JPH03109084A - Patient positioning apparatus - Google Patents

Abstract

PURPOSE:To perform an X-ray photographing of a diseased part of a patient in a short time and to perform accurately the diseased part of the patient by displaying two images on two image displays of an image displaying device and calculating the three dimensional position of the diseased part of the patient from two designated positions of the diseased part of the patient by means of triangular surveying. CONSTITUTION:A diseased part of a patient is fixed at an original position A of an X-ray tube 1a of an X-ray TV camera input apparatus and the diseased part S of the patient is irradiated with an X-ray. Transmitted X-ray image is detected by means of an X-ray receiving part 1b and an image signal is made into a digital signal by means of a digital image processor 3 and it is displayed on an image displaying part 4. In addition, the second photographing is performed at a position B to which the X-ray tube 1a is moved vertically and lower by means of a supported rail 2 and both it and the first one are displayed on image displays 4a and 4b of an image displaying part 4. In this case, a treating apparatus 8 performs an operation based on an information obtd. by a triangular surveying and determines values on three dimensional position coordinates (Sx, Sy and h) and a bed 6 is moved to a required position based on a command of a bed controller 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a radiation therapy device that treats cancer using radiation such as heavy ion beams, and particularly relates to a radiation therapy device that uses radiation such as heavy ion beams to treat cancer. The present invention relates to a patient positioning device that can accurately detect patients.

[Conventional technology]

FIG. 4 is a partially sectional view showing the configuration of this type of conventional patient positioning device. In the figure, (101) is a positioning
ray tube, (102) is a positioning x & i tube (
(101) is an X-ray film that is placed opposite to the X-ray film that captures the transmitted X-ray image transmitted through the patient; (103) is a patient bed on which the patient is placed; (104) is a therapeutic X-ray that generates therapeutic agent X-rays;
It is a radiation source. Here, the center of the X-ray film (102),
A positioning X-ray tube (101), and a therapeutic X-ray source (
104) are on the same central axis, and the positioning X-ray tube (101) is moved from this central axis during treatment.

The conventional patient positioning device is configured as described above, and in order to position the patient, first, a transmitted X-ray image from the affected area of the patient lying on the patient bed (103) is transferred to the X-ray film (102).
Based on this, the operator interprets the affected area of the patient. Then, the patient bed (1, 03) is manually moved so that the affected area is on the central axis. Then, the patient's affected area after being moved is photographed again on an X-ray film (102) to confirm whether the patient has been moved as planned. If fine adjustment is necessary, repeat the above procedure to determine the position. When positioning is completed, the positioning X-ray tube (101) is removed from the central axis, and the therapeutic X-ray source (104) irradiates the patient's affected area with X-rays.

[Problem to be solved by the invention]

The conventional patient positioning apparatus described above requires a process of photographing and developing a film each time the patient's affected area is positioned with respect to X-rays, and there is a problem in that it takes a long time to position the patient. In addition, information about the patient's affected area can only be obtained as a planar image, and the actual three-dimensional location of the affected area (in the direction of the patient's central axis) cannot be accurately determined. Therefore, heavy particles such as protons are used as therapeutic radiation sources. There has been a problem in that it is not possible to respond to a case where three-dimensional positional accuracy of a patient's affected area is required in a treatment device using ions.

This invention was made in order to solve such problems, and the X1! To provide a patient positioning device capable of performing imaging in a short time and accurately detecting its three-dimensional position (plane position and central axis direction position) to accurately three-dimensionally position an affected part of a patient. With the goal.

[Means to solve the problem]

The patient positioning device according to the present invention includes an X-ray tube that generates X-rays, and a pair of X-ray tubes that generate X-rays by irradiating X-rays from the X-ray source onto the same affected area of a patient from different positions. an X-ray television camera input means having an X-ray light receiving section for detecting a transmitted X-ray image; bed means relatively movable in a vertical direction; digital image processor means for digitizing a transmission X-ray image signal from the X-ray television camera input means; and a digital transmission X-ray image from the digital image processor means. An image display means for displaying a signal and the X-ray television camera input means or the bed means are moved to take images of the same affected area twice from different positions, thereby allowing the image display means to interactively view the affected area. The three-dimensional position of the affected area is determined by a pointing means for pointing and displaying a pointing instruction, and the output of the digital image processor means, and the X-ray television camera input means or the bed means is moved to automatically position the patient. and a control means for controlling the operation.

[For production]

In this invention, the X-ray television camera input means and the digital image processor means detect a transmitted X-ray image from the patient's affected area, digitize it, and display it on the image display means through the control means.

Further, the pointing means specifies and displays the affected part of the patient on the image display means using two images of the same affected part of the patient taken from different vertical positions. Further, the pointing means displays two images on two image displays of the image display means, and the operator sequentially points at the same affected area position on each screen while comparing the two images. Furthermore, by sequentially displaying two images on one image display of the image display means and pointing to a predetermined patient's affected area each time, it becomes possible to indicate the affected area at different imaging positions. Further, the control means calculates the three-dimensional position of the patient's affected area from the two designated patient affected area positions by triangulation.

〔Example〕

FIG. 1 is a partially sectional block diagram showing an embodiment of the present invention. In the figure, (1) is an X-ray television (
This is an X-ray TV camera input device as a camera input means, and includes an X-ray tube (1a) that generates X-rays for imaging and is movable in the vertical direction, and an An image intensifier (hereinafter referred to as "image intensifier") which is paired to constitute the TV camera input device (1) and detects a transmitted X-ray image obtained by irradiating the patient's affected area with X-rays from the X-ray tube (1a). 1. It has an X-ray receiving section (1b) consisting of a (2) is a support rack rail that supports the X-ray tube (1a) vertically movably; rail 3) is connected to the X-ray receiver (1,b);
When the video signal, which is the X-ray transmission image detected in step 1b), is input, it is digitized and, if necessary, corrects image distortion (for example, pincushion distortion, etc.) included in the video signal as a digital image processor means. The digital image processor (4) is an image display section serving as an image display means for displaying the processed video signal as an image, and has image displays (4a) and (4b). (5) is connected to the image display section (4), and points (instructs) and displays an arbitrary position in the image displayed on the image display (4a), (4b);
For example, a pointing device constituted by a tablet, a joystick, a trackball, etc.; (6) a bed as a movable bed means on which a patient is placed and fixed; (a)
is a bed controller that is coupled to this bed (6) and controls its horizontal and vertical movement; (8) is a digital image processor (3), an image display section (4), a pointing device (5), and a bed controller. controller(
7), which controls these devices and calculates the exact three-dimensional coordinates of the patient's affected area using an algorithm similar to triangulation based on the two coordinate values of the patient's affected area position input from the pointing device (5). It is a processing device as a control means that calculates a value and is composed of, for example, an electronic calculation camera.

The operation of the patient positioning device configured as described above will be explained in detail below with reference to FIGS. 2 and 3.

First, three-dimensional coordinate axes (x, y, z) are determined as shown in FIG. The origin O is set on the vertical axis of the initial position A of the X-ray tube (1a) directly below the bed (6) and on the tube surface of the X-ray receiver (1b). Therefore, if Ha is the distance between the initial position A of the X-ray tube (1a) and the tube surface of the X-ray receiver (1b), the coordinates of the initial position A are (0°0, F(a)).

The position where the X-ray tube (la) has been moved vertically downward, that is, in the negative direction of the Z axis by a specified distance l, is defined as B, and B and the X-ray receiver (1b
) If the distance from the pipe surface is Hb, the coordinates of B are (0, O,
Hb), and the images of the patient's affected area S at X-ray tube positions A and B are Sa and Sb, respectively. Here is the X-ray tube position A.

The images in B are shown in FIGS. 3(a) and 3(b), respectively. In the figure, a projected image S of the patient's affected area
The positional coordinates of a and Sb are expressed by a specific point on the affected area (which usually has a wide area) (in the center of the affected area or around the affected area).

Imaging of the patient's affected area is first performed by the X1iTV camera input device W (1
) is fixed at the initial position A of the X-ray tube (1a), the patient's affected area S is irradiated with X-rays, and a transmitted X-ray image is detected by the X-ray receiver (lb). The detected video signal is then digitized by a digital image processor (3), sent to a processing device (8), and then digitized by an image display section (4).
will be displayed. Furthermore, the X-ray tube (1a) is moved vertically downward by the support rack rail (2)! A second image is taken with the WB as far as it has been moved, and is displayed together with the first image on the image displays (4a) and (4b) of the image display section (4). The operator indicates the position of the patient's affected area on the image displays (4a) and (4b) using the pointing device (5). Here, the processing device (8) executes the following calculations based on the above information.

(1) Determine the coordinate values of Sa and Sb. Here, Sa,
Let N and M be the coordinates of Sb in the Y-axis direction.

Furthermore, in FIG. 2, S indicates the projected position of the patient's affected area on the YZ plane.

(2) From Figure 2, triangle (hereinafter abbreviated as Δ) AB
Since C and ΔOMB are similar, point C is the intersection of vector MB and the horizontal line passing through A.

(3) From FIG. 2, since ΔMNS and ΔCAS are similar, if the height of the patient's affected area S from the tube surface of the X-ray receiving section (1b) is h, then the following equation is obtained.

(4) By eliminating the length AC from equations ■ and ■, from the above (5), Ha and Hb are known quantities, and the lengths NO and MN can be easily obtained from Figure 3, so the height of the patient's affected area S is h can be found.

(6) In Figure 2, sy? : If s is the foot of the perpendicular line to the Y axis, then S and y are the Y axis coordinate values of the position of the patient's affected area.

Since ΔNS3/S and ΔNOA are similar, from now, is obtained.

Similarly, if the X-axis coordinate of the patient's affected area S is Sx, it is given as follows. However, as shown in FIG. 3, this is the leg of the perpendicular to the X-axis of the affected area image Sa.

As described above, the calculations (1) to (6) are performed by the processing device (8), and the three-dimensional position coordinate values (Sx, Sy, h) are determined.

After the above processing, the processing device (8) calculates the difference between the desired patient affected part position and the above-mentioned current patient affected part position, and instructs the bed controller (7) to move the bed (6) horizontally and horizontally by the difference amount. Issue a command to move vertically. The bed controller (7) moves the bed (6) to a desired position based on this command.

In this way, the position of the patient's affected area S is adjusted to a predetermined three-dimensional position.

In the above embodiment, an example in which the X-ray TV camera input device is moved in the vertical direction has been described.

By fixing this and moving the bed vertically,
A similar effect can be expected even if multiple images are taken. This eliminates the need for a drive device for the input device of the X-ray TV camera and a support rack rail.

Furthermore, in the above embodiment, an example is shown in which two image displays are used, but two images to be captured can be captured in one display.
A similar effect can be expected even if the images are displayed sequentially on the image display of the stand, and a predetermined patient's affected area is pointed each time to indicate the affected area position at a different vertical imaging position.

〔Effect of the invention〕

As explained above, this invention consists of an X-ray tube that generates X-rays, a pair of this X-ray tube, and an X-ray tube that is obtained by irradiating X-rays from this X-ray source to the same affected area of a patient from different positions. an X-ray television camera input means having an X-ray receiver for detecting a transmitted X-ray image; bed means that is vertically movable; digital image processor means for digitizing a transmission X-ray image signal from the X-ray television camera input means; and a digital transmission X-ray image signal from the digital image processor means. The same affected area can be viewed from two different positions by moving the image display means for displaying the image and the X-ray television camera input means or the bed means.
pointing means for interactively pointing and displaying the affected area on the image display means; and pointing means for interactively pointing and displaying the affected area on the image display means; By providing a John camera input means or a control means for automatically positioning the patient by moving the bed means, images of the affected area of the patient can be obtained in real time, and three-dimensional positioning of the affected area of the patient can be performed accurately and efficiently. It has the effect of being practical.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention in partial cross section, FIGS. 2 and 3 are explanatory diagrams for explaining the operation of the embodiment of FIG. 1, and FIG. 4 is a conventional block diagram. 1 is a configuration diagram showing a patient positioning device of FIG. In the figure, (1) is the X1iTV camera input device, (1
a) is an Xm tube, (1b) is an X-ray receiver, (3) is a digital image processor, (4) is an image display unit, (5)
is a pointing device, (6) is a bed, (7) is a bed controller, and (8) is a processing device. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] An X-ray tube that generates X-rays and an X-ray system that is paired with this X-ray tube and detects transmitted X-ray images obtained by irradiating the same affected area of the patient with X-rays from different positions. X-ray television camera input means having a light receiving section; and a bed on which the patient is placed, which is not only movable horizontally but also vertically movable relative to the X-ray television camera input means. means, digital image processor means for digitizing the transmitted X-ray image signal from the X-ray television camera input means, image display means for displaying the digital transmitted X-ray image signal from the digital image processor means; pointing means for moving the X-ray television camera input means or the bed means to image the same affected area twice from different positions, thereby interactively pointing and displaying the affected area on the image display means; and control means for determining the three-dimensional position of the affected area based on the output of the digital image processor means, moving the X-ray television camera input means or the bed means, and automatically positioning the patient. A patient positioning device characterized by: