WO2020036232A1 - Radiation measuring body, and radiation exposure dose measuring device - Google Patents

Abstract

The objective of the present invention is to provide a radiation measuring body and a radiation exposure dose measuring device which can be realized relatively inexpensively using a simple structure, and with which the exposure dose to which the crystalline lens of a subject, for example, is subjected can be measured rapidly and accurately. The radiation measuring body can be realized by forming a transparent dosimeter on a lens in the form of known spectacles, goggles, retrofitted sunglasses and the like, or protective glasses. The radiation exposure dose measuring device consists of a light shielding box in which the radiation measuring body is confined in order to block external light, and a computer. The computer includes a sequence control unit which controls a switch for blocking noise when the radiation measuring body is irradiated with exciting light and an amount of emitted light is measured.

Description

Radiation measuring body and radiation exposure measuring device

The present invention relates to a radiation measuring body and a radiation exposure measuring device.

In recent years, as a minimally invasive medical practice, interventional radiology (Interventional Radiology, IVR) is becoming widespread. Under this image-based treatment, intermittent and long-term radiation exposure of caregivers, who are mainly healthcare workers, is a problem under medical conditions that require a radiation generator such as X-rays. become.

(4) Radiation generally used in medical equipment using radiation has a higher density than radiation that is normally exposed to the human body in a normal environment. The medical device using radiation can provide a high therapeutic effect to the affected part of the patient by the high-density radiation dose (dose). However, overirradiation of the affected area of the patient with radiation in excess of an appropriate dose and irradiation of non-treated areas other than the affected area with radiation must be avoided. In order to minimize the negative effects of such radiation, dose management at non-treatment sites other than the affected area of the patient is important.

In particular, health care providers who perform IVRs, such as Percutaneous Coronary Intervention (PCI), are exposed to continuous and prolonged radiation exposure in the course of treatment. Then, there is a possibility that a high dose of radiation is unequally applied to a local part of a human body such as a lens of a medical worker. These local parts of the human body are dangerous because some parts are particularly sensitive to radiation. In the worst case, there is a risk of deterministic effects such as cataracts.

If a severe accident occurs at a facility that handles radioisotopes (hereinafter referred to as “radioisotope handling facility”), radiation generators, or nuclear facilities, workers near the accident site May be subject to uneven exposure (where there are other sites that are more likely to be exposed than the male chest and female abdomen). Therefore, in a normal state where no severe accident has occurred, radiation measurement management that assumes various types of radiation generation and exposure to workers in radioisotope element handling facilities, radiation generators, nuclear facilities, etc. Need to be continuously implemented under appropriate management.

Conventionally, ion beams such as heavy ion beams and proton beams generated from large accelerator facilities, neutron beams, medical radiation such as γ-rays and X-rays, etc. And generalization are progressing. As such generalization progresses, the possibility that a greater variety of unequal exposures will occur to healthcare workers, patients, patient caregivers, and other intervening persons present at the time of the medical procedure. I have.

Currently, personal dosimeters are used to measure and manage external dose at each individual level. Personal dosimeters include radio-photoluminescence (RPL) fluorescent glass dosimeters, thermoluminescence dosimeters (Thermo-Luminescence Dosimeter; TLD), photostimulable (Optically Stimulated Luminescence: OSL) dosimeters, There are integrating dosimeters such as film badges, which are used in conjunction with semi-real-time personal dosimeters such as ionization chamber dosimeters and electronic dosimeters. The operation of these dosimeters is managed in accordance with laws and regulations. In Japan, the International Commission on Radiation Protection (ICRP) has implemented a law on prevention of radiation hazards that incorporates the 1990 recommendations from April 1, 2001. Of these, the lens of the eye is managed according to a dose standard of 150 mSv / year as an equivalent dose limit for an individual site.

However, in recent years, thresholds for lens exposure have been reviewed in view of the fact that the threshold dose of the lens has been underestimated. Specifically, it is argued that the value should be set to 5 Gy to 0.5 Gy, which is 1/10 of the conventional value. The ICRP's 2011 recommendation indicated a significant reduction in the equivalent dose limit of the lens of radiation workers from 150 mSv per year to an average of 20 mSv per year (50 mSv for one year, 100 mSv for one year, and 100 mSv for five years). 3, 4). Ratification is scheduled in the future, for example in Europe in 2018. For this reason, the possibility of extremely strictly adapting the exposure control of the lens in Japan is increasing. However, personal dosimeters currently used in various fields are difficult to cover the eyes, and can only estimate the dose corresponding to lens exposure. For this reason, the use of current personal dosimeters in uneven exposure environments is not recommended.

Prior art documents close to the technical field of the present invention are shown in Patent Documents 1, 2, and 3 and Non-Patent Documents 1 to 5.
Patent Literature 1 discloses a technique related to a dosimeter that realizes both improvement of an electromagnetic shielding function and reduction in size, weight, and cost.
Patent Literature 2 discloses a technique relating to an absorbed dose management device for precisely managing the absorbed dose of medical staff.
Patent Literature 3 discloses a technique related to an eyeglass-type structure device for reducing the radiation dose to the lens of the eye.
Non-Patent Documents 1 and 2 disclose various dosimeters that are assumed to be used under protective glasses.
Non-Patent Literature 3 and Non-Patent Literature 4 disclose guidelines on the equivalent dose limit of the crystalline lens of a radiation worker.
Non-Patent Document 5 describes that a radiation dosimeter according to the prior art has a problem in direction dependency.
Non-Patent Document 6 describes technical information on protective equipment such as protective clothing and protective glasses for protecting a human body against diagnostic X-rays.

JP 2005-221463 A Japanese Patent No. 5072662 JP-A-2005-152548

In response to the change of the lower limit of the lens exposure dose made in the 2011 ICRP recommendation, the lens exposure dose evaluation method for individuals has not been completely established and is a social issue. Regarding the protection of the lens of the human eye, in a structure that satisfies the requirements of “protective clothing, protective glasses, and patient protective equipment” listed in JIS T 61331-3, regardless of the presence or absence of the IVR procedure, Several X-ray protective glasses have been developed to be worn by an operator and to protect their eyes. In addition to devices that describe lead equivalents using photon attenuation by lead, there are devices that claim dose attenuation with a structure as described in Patent Document 3, but how much dose is actually given through these devices. No measurement has been made on whether this is the case, and local dosimetry is required, especially at the lens.
Chiyoda Technol Co., Ltd., one of the domestic companies, has begun deploying the TLD dosimeter DOSIRIS (registered trademark) developed by the French Institute for Radiation Protection and Nuclear Safety (IRSN), (See Non-Patent Document 2). However, DOSIRIS (registered trademark) using one measurement point has a problem in direction dependency, and there is also a report that the dose from the lower part of a medical worker such as a patient's body cannot be accurately evaluated (Non-patent Literature) 5), it is assumed that there remains a problem that has not been solved yet in operation as a radiation measuring device for measuring a lens exposure dose.

On the other hand, the downsizing of devices used in conventional technologies such as X-rays has been remarkable, such as the practical use of hand-held X-ray devices in dental diagnosis and the like, and the risk of exposure of patients other than the diseased part estimated by their practical use is expanding. . Discussions on radiation exposure management, etc. for non-medical workers are limited and incomplete. In other words, there is a potential need for dosimetry for patients who are not radiation workers while minimizing the burden on the individual. However, it is necessary to have an effective measurement method for determining the irradiation dose to the lens that is simple and effective, and the detection volume and radiation effective area are large and the dose can be evaluated. There was a problem that a measurement method could not be provided.

水晶 Besides the medical radiation field, since the lens exposure limit is applied, it is important to develop a dosimeter that can be widely used in nuclear facilities. However, in various radiation fields, in particular, in various environments in which β-rays and α-rays are to be included in the assumed measurement target, various leading dosimeters such as DOSIRIS, which are expected to be used under protective glasses (Non-Patent Document 1, 2), the dose cannot be sufficiently evaluated, and the amount of uneven exposure may be underestimated. For this reason, an exposure dose measurement method that can be used for evaluation of the lens exposure over a wider range, and has a structure that covers the eye lens over a wide area and has a structure that can also assume β-ray incidence between the radiation source and the dosimeter and the lens Maintenance is required.

In other words, there is a certain situation that the lower limit of the exposure dose limit of the lens is greatly reduced to 0.5 Gy, which is 1/10 from 5 Gy in the related art. In such a situation, there is no means at present at present that can easily, quickly, and accurately measure the dose of the subject such as the crystalline lens.

The present invention has been made in view of the above circumstances, has a simple structure, can be realized at relatively low cost, and can quickly and accurately measure an exposure amount of a subject such as a crystalline lens. An object of the present invention is to provide an exposure dose measuring device.

In order to solve the above problems, the radiation measuring body of the present invention is a visible light transmitting member formed with a dosimeter capable of transmitting visible light at least partially, the visible light transmitting member of at least one of the crystalline lens of the wearer A placement tool to be placed in the vicinity, and a visible light transmitting member fixing tool interposed between the visible light transmitting member and the placement tool for fixing the visible light transmitting member to the placement tool are provided.

According to the present invention, it is possible to provide a radiation measuring body and a radiation exposure dose measuring device which can be realized at a relatively low cost with a simple structure and can quickly and accurately measure the exposure dose of a subject such as a crystalline lens. Can be.
Problems, configurations, and effects other than those described above will be apparent from the following description of the embodiments.

It is an outline view of a radiation measuring object concerning the first, second, and third embodiments of the present invention. It is the schematic which shows the manufacturing method of the planar lens which concerns on a 1st modification. It is a schematic diagram explaining a fluorescent phenomenon formed in a dosimeter glass plate as a result of irradiating a flat dosimeter glass plate with X-rays or γ-rays perpendicularly and at a predetermined angle. It is the schematic explaining the manufacturing method of the dosimeter powder which concerns on a 2nd modification. It is the partially expanded view which shows the lens which has the function of the dosimeter which concerns on the 3rd modification, and a partial cross section. It is the schematic explaining the application range of the dosimeter powder in the lens of a radiation measurement body which concerns on the 4th and 5th modification, and the schematic which illustrates the state irradiated with radiation. It is the schematic which shows the whole structure of a radiation exposure measuring device. FIG. 3 is a block diagram illustrating a hardware configuration of the radiation exposure dose measuring device. It is a block diagram which shows the software function of a radiation exposure measuring device. 5 is a graph of a signal obtained from a linear amplifier and a graph of a current flowing through an excitation light emitting unit. It is a functional block diagram which shows the detail of the process which estimates the radiation exposure dose in a wearer's lens and each organ performed by the input-output control part. It is the schematic of the holding stand and partition provided in the inside of a light shielding box.

[Radiation measurement body: Variation of overall configuration]
FIG. 1A is an external view of a radiation measurement body 101 according to the first embodiment of the present invention.
The radiation measurement body 101 has a well-known eyeglass shape. The lenses 102a and 102b of the radiation measuring body 101 are inexpensive, and the lenses 102a and 102b are a dosimeter (Radio-Photoluminescence dosimeter: fluorescent glass dosimeter (RPL), a thermoluminescence dosimeter (Thermo- It has a Luminescence Dosimeter (TLD) and a photostimulated luminescence (Optically Stimulated Luminescence: OSL) dosimeter. The material and manufacturing method of the dosimeter will be described later with reference to FIG.
The left and right lenses 102a and 102b having the function of the dosimeter are fixed by rims 103a and 103b constituting a part of the frame of the glasses. The rims 103a and 103b are fixed by bridges 104.
Further, the rims 103a and 103b are connected to the temples 107a and 107b via clasps 105a and 105b and hinges 106a and 106b.

The bridge 104 for fixing the rims 103a and 103b, and the tongues 105a and 105b, the hinges 106a and 106b, and the temples 107a and 107b are those who mount the lenses 102a and 102b as visible light transmitting members on the radiation measuring body 101 (wearing). ) Has a function as a placement tool placed near at least one of the eyelids. The rims 103a and 103b are interposed between the visible light transmitting member and the placement device, and serve as visible light transmitting member fixing devices for fixing the visible light transmitting member to the placement device. Here, the wearer refers to a person who wears and uses the radiation measurement body in a state close to his / her eyes, such as eyeglasses.

As is well known, the eyelid is an organ that covers the eyeball, and the eyeball contains the lens. Therefore, the bridge 104 for fixing the rims 103a and 103b, and the chimneys 105a and 105b, the hinges 106a and 106b, and the temples 107a and 107b are provided with the lenses 102a and 102b that are visible light transmitting members and the person who wears the radiation measurement body 101. It can also be said that it has a function as a placement tool placed near at least one lens of the (wearer).

That is, the radiation measuring body 101 is a well-known eyeglass itself except that the lenses 102a and 102b having no power have a function of a dosimeter capable of transmitting visible light.
In addition, there is an article called overglass which is one size larger than normal glasses and can be worn so as to cover normal glasses used by the wearer. However, the radiation measurement object 101 according to the first embodiment of the present invention is described. May be configured with the shape and size of the overglass.

FIG. 1B is an external view of a radiation measurement body 121 according to the second embodiment of the present invention.
The radiation measuring body 121 has a shape of a well-known goggle. The transparent lens 122, which is a main component of the goggles, has a dosimeter capable of transmitting visible light.
The lens 122 having a dosimeter function is fixed by a goggle frame 123. A face pad 124 is provided on the side of the frame 123 that contacts the face of the wearer.
To both ends of the frame 123, straps 125 made of elastic rubber bands are connected.

The strap 125 is an arrangement tool that arranges the lens 122, which is a visible light transmitting member, near at least one of the eyelids of the wearer by being wrapped around the wearer's head. The frame 123 is interposed between the visible light transmitting member and the placement device, and functions as a visible light transmitting member fixing device for fixing the visible light transmitting member to the placement device.

That is, the external shape of the radiation measurement body 121 is a well-known goggle, except that the lens has a function of a dosimeter capable of transmitting visible light.
Further, the radiation measurement body 121 according to the second embodiment of the present invention may be configured to have a shape and a size that can be put on ordinary glasses.

FIG. 1C is an external view of a radiation measuring body 131 according to the third embodiment of the present invention.
The radiation measuring body 131 has a shape of a well-known retro sunglass. The lenses 132a and 132b without transparency, which are the main components of the retrofit sunglasses, have a dosimeter that can transmit visible light.
The left and right lenses 132a and 132b having a dosimeter function are fixed by screws or the like by a bridge 133. The bridge 133 is provided with a clip 134 for holding the lens of the glasses.

The clip 134 has a function of fixing the lenses 132a and 132b, which are visible light transmitting members, to at least one of the eyelids of the wearer by fixing the glasses to the glasses worn by the wearer. The bridge 133 is interposed between the visible light transmitting member and the placement device, and functions as a visible light transmitting member fixing device for fixing the visible light transmitting member to the placement device.

That is, except that the lenses 132a and 132b have the function of a dosimeter capable of transmitting visible light, the radiation measuring body 131 is a well-known retro sunglass itself.
Note that the method of fixing the left and right lenses is not limited to screwing the bridge 133 described above, and rims 103a and 103b and a bridge 104 similar to FIG. 1A may be used.
The radiation measurement body 131 according to the third embodiment of the present invention can be worn in the same usage form as the retrofit sunglasses by attaching the radiation measurement body 131 to the lens of the eyeglasses used by the wearer with the clip 134.
Further, the radiation measuring body 131 can be attached to a safety hat instead of the wearer's glasses by configuring the clip 134 to be rotatable or by providing a predetermined attachment.

When the dosimeter irradiated with X-rays or γ-rays is irradiated with excitation light, it emits fluorescence having a wavelength corresponding to a level formed by radiation such as orange. The intensity and time of the fluorescent light emission are proportional to the intensity of the X-ray or γ-ray and the irradiation time, that is, the exposure dose. By measuring the amount of fluorescence emitted from the dosimeter, the amount of radiation exposure can be measured.

A worker who does not need to use eyeglasses in daily life and has a normal eyesight can use the eyeglass-shaped radiation measurement body 101 shown in FIG. 1A or the goggle shown in FIG. The radiation measuring body 121 having a shape is mounted. Alternatively, the radiation measuring body 131 in the form of retrofit sunglasses shown in FIG.
Workers who need to use eyeglasses in daily life, such as myopia, hyperopia, or astigmatism, need to use the overglass shape shown in FIG. The radiation measurement body 101 shown in FIG. 1B, the goggle-shaped radiation measurement body 121 shown in FIG. 1B is attached, or the retrofitted sunglasses-shaped radiation measurement body 131 shown in FIG.

[Modification of lens: flat lens and manufacturing method thereof]
The lenses applied to the first, second, and third embodiments need to have a dosimeter function. A lens provided with a dosimeter function can be configured in various forms. Hereinafter, modified examples of these lenses will be described.
First, a flat lens according to a first modification will be described with reference to FIGS. 2A, 2B, 2C, and 2D.
FIG. 2A is a schematic view illustrating a first step of a method of manufacturing a flat lens according to a first modification.
Taking a dosimeter (Radio-Photoluminescence dosimeter: fluorescent glass dosimeter (RPL)) capable of transmitting visible light as an example, a powder M202 of NaPO ₃ , a powder M203 of Al (PO ₃ ) ₃ in a crucible 201 made of alumina, Then, AgCl or CuCl powder M204 as an active center activating material (activator) is charged and stirred.
FIG. 2B is a schematic view showing a second step of the method for manufacturing a flat lens.
In the stage of FIG. 2A, the temperature of the crucible 201 into which the material powder has been charged is raised from room temperature to 1000 ° C. over 1 hour. Thereafter, the state at 1000 ° C. is maintained for one hour. In FIG. 2B, the heating is indicated by the gas burner S205 or the like, but an electric furnace may be used.

FIG. 2C is a schematic view showing a third step of the method of manufacturing a flat lens.
2B, the dosimeter material melted in the crucible 201 is poured onto the aluminum plate 206 at room temperature. That is, the dosimeter material is cooled by the rapid cooling method. Then, a glass plate 207 having a dosimeter function is formed.
FIG. 2D is a schematic view showing a fourth step of the method of manufacturing a flat lens.
In the stage of FIG. 2C, the glass plate 207 having a dosimeter function formed on the aluminum plate 206 is cut into a desired shape using a contour saw or the like.
That is, in the lens formed by the process of FIG. 2, the entire lens is made of glass having a dosimeter function.
Although FIG. 2 illustrates an example of the RPL glass made of NaPO ₃ and Al (PO ₃ ) _3, a lens may be formed using other materials such as RPL glass, OSL material, and TLD material.

[Characteristics of flat lens]
FIG. 3A is a schematic diagram illustrating a fluorescence phenomenon formed in the dosimeter glass plate 301 as a result of vertically irradiating the dosimeter glass plate 301 with a charged particle beam.
FIG. 3B is a schematic diagram illustrating a fluorescence phenomenon formed in the dosimeter glass plate 301 as a result of irradiating the flat dosimeter glass plate 301 with a charged particle beam at a predetermined angle.
In a flat dosimeter glass plate 301 having a thickness of about 1 μm or more, a large number of conical fluorescent change portions 302 appear in a direction parallel to the irradiation directions V303 and V304 of the charged particle beam. As described above, after irradiating the charged particle beam to the dosimeter glass plate 301 having a predetermined thickness, the dosimeter glass plate 301 is enlarged by a microscope or the like in the stage of measuring the amount of light emission by irradiating the excitation light. This makes it possible to confirm the irradiation direction of the radiation.
That is, in the lens formed by the process of FIG. 2, due to the radiation exposure, a fluorescence changing portion 302 shown in FIG. 3A and FIG.

The flat lens formed by the manufacturing method according to the first modification shown in FIG. 2 is heated to about 300 ° C. after being irradiated with radiation and further irradiated with excitation light by a measuring device described later. As a result, an annealing phenomenon occurs, and the sensitivity to radiation can be restored again. That is, the lens can be repeatedly used by heating.
The entire frame of the eyeglass-shaped radiation measurement body 101 shown in FIG. 1A is made of a heat-resistant material, so that the entire radiation measurement body 101 can be heated and reused.
The goggle-shaped radiation measurement body 121 shown in FIG. 1B is configured so that the lens can be detached from the frame, so that the lens can be removed from the frame, heated, and reused.
The radiation measurement body 131 in the form of retrofit sunglasses shown in FIG. 1C is configured so that the lens can be detached from the bridge, so that the lens can be removed from the bridge, and the lens can be heated and reused. Further, the bridge and the clip may be made of a material having heat resistance, and the entire radiation measuring body 131 may be heated and made reusable similarly to the radiation measuring body 101 of FIG. 1A.

[Modification of Lens: Dosimeter Powder and Manufacturing Method]
The lens disclosed in FIGS. 1 and 2 is entirely formed of a glass plate having a dosimeter function. Although this lens can be repeatedly reused by annealing, the cost of the material itself is high, and an expensive machine tool or the like must be used to form a curved shape. Therefore, as a method of forming a cheaper lens, a method of manufacturing the dosimeter powder according to the second modified example will be described with reference to FIGS. 4A, 4B, 4C, and 4D.

FIG. 4A is a schematic diagram illustrating a first step of a method for manufacturing dosimeter powder 403 according to a second modification. First, the dosimeter glass plate 301 prepared in FIG. 2C or FIG. 2D is finely crushed using a well-known pestle and mortar to obtain a raw dosimeter powder 401.
FIG. 4B is a schematic diagram illustrating a second step of the method for manufacturing dosimeter powder 403. The dosimeter raw powder 401 created in FIG. 4A is classified using 1 mm and 0.5 mm sieves 402a and 402b to extract a 0.5-1 mm diameter dosimeter powder 403.

FIG. 4C is a schematic diagram illustrating a third step of the method for manufacturing dosimeter powder 403. The dosimeter powder 403 extracted in FIG. 4B is put into the crucible 201 together with the carbon powder and stirred. Then, it heats at 550 degreeC for 3 hours.
FIG. 4D is a schematic diagram illustrating a fourth step of the method of manufacturing dosimeter powder 403. The dosimeter powder 403 heated in FIG. 4C is cleaned in pure water 404 using an ultrasonic cleaner.

す る と If the powder dosimeter is formed, the observation of the conical fluorescence changing portion 302 shown in FIG. 3 becomes impossible. However, by applying the dosimeter powder 403 to the entire surface of a low-cost transparent synthetic resin plate such as acrylic or vinyl chloride, a disposable but inexpensive radiation measuring body can be realized.

Various methods can be considered for forming a thin layer of dosimeter on the front and / or back surface of the transparent synthetic resin plate by fixing the dosimeter powder 403 or the fine particles of the dosimeter on the surface of the transparent synthetic resin plate. Can be For example, it is applied by being mixed with a synthetic resin adhesive, paint or binder. In addition, vacuum evaporation such as sputtering, resistance heating evaporation, and electron beam evaporation is also possible in principle.

That is, in the existing manufacturing process of eyeglasses and goggles, it is possible to easily and inexpensively realize a radiation measuring body simply by adding a process of applying a powder dosimeter to the manufacturing process of the lens. Of course, the dosimeter powder 403 may be applied to existing commercially available glasses, Date glasses, goggles, retrofit sunglasses and other lenses, or lead-containing glass lenses of protective glasses described in Non-Patent Document 6.

[Modification of lens: disposable lens having scintillator function]
FIG. 5A is a partially enlarged view showing a lens 501 having a dosimeter function according to a third modification.
FIG. 5B is a partial cross-sectional view of a lens 501 having a dosimeter function according to a third modification.
The lens 501 illustrated in FIGS. 5A and 5B is assumed to be applied to the radiation measurement body 101 according to the first embodiment illustrated in FIG. 1A and the radiation measurement body 131 according to the third embodiment illustrated in FIG. 1C. Although the shape is the same, the same technical idea can be applied to the radiation measurement body 121 according to the second embodiment shown in FIG. 1B.
The lens 501 shown in FIGS. 5A and 5B has a dosimeter layer 503 formed by applying the dosimeter powder 403 described in FIG. 4 to the entire surface of a transparent synthetic resin base material 502. Further, a transparent scintillator 504 such as cesium iodide is applied on the periphery of the dosimeter layer 503.

The dosimeter does not emit light only when irradiated with radiation, but emits light only when irradiated with stimulating light such as ultraviolet light from an excitation light source. That is, even if excessive radiation is applied to the wearer of the radiation measurement body, it is impossible to determine in real time whether or not the currently exposed state is dangerous. Therefore, if the scintillator 504 is applied to the periphery of the lens 501 of the radiation measurement body, the scintillator 504 emits light in real time when radiation is irradiated. In the light emission state of the scintillator 504, the wearer of the radiation measuring body can instantaneously determine that danger is imminent on his or her body. Note that the reason for applying the scintillator 504 only to the periphery of the lens 501 is that if the scintillator 504 is applied to the entire surface of the lens 501, it obstructs the field of view of the wearer of the radiation measurement body and significantly impedes the evacuation behavior of the wearer. This is a result in consideration of fear.
Note that the dosimeter layer 503 may be formed on the back surface or both surfaces of the base material 502 by coating or the like.

[Modification of lens: disposable lens with minimum application range of dosimeter powder 403]
In the second and third modifications described above, the dosimeter powder 403 is applied to the entire surface of the lens made of a synthetic resin. However, in the radiation exposure dose measuring device described later with reference to FIG. 7 and subsequent figures, the area for measuring the emission of the dosimeter applied to the lens is limited because the excitation light is focused on the surface of the lens by the optical system. In other words, even if the dosimeter powder 403 is not applied to the entire surface of the lens, if the dosimeter powder 403 is applied to the minimum necessary portion, the desired purpose of measuring the radiation exposure of the lens of the wearer can be achieved. It is possible.

FIG. 6A is a schematic diagram illustrating an application range of the dosimeter powder 403 on the lenses 601a and 601b of the radiation measurement body 101 according to the fourth modification.
FIG. 6B is a schematic diagram illustrating a state in which radiation is applied to the dosimeter powder 403 applied to the lenses 601a and 601b of the radiation measurement body 101 according to the fourth modification.
6A, 6B, 6C, and 6D, the radiation measurement body 101 according to the first embodiment illustrated in FIG. 1A is described as an example, but according to the second embodiment illustrated in FIG. 1B. The same technical idea can be applied to the radiation measurement body 121 and the radiation measurement body 131 according to the third embodiment shown in FIG. 1C.

The lenses 601a and 601b of the radiation measurement body 101 shown in FIGS. 6A and 6B have first detection areas 602a and 602b in which dosimeter powder 403 is applied near the bridge (closer to the wearer's nose). The second detection regions 603a and 603b on which the dosimeter powder 403 is applied (on the side close to the wearer's ear) are provided. The radiation measurement body 101 in the form of glasses is curved along the contour of the wearer's face as shown in FIG. 6B. When radiation is applied to the curved lenses 601a and 601b from the irradiation direction V604, the irradiation angles of the radiation are different between the first detection areas 602a and 602b and the second detection areas 603a and 603b. There is a difference in the amount of exposure in each detection area. In particular, since the second detection areas 603a and 603b are formed on the side closer to the wearer's ear, it is possible to objectively infer whether the radiation is emitted from the right side or the left side of the wearer. .

In FIG. 6B, the right second detection region 603a has a relative angle relationship closer to a right angle with respect to the radiation irradiation direction V604 than the left second detection region 603b. Therefore, when the excitation light is applied to the second detection area 603a on the right and the second detection area 603b on the left, it is considered that the fluorescence emission time of the second detection area 603a on the right is longer than that of the second detection area 603b on the left. .
Therefore, the irradiation direction of the radiation can be inferred from the difference in the amount of light generated when the second detection regions 603a and 603b are irradiated with the stimulating light such as the ultraviolet light from the excitation light source.

[Modification of lens: disposable lens formed to further determine the irradiation direction of radiation]
FIG. 6C is a schematic diagram illustrating an application range of the dosimeter powder 403 on the lenses 611a and 611b of the radiation measurement body 101 according to the fifth modification.
FIG. 6D is a schematic diagram illustrating a state in which radiation is applied to the dosimeter powder 403 applied to the lenses 611a and 611b of the radiation measurement body 101 according to the fifth modification.
The first detection regions 612a and 612b of the lenses 611a and 611b of the radiation measurement body 101 illustrated in FIGS. 6C and 6D are equivalent to the lenses 601a and 601b according to the fourth modification illustrated in FIGS. 6A and 6B. However, in the second detection area, tongue-shaped extension protrusions 613a and 613b are further formed near the temple (on the side near the ear of the wearer), and the dosimeter powder 403 is applied to the extension protrusions 613a and 613b. . The extended projections 613a and 613b that form the second detection area are formed closer to the wearer's ear than the second detection areas 603a and 603b in the fourth modification. For this reason, it is possible to objectively analogize whether the radiation is emitted from the right side or the left side of the wearer more clearly than in the fourth modification.

The radiation measurement body according to the present invention described above has the following embodiments.
(1) As shown in FIG. 1A, a radiation measuring body 101 in the shape of glasses.
(2) As shown in FIG. 1B, the radiation measuring body 121 has a goggle shape.
(3) As shown in FIG. 1C, the radiation measuring body 131 is a sunglass-shaped retrofit.
The lens (visible light transmitting member) applied to the radiation measuring object according to the present invention described in the above (1), (2) and (3) has the following modifications.
(4) As shown in FIG. 2, the entire lens is formed by a dosimeter.
(5) As shown in FIG. 4, the base material of the lens is formed of a transparent synthetic resin, and dosimeter powder 403 is applied to the entire surface.
(6) As shown in FIG. 5, the base material 502 of the lens 501 is formed of a transparent synthetic resin, the dosimeter powder 403 is applied to the entire surface, and the scintillator 504 is further applied to the lens periphery. I have.
(7) As shown in FIGS. 6A and 6B, the base material of the lenses 601a and 601b is formed of a transparent synthetic resin, and the first detection regions 602a and 602b are provided on the side near the nose of the wearer as ears of the wearer. The dosimeter 403 is applied as the second detection areas 603a and 603b on the side closer to.
(8) As shown in FIGS. 6C and 6D, extension protrusions 613a and 613b are formed near the wearer's cheekbone of the lenses 611a and 611b, and dosimeter powder 403 is applied to the extension protrusions 613a and 613b. .

[Radiation Exposure Measurement Device 701: Overall Schematic and Hardware Configuration]
The radiation measurement body alone cannot measure the radiation exposure dose. As described above, the radiation exposure dose can be measured for the first time by irradiating the dosimeter formed on the lens with the excitation light to fluoresce and measuring the light emission amount.
FIG. 7 is a schematic diagram showing the overall configuration of the radiation exposure dose measuring device 701.
The radiation exposure dose measuring device 701 includes a light shielding box 703 for confining the radiation measuring body 702 and a computer 704 connected to the light shielding box 703. In FIG. 7, a well-known personal computer is connected as an example of the computer 704, but a well-known one-board microcomputer may be used.

FIG. 8 is a block diagram illustrating a hardware configuration of the radiation exposure dose measuring device 701.
The light shielding box 703 includes a holding table 801 for holding the radiation measurement body 702 therein, a motor 802 for driving the holding table 801, an excitation light emitting unit 803 for irradiating the radiation measurement body 702 with excitation light, It has a fluorescence receiving unit 804 for converting fluorescence generated from the radiation measurement body 702 into an electric signal, an optical system 805a for condensing excitation light on the radiation measurement body 702, and an optical system 805b for condensing fluorescence to the fluorescence reception unit 804. .
The holding table 801 and the motor 802 are provided to change the relative positional relationship between the optical systems 805a and 805b and the radiation measurement body 702.
The weak voltage signal output from the fluorescent light receiving unit 804 including a photodiode, a phototransistor, a CMOS sensor, and the like is integrated by the charge amplifier 806 and further amplified by the linear amplifier 807. The output signal of the linear amplifier 807 is converted into digital data by the A / D converter 819 of the computer 704.
Note that the A / D converter 819 may be provided in the light shielding box 703.

The computer 704 includes a CPU 812, a ROM 813, a RAM 814, a display unit 815, an operation unit 816, a nonvolatile storage 817, a serial interface such as a USB (hereinafter, abbreviated as “serial I / F”) 818 connected to the bus 811, and A A / D converter 819 is provided.
The non-volatile storage 817 stores a program for operating the computer 704 as the radiation exposure dose measuring device 701.
A motor 802 and an excitation light emitting unit 803 are connected to the serial I / F 818.

[Radiation exposure dose measuring device 701: software function]
FIG. 9 is a block diagram illustrating a software function of the radiation exposure dose measuring device 701.
Digital data output from the A / D converter 819 is input to the input / output control unit 902 via the switch 901. The switch 901 is on / off controlled by the sequence control unit 903. The input / output control unit 902 performs a time integration process on data input via the switch 901 to calculate a radiation exposure dose. Then, the calculated radiation exposure amount is displayed on the display unit, and is recorded in a predetermined file in the nonvolatile storage.
The sequence control unit 903 transmits an on / off control signal to the excitation light emitting unit 803 and the switch 901. Specifically, the switch 901 is turned on after a predetermined time interval has elapsed after the excitation light emitting unit 803 emits light for a predetermined time.

FIG. 10 is a graph of a signal obtained from the linear amplifier 807 and a graph of a current flowing through the excitation light emitting unit 803.
When the excitation light is emitted from the excitation light emitting unit 803 to the dosimeter for a certain period of time (from T1001 to T1002), a signal is generated from the fluorescent light receiving unit 804 slightly after the start of the excitation light irradiation (T1001) (T1003). Slightly after the end of the excitation light irradiation (T1002), the signal generated from the fluorescent light receiving unit 804 temporarily stops (T1004). The signal obtained from the linear amplifier 807 between the time points T1003 and T1004 is noise that depends only on the irradiation time of the excitation light.
Then, after a short time interval from the time T1004, the dosimeter starts to emit light spontaneously (T1005). This light emission continues until time T1006. The light emission from the time T1005 to the time T1006 is a fluorescence phenomenon depending on the radiation exposure dose, and the end time of the time T1006 fluctuates before and after depending on the radiation exposure dose.

The input / output control unit 902 must exclude the noise from the time point T1003 to the time point T1004 among the signals obtained from the linear amplifier 807 and make only the signal due to the fluorescent phenomenon from the time point T1005 to the time point T1006 into the calculation target. Must. A sequence control unit 903 is provided to mask the signals from time T1001 to T1005.

Since the lens of the wearer's crystalline lens itself acts as a radiation shielding material, the radiation exposure dose of the crystalline lens is lower than when the radiation measuring body 702 is not mounted. Further, since the lens of the radiation measurement body 702 and the lens of the wearer have different compositions and densities, the absorbed dose of radiation differs.
The correlation between the radiation dose of the radiation measurement body 702 and the radiation dose of the lens exposure is estimated by simulation.
The input / output control unit 902 of the radiation exposure dose measuring device 701 has a correction operation function based on the above-described dose estimation method.

(4) If the wearer does not wear radiation protective clothing, it is considered that equal exposure (a situation in which the whole body of the person to be exposed to radiation is almost uniformly exposed to radiation) is applied. In this case, the radiation exposure dose to the wearer's lens calculated from the radiation measurement body 702 is multiplied by a predetermined coefficient to estimate the radiation exposure dose to other organs or tissues other than the wearer's lens. It becomes possible to do.

FIG. 11 is a functional block diagram illustrating the details of the processing performed by the input / output control unit 902 for estimating and calculating the radiation exposure dose to the wearer's lens and each organ.
The RPL read amount input from the A / D converter 819 and read from the left lens of the radiation measurement object is M _rad (L), and the RPL read amount read from the right lens is M _rad (R). The left and right lens RPL reading amounts 1101 consisting of M _rad (L) and M _rad (R) are respectively multiplied by the absorption dose calibration constant 1102 of the radiation absorber determined in the calibration standard field by the first multiplier 1103. Note that the 11 and absorbed dose calibration constant 1102 on formulas and _{N D.}
As a result, the absorbed dose D _rad (L) of the left lens of the radiation measuring object and the absorbed dose D _rad (R) of the right lens of the radiation measuring object are derived by the following equations.
_{D rad (L) = N D} × M rad (L)
_{D rad (R) = N D} × M rad (R)

With respect to the left and right lens absorbed dose 1104 composed of D _rad (L) and D _rad (R), an average absorbed dose 1106 is calculated by the average calculator 1105.

The ratio between the 3 mm dose equivalent H _p (3) in the Monte Carlo simulation and the average absorbed dose of the radiation measuring body in the Monte Carlo simulation, which has been calculated in advance by the Monte Carlo simulation, is defined as a 3 mm dose equivalent calibration constant 1107. The 3 mm dose equivalent is a dose equivalent at a depth of 3 mm from the body surface, which is used as an index of the dose equivalent of the crystalline lens.

The average value 1106 of the absorbed dose is multiplied by a 3 mm dose equivalent calibration constant 1107 by the second multiplier 1108 to derive a 3 mm dose equivalent 1109. That is, the 3 mm dose equivalent 1109 is calculated by the following equation.

On the other hand, the left and right lens absorbed dose 1104 composed of D _rad (L) and D _rad (R) is also input to the radiation incident angle calculation unit 1110.
The radiation arrival angle calculation unit 1110 derives a relation of the radiation arrival angle 1111 with high expectation to the left and right dose ratio D _rad (L) ÷ D _rad (R) in the left and right lens absorbed dose 1104 in advance by Monte Carlo simulation. , In a table or the like. Then, a radiation flying angle 1111 corresponding to the input left and right lens absorbed dose 1104 is output.
Note that the radiation arrival angle 1111 in FIG. 11 and the mathematical expression is θ _rad .

Furthermore, pre had been calculated by Monte Carlo simulation, and organ absorbed dose D _T organ T of each radiation flying angle in Monte Carlo simulations, the ratio of the absorbed dose mean value of the radiation measurement body in the Monte Carlo simulation, Tables And so on. This table is defined as the flying angle absorbed dose ratio 1112 for each organ.

The absorbed dose average value 1106 and the radiation angle of incidence 1111 are input to the organ absorbed dose calculation unit 1113. The organ absorbed dose calculation unit 1113 searches for the organ incident angle absorbed dose ratio 1112 at the radiation incident angle 1111, derives a table of coefficients for each organ at the corresponding radiation incident angle, and multiplies by the absorbed dose average value 1106. .
That is, the organ absorbed dose 1114 in the organ T is calculated by the following equation.

[Radiation exposure dose measuring device 701: partition]
FIG. 12 is a schematic diagram of the holding table 801 and the partition 1201 provided inside the light shielding box 703.
A dosimeter formed on a lens irradiated with radiation emits visible light by a fluorescent phenomenon when irradiated with excitation light. In order to accurately measure the light emission caused by this fluorescence phenomenon, it is necessary to shield light that does not originate from the fluorescence of the dosimeter when operating the fluorescence receiving unit 804. For this reason, the radiation measurement body 702 is put in the light shielding box 703, and measures the light emission amount of the dosimeter in a state where external light is shielded.

(4) The excitation light emitting unit 803 such as an ultraviolet LED or a laser diode is driven to emit light with constant power using a known constant current circuit. For the purpose of irradiating the dosimeter with excitation light generated by constant power, if the dosimeter-formed lens is irradiated with excitation light over a wide area, the excitation light will be dispersed over a wide area and the fluorescent light generated over a wide area It is difficult to condense the light on the fluorescent light receiving unit 804 without leaving the light. In addition, as described with reference to FIG. 6, it is not preferable to irradiate the lens with excitation light over a wide range because the luminance at different portions of the dosimeter changes depending on the radiation irradiation direction. Therefore, the excitation light generated from the excitation light emitting unit 803 is focused on a part of the lens where the dosimeter is formed by the optical systems 805a and 805b.

As the types of optical systems 805a and 805b that can be used in the radiation exposure dose measuring apparatus 701 according to the embodiment of the present invention, an optical system called a PL system (Photoluminescence) in which a light emitting optical system and a light receiving optical system are separately configured. There is an optical system called a confocal system and a light emitting optical system and a light receiving optical system that share an objective lens. Regardless of the type of optical system, it is common that the excitation light needs to be focused on one location of the visible light transmitting member. For this reason, it is necessary to perform the operation of condensing the excitation light and measuring the fluorescence on a plurality of portions of the visible light transmitting member a plurality of times. In particular, in the first embodiment (eyeglass-type radiation measurement body) and the third embodiment (rear-mounted sunglass-type radiation measurement body), measurement work is separately performed on the right eye side and the left eye side of the visible light transmitting member. There is a need to. The holding table 801 and the motor 802 are provided to change the relative positional relationship between the optical systems 805a and 805b and the visible light transmitting member, and execute measurement at a plurality of positions on the lens.

On the other hand, a visible light transmitting member such as a lens constituting the dosimeter is made of glass or a transparent synthetic resin, and thus has optical characteristics such as refracting and reflecting light. The excitation light is no exception, and a part of the excitation light applied to the visible light transmitting member is irregularly reflected in various directions. Then, the irregularly reflected excitation light is irradiated on the dosimeter on the visible light transmitting member outside the measurement target, and fluorescence may be generated in another measurement portion even though measurement is not performed.

In order to prevent the excitation light from leaking into the places where the optical systems 805a and 805b are not to be measured and to minimize the fluorescence measurement error, the optical system 805a and 805b cross the center of the radiation measurement body 702 fixed to the holding table 801. In order to optically shield the right eye side and the left eye side of the visible light transmitting member from each other, a partition 1201 is provided. The partition 1201 eliminates the possibility that, when measuring the fluorescence of one visible light transmitting member, the excitation light that has been irregularly reflected is applied to the other visible light transmitting member.

In the embodiment of the present invention, the radiation measuring body and the radiation exposure dose measuring device 701 having various forms are disclosed.
The radiation measuring body can be realized by forming a transparent dosimeter on a lens in the form of well-known glasses, goggles, retro-fitted sunglasses, or the like.
The entire lens may be formed of dosimeter glass, or dosimeter powder obtained by pulverizing dosimeter glass may be applied to a transparent synthetic resin. Further, a scintillator may be formed on the periphery of the lens or on the entire surface or a part of the lens.
The range in which the dosimeter is formed on the lens may be the entire lens, but if the dosimeter layer is formed on the front and / or back surface of the lens on the side near the right ear and the side near the left ear of the wearer by coating or the like. In addition, there is an advantage that the irradiation direction of radiation can be inferred. Further, in order to further pursue this advantage, the extension protrusions 613a and 613b may be formed on the lens.

The radiation exposure dose measuring device 701 includes a light shielding box 703 for confining the radiation measuring body 702 and blocking external light, and a computer 704. The computer 704 includes a sequence control unit 903 that controls a switch 901 that shuts off noise when irradiating the radiation measurement body 702 with excitation light and measuring the amount of light emission.
Further, a partition 1101 is provided inside the light shielding box 703 to prevent light from leaking.

As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above embodiment, and other modified examples and application examples may be provided without departing from the gist of the present invention described in the claims. Including.

101: radiation measuring body, 102a, 102b: lens, 103a, 103b: rim, 104: bridge, 105a, 105b: tomo, 106a, 106b: hinge, 107a, 107b: temple, 121: radiation measuring body, 122: lens , 123 ... frame, 124 ... face pad, 125 ... strap, 131 ... radiation measuring body, 132a, 132b ... lens, 133 ... bridge, 134 ... clip, 201 ... crucible, 206 ... aluminum plate, 207 ... glass plate, 301 ... Dosimeter glass plate, 302: fluorescence changing portion, 401: dosimeter raw powder, 402a, 402b: sieve, 403: dosimeter powder, 404: pure water, 501: lens, 502: base material, 503: dosimeter layer, 504 ... Scintillator, 601a, 601b ... lens, 602a, 02b: First detection area, 603a, 603b: Second detection area, 611a, 611b: Lens, 612a, 612b: First detection area, 613a, 613b: Extended projection, 701: Radiation exposure dose measuring device, 702: Radiation Measurement object, 703: light shielding box, 704: computer, 801: holding table, 802: motor, 803: excitation light emitting unit, 804: fluorescent light receiving unit, 805a, 805b: optical system, 806: charge amplifier, 807: linear Amplifier, 811 bus, 812 CPU, 813 ROM, 814 RAM, 815 display unit, 816 operation unit, 817 nonvolatile storage, 818 serial interface, 819 A / D converter, 901 switch , 902, an input / output control unit, 903, a sequence control unit, 1101, a left and right lens RPL reading amount, 1102 Absorbed dose calibration constant, 1103 first multiplier, 1104 left and right lens absorbed dose, 1105 average value calculation unit, 1106 absorbed dose average value, 1107 3 mm dose equivalent calibration constant, 1108 second multiplier, 1109 3mm dose equivalent, 1110 ... radiation flying angle calculation unit, 1111 ... radiation flying angle, 1112 ... organ flying angle absorption dose ratio, 1113 ... organ absorption dose calculation unit, 1114 ... organ absorption dose, 1201 ... partition

Claims (14)

1. A visible light transmitting member formed with a dosimeter capable of transmitting visible light at least in part,
   An arrangement tool for arranging the visible light transmitting member near at least one crystalline lens of a wearer,
   A radiation measuring body, comprising: a visible light transmitting member fixing device interposed between the visible light transmitting member and the placement device to fix the visible light transmitting member to the positioning device.
2. The radiation measuring body according to claim 1, wherein the dosimeter is an integrating dosimeter element.
3. The visible light transmitting member is a lens of spectacles,
   The placement device is a temple of glasses,
   The visible light transmitting member fixture has a bridge and a rim of spectacles,
   The radiation measurement body according to claim 2.
4. The visible light transmitting member is a goggle lens,
   The placement device is a goggle strap,
   The visible light transmitting member fixing device has a goggle face pad,
   The radiation measurement body according to claim 2.
5. The visible light transmitting member is a lens of a retrofit sunglass,
   The placement instrument is a clip of retro sunglasses,
   The visible light transmitting member fixing device has a bridge for retrofit sunglasses,
   The radiation measurement body according to claim 2.
6. The arrangement tool and the visible light transmitting member fixing tool have heat resistance to withstand the annealing treatment of the visible light transmitting member,
   A radiation measuring body according to claim 3.
7. The visible light transmitting member is detachable from the visible light transmitting member fixture, and has heat resistance to withstand an annealing process.
   The radiation measuring body according to claim 4.
8. The visible light transmitting member has a scintillator formed at least in part,
   The radiation measuring body according to claim 3, 4, or 5.
9. In the visible light transmitting member, a dosimeter layer is formed on each of a surface near the right ear and a side near the left ear of the wearer on the front surface and / or the back surface.
   The radiation measuring body according to claim 3, 4, or 5.
10. In the visible light transmitting member, an extension protrusion is formed at an angle along the face of the wearer on each of a surface near the right ear and a side near the left ear of the wearer on the front surface and / or the back surface, A dosimeter layer is formed on the extension protrusion,
    The radiation measuring body according to claim 3, 4, or 5.
11. A visible light transmitting member formed with a dosimeter capable of transmitting visible light in at least a part thereof, an arrangement tool for arranging the visible light transmitting member near at least one crystalline lens of a wearer, the visible light transmitting member, and Radiation exposure of a wearer who wears the radiation measuring body using a radiation measuring body including a visible light transmitting member fixing device that fixes the visible light transmitting member to the positioning device, interposed between the positioning device and the visible light transmitting member. A radiation exposure measuring device for measuring the amount of radiation,
    A light shielding box for enclosing the radiation measurement body and preventing the incidence of visible light,
    An excitation light emitting unit that irradiates excitation light to the radiation measuring body inside the light shielding box,
    A fluorescent light receiving unit that converts a light emitting state of the radiation measuring body into a predetermined electric signal,
    An input / output control unit that outputs a radiation exposure amount in the eyeball of the wearer by calculating a radiation exposure amount of the radiation measurement body based on an output signal of the fluorescence light receiving unit; apparatus.
12. Furthermore,
    A switch that is provided between the fluorescent light receiving unit and the input / output control unit and that shuts off noise that is included in an output signal of the fluorescent light receiving unit and that occurs at a predetermined time after emission of the excitation light emitting unit ends When,
    The radiation exposure dose measuring device according to claim 11, further comprising: the excitation light emitting unit; and a sequence control unit that performs on / off control of the switch.
13. The radiation exposure dose according to claim 12, wherein the input / output control unit further multiplies the radiation exposure dose in the eyeball of the wearer by a predetermined coefficient to output a radiation exposure dose in various organs of the wearer. Measuring device.
14. The visible light transmitting member of the radiation measurement body, a dosimeter is formed on each of the side near the right ear and the side near the left ear of the wearer,
    The light shielding box is provided with a partition that prevents leakage of mutual light emission between the left and right dosimeters formed in the visible light transmitting member,
    The radiation exposure dose measuring device according to claim 13.
    

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