JP2006038974A - Medical cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical cassette which has the increased degree of freedom in design of the outside dimension, and also is constituted without using lead. <P>SOLUTION: The medical cassette 1 incorporates a recording medium 10 on which an image transmitted through an object can be recorded, and at least one member 12 located opposite to the object with reference to the recording medium is constituted of a composite material containing one or more kinds of heavy metal having a specific gravity of ≥4g/cm<SP>3</SP>excluding lead. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medical cassette including a recording medium capable of recording an image transmitted through a subject.

  In the medical field, lead foil (sheet) has been widely used for shielding X-rays and radiation. This lead material is a preferable material from the viewpoint of the shielding function of X-rays and radiation (see Patent Document 1 below), but is not a preferable material from the viewpoint of environmental impact, and its use is severely restricted in general parts and general equipment. Therefore, “managed disposal” is also required for lead-containing medical parts, medical devices, etc., and the search for lead substitute materials is urgent, especially in the medical device field.

  Moreover, the said lead sheet is generally affixed and used for each member of the periphery of a recording medium (for example, refer the following patent document 2). FIG. 5 shows a conventional example of a cassette for medical X-ray imaging. The conventional medical X-ray imaging cassette shown in FIG. 5 includes a front plate 101 on the side irradiated with X-rays, a back plate 102 on the opposite side, and a frame 103 on the outer peripheral side surface. A recording medium plate 100 made of a sheet film for recording an X-ray image, a stimulable phosphor plate, or the like is accommodated. A lead sheet 104 is disposed on the inner surface of the back plate 102 in order to eliminate the influence of backscattered rays at the time of photographing, and the distance between the recording medium plate 100 and the surface of the lead sheet 104 is uniform. Has been.

  For example, this lead sheet 104 is affixed to the back plate 102 of the cassette with a double-sided tape or the like. However, if air bubbles partially occur without being evenly affixed, it will affect the image, so it will be affixed again. . At this time, since the lead sheet once peeled is no longer maintained in a flat state, it cannot be used for reattachment, and a new lead sheet has to be used. As a result, a lead sheet to be discarded is generated.

In addition, since the double-sided tape itself has a predetermined thickness, in order to make the cassette external dimensions the same, it is necessary to absorb by the thickness of the back plate or the recording medium itself, and there is a problem with strength, for example, insufficient rigidity. Design considerations were necessary.
JP 59-17198 Japanese Patent Application Laid-Open No. 07-20591

  The present invention has been made in view of the above-described problems of the prior art, and it is an object of the present invention to provide a medical cassette that can be configured without using lead while increasing the degree of freedom in designing a cassette external dimension.

In order to achieve the above object, a medical cassette according to the present invention is a medical cassette containing a recording medium capable of recording an image transmitted through a subject, and is located on the side opposite to the subject of the recording medium of the medical cassette. The at least one member is made of a composite material containing one or more heavy metals having a specific gravity of 4 g / cm ³ or more excluding lead.

According to this medical cassette, the member on the side opposite to the subject with respect to the recording medium of the medical cassette is composed of a composite material containing one or more heavy metals having a specific gravity of 4 g / cm ³ or more excluding lead. Since the double-sided tape to which the lead sheet is attached is not necessary, the degree of freedom in designing the cassette outer dimensions can be increased and the structure can be configured without using lead. Moreover, it is not necessary to attach the lead sheet itself, which is preferable because the man-hour for assembling the cassette is shortened. The composite material is preferably a material obtained by dispersing or kneading a heavy metal having a specific gravity of 4 g / cm ³ or more excluding lead in a powder state.

  The medical cassette includes a front member disposed on the subject side, and a back member that forms an internal space containing the recording medium together with the front member, and the back member is formed of the composite material. It is preferable.

  Moreover, it is preferable that the said back member has a frame member in the outer periphery, and the said frame member is integrally shape | molded with the said back member by the said composite material. As a result, the degree of freedom in designing the inside dimensions of the cassette is increased, and the number of man-hours for assembling the cassette is shortened.

  The recording medium may be a film, but may be a flat panel detector (FPD) or a stimulable phosphor.

  According to the medical cassette of the present invention, it is possible to increase the degree of design freedom of the cassette outer dimension and to configure without using lead.

  The best mode for carrying out the present invention will be described below with reference to the drawings. First, the X-ray shielding property of a heavy metal other than lead and the X-ray shielding property of a composite material that is preferably applied to a medical cassette using the heavy metal will be described.

  FIG. 1 is a diagram showing the X-ray transmittance (tube voltage 100 kVp) of various metals in relation to the thickness. FIG. 2 is a diagram showing a change in thickness of the X-ray transmittance (tube voltage 90 kVp) of the composite material containing tungsten according to the present embodiment. FIG. 2 also shows the case of lead for comparison.

  As shown in FIG. 1, the X-ray shielding rate (attenuation rate) is higher than that of conventional lead (Pb) if the metal has a high specific gravity such as tungsten (W). It is possible to make the thickness thin or equivalent. In the case of a metal having a specific gravity lower than that of lead, such as copper (Cu) or molybdenum (Mo), it is thicker than lead.

  The composite material shown in FIG. 2 is obtained by dispersing tungsten powder in a resin material and setting the total specific gravity to, for example, 3.5. This composite material is obtained by dispersing a powder of tungsten having a thickness of 0.1 mm in a resin material. From FIG. 2, the thickness of the composite material satisfying the lead equivalent of 0.13 mm is 0.5 mm. By using a composite material in which this tungsten powder is dispersed in a resin material, lead can be used and an X-ray shielding / backscattering prevention function equivalent to that of lead can be obtained. Therefore, by forming a cassette using such a composite material, an X-ray shielding / backscattering prevention effect equivalent to that of lead can be obtained without using lead.

Next, the medical cassette according to the present embodiment will be described with reference to the drawings.
FIG. 3 is a side sectional view schematically showing the medical cassette according to the present embodiment.

  The medical cassette 1 shown in FIG. 3 has a rectangular planar front member 11 that is located on the subject side and is irradiated with X-rays through the subject, and a rectangular planar back member 12a that is positioned to face the front member 11. And a frame member 12b that forms the outer peripheral side surface of the cassette 1 and an integrated member 12 configured integrally. In an internal space 13 formed by the front member 11 and the integral member 12, a recording medium plate 10 made of a stimulable phosphor and recording an X-ray image transmitted through the subject is accommodated. The integral member 12 has a U-shaped cross section in which the frame member 12b is substantially upright with respect to the back member 12a.

The integral member 12 is composed of a composite material including one or more heavy metals having a specific gravity of 4 g / cm ³ or more excluding lead. For example, a tungsten powder having a specific gravity of 19.3 g / cm ³ is dispersed in a resin material. It can be manufactured by molding with a composite material having a specific gravity of, for example, 3.5. Specifically, a high specific gravity resin of Kanebo Synthetic Co., Ltd. in which tungsten powder is dispersed in a polyamide resin can be used as the composite material in which such heavy metals are dispersed.

According to the medical cassette 1 of FIG. 3, the back member 12a and the frame member 12b are made of a composite material containing heavy metals having a specific gravity of 4 g / cm ³ or more excluding lead, so that the X-ray shielding characteristics can be obtained. Since the member 12b itself has, the conventional lead sheet and the double-sided tape for pasting become unnecessary. Accordingly, the cassette 1 can be configured to be thin, and the degree of freedom in design corresponding to the thickness of the lead sheet and the double-sided tape is increased, which is preferable. In addition, it is not necessary to perform the pasting of the conventional lead sheet itself, which is preferable because the man-hour for assembling the cassette is shortened.

  Further, when the cassette is disposed of, since the cassette 1 does not use lead, no special disposal management is required. Further, it is preferable that the back member 12a and the frame member 12b are integrally formed as an integral member 12, which increases the degree of freedom in designing the internal dimensions and shortens the number of assembly operations for the cassette.

In the case where the medical cassette is a type having a buffer member or a member that functions when reading the recording medium plate 10 between the back member 12a and the recording medium plate 10, the buffer member or the functional member at the time of reading has a specific gravity excluding lead. It can be comprised from the composite material containing 4 g / cm < ³ > or more heavy metal.

  Next, a medical cassette containing an X-ray imaging film will be described with reference to FIG. FIG. 4 is a side sectional view schematically showing a medical cassette containing an X-ray film.

  The medical cassette 2 shown in FIG. 4 has a rectangular planar front member 21 that is located on the subject side and is irradiated with X-rays through the subject, and a rectangular planar back member 22 that is positioned to face the front member 21. And comprising. The front member 21 is configured to be rotatable relative to the back member 22 around a rotating portion 26.

  In an internal space formed by the front member 21 and the back member 22, a rectangular X-ray imaging film 20 for recording an X-ray image transmitted through the subject is accommodated. An elastic member 24 is accommodated as a cushion material in a space formed by the back member 22 and the frame member 23, and an intensifying screen 25 is placed on the elastic member 24. The intensifying screen 25 and the front member An X-ray imaging film 20 is disposed between the X-ray imaging film 21 and the X-ray imaging film 21.

The elastic member 24 includes one or more heavy metals having a specific gravity of 4 g / cm ³ or more excluding lead in a foamed material such as a foamed resin. Can do.

  Before performing X-ray imaging using the medical cassette 2, the front member 21 is rotated about the rotating portion 26 to be opened, and the intensifying screen 25 and the elastic member 24 on the back member 22 side are opened. After the unphotographed X-ray film 20 is set, the front member 21 is rotated to close the inside. At this time, the elastic member 24 functions as a cushion, and the intensifying screen 25 and the X-ray film are taken. The film 20 can be uniformly adhered.

According to the medical cassette 2 of FIG. 4, the elastic member 24 for uniformly bonding the intensifying screen 25 and the X-ray imaging film 20 contains a heavy metal having a specific gravity of 4 g / cm ³ or more excluding lead. An X-ray shielding effect can be obtained as compared with the prior art. For this reason, the cassette 2 can be configured thinner than the conventional one. Further, when the cassette is disposed of, since the cassette 2 does not use lead, no special disposal management is required.

  As described above, the best mode for carrying out the present invention has been described. However, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of the present invention. For example, a flat panel detector (FPD) may be accommodated in the internal space 13 instead of the recording medium plate 10 of FIG. 3 using the cassette structure of FIG.

In the medical cassette 1 shown in FIG. 3, the back member 12a and the frame member 12b are integrally formed. However, they may be formed of separate members. In this case, the back member has a specific gravity of 4 g / cm ³ or more excluding lead. Further, the frame member may be composed of the same composite material.

In addition to tungsten, for example, molybdenum or copper may be used as the heavy metal having a specific gravity of 4 g / cm ³ or more excluding lead.

It is a figure which shows the X-ray transmittance (tube voltage of 100 kVp) of various metals in relation to thickness. It is a figure which shows the change by the thickness of the X-ray transmittance (tube voltage 90kVp) of the composite material containing tungsten in this Embodiment. It is a sectional side view which shows roughly the medical cassette by this Embodiment. It is a sectional side view showing roughly another medical cassette by this embodiment. It is side sectional drawing which shows schematically the prior art example of the cassette of medical X-ray imaging.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Medical cassette 2 Medical cassette 10 Recording medium plate (recording medium)
DESCRIPTION OF SYMBOLS 11 Front member 12 Integrated member 12a Back member 12b Frame member 13 Internal space 19 Specific gravity 20 Film for X-ray photography 21 Front member 22 Back member 23 Frame member 24 Elastic member 25 Intensifying screen

Claims (5)

A medical cassette containing a recording medium capable of recording an image transmitted through a subject,
The medical cassette is characterized in that at least one member on the side opposite to the subject with respect to the recording medium of the medical cassette is made of a composite material containing one or more heavy metals having a specific gravity of 4 g / cm ³ or more excluding lead. Cassette. A front member disposed on the subject side; and a back member that forms an internal space containing the recording medium together with the front member;
The medical cassette according to claim 1, wherein the back member is formed of the composite material.   The medical cassette according to claim 2, wherein the back member has a frame member on an outer periphery thereof, and the frame member is integrally formed with the back member by the composite material.   The medical cassette according to claim 1, wherein the recording medium is a flat panel detector (FPD). The medical cassette according to claim 1, wherein the recording medium is a stimulable phosphor.

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