangular diaphragm in order to clearly identify the monitor image, but also adjusts the opening of the X-ray emission cone. It is required to be rotated by hand, and some devices use manual rotation. The movable aperture device used in such devices must be as small and lightweight as possible, and for this reason various mechanisms for opening, closing, and rotating the aperture leaves using combinations of gear trains have been considered, but all of them have complicated configurations and are large. There is a flaw in the form. In other words, when rotating the leaf, the entire drive mechanism for opening and closing the leaf must be rotated, which occupies a large amount of space, and since the motor for opening and closing the leaf moves, its electrical wiring must also be flexible. Furthermore, there are many problems such as the weight balance of the C-arm 2 being lost due to the movement of the motor. Furthermore, if we were to adopt a structure in which the leaf opening/closing motor was also fixed, the degree of leaf opening would change as the leaf rotated, which was not intended by the surgeon, and the X-rays would disappear during diagnosis. It becomes impossible to put it into practical use. This idea was made in view of the above-mentioned current situation, and it eliminates the drawbacks of the electric movable diaphragm device of conventional X-ray fluoroscopic imaging equipment, fixes the drive source for both rotation and opening/closing of the leaf, and provides both. For example, the driven gear of the transmission gear train of the drive source is a double gear whose rotation center is the X-ray radiation conical axis, and one gear train rotates the leaf, and the other gear train opens and closes the leaf. The gear ratios of both gear trains are made equal, and when the leaf opens and closes, only one gear train rotates, and when the leaf rotates, both gear trains rotate synchronously, so that the leaf opens when the leaf rotates as described above. The present invention aims to provide a device that can track the affected area in a timely manner without changing the intensity, can obtain high-quality images, and can significantly reduce the radiation exposure dose for the patient and the operator.

Embodiments of this invention will be described below with reference to the drawings. Fig. 2 is a front view showing the configuration of the first embodiment of the X-ray movable aperture device of this invention, Fig. 3 is a side view, the right half is a cross-sectional view of Fig. 2, and Fig. 4 is a left side view. The right half of the figure is a sectional view taken along the line -' in FIG. 4H in Figure 3 is the X of the X-ray generator 4 in Figure 1.
It engages with the case 6 of the diaphragm device 5 at the ray irradiation port. The two-dot chain line X is an X-ray radiation cone. Reference numeral 7 denotes an aperture device board on which a leaf rotation motor 8 and a leaf opening/closing motor 9 are fixed, and in the center thereof, a rotation motor meshes with a pinion 10 of the rotation motor 8 and is reversibly driven by the motor 8. A spur gear 11 is rotatably supported on the base plate 7. This rotating spur gear 11
is ring-shaped, and its inner hole 11H is wide open to the X-ray radiation cone X. This 11 gear is a first flat plate-shaped rotating member, and two guide rails 12 are supported and integrated with this 11 by four support columns 12P (dotted lines). Guide rail 1
Both ends of the aperture leaf 13 are fitted into the second groove 12D. A lead plate Pb is connected to the lower surface of the aperture leaf 13, and a pin guide groove 13D is formed on the upper surface. On the other hand, a spur gear 14 rotatably assembled on the guide rail 12 meshes with a pinion 15 of the leaf opening/closing motor 9 and is reversibly driven by the motor 9. This leaf opening/closing spur gear 14 is a second flat rotating member, and the guide pin 1 fits into the pin guide groove 13D described above.
6A and 16B are installed at contrasting positions. 17
is a gear support plate that engages with four pillars 18 installed on the base plate 7 and presses the leaf opening/closing spur gear 14 from above in a slidable manner, and has the same dimensions as the guide rail 12 described above and is shown in FIG. The figures are duplicated here. On the left side of the center line in Fig. 2 is the leaf opening/closing spur gear 14.
The right half is a diagram showing the state in which the spur gear 14 is assembled, and 14H is a rectangular window of the spur gear 14. With the above configuration, the rotation of the leaf opening/closing motor 9 rotates the leaf opening/closing spur gear 14, and its guide pins 16A, 16B open and close the 132 aperture leaves to direct the X-ray radiation cone from the X-ray focal point F. It narrows down X. FIG. 5 is a schematic diagram illustrating the operation of the embodiment apparatus shown in FIGS. 2 to 4, and the same symbols in the figures will not be explained. If the aperture opening amount of the aperture leaf 13 in the position shown in the figure is L, then L = 2 (RCosθ ₀ −a). However, if in this device, only the leaf rotation motor 8 is driven in the direction of arrow C, the leaf If the opening/closing motor 9 is stopped, the pinion 10 rotates the rotating spur gear 11 by θ as shown in the figure, and if it is set to 11', the leaf opening/closing spur gear 14 does not rotate, so the guide pin 16A ,16B
Since the position of remains the same, the rotation angle θ of 11 and θ ₀
In a case like 11 _' in this figure, the opening amount L' is wider than L, and Δ〓>θ ₀
In this case, L' becomes narrower than L. Like this θ
It is inconvenient that the aperture amount L of the leaf changes depending on the angle of , which means that the best image cannot be obtained when the operator tracks the affected area. In order to prevent this and keep the aperture amount L constant while rotating θ at any angle up to 90 degrees, we devised the control circuit shown in Figure 5. The gear trains 10 and 11 for leaf opening and closing and the gear trains 15 and 14 for opening and closing the leaves have the same tooth ratio, for example, 1.6. Figure 6 T ₁ and T ₂ are AC power supply terminals, SR is a switch for leaf rotation, R ₁ and R ₂ are relays that switch forward rotation c and reverse rotation d of the leaf rotation motor M _R (Figure 2 8). R _1a1 and R _1a2 are both the a contact of relay R ₁ (normally open, closed when activated), R _2a1 ,
R _2a2 are both a contacts of relay R ₂ , R ₁ b, R ₂ b are R ₁ ,
This is the b contact of _R2 (normally closed, open when activated). M _S is the leaf opening/closing motor shown in Fig. 2, 9, 8c and 9c are the split phase capacitors of the respective motors, S _s is the leaf opening/closing switch, and its contact C ₁ is the side e that squeezes the leaf.
C ₂ is the contact on the side f that opens the leaf.
If you want to open and close the leaf without rotating the leaf 13 in this configuration, turn the _S2 switch to _C1 or _C2 .
do it. Next, when rotating the leaf 13, turn on _R1 using switch S _R.
When R _1a1 and R _1a2 are turned on and M _R rotates in the c direction, M _S rotates in the e direction in synchronization, and as shown in FIG. synchronously rotate in the same direction, that is, move pins 16A and 16B in the direction of arrow g,
By maintaining the relative positions shown in the figure, the opening amount L can be kept constant. This is a synchronous operation mechanism for the first and second rotary drive bodies (motors on this side).

The structure and operation of the device according to the first embodiment of this invention have been described above. Next, the device according to the second embodiment of this invention will be explained with reference to FIGS. 7 to 9. Figure 7 is a front view, Figure 8 is a side view, and the right half is -' of Figure 7.
9 is a left side view of FIG. 2, and the right half is a cross-sectional view taken along the line -' of FIG. 2. Second
Portions with the same symbols in Figures 4 to 4 are the same and will not be described further. 11A is the pinion 1 of the leaf rotation motor 8
The ring portion 11E of the spur gear is rotatably supported by twenty or more pulleys rotatably provided on the base plate 7. The shape of the spur gear 11A is similar to the first gear, and is ring-shaped and has a large opening as shown in 11H relative to the X-ray radiation cone X. Reference numeral 21 denotes links A, and the two left and right sides are swingably supported by link A rotation shafts 22 installed at two left and right locations on the center line C ₀ of the leaf rotation spur gear 11A. Reference numerals 23a and 23b are links B, and these two links are swingably connected to the two links A through a connecting shaft 24, forming a parallelogram. 25 is a drawing leaf that joins the lead plate Pb, and its ends 25T ₁ and 25T ₂ are connected to 23 of link B, respectively.
a and 23b, and the other end 25E ₁ ,
Between _25E2 and links 23b and 23a of link B, there is provided an opening at the position of gap G. Reference numeral 26 denotes a support plate for the leaf opening/closing spur gear 14A fixed to the base plate 7, and the ring portion 1 of the spur gear 14A is connected to the support plate 26 via several pulleys 27 rotatably provided.
4E is rotatably supported. Reference numeral 28 denotes a link drive pin installed at one location on the periphery of the leaf opening/closing spur gear 14A, and is pivotally engaged with the center of one 23b of the link B. In this configuration, the radius r ₁ from the center F of the X-ray radiation cone to the center of the link drive pin 28 is made equal to the radius r ₂ from the center of the link A rotating shaft 22 to the center of the connecting shaft 24. This link mechanism is a mechanism that converts the rotational movement of the leaf opening/closing spur gear 14A, that is, the second flat rotating body, into the opening degree of the throttle mechanism. This effect will be explained with reference to FIG. Now, when the pinion 15 rotates clockwise, the spur gear 14A rotates in the i direction, and the pin 28 pushes the link 23b of the link B in the i direction as well.
Due to this action, link mechanisms A and B whose intersecting angle α is 90°
is a parallelogram A′ with intersection angles of acute angle β and obtuse angle γ,
Transforms into B′. In other words, 21 of the two links A
is tilted about its rotating shaft 22 as a fulcrum, and links 23a and 23b of link B are tilted about 24 of connecting shafts 24a to 24d.
By moving in parallel by moving from a' to 24d', the aperture leaf 25 is moved as explained in FIG.
Since one end is fixed to the link B, it moves in the directions h ₁ and h ₂ and moves in parallel as shown by the dotted line 25' to close the aperture leaf. pinion 15
When the rotation is counterclockwise, it operates in the opposite direction to that shown in FIG. 10 and opens the aperture leaf. The gear ratios of the pinions 8, 15 of both motors and their respective driven gears 11A, 14A of this second embodiment device are the same, for example 1.6, and the drive control circuits of both motors are the same as those of the first gear. This is exactly the same as FIG. 6 described in the embodiment. This configuration allows the amount of leaf throttling to be kept constant during leaf rotation, which is the same as in the first embodiment, but in the first embodiment, the leaf opening/closing operation is controlled by pin 1.
6A, 16B and the leaf groove 13D, and the leaf 13 and its guide groove 12D, the sliding movement is caused by looseness due to the degree of play between these mechanisms and wear due to use, resulting in lack of smoothness. There is a risk. In contrast, the leaf opening/closing operation of the second embodiment device is entirely based on the rotational movement of the rotating shaft of each part of the link mechanism, so the amount of backlash depends on the size of the fitting gap between the rotating shaft and its bearing. It can be held down, operates smoothly, and is stable without fear of wear, making it suitable for long-term use.

The above is the structure and operation of the first and second embodiment devices of this invention, but this invention is not limited to the illustrations and explanations. Transmission mechanisms such as sprockets or belts and pulleys may be used;
Further, the drive source is not limited to the motor, but may be any other, for example, hydraulic drive source. Furthermore, it can be applied not only to a pair of aperture leaves but also to multiple pairs of leaves.

This invention is constructed as described above, so it eliminates the drawbacks of the electric variable diaphragm device of conventional X-ray equipment, and by fixing the drive motor for both rotation and opening/closing of the leaf, it is possible to easily replace the movable diaphragm device. The structure is compact, the motor wiring is easy, there is no risk of wire breakage, and since the motor does not move, it is easy to balance the weight of the C-arm, etc., and the direction of the aperture can be changed freely and smoothly. As a movable aperture device for surgical or cardiovascular X-ray equipment that requires timely tracking of the affected area, the amount of aperture can be kept constant while the leaf is rotating, allowing high-quality images as intended by the surgeon to be obtained at low radiation doses. We have been able to provide a device that achieves great effects.

[Brief explanation of the drawing]

Fig. 1 is an external view of a C-arm type X-ray television device for surgery or circulatory system using the movable aperture device of this invention, Fig. 2 is a front view of the movable aperture device of the first embodiment of this invention, and Fig. 3 The figure above shows the side view (partial cross section)
Figure 4 is the left side (partial cross-section) view of the above, Figure 5 is
The figure is a principle diagram explaining the reason why the leaf rotation motor and the leaf opening/closing motor are operated synchronously, Figure 6 is an example diagram of the drive control circuit for the leaf rotation/opening/closing motor of this invention, and Figure 7 is this diagram. A front view of the device according to the second embodiment of the invention, FIG. 8 is the above-mentioned side (partially sectional) view, FIG. 9 is the above-mentioned left side (partially sectional) view,
FIG. 10 is an explanatory diagram of the operation of the above link mechanism. 4... X-ray generator including an X-ray tube, 4H... X-ray tube irradiation port, 5... X-ray movable aperture device, X... X-ray radiation cone, 7... Aperture device board, 8... 1 rotary drive body (reversible rotary motor in this example), 9... second rotary drive body (reversible rotary motor in this example),
10... Pinion of the above 8, 11, 11A... A first flat rotating member (this member) having an opening window 11H for the radial cone and supported on the device board 7 so as to be rotatable about the radial cone axis as the central axis. In the example, a ring-shaped spur gear), 12... Leaf guides of the throttle mechanism supported by the first flat rotating member, 13, 25...
...Aperture leaf made of Pb (lead plate, etc.) with a large X-ray absorption coefficient, 14, 14A...The center of rotation is aligned with the first rotating member, and the leaf is rotatably attached to the first rotating member or the device board 7. The second flat rotary member (in this case spur gear) supported, 16A, 16
B...Guide pins 21, 23a, 23 that convert the rotational movement of the above 14 into the opening/closing operation of the aperture mechanism 13
b...parallelogram links A and B that convert the rotational movement of 14A above into the opening and closing operation of the diaphragm mechanism,
22...Rotation axis of the link A (installed on the second flat rotating member 14A, 24...The above link A,
Connection shafts at four locations of the link B, 26...support plate supporting the second flat rotating member 14A with respect to the device board 7, 28... installed on the second flat rotating member 14A Link mechanism drive pin, S _R ...
Leaf rotation changeover switch, R ₁ , R ₂ ... Relay for leaf rotation, R _1a1 , R _1a2 , R 1 b ... A and b contacts _of relay R ₁ , R _2a1 , R _2a2 , R ₂ b ... Relay R ₂ a, b contacts, S _s ... Leaf open/close changeover switch,
θ...Rotation angle of the aperture leaf with respect to the X-ray radiation cone axis, L...Aperture opening degree of the leaf's radiation cone.

Claims (1)

[Scope of utility model registration request] The X-ray tube is located at the front surface of the X-ray tube, has an opening window for the radiation cone, is rotatably supported by the apparatus board about the axis of the radiation cone as a central axis, and is interlocked with the first rotary drive body. a first flat rotating member that rotates reversibly;
A diaphragm mechanism made of a member with a large X-ray absorption coefficient is supported on the rotating member so as to be openable and closable; a second plate-like rotating member that rotates reversibly in conjunction with the second rotational drive body; a mechanism that engages with the second rotating member and converts the rotational movement into an opening/closing operation of the aperture mechanism; and a synchronized actuation mechanism for the first and second rotary driving bodies, which causes the second rotary member to rotate synchronously in the same direction when the first rotary member rotates, An X-ray movable aperture device characterized in that the direction and the aperture opening of the radiation cone are variable.