JP2002000705A - Electron beam radiating apparatus of medical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam radiating apparatus capable of simultaneous both-sided irradiation even in the case of disposing two electron beam accelerators on both right and left sides of a conveyer with the conveyer interposed between them without breakage of the accelerators. SOLUTION: In this electron beam radiating method for radiating high-energy electron beams to a medical apparatus the interior of which is filled with a liquid therein, this electron beam radiating apparatus includes a radiation conveyer for transporting the medical apparatus to an electron beam radiating area, and a pair of electron beam accelerators disposed on both sides of the radiation conveyer. The accelerators are inclined at a designated angle on the upstream side or the downstream side in the conveyer transport direction to make an acute angle to the center line of the conveyer, and retreated from the electron beam radiating areas of the mutual opposite side accelerators so that the transmitted electron beams not absorbed in the medical apparatus do not collide with the opposite side accelerators.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam irradiation apparatus for medical equipment which achieves an intended purpose such as sterilization while irradiating a medical equipment such as an infusion bag with a high energy electron beam. The present invention relates to an electron beam irradiation method and an apparatus for achieving an intended purpose such as sterilization while simultaneously irradiating electron beams from both sides.

[0002]

2. Description of the Related Art Conventionally, high-pressure steam sterilization, ethylene oxide gas sterilization, γ-ray sterilization, electron beam irradiation sterilization, and the like have been used for sterilizing medical devices such as infusion bags. In particular, in the case of sterilization treatment of medical equipment and the like, as a matter of course, it is necessary to sufficiently sterilize and use, and as a sterilization method, an electron beam irradiation sterilizer has been developed.

In such an apparatus, medical devices and the like can be sterilized by increasing the accelerating voltage of an electron beam, and there is no concern about heat resistance and residual toxicity of an irradiation object, and further, sterilization processing time is not long. Processing can be performed in a short time, and when the power is turned off, irradiation can be stopped instantaneously, which has advantages such as high environmental safety and low cost. Further, the difference from γ-ray irradiation is that it is said that material deterioration is small. For this reason, there is an advantage that the range of material selection is wide.

However, the drawback of electron beam irradiation is that, unlike γ-ray irradiation, the penetrating power is small, and it is said that the transmission distance depends on the product of the density and thickness of the material to be irradiated. Therefore, in the case of thick and high-density medical devices, there has been a problem that the dose distribution (the ratio between the maximum dose and the minimum dose) between each part in one product becomes large at the time of electron beam irradiation. .

More specifically, if the irradiation standard is adjusted to the maximum dose site, sterilization at the minimum dose site becomes insufficient, and if the irradiation standard is adjusted to the minimum dose site, medical devices such as infusion bags are generally organic. Because it is made of a material, it is over-irradiated at the position of the maximum dose, which may cause deterioration or coloring of the material.

For this reason, in order to compensate for the shortage of transmission power due to irradiation, a double-sided irradiation method in which electron beams are irradiated from both front and back sides has been considered. A double-sided irradiation method is conceivable in which the electron beam irradiation device (hereinafter, referred to as an electron beam accelerator) is displaced and arranged on both sides of a conveyor for irradiating an object, and irradiates electron beams from both front and back sides of the conveyor. However, in the case of irradiating an electron beam across a conveyor, the electron beam accelerators 5A and 5B on the opposite side are directly faced each time the irradiation object passes, and the accelerators 5B and 5A on the opposite side are destroyed. Occurs.

In order to solve such a problem, the two electron beam accelerators are arranged on both left and right sides of the conveyor 2 with the conveyer 2 interposed therebetween.
A technique of displacing the conveyor upstream and downstream at a position shifted back and forth is being studied. However, when such a method is adopted, the following problems occur particularly in an infusion bag in which a liquid is filled.

[0008]

That is, since the high-energy electron beam also has a large thermal energy, the liquid inside the object to be irradiated is heated by the first electron beam irradiation on the front surface side and the convection occurs. The liquid in the heated, in other words, sterilized front-side portion and the liquid in the non-sterilized rear-side portion are mixed, or the heated liquid in the sterilized portion moves upward, and then the second liquid from the rear-side portion. Irradiation with an electron beam by the device described above may result in a non-sterilized portion in the liquid portion located on the opposite side.

The present invention has been made in view of the problems of the prior art, and
It is an object of the present invention to provide an electron beam irradiation apparatus capable of simultaneous irradiation on both sides without damaging each other even when two electron beam accelerators are disposed on the left and right sides of the conveyor. Another object of the present invention is to provide an apparatus for effectively sterilizing a solid-filled object filled with a liquid, such as an infusion bag used for infusion.

[0010]

According to the first aspect of the present invention,
In an electron beam irradiation apparatus configured to irradiate a high-energy electron beam to a medical device filled with a liquid, an irradiation conveyor for transferring the medical device to an electron beam irradiation area, and disposed on both sides of the irradiation conveyor And a pair of electron beam accelerators, the accelerators are inclined at a predetermined angle toward the upstream side or the downstream side in the conveyor conveyance direction so as to be at an acute angle with respect to the center line of the conveyor, and are absorbed by the medical device. In this case, the transmitted electron beams are retracted from the electron beam irradiation area of the facing accelerator so that the transmitted electron beams do not collide with the facing accelerator.

According to this invention, even if the pair of accelerators is disposed at a position where simultaneous irradiation on both sides is possible with the irradiation conveyor interposed therebetween, the accelerators are not in a direction orthogonal to the conveyor but in the upstream direction in the conveyor conveyance direction. Because the electron beam is irradiated from the inclined direction toward the electron beam irradiation area from the side (or from the downstream side), the electron beam transmitted without being absorbed by the medical device may collide with the facing accelerator. Not
It can be retracted from the electron beam irradiation area of the accelerators facing each other.

Therefore, even when two electron beam accelerators are simultaneously irradiated on both sides with a conveyor interposed therebetween, the two devices are not damaged, and the irradiation object filled with liquid, such as an infusion bag used for infusion injection, is used. Even if there is, it can be sterilized effectively. Further, in the electron beam irradiation apparatus, it is preferable that the tilt angle and the arrangement position of the pair of electron beam accelerators are symmetric.

According to this invention, rotating the object to be irradiated in the irradiation area while the object is being conveyed on the irradiation conveyor requires a rotation mechanism to be attached to the conveyor, which makes the structure extremely complicated. Since it is only necessary to simultaneously irradiate both surfaces in the electron beam irradiation area without rotating the medical device, it is possible to sterilize effectively without complicating the conveyor mechanism and the transport mechanism.

According to a second aspect of the present invention, the electron beam emitted from the irradiation window on the front side of the scanning horn of the accelerator converges to an electron beam that does not widen, for example, a parallel electron beam or the center side. It is an electron beam.

According to the invention, since the electron beam is not widened and emitted, it is possible to reduce the decrease in the electron beam in proportion to the distance. Also, in the case where the accelerator is arranged at a predetermined angle with respect to the conveyor conveyance direction, It is also possible to accurately irradiate the medical device to be irradiated, and the electron beam protruding from the irradiated portion does not erroneously expose the facing accelerator or the like, and furthermore, it is not necessary to install the device over a wide area such as a beam stop.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely examples. Only.

In the present embodiment, an infusion bag used for drip injection or the like is used as an object to be sterilized. Such infusion bags are generally formed of organic materials,
It has a flexible wall and a non-constant volume, and has a body filled with a chemical solution, seals at both ends thereof, and openings and suspensions located at the respective ends. Such an infusion bag has various sizes depending on the application. However, a large infusion bag may have an inner volume of 1 liter or more and a short axis width 1 (center portion) of the container body of 60 mm or more. Further, air may be mixed into such an infusion bag in order to make it easy to see the residual liquid amount, and the air amount is usually 30 to 100 ml or more.

FIG. 2 shows an electron beam accelerator applied to the present invention. The deflecting magnet plates 19A and 19A are provided so that the electron beam emitted from the irradiation window on the front side of the scanning horn becomes a parallel electron beam without widening. 19B is used. Such an electron beam has been disclosed by the present applicant as a prior application in Japanese Patent Application No. 11-14206.
No. 3, but still unknown. In the figure, reference numeral 5 denotes an electron beam accelerator for generating a high-energy electron beam (electron beam). The electron beam generator 50 includes, for example, an electron gun for emitting an electron beam, and an electron beam emitted from the electron gun. An accelerating tube for accelerating the electron beam to have a predetermined energy, and a klystron for supplying microwave energy to the accelerating tube for accelerating the electron beam.

The accelerated electron beam (electron beam) is guided to a converging electromagnet (beam stop lens) 14 through a cylindrical beam guide tube 13, and converges the electron beam in the diameter direction, in other words, the beam To reduce the diameter and increase the energy density.

The converging electron beam, which has been densified by the converging electromagnet 14, is introduced into an irradiation horn 16 in the shape of a truncated flat pyramid which is expanded in the beam scanning direction as it advances toward the front.

The irradiation horn 16 has a scanning electromagnet 15
Has a slit-shaped irradiation window 17 on the front surface,
7 is sealed with an electron beam transmitting film such as a titanium film, and the inside is maintained in a vacuum space.

The convergent beam introduced into the irradiation horn 16 is deflected and scanned by the scanning electromagnet 15 at a predetermined deflection angle and a predetermined deflection frequency (reciprocating deflection frequency). In order to control the scanning speed, in other words, the angular velocity, a control signal for controlling the voltage applied to the scanning electromagnet 15 is fetched from the scanning electromagnet controller 10, and the scanning electron beam deflected and scanned while controlling the angular velocity. Line 8 is an irradiation horn 16 in the shape of a flat truncated pyramid.
A predetermined sterilization operation is performed by irradiating the entire length of the irradiation target 1 while scanning in the base line direction of the irradiation target (infusion bag) 1 through the inside and the irradiation window 17. Note that, on both sides of the irradiation conveyor 2 that conveys the irradiation target 1, fixed guide rails 4 having a function of preventing the irradiation target 1 placed on the conveyor 2 from falling are provided.

The scanning angle of the electron beam in such an apparatus is fan-shaped, but when the scanning angle for scanning the electron beam in a fan-shaped manner increases, not only does the absorbed dose of the scanning electron beam 8 of the medical equipment decrease, but also the medical equipment. The absorbed dose varies at each site. Further, when the electron beam scanning angle increases in a fan shape, the portion of the electron beam protruding from the irradiation object 1 increases, and as a result, the reflector (beam stop) 6 located on the back side of the non-irradiation object has to be enlarged. Absent.

Therefore, in the present invention, the irradiation horn 1
The power source for magnets 18 is adapted to become wider as it goes outward from the center side in accordance with the deflection angle of the scanning beam passing through the inside of the magnet 18.
Deflecting magnet plates 19A and 19B, which are formed of substantially right-angled triangular electromagnets whose voltage is controlled by, are disposed immediately before the irradiation window. According to this embodiment, the deflection magnet plates 19A, 1
9B, the fan-shaped scanning electron beam oscillates toward the center side. However, the scanning electron beam 8 that oscillates in a fan-shape with the irradiation horn 16 changes the deflection angle toward the center as the deflection angle increases, in other words, as the beam moves outward. It is necessary to take a large amount in the direction in which the device is located). For this reason, the deflection magnet plates 19A and 19B are formed to have a flat right-angled triangular shape in which the upper surface is gradually inclined obliquely upward as it goes outward from the center side, in other words, is extended so as to become gradually wider. I have.

FIG. 1 is a schematic side view of an electron beam sterilizer according to an embodiment of the present invention as viewed from the side of a conveyor. In such an embodiment, the infusion bag 1 was used as the irradiation target as in FIG.

In FIG. 1, the electron beam accelerators 5A, 5A
B is a scanning horn 1 having a flat pyramid shape formed in a divergent shape.
6 are arranged symmetrically at a predetermined angle θ on both sides of the conveyor 2 so that the conveyor 6 is vertical. Incidentally, the electron beam accelerator 5A,
Although 5B does not need to be provided particularly at a symmetrical position, it is possible to efficiently irradiate the light by arranging in this manner. The inclination angle θ is set in the range of, for example, 30 to 75 ° by being distributed right and left from the axis of the conveyor center. The divided tilt angle θ is determined by the electron beam irradiation area of the facing accelerators 5B and 5A without the electron beam transmitted without being absorbed by the infusion bag 1 colliding with the facing accelerators 5B and 5A. The angle may be less than or equal to 60 ° to 75 ° or less, depending on the size of the infusion bag 1. And sterilization is inadequate.

The accelerators 5A and 5B have an energy of 10M.
An electron beam of eV is configured to be able to be emitted from the irradiation window 17 at the exit of the scanning horn 16, and the beam is scanned vertically along the central axis of the irradiation object. A pair of deflection magnets 19 provided on the window 17 side
A and 19B constitute a parallel electron beam. As a result, in a state where the infusion bags 1 are arranged in a line along the conveying direction of the irradiation conveyor 2, while transferring the irradiation conveyor 2, the energy 1 is supplied from the electron beam accelerators 5A and 5B.
By irradiating the infusion bag 1 with a beam of 0 MeV electron beam, the infusion bag 1 can be evenly irradiated with the 10 MeV electron beam from both the left and right sides.

A reflector 6 functioning as a beam stop is installed on the opposite side of each of the accelerators 5A and 5B with the infusion bag 1 interposed therebetween, and a beam stop of the electron beam by the reflector 6 and the reflector The surface of the infusion bag 1 is additionally irradiated with the reflected electron beam reflected from 6. The electron beam reflecting plate 6 is formed of a metal having a large atomic number, for example, a tungsten plate or a stainless steel plate plated with gold, and has a possibility of generating heat by absorbing the electron beam. It is composed of a reflector having a cooling function provided with the portion 6a.

[0029]

As described above, according to the present invention, even when two electron beam accelerators are disposed on both the left and right sides of a conveyor, both devices are not damaged.
An electron beam irradiation apparatus capable of simultaneous irradiation on both sides can be provided, and in particular, a three-dimensional irradiation object filled with a liquid such as an infusion bag used for infusion can be effectively sterilized.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an electron beam sterilizer for an infusion bag according to an embodiment of the present invention, as viewed from the side of a conveyor.

FIG. 2 is a schematic configuration diagram of an electron beam accelerator according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infusion bag 2 Conveyor 5A, 5B Electron beam accelerator 6 Beam stop 19A, 19B Deflection magnet plate

Claims (2)

[Claims] 1. An electron beam irradiator configured to irradiate a high-energy electron beam to a medical device filled with a liquid therein, comprising: an irradiation conveyor for transporting the medical device to an electron beam irradiation area; A pair of electron beam accelerators disposed on both sides of the conveyor, wherein the accelerators are inclined at a predetermined angle toward the upstream or downstream side in the conveyor transport direction so that the accelerators are at an acute angle with respect to the center line of the conveyor. An electron beam irradiation apparatus for a medical device, wherein electron beams transmitted through the medical device without being absorbed by the medical device are retracted from electron beam irradiation regions on the opposite surface so as not to collide with the accelerator on the opposite surface. 2. An electron beam emitted from an irradiation window on the front side of a scanning horn of the accelerator, wherein the electron beam is not widened.
2. The electron beam irradiation apparatus for medical equipment according to claim 1, wherein the electron beam is a parallel electron beam or an electron beam converging toward the center.