JPH1033516A - X-ray diagnostic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To support the perception work for stereoscopic structure by an observer by periodically swinging a C arm for holding an X-ray device and an image pickup device. SOLUTION: A horizontal arm 15 is attached onto a stand 13 for which casters 11 are attached to its bottom part. A C arm holder 17 is provided at one end of the horizontal arm 15 so as to be freely horizontally rotated. A C arm 19 is provided at this holder so as to be freely slid and rotated in circumferential direction. A double focal point type X-ray device 21 is held at one end of the C arm 19. A swing mechanism 25 is provided inside the C arm holder 17 and the C arm 19 is repeatedly slid and rotated backward and forward alternately within a comparatively fine angle range. Through this swing movement, the direction of image pickup from the X-ray device 21 toward an image pickup device 23 is periodically changed and the state of overlapped blood vessels on an image, for example, is changed. Therefore, the observer can easily comprehend the stereoscopic constitution of object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray diagnostic apparatus for capturing an X-ray fluoroscopic image of a subject.

[0002]

2. Description of the Related Art In stereoscopic fluoroscopy, a right-eye image (L image) and a left-eye image (R image) imaged by giving binocular parallax are observed by the left and right eyes, respectively. This is a technique for perceiving the structure.

[0003] An X-ray tube for stereoscopic fluoroscopy usually includes:
Two focal points are provided at a distance corresponding to binocular parallax. One focus corresponds to the right eye and the other focus corresponds to the left eye. An X-ray flux is alternately emitted toward the subject from the two focal points. In the imaging device, the L image and the R image are alternately captured in synchronization with the switching of the focus.

An L image and an R image are alternately displayed on the display, and the observer sees the L image and the R image with the right eye and the left eye through time-division glasses or polarized glasses, respectively. 3D structure (feeling of depth) can be perceived.

However, in such stereoscopic fluoroscopy, since the three-dimensional structure of the object is a system reconstructed in the observer's head, it is necessary to perceive the three-dimensional structure or to accurately perceive the three-dimensional structure. Observers also required some skill.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an X-ray diagnostic apparatus capable of assisting a viewer in perceiving a three-dimensional structure in stereoscopic fluoroscopy.

[0007]

According to the present invention, there is provided an X-ray diagnostic apparatus in which a C-arm for supporting an X-ray apparatus and an imaging device is slidably provided. Means is provided.

According to the present invention, there is provided an X-ray diagnostic apparatus in which a C-arm for supporting an X-ray apparatus and an imaging device is rotatably provided with respect to a horizontal axis, wherein a means for swinging the C-arm is provided. Features. (Operation) According to the present invention, the C-arm swings, that is, reciprocates in the slide rotation or the horizontal axis rotation. C
When the arm reciprocates, the directions of the X-ray apparatus and the imaging apparatus with respect to the subject, that is, the imaging directions change accordingly. When the imaging direction changes, for example, the degree of overlap of blood vessels on the image changes accordingly, so that the observer can easily understand the three-dimensional structure of the target.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A preferred embodiment of the line diagnostic apparatus will be described. FIG.
1 shows a side view of a main structure of the X-ray diagnostic apparatus according to the present embodiment. A horizontal arm 15 is attached to an upper part of a stand (stand) 13 on which the casters 11 are attached at the bottom. At one end of the horizontal arm 15, a C-arm holder 17 rotates about a horizontal rotation axis (horizontal axis rotation).
It is provided freely. The C-arm holder 17 is provided with a semi-ring-shaped C-arm 19 which is slidable and rotatable along its circumferential direction.

At one end of the C-arm 19, an X-ray device 21 having a bifocal X-ray tube, a diaphragm device and the like is supported. C
The other end of the arm 19 supports an imaging device 23 having an image intensifier, an optical system, a TV camera, and the like. The two focal points of the X-ray tube are separated by a distance corresponding to the binocular parallax,
One corresponds to the right eye and the other corresponds to the left eye. In stereoscopic fluoroscopy, the subject is irradiated with X-rays alternately from the two focal points at a fixed period. In the TV camera, a right-eye image (R image) and a left-eye image (L image) are synchronized with the switching of the two focal points. Images are taken alternately.

Here, C arm 19, C arm holder 1
7. The three members of the horizontal arm 15 are the central axis of the X-ray flux irradiated from the X-ray tube toward the image intensifier, more precisely, the center line of the central axes of the X-ray fluxes from the two focal points and the horizontal rotation axis. And are intersected at the center of the slide rotation of the C-arm 19 in a geometric relationship. Therefore, even if the C-arm 19 rotates horizontally or slides, the geometric center point is not spatially displaced and is always located at the center of the image frame of the TV camera. This point is defined as "isocenter".

The swing mechanism 25 swings the slide rotation of the C arm 19, that is, the C arm 19 alternately repeats forward slide rotation and reverse slide rotation within a relatively small angle range. To reciprocate, C
It is provided inside the arm holder 17.

A mechanism similar to the swing mechanism 25 swings the horizontal rotation of the C-arm 19, that is, the C-arm 19 rotates in a direction opposite to the horizontal rotation in the forward direction within a relatively small angle range. In order to make reciprocating rotation that alternately repeats horizontal axis rotation, a reciprocating rotation is provided inside the horizontal arm 15. Since this structure and operation are substantially the same as the rocking mechanism 25, the following rocking mechanism is used. In the description of the structure and operation of 25, “slide rotation” is “horizontal axis rotation”, “C arm holder 17” is “horizontal arm 15”, and “outer circumference (surface) of C arm 19” is “horizontal rotation of C arm 19”. Around the axis (surface) "
Please read and understand each.

FIG. 2 is a detailed side view of the swing mechanism 25, and FIG. 3 is a sectional view taken along the line AA of FIG. The cylindrical slider 27 approaches the outer peripheral surface of the C-arm 19 and separates from the outer peripheral surface of the C-arm 19 in a state where the rotation of the shaft is locked (a state where the rotation of the shaft is impossible (prohibited)). Is provided on a slide rail 35 provided on the C-arm holder 17 so as to be slidable. The movement of the slider 27 approaching / separating from the outer peripheral surface of the C arm 19 is realized by an operator operating the lever 32 from outside the C arm holder 17.

A cylindrical friction roller 33 is inserted into the slider 27 via a bearing 29. Friction roller 33
The slider 27 is connected to the slider 27 by a spiral spring 31, and the axial rotation of the friction roller 33 is moderately restricted according to the spring strength of the spiral spring 31.

When the slider 27 is sufficiently close to the outer peripheral surface of the C-arm 19, the friction roller 33 is pressed against the outer peripheral surface of the C-arm 19. The roller 33 is separated from the outer peripheral surface of the C arm 19. Friction roller 33 is C arm 1
9 is strongly pressed against the outer peripheral surface of the C-arm 19, the frictional force between the friction roller 33 and the outer peripheral surface of the C arm 19 is reduced.
3 and the C-arm 19 are strong enough to be transmitted to the other with little loss.

When the friction roller 33 is separated from the outer peripheral surface of the C arm 19, the C arm 19 can slide and rotate in a completely free state, and can stop at an arbitrary position.

On the other hand, when the friction roller 33 is strongly pressed against the outer peripheral surface of the C-arm 19, the slide rotation of the C-arm 19 is restricted by the spiral spring 31. In this state, the state in which the spiral spring 31 is in an equilibrium state is defined as an initial state of swing, and the angle of the C-arm 19 in this initial state is treated as 0 °.

From this initial state, when the C-arm 19 is forcibly slid in the forward direction by, for example, an arbitrary relatively small angle θ ° by the operator, the friction roller 33 is also axially rotated in the forward direction, and the spiral spring 31 is rotated. Is under positive pressure.

Then, when the operator releases the hand, the reverse restoring force of the spiral spring 31 to return to the equilibrium state causes the friction roller 33 to pivot in the reverse direction, and furthermore, C
The arm 19 slides and rotates in the opposite direction.

When the C-arm 19 passes through the 0 ° position due to its inertial force, the spiral spring 31 is subjected to pressure in the opposite direction. When the inertial force and the restoring force of the spiral spring 31 are balanced, the slide rotation of the C arm 19 in the opposite direction stops.

The forward restoring force of the spiral spring 31 to return to the equilibrium state causes the friction roller 33 to rotate in the forward direction and the C arm 19 to slide in the forward direction.

Such a reciprocating rotation of the C arm 19,
That is, the swinging motion is attenuated until it returns to the initial state. While the C-arm 19 is oscillating, X
The imaging direction from the line device 21 to the imaging device 23 changes periodically and sequentially with respect to the subject. When the imaging direction changes, for example, the degree of overlap of blood vessels on the image changes accordingly, so that the observer can easily understand the three-dimensional structure of the target.

When the region of interest coincides with the isocenter as shown in FIGS. 4A and 4B, the position of the region of interest on the screen of the display 51 is maintained even if the C-arm 19 swings. Although it is fixed, as shown in FIGS. 4C and 4D, when the region of interest does not coincide with the isocenter, when the C arm 19 swings, the position of the region of interest on the screen of the display 51 becomes Fluctuating, making stereo fluoroscopy very difficult. Therefore, in the present embodiment, this problem is solved by the following image shift processing.

FIG. 5 is a block diagram showing a main part relating to image shift of the X-ray diagnostic apparatus according to the present embodiment. An X-ray signal emitted from the X-ray to the subject and reflecting an attenuation rate corresponding to each path is periodically transmitted at a specific frame rate in synchronization with switching of two focal points of the X-ray tube. An image is taken by 39. The L image data captured in synchronization with the exposure from the right-eye focal point of the two focal points passes through a front-stage switch 41, an L-image frame memory 43, and a rear-stage switch 47 in that order to form a digital scan converter (DSC). ) 49. The R image data captured in synchronization with the irradiation from the left and right eye focal points of the two focal points is stored in the front-stage switch 41 and the R image frame memory 4.
5. The signal is supplied to the digital scan converter 49 via the subsequent switch 47 in order.

The digital scan converter 49 performs interpolation processing as necessary, and alternately supplies L image data and R image data to the display 51 in synchronization with the frame rate of the display 51.

The angle sensor 53 detects the angle θ (t) of the oscillating C arm 19 from the initial state. Provided for The shift controller 55 is designed so that the region of interest in the L image and the R image does not move at a specific position on the screen of the display 51, for example, even at the center of the screen, even if the C arm 19 performs the swinging motion. 6, based on the angle θ (t) detected by the angle sensor 53, the shift amount of the L image and the R image on the screen of the display 51 as shown in FIGS. Let S (t) be S (t) = α × a (t) = α × L × sinθ (t) where α is a conversion coefficient a (t) between the distance in real space and the distance on the display screen. The vertical distance L from the region of interest to the center axis of the X-ray flux is calculated from the distance from the isocenter to the region of interest, and the L image data and R image data are written to the digital scan converter 49 according to the shift amount S (t). Reading of L image data and R image data from scan converter 49 To control.

The distance L from the isocenter to the region of interest may be determined as the maximum distance while the C-arm 19 is slid, for example, or any other method may be employed.

Therefore, even if the region of interest does not coincide with the isocenter, the position of the region of interest on the screen of the display 51 does not change even if the C-arm 19 swings. It is possible to solve the problem that stereoscopic fluoroscopy becomes difficult due to fluctuations on the screen.

The present invention is not limited to the above embodiment, but can be implemented in various modifications. The present invention is not limited to stereo perspective, but may be practiced in normal perspective (monaural perspective).

[0031]

According to the present invention, there is provided an X-ray diagnostic apparatus in which a C-arm for supporting an X-ray apparatus and an imaging apparatus is slidably provided with a means for periodically swinging the C-arm. It is characterized by the following.

According to the present invention, there is provided an X-ray diagnostic apparatus in which a C-arm for supporting an X-ray apparatus and an imaging device is rotatably provided with respect to a horizontal axis, wherein a means for swinging the C-arm is provided. Features.

According to the present invention, the C-arm swings, that is, reciprocates in the slide rotation or the horizontal axis rotation. When the C-arm reciprocates, the directions of the X-ray apparatus and the imaging apparatus with respect to the subject, that is, the imaging directions change accordingly. When the imaging direction changes, for example, the degree of overlap of blood vessels on the image changes accordingly, so that the observer can easily understand the three-dimensional structure of the target.

[Brief description of the drawings]

FIG. 1 is a side view of a main structure of an X-ray diagnostic apparatus according to an embodiment.

FIG. 2 is a detailed view of the swing mechanism of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a diagram illustrating a problem when the C-arm swings.

FIG. 5 is a block diagram of a main part related to image shift of the X-ray diagnostic apparatus according to the embodiment.

FIG. 6 is an explanatory diagram of parameters handled in image shift.

FIG. 7 is a diagram showing a change in an image shift amount with respect to a displacement of a swinging motion of a C-arm.

FIG. 8 is an explanatory diagram of an image shift on a display screen of a display.

[Explanation of symbols]

 11: caster, 13: stand (stand), 15: horizontal arm, 17: C arm holder, 19: C arm, 21: X-ray device, 23: imaging device, 25: swing mechanism. 27: slider, 29: bearing, 31: spiral spring, 33: friction roller, 35: slide rail, 37: lever.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuhiro Mamada 1385-1 Shimoishigami, Otawara-shi, Tochigi Pref.

Claims (6)

[Claims] 1. An X-ray diagnostic apparatus in which a C-arm supporting an X-ray apparatus and an imaging device is slidably provided with a means for periodically swinging the C-arm. X-ray diagnostic device. 2. The device according to claim 1, wherein the swinging means includes a friction roller that is in contact with the outer peripheral surface of the C-arm, and a spiral spring that drives the friction roller to reciprocate. X-ray diagnostic equipment. 3. The C-arm according to claim 2, wherein the image picked up by the imaging device is displayed at a fixed position on a display screen while the C-arm is swinging. The display position of the image on the display screen is shifted in accordance with the swing displacement of the image.
The X-ray diagnostic apparatus according to claim 1. 4. An X-ray diagnostic apparatus in which a C-arm supporting an X-ray apparatus and an imaging device is provided rotatably with respect to a horizontal axis, the apparatus further comprising: means for swinging the C-arm. X-ray diagnostic device. 5. The device according to claim 4, wherein the swinging means includes a friction roller that is in contact with an outer peripheral surface of the C-arm, and a spiral spring that reciprocally drives the friction roller. X-ray diagnostic equipment. 6. The C-arm so that an image taken by the imaging device is displayed at a fixed position on a display screen while the C-arm is swinging. 5. The display position of the image on the display screen is shifted according to the swing displacement of the image.
The X-ray diagnostic apparatus according to claim 1.