JPH0272490A - Electronic density converting type digitizer input mechanism - Google Patents

Abstract

PURPOSE:To easily obtain an electronic matrix by converting a signal outputted from a tablet added with a pen-shaped optical sensor into an electronic density by means of a film density electronic density converting mechanism, and executing a mean value processing. CONSTITUTION:A data accumulating mechanism 7, which accumulates the instantaneous value of the electronic density value determined by the designation of a film density electronic density conversion designating mechanism 5 from the output signal of an A/D converter 3 for a constant time, a mean value display mechanism 8, which displays the mean value during a period from the data accumulation up to an arbitrary elapsed time, and a mechanism 11, which stores the plural mean values as an intra-contour electronic density in a prescribed tracing range, are provided. By tracing the arbitrary shape of a CT picture film with the use of a tablet 1A added with the pen-shaped optical sensor, the mean electronic density in the arbitrary shape is known, and by referring to a standard deviated value and a most frequently emerging value, the optimum electronic density is determined. Thus, the electronic density matrix can be obtained for the video on the film by a simple method.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electron density conversion type digitizer input mechanism,
In particular, the present invention relates to a CT image electron density conversion type digitizer input mechanism in a radiation therapy planning system.

[Conventional technology]

Conventionally, this type of electron density conversion mechanism converts digital values directly into electron density by directly inputting CT images, magnetic tape, flexible disk media, or online into a radiation treatment planning system. Alternatively, there is an indirect method of manually tracing both CT images that have become a film and manually inputting the electron density value for each organ contour, or an indirect method of manually tracing the film and inputting the electron density value for each organ contour. This was done by semi-indirect means such as conversion based on a predetermined conversion formula.

[Problem to be solved by the invention]

The conventional electron density conversion mechanism described above converts both CT images into electron density to obtain basic data for calculating the radiation distribution inside the body.However, in the digital CT image direct conversion mechanism, the CT It has the disadvantage that it requires multiple types of conversion programs due to the problem of different image formats. In addition, manual indirect input means does not perform electron density conversion and is directly specified manually, which has a drawback in terms of accuracy. Furthermore, the method of electrically tracing the film requires the installation of a separate tracing device, which has drawbacks in terms of setup space, installation cost, and conversion accuracy.

[Means to solve the problem]

The electron density conversion type digitizer input mechanism of the present invention is a backlight type digitizer input mechanism that includes a tablet with a pen-shaped light sensor, an A/D converter for AD converting the light sensor output of the tablet, and a film density/electronic a density conversion designation mechanism; an instantaneous value display mechanism that displays moment by moment the instantaneous value of an electron density value determined from the output signal of the A/D converter by designation of the film density electron density conversion designation mechanism; and the instantaneous value. A data storage mechanism that stores data for a certain period of time, an average value display mechanism that displays the average value from the time the data is stored to an arbitrary elapsed time, a mechanism that displays the standard deviation value, and a maximum occurrence value that displays the most frequently occurring value. A value display mechanism, a mechanism for storing a plurality of the average values as contour electron densities in a predetermined tracing range, and an electron density table mechanism for finally calculating an entire electron density table for one original image. Structure 9 [Example] Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

Ben 1 is supplied to optical sensor 2 to form a Ben-shaped optical sensor-attached tablet IA. Ben 1, equipped with a light sensor, arbitrarily traces within a certain contour on a CT screen film photograph placed on a backlit digitizer input mechanism. The signal output from the pen-shaped optical sensor-equipped tablet IA is converted from an optical signal to a digital signal by the A/D converter 3. A CCD element is generally incorporated into the tablet IA with a pen-shaped optical sensor, and the intensity of the output signal changes depending on the light intensity. Both CT image film images are C'r
Since the image is filmed according to the difference in density between black and white, the difference in density of the film can be read as a difference in luminous intensity with a CCD element and compared with the original CT value.

The keyboard 4 accesses the film density electron density conversion designation mechanism 5 in order to define conversion rules for converting the level of the output value of the A/D converter 2 into an electron density proportional to the radiation absorption density.

When the optical sensor-equipped pen 1 traces within a certain outline on a CT image film photograph, the electron density at that point is displayed on the instantaneous value display mechanism 6 as an instantaneous value.

When Ben 1 traces an arbitrary position, the data storage mechanism 7 stores the instantaneous value at any time.The size of the data storage mechanism 7 can be changed depending on the system mechanism, but the tracing range is 50 to 100 points. It is done to have it as a limit. As long as this limit is not exceeded, the input signal is stored in the data storage mechanism 9. The output of the A/D converter 3 is converted into electron density by the film density electron density conversion mechanism 5, and all the data collected by the instantaneous value display mechanism 6 and data storage mechanism 7 is data after conversion into electron density. . An arbitrary trace within a certain area is continued, and when a representative trace within the dome area is completed, the average value display mechanism 8 up to an arbitrary elapsed time displays the average value, and the standard deviation value display mechanism 9 displays the standard deviation value, and the most frequently occurring value display mechanism 10 displays the most frequently occurring value within the traced range. The CT image film to be traced is divided into a plurality of contours in advance, but when the electron density inside the contour is determined as one representative value, the average value indicated by the average value display mechanism 8 is taken, but the standard deviation Adjust the average value arbitrarily from the keyboard using the standard deviation value shown by the display mechanism 9 as a reference, or
The representative value is determined by arbitrarily modifying the average value with reference to the most frequently occurring value shown by the most frequently occurring value table and display mechanism 10. The electron density is determined for each of a plurality of contours, and the CT image film photograph is stored in the contour electron density storage mechanism 11, and the electron density is determined on a predetermined matrix and defined in the electron density table 12. Generally, the contour boundary line and the electron density matrix defined in a lattice do not match, so when allocating the electric density to each lattice of the electron density matrix, multiple contour data are calculated at the boundary value and the electron density is calculated. decide.

As shown in FIG. 2, the CT image film photograph 20 has already been taken inside the body! Assuming that the contours 21 to 25 of the device are traced, the pen 1 with the optical sensor traces the vicinity of the body surface 26 and obtains the average electron density in the vicinity of the body surface 26. Similarly, the contour portion 23, the contour portion 24, and the contour portion 25 are each traced in a zigzag manner using a bevel 1 equipped with an optical sensor to obtain an average electron density.

FIG. 3 is an electron density diagram obtained by determining the electron density within each contour and then allocating the electron density to lattice points on a predetermined electron density matrix. The magnitude of electron density is expressed by the density difference between black and white, and the electron density is determined on the calculation matrix within the range handled by calculation.

〔Effect of the invention〕

As explained above, the present invention traces an arbitrary shape of a CT image film photograph using a pen-shaped tablet with a light sensor, thereby knowing the average electron density within an arbitrary shape, and determining the standard deviation value and the maximum number of occurrences. This method provides a means for determining the optimum electron density by referring to the values, and has the effect that an electron density matrix can be easily obtained for an image on a film.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a trace situation diagram, and FIG. 3 is an electron density matrix diagram. ■...Pen, 2...Light sensor, 3...
...AXD Transformer, 4... Keychain, 5
...Film density electron density conversion specification mechanism, 6.
...Momentary value display mechanism, 7...Data accumulation mechanism, 8...Average value indication mechanism, 9...Standard deviation value specification mechanism, 10... Most frequently occurring value display mechanism,
11... Contour electron density storage mechanism, 12...
...Electron density table, 20...Body contour, 21
~25...contour, 26...near the body surface.

Claims (1)

[Claims] In the backlight type digitizer input mechanism, a tablet with a pen-shaped light sensor, an A/D converter for AD converting the light sensor output of the tablet, a film density/electron density conversion specification mechanism, and the A/D converter an instantaneous value display mechanism that displays moment by moment the instantaneous value of the electron density value determined by the specification of the film density electron density conversion specification mechanism from the output signal of the film density electron density conversion specification mechanism; a data storage mechanism that stores the instantaneous value for a certain period of time; an average value display mechanism that displays the average value from the time it is stored until an arbitrary elapsed time, a mechanism that displays the standard deviation value, a most frequently occurring value display mechanism that displays the most frequently occurring value, and a predetermined trace of the average value. An electron density conversion type digitizer input comprising a mechanism for storing a plurality of electron densities within the contour of a range, and an electron density table mechanism for finally calculating an entire electron density table for one original image. mechanism.