SU1679172A1 - Scale measurement instrument - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the natural size and depth of projection enlarged images on a film, in particular, when conducting x-ray diagnostic studies. The purpose of the invention is to increase productivity and enhance functionality. The device is a transparent rectangular 5-8 plate with a dividing line 3, which divides it into parts 1 and 2. and a slider 4, which can be moved in the perpendicular line 3 direction. Part 1 of the plate contains a natural scale 5, a scale of 6 magnification factors, a scale grid 7 and an index of 14. In part 2 of the plate an additional scale of 12 factors of magnification is placed, a scale of 9 focal lengths, a grid of 11 coefficients of projection magnification, a grid of 10 parallel direct and zero line 13. The width of the slider 4 is equal to the width of each part of 1 or 2 plates. On the zero line 13 in part 2 of the plate, by moving the slide 4, initial conditions are established on the device, and according to index 14 in part 1 of the plate, the true dimensions of the object under test are read. 1 il. (L S o yu

Description

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The invention relates to a measurement technique and can be used to measure the natural size and depth of projection enlarged images on a film, in particular, when conducting x-ray diagnostic medical examinations.

The aim of the invention is to improve the performance when measuring the overall size of projected enlarged images on an X-ray film and expanding the functionality.

The drawing shows a General view of the device.

The device contains a plate of transparent material divided into two equal upper 1 and lower 2 parts by separating line 3. Slider 4 is movably mounted on the plate, the width of which is equal to the width of part 1 or 2 of the plate. Parallel to line 3, a scale of 5 natural scale is applied along the edge of the upper part 1 of the plate, and perpendicular to it is a scale of 6 coefficients of the projection4

increase. A scale grid 7 is applied on the upper part of the plate 1. The divisions 8 of the grid 7 are constructed as a continuation of the scale divisions 5 and extend to the line 3 of the section of the plate in proportion to the coefficients of the projection magnification. The lower part 2 of the plate is a calculator, formed by a scale of 9 focal lengths with divisions 10, applied parallel to line 3 along the edge of part 2 of the plate, and a grid of 11 projection magnification coefficients, constructed using the formula

K - L - K - F - p

where K is the projection magnification factor;

F is the focal distance;

I is the distance from the object to the x-ray film.

On the lower part 2 of the plate perpendicular to the scale of the 9 focal lengths there is a scale of 12 projection magnification factors, identical to the scale of b. The zero line 13 on the slider 4 is its lower edge, and the index 14 is the upper edge of the slider 4.

The instrument is used as follows.

Let an X-ray image (tomogram) be obtained with the following initial parameters: the focal distance F 1000 mm (it is always known, as noted on the stand of the radiator); object distance

to an x-ray film I 200 mm (this distance is the sum of the measured variable distance from the table deck to the level of the object under study and constant

distance from the deck of the table to the film).

With the indicated parameters, the zero line 13 of the slider 4 is aligned on the lower part 2 of the plate (calculator) with the point at which the division 10 of the scale 9 intersects.

0 focal length, corresponding to 1000 mm, and one of the curves of the grid 11, built for I 200 mm. In this case, index 14 of the slider 4, located on the upper part 1 of the plate, informatively shows the coefficient of projection magnification on a scale of 6 and a place on the scale grid 7, which must be superimposed on an object on an x-ray film in order to obtain the true size of this object on the scale five

0 natural scale. After that, the upper part 1 of the plate is superimposed on the object to be measured so that index 14 of the slider 4 intersects it, and on the scale of 5 the true size of the projection magnification of the object is read.

With the help of the described ruler, it is possible to measure the depth of the object under investigation from a test object when its true dimensions and focal length are known. Let F 500 mm, and the true size of the test object is 10 mm. Put the upper part 1 of the plate on the image of the test object, placing the last fs 5e divisions 8 scale

5 grids 7.1 corresponding to a scale of 5 natural scale 10 mm. After that, move the plate so that the object fits into the same 10 mm, but projected enlarged. In this position move

0 slider 4, combining its index 14 with the image of the object. In this case, the point of intersection of the zero line 13 of the slider 4 with the division of 10 scale 9 focal lengths, which is 500 mm, and the corresponding curve

5 grids 11 on the lower part 2 of the plate (calculator) will show the distance from the object to the x-ray film. With these parameters, it is 200 mm. Know the distance from the deck to the x-ray film, which

0 is constant, it is possible to determine the true occurrence of a test object by subtracting the deca-film distance from the film-object object. For example, at a decay distance of about 90 mm, the true depth of the test object of the raan is 110 mm.

In this way; the invention makes it possible to objectify x-ray studies, i.e. measure the true dimensions on images and tomograms of objects, like,

for example, the Turkish saddle (structures of the bones of the skull), large vessels, lacunae, bronchi, and, if necessary, determine the depth of the test object. As a result, it is possible to compare the parameters obtained in different medical institutions.

Claims (1)

Claims An apparatus for scale measurements, comprising a rectangular plate of transparent material, located along its mutually perpendicular edges, respectively, a natural scale and a scale of magnification factors, a scale grid applied to the plate, dividing which comes from a natural scale, and mounted on the plate with the possibility moving along a scale of magnification factors, a slider with a zero line and an index different in that. that, in order to increase the performance when measuring the natural dimensions of projected enlarged images on X-ray film and expanding the functionality, a dividing line is applied to the plate along the natural scale, dividing it into two equal parts, the slider width is equal to the width of each of the plate parts, as zero the lines and the index are selected parallel dividing lines, the corresponding edges of the slider, a natural scale, a scale of magnification factors and a large-scale grid are located in a part of the plan slime, which is placed in the index, and the other part of the additional scale plate coated magnification factors, similar to the main and continuation scale, the focal length scale, located perpendicular to the additional scale of the projection zoom factors, the grid projection magnification coefficients and a grid of parallel straight lines, the division of which is based on the focal distance scale.