JP7370107B2 - Composite protective equipment and instruments that reduce exposure and protective loads - Google Patents

Description

The present invention is a medical undertube-type X-ray device that can reduce the exposure dose and radiation protection burden for medical workers and patients in the medical field that uses X-ray (hereinafter referred to as "X-ray") fluoroscopy equipment. We provide complex protective equipment and equipment that can be added to fluoroscopy equipment.

The use of radiation in the medical field is becoming more widespread. A typical example is treatment using interventional radiology (hereinafter referred to as "IVR"). In IVR, a thin tube or needle called a catheter is inserted into the body while observing X-ray fluoroscopic images and angiographic images. This allows diseases to be treated without surgical intervention and without leaving any scars on the body.

Today, X-ray fluoroscopes are used by specialists in various medical departments (hereinafter referred to as "surgeons") who perform numerous operations as clinical procedures. The use of radiation in clinical practice is steadily increasing, and procedures involving exposure of patients and healthcare workers are frequently performed. Recently, techniques such as pulsed fluoroscopy and selective angiography have advanced further. However, as opportunities for use increase, the exposure time due to X-ray irradiation tends to become longer, leading to an increase in medical exposure for patients and occupational exposure for medical workers. In addition, in some cases radiation protection measures are lagging behind, increasing the risk of radiation sickness for medical workers and patients.

In angiography, an X-ray fluoroscopy device (hereinafter referred to as an “angiography device”) is used. Angiography is a method of injecting a contrast medium into a blood vessel and photographing its flow using X-rays to observe the shape of the blood vessel itself. By injecting a contrast agent, which is difficult for X-rays to pass through, into the target blood vessel and then taking an X-ray photograph, it is possible to clearly visualize the shape of the blood vessel where the contrast agent has entered. In addition, with the angio equipment, fluoroscopy or observation is always performed during the surgery. Therefore, medical procedures that use angio equipment expose medical workers and patients to high doses of radiation. Some recent angiography devices emit pulsed X-rays in order to reduce medical exposure and occupational exposure of medical personnel.

Here, the structure and usage of angio equipment and the behavior of X-rays will be explained using angio equipment as a representative example. A typical structure of an angio apparatus is that an X-ray tube is installed either above or below a bed (hereinafter referred to as a "table") on which a patient lies. In addition, a pair of X-ray receivers installed in opposite directions receive the X-rays that have passed through the patient. In an angiography system, the direct X-ray rays originally follow a straight, unidirectional irradiation path in which they exit the X-ray tube in the X-ray source, pass through the patient, and reach the image receiver. A small portion of the X-rays emitted from the X-ray tube and passed through the patient enters the image receiver. A portion of the incident X-rays is transmitted as fluoroscopic image data and displayed on a liquid crystal TV screen. However, most of the X-rays are scattered by the patient's body and emitted as scattered radiation around the apparatus.

In the case of an undertube type angio device in which the X-ray source is placed below the table, the primary X-rays from the X-ray tube and their small-angle scattered X-rays travel upward. However, the X-rays scattered by the table and the patient's body travel not only upward, but also to the sides and downward. Note that, according to Non-Patent Document 1 (ICRP, 2017), it is stated that in the undertube type scattered X-ray, the number of photons is the largest below the table.
Patent Document 1 states that, for example, in the case of an undertube type primary X-ray of about 100 KeV, the ratio of scattering and absorption is as follows. Approximately 80% of the light is scattered by body tissues, and 10-odd% is absorbed. Most is scattered by the table and about 3% is absorbed. This results in approximately 3% being transmitted to the X-ray receiver.

For radiation protection of medical workers and patients, Non-Patent Document 1 (ICRP, 2017) proposes the use of protective equipment. This personal protective equipment includes a lead apron, eye protection (safety glasses), and thyroid protection. In addition, for multiple people, there are protective curtains, ceiling-suspended shielding boards, and mounted shielding boards. However, these radiation protection devices are designed to protect only from X-rays that come in a planar direction toward a specific direction, that is, from only the intended direction. Therefore, the effect of reducing exposure by these radiation protective equipment is limited to a specific direction. Therefore, the purpose of these protective equipment is to reduce to some extent the radiation exposure of medical personnel who move around during surgeries. These protective equipment do not provide a fundamental solution to reducing exposure to X-rays scattered from various directions.

In particular, in recent years, legal regulations have placed limits on the lens dose in order to reduce radiation exposure to the eyes of the operator. As a result, more and more IVR doctors are wearing crystalline lens dosimeters in addition to protective glasses. However, small-angle scattered X-rays from the periphery of the irradiation field in the undertube type have high energy and have an intensity comparable to that of the primary X-rays. These forward scattered X-rays are irradiated to the operator's eyes. Therefore, current lead glasses, goggles, and the like do not provide sufficient shielding for the bottom and side surfaces of the glasses. However, the weight of the protective glasses must be small in order to reduce the physical burden. Therefore, there is a certain limit to sufficiently lowering the lens dose to the operator.

As mentioned above, the scattered X-rays come from three directions: front, side, and rear when viewed from the patient's body. The energy of these scattered X-rays is roughly divided into three types depending on the source and their effective energy. The highest energy is the small-angle scattered X-rays that are generated upward (in front of the undertube) from the irradiation field and its surroundings. Small angle scattered X-rays are included in forward scattered X-rays. The next highest energy is scattered X-rays that are generated in three directions (hereinafter referred to as "all directions") from a location close to the irradiation field: front, side, and rear. The lowest energy is scattered X-rays generated from the whole body of a patient within 40 cm from the irradiation field and rescattered several times by human tissue (hereinafter referred to as "scattered X-rays from the whole body").

Patent Document 1 relates to a composite absorption material for scattered X-rays by the same inventor. Patent Document 1 proposes a composite absorbing material that attenuates and absorbs scattered X-rays using a multilayer structure in which three or more layers having different roles are closely stacked. The composite absorption material is composed of a lead (Pb) low reflection attenuation layer (initial layer) and a multilayer absorption layer (diffuse absorber, electron absorber). In many cases, the multilayer absorption layer consists of flat plates or metals such as tin (Sn), niobium (Nb), molybdenum (Mo), copper (Cu), iron (Fe), titanium (Ti), aluminum (Al), etc. Foil is used. By arranging one to three pairs of diffusion absorbers and electron absorbers overlapping each other without any gaps, the linear energy of incident scattered X-rays is efficiently absorbed. Characteristic X-rays and secondary X-rays due to braking X-rays are generated by the absorption of ray energy. The generated secondary X-rays are scattered in all directions including the direction of incidence. The scattered secondary X-rays travel toward the surrounding and side layer materials, where similar reactions occur. This is diffusion pushback. In all of these processes, the X-rays disappear by converting their energy into kinetic energy such as photoelectrons. Scattered X-rays generated in the patient's body during surgery can be attenuated and absorbed by this composite absorbing material.

Furthermore, in Example 17 and FIG. 13 of Patent Document 1, a cloth for a patient's body, a sheet for a table, clothing, and a head cover using a composite absorbent material are shown as examples. Scattered X-ray absorbers such as blankets, clothing, and head covers mainly use flexible composite absorbing materials. The table top may be made of a rigid composite absorbent material. Furthermore, the above-mentioned hanging cloth and bed sheet have the irradiation field cut out. Note that Patent Document 1 is a material patent.

Patent Document 2 is related to a medical table (hereinafter referred to as a "high-performance table") that transmits X-rays well and reduces scattering by the same inventor. This highly functional table consists of the following three stages at maximum. This consists of a top plate tier that supports the weight of the patient and absorbs scattered X-rays, an intermediate tier that serves as a movable diaphragm for the irradiation field and an absorber, and a bottom plate tier made of low-reflection and low-scattering material. . A certain function can be achieved even with only one or two of these three stages.
In this table, the primary X-rays pass through a hollow space and then pass through a transmission plate unit made of a mesh on the table top or a thin film such as CFRP, and reach the irradiation field of the affected part of the patient's body without interaction. The table top attenuates and absorbs scattered X-rays generated by the patient's body using a composite absorbing material.
The irradiation field portion of the bottom plate is cut out to allow primary X-rays to pass through without scattering. In addition, the position of the irradiation field through which the primary X-rays are transmitted and the minimum opening size are adjusted using various adjustment functions. These parts include the transparent plate unit on the top plate level, the slide table and aperture plate on the middle level, and the opening/closing plate on the bottom plate level.
As a result, in the highly functional table, primary X-rays are transmitted with little scattering and high positional accuracy. Therefore, the image quality of the X-ray receiver becomes clearer. If the image quality of an X-ray receiver becomes clearer, an X-ray fluoroscope can be used with lower primary X-ray energy.
On the other hand, in areas other than the irradiation field, line attenuation and line energy absorption are effectively performed using shielding materials or composite absorbing materials (hereinafter referred to as "functional materials"). At the same time, the intensity of downwardly scattered X-rays is reduced. These allow primary X-rays to pass through well and reduce the exposure dose for medical personnel and patients.

Patent Document 3 is an additional shield designed by the same inventor for the purpose of reducing radiation exposure and reducing the protective load.in the boxIt is related to The structure of the box of this invention is as follows. It consists of a box body, a box top plate, a viewing window, a patient port, a shielding sheet for the left side, a sleeve port, and a sleeve structure for the left side. In addition, in Patent Document 3, the shielding sheet is treated together with the hanging cloth, and they are collectively referred to as the hanging cloth. In the present invention, these are treated separately.
The additional shield box is assembled and installed on the table surrounding the irradiation field of the patient's trunk, etc. When this box is left at rest and no surgery is being performed, there is no opening communicating with the external space in any three-dimensional direction. The patient's body passes through the box through patient ports provided at both ends in the height direction (hereinafter referred to as the "body axis direction"). The head and lower extremities are placed outside the box to avoid exposure. Here, the remaining space of the patient port is closed off with a flexible shielding sheet.
Furthermore, during surgery, medical personnel can view the inside of the box through a viewing window with shielding capabilities. At the same time, a medical procedure is performed by inserting a hand or arm through a sleeve structure attached to a sleeve port. Sleeve structures also have shielding capabilities.

The additional shield box of Patent Document 3 attenuates small-angle scattered X-rays upward from the periphery of the irradiation field due to primary X-rays and upwardly or laterally scattered X-rays generated in the patient's body. For the material of the box, functional materials with different combinations of types and thicknesses are used depending on the dose rate. A structure made of this functional material three-dimensionally surrounds the irradiation field.
A line-attenuating material whose effective energy of small-angle scattered X-rays is below the K absorption edge is used as a shield for the top of the box. This protects the operator's crystalline lens from radiation. Additionally, the viewing window is provided with a shielding ability commensurate with the linear attenuation material. In addition, a composite absorbing material or the like is placed on the inside surface of the box at various locations to absorb the linear energy of the linearly attenuated X-rays.

The additional shield box disclosed in Patent Document 3 has the following two types depending on the structure of the X-ray receiver. These are split box type boxes and flat paneldetector(FPD) It is a built-in box.
In the first split box type box, the receiver arm of the X-ray receiver is installed between the split boxes into the receiver port on the box ceiling. Therefore, the box must be divided into two or more parts. Some of these are compatible with C-arms.
In the second FPD built-in box, the FPD itself, which is an X-ray receiver, is installed inside the box. For handling purposes, it is best to use a split box, but an integrated box is also acceptable.
High-dose boxes have been proposed as options for both of the above-mentioned types. This is an option when the energy of small angle scattered X-rays is high.
That is, the additional shielding box can reduce the intensity of small-angle upward scattered X-rays and upward and sideward scattered X-rays. This makes it possible to reduce the air dose rate in the treatment room and the like. At the same time, the radiation exposure of medical workers and patients can be reduced. Furthermore, the protective burden on medical personnel can be reduced.

In the above description, protective devices such as the high-performance table of Patent Document 2 and the additional shield box of Patent Document 3 have been described. A highly functional table takes care of reducing scattered X-rays. Similarly, the additional shield box is divided into upper and side parts. However, it is impossible in principle to shield scattered X-rays generated from a patient's body in all directions with one of these protective devices. That is, the intensity of scattered X-rays in all directions must be reduced by a combination of these. Note that the intensity of X-rays herein means the Riemann sum of the number of photons of X-rays in the target energy range.

In the background art of Patent Document 1, the results of investigation on the structure and materials of the prior art protective equipment are described. No other materials for these protective gears are said to be comparable to this invention. That is, there is no material that attenuates and absorbs scattered X-rays by using three or more multilayers in which a low reflection attenuation layer and a multilayer absorption layer are closely stacked and the outermost layer is an electron absorber. Therefore, there is no material similar to the composite absorbent material of Patent Document 1. Note that Patent Document 1 is a material patent and does not claim a protective equipment or its structure.
In the background art of Patent Document 2, the results of investigation on the structure and materials of the table and its accessories in the prior art are described. These tables do not have a mechanism for transmitting X-rays in the irradiation field or an aperture mechanism. Furthermore, these tables do not have the function of attenuating and absorbing scattered X-rays using the material of the top plate. Therefore, there is no table similar to the high-performance table of Patent Document 2.
In the background art of Patent Document 3, the research results of prior art human body protection devices, radiation shield devices, and radiation protection cabins are described. These devices have no mechanism to protect the operator's hands and arms in common. Furthermore, these devices do not have a rectangular box that three-dimensionally surrounds the irradiation field. Furthermore, these devices do not have the ability to attenuate and absorb scattered X-rays by the material of the box. Moreover, the radiation shielding device does not provide lateral shielding in the axial direction of the patient. The radiation protection cabin has no shielding above the table. That is, nothing similar to the additional shield box of Patent Document 3 has been found.
The present invention is a combination of Patent Document 1, Patent Document 2, and Patent Document 3, and is further developed. In Patent Documents 1 to 3, there was no prior art similar to each invention. Therefore, the subject matter of the present invention is not present in the prior art.

Patent Document 4 is a table-shaped protective device in which a lead material is attached to the top plate of a simple table with four legs that is installed on a medical table. The simple table is placed so that it covers the patient's neck and toes. Further, the simple table may be covered with a shielding sheet. This aims to reduce scattered X-rays when using IVR.
However, this simple table does not have a mechanism for transmitting X-rays in the irradiation field or an aperture mechanism. That is, there is no table similar to the high-performance table of Patent Document 2.
In addition, this device does not have a rectangular box that three-dimensionally surrounds the irradiation field. Additionally, there is no mechanism to protect the operator's hands and arms. That is, nothing similar to the additional shield box of Patent Document 3 has been found.

Edited by ICRP Recommendation Translation Review Committee, ICRP Pub. 117 “Radiation protection in fluoroscopically guided procedures performed outside the diagnostic imaging department”, Japan Isotope Association, March 31, 2017. Shiori Hamakawa et al., “Exposure dose and protection of major organs during pediatric head CT examination,” Journal of the Department of Medical Radiology Technology, No. 13 (2015)

Japanese Patent Application No. 2022-161788 (domestic priority application, earlier application is Japanese Patent Application No. 2022-001336) Japanese Patent Application No. 2022-123002 (domestic priority application, earlier application is Japanese Patent Application No. 2022-018334) Patent Application No. 2022-075633 JP 2017-6358 Publication

Conventional protective equipment is heavy (hot) and can only provide radiation protection in certain directions. The present invention reduces the exposure dose and the physical burden of protection for medical personnel due to X-rays scattered in all directions from a patient's body. Furthermore, the present invention increases operability while maintaining protective performance. Note that the present invention is directed to a medical undertube type X-ray fluoroscope.

The present invention has devised a complex protective device/instrument by combining devices, instruments, and protective equipment. These devices attenuate and absorb scattered X-rays generated from the patient's body in all directions (front, side, and rear), reducing the exposure dose for medical workers and patients. At the same time, the burden of radiation protection on medical workers can be reduced. Note that protective devices, instruments and tools (PDITS) is a general term for protective devices, protective equipment, and protective equipment. There are two main ways to solve problems:
The first means uses a combination of two protective devices (PDs): first protection and second protection. The first protection is the table . The second protection is the box . This allows primary X-rays to pass through well and reduces the intensity of scattered X-rays in all directions.
The second method uses a combination of protective instruments (PI) as third protection in addition to the above-mentioned protective device (PD). This reduces the intensity of scattered X-rays leaking laterally from the through port of the shielded box as the human body moves during surgery. The third type of protection, personal protective equipment (PI), includes draperies on the patient's body, patient clothing, and head covers. In addition, there are additional protective equipment and simplified protective equipment described below.
Protective tools (PT) such as protective clothing worn by medical personnel are often limited to one specific direction and cannot be expected to provide major radiation protection. PT and other medical workers wear protective aprons, protective glasses, and thyroid protectors. Therefore, in the present invention, PT is positioned as an additional means of PD and PI.

First, we will organize the types of scattered X-rays that are generated from the patient's body in all directions.
The average value of the energy of scattered X-rays generated in all directions from the patient's body is as follows. Here, the highest value is the forward scattered X-rays above the table. The next highest is the side scattered X-rays in the 360° direction of the horizontal plane on the side of the table. The lowest is the backscattered x-rays below the table.
Example 2 of Patent Document 1 and b. of FIG. In this section, the median energy of X-rays scattered by the patient's body in angio equipment is described. This is 65 kiloelectron volts (KeV) on the side of a 90° scattering angle when the tube voltage of the X-ray source is 110 kilovolts (kV). Similarly, the value behind a scattering angle of 150° at 100 kV is 40 KeV.
On the other hand, there is literature information that reports a high value for the energy of upwardly forward scattered X-rays. This is natural since it includes small-angle scattered X-rays of primary X-rays. However, the results were measured using an area dosimeter, and no literature could be found that accurately determined the measurement location.

Next, materials used for protective devices and instruments (PDITS) will be explained. Here, existing materials containing elements such as lead (Pb), barium (Ba), or tungsten (W) and having shielding ability are referred to as "shielding materials."
A material defined in Patent Document 1 that can effectively attenuate and absorb scattered X-rays by using a multilayer structure of three or more closely stacked layers is called a "composite absorption material." The composite absorption material is composed of a low reflection attenuation layer (first layer Pb) and a multilayer absorption layer.
Shielding materials such as Pb alone greatly attenuate scattered X-rays. However, since the composite absorption material has multiple absorption layers, in addition to attenuating X-rays, it also absorbs a large amount of linear energy of scattered X-rays of 87 KeV or less. Furthermore, in the present invention, both the above-mentioned shielding material and composite absorbent material having shielding ability are collectively referred to as "functional material."
Further, the differences between the "table" and "high-performance table" and the "box" and "additional shield box" of the present invention are shown below.
The "table" of the present invention is a flat table on which a functional material capable of shielding against scattered X-rays from a patient placed thereon is disposed. A highly functional table takes care of the lower part in reducing the intensity of scattered X-rays. The table is one of the protective devices (PD).
The "high-performance table" of the present invention increases the transmittance of primary X-rays and reduces scattered X-rays. In addition to the table above, this has the function of increasing the transmittance of primary X-rays by suppressing absorption and scattering of primary X-rays by the top plate, and reducing the intensity of scattered X-rays downward from near the irradiation field of the patient's body. This is a table with additional functions. A more precise definition is that a high-performance table has a net made of elements or compounds with an atomic number of 14 or less installed on the step of the top plate, and X-rays are transmitted through the net. This is a table that suppresses absorption and scattering of X-rays. A high-performance table is a narrow concept within a table that is the first protection, and is one of the protective devices (PD).
The "box" of the present invention is a rectangular box that is placed on a table and has a functional material arranged on the surface or inside of which the scattered X-rays are incident. The box shares the upper and side parts in reducing the intensity of the scattered X-rays. It is essential for the box of the present invention to incorporate the X-ray receiver into the box. Providing a patient port through the patient's body is optional. However, it is recommended that they be installed as an additional function in order to control medical radiation exposure to patients and to reduce the psychological burden on patients. A box is a type of protective device (PD).
The "additional shield box" of the present invention is a box-shaped additional shield that reduces radiation exposure and protection load for medical personnel. This box has the functions of a device for visually checking the inside of the box, such as a viewing window, and a device for operating the inside of the sleeve port, etc. The box top plate's radiation attenuating material attenuates and absorbs small-angle scattered X-rays, which have a high intensity upward from near the irradiation field of the patient's body. The additional shield box is a narrow concept within the box that is the second protection and is one of the protective devices (PD).
Furthermore, the definition of "omnidirectional" in the present invention and the difference between "aperture" and "no aperture" are shown below.
In the present invention, "omnidirectional" means all directions of 360 degrees, including all directions, up, down, left and right, which are equal to the direction of the radiation spreading from the radiation source located at the center of the sphere. In the present invention, when the vertically upper part of the sphere is 0 degrees (base point) and the vertically lower part is 180 degrees, the sphere with a center angle of 0 to 45 degrees and an upper side of 360 degrees is upward and a center angle of 135 to 180 degrees. The lower sphere of 360 degrees to the sides is called the lower part, and the remaining sphere of 360 degrees to the sides with a center angle of 45 to 135 degrees is called the side.
The term "opening" in the present invention refers to the mouth in an open state. Penetration ports that are blocked by a structure in which a functional material with shielding ability is disposed on or inside the structure are excluded from the list of openings, which are referred to as "openings in which transmission of X-rays cannot be reduced." That is, in the present invention, "no opening" means a state in which the structure is surrounded in all directions by a structure in which a functional material with shielding ability is arranged on the surface or inside.

In the first method, two protective devices (PDs), the first protection and the second protection, are used in combination. The first protection is the table . The second protection is the box. A means of combining and utilizing two protective devices, the first protection and the second protection, is called a "combination case" of a box and a table.

The first protection table linearly attenuates the backscattered X-rays downward from the patient's body and absorbs the linear energy.
First, the table top with functional material placed on the patient-side surface can reduce the intensity of low-energy backscattered X-rays downward from the whole body.
Furthermore, the intensity of backscattered X-rays downward from the periphery of the irradiation field can be reduced by the intermediate slide table and aperture plate with functional materials placed on the patient-side surface. Backscattered X-rays from this region have higher energy than other regions.

The second protection, the box, absorbs linear energy by attenuating forward scattered X-rays upward and side scattered X-rays from the patient's body. A rectangular box has a structure in which a functional material exists in any three-dimensional direction. The functional materials placed on the inner surface and the structural materials of the box reduce the intensity of side-scattered X-rays, which are considered to be of medium energy. There are two types of additional shield boxes: a split box type and a built-in FPD type.

When the energy of small-angle scattered X-rays coming from the periphery of the irradiation field exceeds 88 KeV, shielding with Pb generates secondary X-rays including the characteristic X-rays of the K shell, resulting in increased reflection and scattering. Therefore, it is difficult to significantly attenuate it using the box's structural material or shielding material. In this case, as described in Patent Document 1 and Patent Document 3, this small-angle scattered X-ray can be absorbed by a box top plate made of a line-attenuating material with an atomic number of 83 or higher, such as uranium (U), and a viewing window with enhanced shielding ability. Attenuate.

In the first measure, two protective devices (PDs) share the orientation from the next patient's body to attenuate and absorb the scattered X-rays. The table is in charge of the lower part. The box is in charge of the top and sides. Combining these two PDs has the following two effects. One is that it transmits primary X-rays well. The other one attenuates and absorbs scattered X-rays generated from the patient's body in all directions, including the periphery of the irradiation field. A PD that combines multiple devices is called a "compound protective device (PD)."
The tube voltage of the X-ray source can be lowered by allowing the primary X-ray to pass through the PD table well. Lowering the tube voltage can reduce the intensity of the generated scattered X-rays. When the intensity of scattered X-rays is reduced, the exposure dose can be reduced. Therefore, these two are related.
Embodiment 1 and FIG. 1, which will be described later, show detailed contents of the concept of a combination case of a box and a table based on the first means. Example 2 and FIG. 2 illustrate a bird's eye view of the combination of two protective devices.

The second means adds a protective instrument (PI) as a third protection in addition to the first protection (table) and second protection (box) of the first means. The reason for adding the third protection is to reduce the intensity of scattered X-rays leaking laterally from the through port of the shielded box as the human body moves during surgery. There are three ways of thinking about adding PI, and the means to implement each are different. The PI is different from the PT worn by medical professionals in the past. All of these PIs are made of functional materials.
One of the second means is to supplement the protection from side scattered X-rays that is insufficient with only a protective device (PD) during surgery by using an additional protective device (PI) to be attached to the patient's body. Here, a hanging cloth (hereinafter referred to as "normal hanging cloth") having a normal mass range and patient's clothing are used as the additional PI. If the neck or head is in the irradiation field, use a head cover in addition to clothing.
The second method uses a newly devised PI. The idea is to strengthen protection against side scattered X-rays by increasing the thickness and mass of a thick cover (hereinafter referred to as a "thick cover") with high shielding ability. In addition, in order to avoid imposing physical stress on the patient due to the weight, a supporting structure is used that supports the thick drapery and directly transmits the weight to the table. The thick drapery and support structure are additional PIs to increase the shielding ability of side scattered X-rays. These are collectively called "Additional Protective Instruments" (API). APIs are also a third type of protection.
The second means 3 is a modification of the second means 2. The protection from side scattered X-rays enhanced by API creates a margin for reducing the protection provided by the "box accessory" that combines the sleeve structure and shielding sheet on the PD side. The idea is that this will improve the operability of the protective equipment (PI) attached to the PD while maintaining the same level of protection performance. PI to improve operability are the strip curtain and gloveless port. The general term for these is "Simple and Easy Protective Instrument" (SEPI).

At the beginning of the second means, the state of the side of the box where there is a possibility of insufficient shielding during surgery will be explained. The rectangular additional shield box has a sleeve port and a patient port at the side ends. Both are collectively referred to as a "through port."
The sleeve port exists for medical personnel to insert the arm and arm into the box during surgery. A sleeve structure with a shielding function is attached to the sleeve port. The sleeve structure allows medical personnel to perform medical procedures within the box with reduced radiation exposure to their hands and arms.
A patient port exists to penetrate the patient's trunk during surgery. The patient's head and extremities are exposed outside the box, which has a shielding function. This can reduce medical exposure to patients and ease the psychological burden caused by confined spaces. The act of penetrating the patient's trunk into the box is performed by a medical worker.
During observation such as before surgery (hereinafter referred to as "standing"), the through port is provided with a structure that has a shielding ability. In the shielding structure of Patent Document 2, the sleeve port has a sleeve structure. Similarly, the patient port has a shield sheet.

One typical example of a sleeve structure is a sleeve. The sleeve is a cone that is open at both ends and is made by molding a flexible functional material. The tip of the sleeve opens at the wrist size. When stored or not in use, it is closed with a rubber band. A medical worker wearing protective gloves inserts the arm during surgery. On top of that, they are working hard to perform medical procedures. Each time this movement occurs, the tip of the sleeve opens and scattered X-rays leak out of the box.
On the other hand, the shielding sheet is an integral sheet made of a flexible functional material. After installing the box through the patient in preparation for surgery, the shielding sheet is installed so as to close off the remaining space of the patient port as much as possible. This shields the patient port when it is stationary. However, during surgery, the closed sheet may shift due to patient movement. If it deviates, scattered X-rays will leak out of the box.

Body tissue passing through the penetration port scatters the X-rays while partially transmitting them. This body tissue is the medical staff's skill and the patient's trunk. That is, when the intensity of the scattered X-rays inside the box is high, some of the scattered X-rays leak out of the box.
In addition, the sleeves and shielding sheets are made of soft and thin materials for delicate medical procedures. That is, due to medical requirements, the thickness of these flexible functional materials cannot be increased. Therefore, when the tube voltage of the X-ray source is high, the shielding ability of these box accessories may be insufficient.

As mentioned above, the through port is shielded when the device is left at rest before surgery. Even when penetrating body tissue, efforts are made to close the gap as much as possible. However, during surgery, the movement of the penetrating body tissue creates a gap between the box and the human body, causing scattered X-rays to leak out of the box. Furthermore, human tissue passing through the through port is transparent to X-rays. Furthermore, when the tube voltage of the X-ray source is high, the shielding ability of the shielding structure may be insufficient. Therefore, the through port cannot completely prevent leakage of X-rays during surgery.

In the second method, the insufficient shielding ability of the protective device (PD) is supplemented by the additional protective device (PI) attached to the patient's body. The PIs to be added in the box are the drape on the patient's body and the patient's clothes. These enhance the ability to shield scattered X-rays to the side of the box where the through port is located. Generally, the thickness of commercially available hanging cloth is 0.25 to 0.5 mm Pb in terms of lead equivalent. Commercially available hanging fabrics in the normal weight range are referred to as "normal hanging fabrics." Currently, there are no commercially available garments for this purpose.
In general, due to its shape effect, radiation can be shielded more efficiently with articles of the same thickness but with smaller weight as they are closer to the radiation source. The drapery on the patient's body and the patient's clothes can shield scattered X-rays emitted from the patient at optimal positions.

A drapery is a flexible sheet made of functional material. In order to allow the primary X-rays to pass through, the cloth is provided with a hollowed-out portion that cuts out the irradiation field of the affected area to a slightly larger size. The hollowed out portion is open upward. Therefore, in the vicinity of the irradiation field, the ability of the cloth to shield scattered X-rays from above is inferior to that from the sides. Additionally, the hanging cloth originally does not have the ability to shield the area from below.

Clothing should be worn by the patient, not by the healthcare worker. The garment is in the form of a flexible short-hem coat (half-coat) made of functional material. The length of the hem is preferably within 40 cm from the edge of the irradiation field. Clothing can block scattered X-rays emitted from the patient in all directions. However, clothing made from functional materials is as heavy as armor. Therefore, it is difficult to use a device with a large mass that exceeds the limit of the physical load on the patient. In addition, the clothing has cutouts slightly larger than the irradiation field on the front and back of the clothing to allow primary X-rays to pass through. Therefore, the ability of clothing to shield scattered X-rays is lower when viewed from below or above than from the sides.
The patient's head cover is a mask made of functional material. Have the patient wear it when the affected neck or head is the irradiation field. The reason for this is that scattered X-rays leak from the head to the outside when the distance from the irradiation field is within 40 cm.

As described above, by combining a plurality of PDs and a plurality of PIs during surgery, it is possible to reduce the leakage of scattered X-rays to the outside of the box, mainly to the sides during the surgery. Therefore, radiation exposure of medical personnel and patients can be reduced.
In Example 4 and FIG. 4, which will be described later, the detailed content of the concept of complex protective equipment and instruments (PDITS) that efficiently reduces exposure dose based on the second means 1 will be shown. In the fifth embodiment, a bird's-eye view of a case in which a new PI is combined will be explained with reference to FIG.

In the second measure 2, another PI is added to further strengthen the shielding ability of the sides of the box, which may be insufficient during surgery with the protective device (PD). That is, in addition to the second measure, the additional protective equipment (API) further strengthens the protection mainly against side scattered X-rays. Additional protective equipment (API) is thick-walled draperies and support structures.

Thick wall coverings have a higher shielding ability than regular coverings. By placing the thick hanging cloth in a portal-shaped manner surrounding the patient in the space above the patient's body on the table, it is possible to enhance the shielding performance of side scattered X-rays during surgery. However, the thickness and mass increase. If this is placed directly on the patient's body, the physical load due to the weight will increase.
Therefore, a thick hanging cloth with a large mass is placed on a support structure installed on a table, and the patient is placed in a semi-cylindrical, trapezoidal or portal shape (hereinafter referred to as a "gate shape") in the space above the patient's body. ). The mass of the thick drapery is now supported directly on the table via the support structure. Therefore, with this method, a high shielding ability can be ensured by using the thick cloth without imposing physical burden on the patient due to the weight.

As described below, the total thickness (total t) of the functional material of the thick hanging cloth is preferably 1 to 3 mm. Its mass is 6-18 kg. The mass of the support structure is approximately 10 kg. Since these devices are large in mass, it is difficult for a medical worker to install them alone. Therefore, it is preferable to have a ready-made attachment mechanism, rather than just manual attachment.
Depending on the type of support structure, the mounting mechanism may be an overhead crane, a horizontally supported truck, or a hinge mechanism. If the attachment mechanism is considered, the thick drape can be pre-attached to the support structure. In this case, the thick hanging cloth may be made of a rigid functional material. This also includes transparent lead-containing acrylic resin plates with high strength. Also, taking into account storage space and load limitations during handling, split-type thick-walled hanging cloth and supporting structures may be used. The attachment mechanism allows the additional protective equipment (API) to be placed on the patient's body lying on the table with easy handling for loading.

As described above, in the second means 2, by combining an additional protective instrument (API), leakage of scattered X-rays to the side during surgery can be further reduced. This means that radiation protection for medical personnel and patients can be strengthened compared to one of the second methods. The attachment mechanism also facilitates handling of additional protective equipment (API).
In Example 7 and FIG. 6, which will be described later, the detailed contents of the above-mentioned new protective equipment (PI) and additional protective equipment (API) will be explained. Additionally, in Example 8 and FIG. 7, details of the structure and attachment mechanism of an integrated or split support structure will be described.

The second means (3) further strengthens the protection against scattered X-rays on the side of the thick hanging cloth that is the protective equipment (PI), and relaxes the protection on the protective equipment (PD) side by that amount. For PD protective equipment, simplified protective equipment (SEPI) with high operability will be adopted. The idea is that this will improve operability while maintaining the same level of protection performance. The second means 3 is a modification of the second means 2 described above.

In the second means (3), shielding of X-rays scattered on the sides inside the box is mainly ensured by the thick hanging cloth. The total thickness of the functional material of the thick hanging cloth is, for example, 1 to 2 mm. Therefore, the burden of shielding the box attachments, which are considered to be insufficiently shielded during surgery, is reduced. By reducing the shielding load, it is possible to adopt SEPI, which has poor shielding ability but is highly operable, as the protective device (PI) in this part of the PD. SEPI in step 3 of the second means is a strip-type curtain and a gloveless port.

Instead of a shielding sheet, a flexible curtain with shielding ability and many partitions (hereinafter referred to as a "strip curtain") is installed in the patient port. This curtain is made by cutting through the thickness of a flexible sheet with shielding properties to create a large number of partitions. The flexible sheet is a resin or rubber sheet. If the material is a rectangular sheet, the partition will be a large number of strip-shaped sheets with a small width in the horizontal direction and a large length in the vertical direction. These suspend from the top of the through port.
Since the strip-type curtain has a large number of flexible partitions, it can be easily opened by pushing with a part of the body. Therefore, the strip-type curtain has high operability. When resting, it hangs down and blocks the through port, acting as a shield. During surgery, the patient's body that is penetrated functions as a shield. A strip-shaped curtain with multiple partitions closes off the extra space between the curtain and the patient's body during surgery. The remaining space that has been blocked off will be shielded with strip-type curtains. Further, it is preferable that a patient port lid is installed in the patient port to reliably reduce the amount of remaining space. The patient port lid is made of the above-mentioned rigid functional material, and is a gate-shaped plate-shaped lid that is hollowed out in the shape of a portal through the patient's body. The patient port lid is a rectangular plate-shaped lid that is made of the same material as the box and has a high shielding ability. The penetration part is processed by cutting the material according to the dimensions of the patient's body. By this method, the strip curtain can reduce the leakage of scattered X-rays to the outside of the box.

The above-mentioned strip curtain or gloveless port is installed in the sleeve port instead of the sleeve structure.
A strip curtain hangs from the top of the rectangular sleeve port. A rectangular sleeve port is installed across part or all of the width of the side of the box with the viewing window. The structure of the strip curtain is the same as in the previous section, and it is highly operable.
When not in use, the rectangular sleeve port is preferably completely closed by a closing shield. The closing shielding lid is a closing plate-shaped lid that is installed on the sleeve port and has a function of shielding radiation from radiation using a rigid functional material. The closing shielding lid is a rectangular plate-shaped lid that is made of the same material as the box and has a high shielding ability. In this way, a sleeve port closed with a closing shield can reduce the leakage of scattered X-rays to the outside of the box.

The gloveless port is also installed in a circular sleeve port that is part of the width of the side of the box where the viewing window is located. This is a circular plate with through cuts radially extending from the center. This is because it has a large number of flexible partitions, so a person can easily open that part by pushing with one part of the body. Gloveless ports are highly maneuverable because medical personnel can easily insert their hands and arms into the box.
When the sheet is left still, it maintains its initial shape due to the reaction force of the flexible sheet itself, closes the port, and functions as a shield. During surgery, the body tissues of the medical personnel's arms and hands serve as the primary shield. A gloveless port with multiple partitions blocks and shields the free space between the hands and arms of medical personnel during surgery.
Further, when not in use, the sleeve port is preferably completely closed by a sealing shield lid. The sealing shielding lid is a circular sealing shielding lid that has radiation shielding ability using a rigid functional material and has its own fixing function. The sealing shielding lid is a disc-shaped lid that is made of the same material as the box and has a high shielding ability. By this method, a gloveless port closed with a sealing shield can reduce the leakage of scattered X-rays to the outside of the box.

A means in which simplified protective equipment (SEPI) is combined as a plurality of protective devices/instruments (PDITS) by means 3 of the second means described above is referred to as an "evolved combination case." With the means described here, it is possible to increase the operability by medical personnel while maintaining the same shielding ability in all directions.
Example 9 and FIG. 8 show detailed contents of the concept of "evolved combination case" which improves operability for medical personnel based on the second means 3. In addition, in Example 10, a bird's-eye view of the "evolved combination case" will be explained with reference to FIG.

There are several more advanced variations of the second means. This variant was devised because it was found that the shielding ability of thick-walled drape was considerably higher. By maximizing the shielding ability (thickness) of the thick hanging cloth, the ``further advanced combination case'' further improves operability for medical personnel. The total thickness of the functional material of the thick hanging cloth here is, for example, 3 mm. In this case, the rectangular sleeve port is expanded to cover the entire width of the side of the box, and an easy-to-operate strip-shaped curtain is attached to it. The only structure at the bottom of the box is the legs that support it. This allows medical personnel to move from side to side without removing their arms from the port. When not in use, it can be completely closed with a closing shielding lid and can be shielded in the same way as a box. An easy-to-operate gloveless port can also be installed on the plate surface of the closing shield lid. When not in use, the gloveless port can be completely closed with a sealed shielding lid and shielded in the same way as a box. This will be explained in detail in Example 11 and FIG. 10, which will be described later.
In addition, in Example 12 and FIG. 11, in accordance with the above, a combination case was created that improved both operability and visibility by using a box made of transparent lead-containing acrylic resin that also served as a viewing window and a thick hanging cloth. Explain the details.
With the means described here, it is possible to increase the operability by medical personnel while maintaining the same shielding ability in all directions. Furthermore, visibility can be improved.

By combining a plurality of protective devices (PDs), the present invention can transmit primary X-rays well and reduce the intensity of scattered X-rays in all directions including the periphery of the irradiation field. The scattered X-rays targeted for reduction are the upper and side areas of the additional shield box of the PD, and the lower side of the high-performance table. In addition, by combining PD with protective equipment (PI: patient's drapes and clothing), it is possible to reduce the intensity of scattered X-rays that leak to the sides from the box's penetration port as the human body moves during surgery. . These protective devices and instruments (PDITS) use composite absorbing materials to attenuate scattered X-rays and absorb ray energy. This reduces the radiation exposure of medical personnel and patients, and also reduces the protective burden on medical personnel.
Further, the PDITS combination is advanced by adding the thick-walled draperies and support structures of Additional Protective Equipment (API) and the strip curtains and gloveless ports of Simplified Protective Equipment (SEPI). This advanced combination allows for increased operability by medical personnel while maintaining the same shielding ability.

FIG. 1 is an explanatory diagram showing the method and effect of a combination case of a box and a table. Here, a. ～b. c. is a case where protective equipment/equipment does not exist; c. ～d. indicates a “combination case” of protective equipment (PD). FIG. 2 is a bird's-eye view of a "combination case" in which multiple protective devices (PDs) can reduce the intensity of scattered X-rays in all directions. FIG. 3 is a concrete explanatory diagram of a new protective instrument (PI) added at the time of surgery. FIG. 4 is an explanatory diagram showing the location of the through port of the box and the method and effect of reducing the intensity of X-rays scattered to the side during surgery. Figure 4 a. ～c. is the state before the countermeasure, d. ～f. is the state after the countermeasures have been taken. FIG. 5 is a bird's-eye view of the "case in which a new PI is combined" as the third protection. FIG. 6 is a detailed explanatory diagram of an additional protective instrument (API) added during surgery to reduce the intensity of side scattered X-rays during surgery. FIG. 7 is an explanatory diagram of the structure of an integrated or split support structure and its attachment mechanism. FIG. 8 is an explanatory diagram showing the method and effect of the "evolved combination case" with improved operability. Figure 8 a. ～d. is the state before compounding, e to j. is the state after compounding. FIG. 9 is an explanatory diagram of an "evolved combination case" with improved operability using simplified protective equipment (SEPI). FIG. 10 is an explanatory diagram of a ``further advanced combination case'' that improves operability by using strip curtains on all sides of the box. FIG. 11 is a bird's-eye view of a "further advanced combination case" that uses transparent lead-containing acrylic resin to improve operability and visibility. FIG. 12 is a configuration diagram of a basic case of the composite absorbent material of Patent Document 1. FIG. 13 is an example of the measurement results of the X-ray transmittance of the composite absorbent material of Patent Document 1 according to the JIS test. FIG. 14 is a bird's-eye view of a high-performance table disclosed in Patent Document 2 that transmits X-rays well and reduces scattering. FIG. 15 is a bird's eye view of the split box type additional shield box disclosed in Patent Document 3.

Embodiments of the present invention will be described based on the drawings.
Note that the protective devices and instruments (PDITS) and their constituent members shown here are merely examples and are not intended to limit the present invention.

In the remainder of this specification, the following terminology will be used with respect to protective equipment, protective appliances, and protective equipment.
Unless otherwise specified, the position of the X-ray tube will be described using an undertube type X-ray fluoroscope placed under the table as an example.
Boxes and tables are called protective devices (PD). The drape over the patient's body, the mattress under the patient's body, the patient's clothing, and the patient's head covering are referred to as protective equipment (PI). Protective aprons, protective goggles, protective gloves, and protective arm covers for medical workers are called personal protective equipment (PT). In addition, protective equipment, protective equipment, and protective equipment are collectively referred to as protective equipment and equipment (PDITS). Further, thick-walled coverings with large thickness and mass and their support structures are collectively referred to as additional protective equipment (API). Strip curtains and gloveless ports are collectively called simplified protective equipment (SEPI).
A high-performance table (table) is a medical table defined in Patent Document 2 that transmits primary X-rays well and reduces scattering. The additional shield box (box) is an additional shield box defined in Patent Document 3 for the purpose of reducing exposure and reducing protection load.
Diagnosis photography rooms, examination rooms, treatment rooms, X-ray treatment rooms, etc. are collectively referred to as ``treatment rooms, etc.''.
Unless otherwise specified, a portion described as an element means a material containing that element, and unless otherwise specified, a material refers to a material containing a single metal element.

In the remainder of this specification, the following terms will be used with respect to the types of X-rays.
The primary source of radiation is an X-ray tube, and this primary X-ray beam is called "primary X-ray." The radiation that is scattered by the primary X-rays when they hit a patient/examiner, a part of the device, etc. is collectively called "scattered X-rays." The energy of X-rays means effective energy unless otherwise specified.
Among the scattered X-rays, X-rays that have been scattered forward at a small angle (hereinafter referred to as "small-angle scattering") while maintaining the energy of the primary X-rays are referred to as "small-angle scattered X-rays." Small-angle scattered radiation occurs in the irradiation field and its surroundings. The periphery of the irradiation field refers to the area within 5 cm from the edge of the irradiation field, which is an area where forward scattered X-rays may be generated due to small-angle scattering with one to several scattering times.
In addition, primary X-rays are scattered by the patient's body or a table, etc., and the X-rays that are scattered forward at an angle of 0 to 45 degrees with respect to the incident angle (hereinafter referred to as "forward scatter") are called "forward scattered X-rays." , X-rays that have been scattered laterally between 45 degrees and 135 degrees (hereinafter referred to as "side scatter") are called "side scattered X-rays", and X-rays that have been scattered backwards between 135 degrees and 180 degrees (hereinafter referred to as "side scattered X-rays"). The X-rays that have been scattered (referred to as "backscattered X-rays") are called "backscattered X-rays." Note that small-angle scattered X-rays are a type of forward-scattered X-rays, and are one of them.

The embodiment of this specification has the following configuration.
Example 1 shows the method and effect of a "combination case" that can reduce the intensity of scattered X-rays in all directions by combining a table and a box, which are protective devices (PD), as shown in Figure 1. explain.
In the second embodiment, a bird's-eye view of the "combination case" will be explained with reference to FIG.
In the third embodiment, a specific example of a new protective instrument (PI) added at the time of surgery will be explained with reference to FIG.
In Example 4, a method and effect of reducing the intensity of X-rays scattered to the side during surgery will be explained with reference to FIG.
In Example 5, a bird's-eye view of a case in which a new PI is combined as the third protection will be explained with reference to FIG.
Example 6 describes a case in which the third protection is combined with either the first protection or the second protection.
In Example 7, a specific example of an additional protective instrument (API) added during surgery in order to reduce the intensity of side scattered X-rays during surgery will be explained with reference to FIG.
In Example 8, the structure and attachment mechanism of an integrated or split support structure will be explained with reference to FIG.
In Example 9, the method and effect of an "evolved combination case" that improves operability by combining simplified protective equipment (SEPI) will be explained with reference to FIG.
In Example 10, a bird's-eye view of the "evolved combination case" will be explained with reference to FIG.
Embodiment 11 will be described with reference to FIG. 10, which is a "further advanced combination case" in which all sides of the box are made of strip-shaped curtains to improve operability.
In Example 12, a bird's-eye view of a "further advanced combination case" in which operability and visibility are improved using transparent lead-containing acrylic resin will be explained with reference to FIG.
Example 13 describes the use of the present invention in IVR surgery.
Example 14 describes the range in which the exposure dose within a patient's body increases during IVR.
Example 15 describes the composite absorbent material of US Pat.
Example 16 explains part of the JIS test results of Patent Document 1.
Example 17 describes an example of a trial calculation of the effect of reducing X-ray transmittance by a composite absorbing material, based on the knowledge of Patent Document 1.
Example 18 describes the high-performance table of Patent Document 2.
Example 19 describes the additional shield box of Patent Document 3.

(Method and effects of "combination case" with table and box)
In Example 1, the method and effect of a "combination case" of a table and a box will be explained. In this case, two protective devices (PD) are combined: the first protection is a high-performance table, and the second protection is an additional shield box. This makes it possible to reduce the intensity of scattered X-rays in all directions including the periphery of the irradiation field. FIG. 1 is an explanatory diagram showing the method and effects of the "combination case". The two-dot chain line and arrow in the middle of FIG. 1 distinguish between the conventional state (on the left) and the state after the present invention (on the right). Figure 1 a. and b. If all protective equipment is not present, c. and d. shows the combination case of box and table.
In FIG. 1, the directions of scattered X-rays are indicated by arrows. Roughly speaking, the thickness of the arrow indicates the number of photons of the scattered X-rays, and the length indicates the energy of the scattered X-rays. In this specification, energy and the number of photons are collectively referred to as intensity.

Figure 1 a. Here, the numerical values of Patent Document 1 are cited and described. Here, assuming that the number of photons of the primary X-ray is "100", the absorption by the body tissue (chest) is "14", the absorption by the CFRP table is "3", and the absorption to the X-ray receiver is "14". I thought the ratio was "3". The remaining 80 was the scattering amount, which was considered to be "12" at a height of 150 cm (upward), "24" at a height of 100 cm (side), and "44" at a height of 50 cm (downward). That is, backscattered X-rays directed downward have a large number of photons. However, the energy of X-rays is expected to be small. Note that this value is a guideline.
The effect of the box and table combination is that d. The intensity of the scattered X-rays outside the box decreases. Figure 1 d. Now let's look at a. without shielding or protective equipment. The degree of the effect is shown by adding a less than inequality sign "<" to the numerical value. That is, the upper part (<<<12) and the lower part (<<<44) are expressed by three less-than inequality signs. The side (<<24) is expressed by two less-than inequality signs. For reasons described later, the scattered X-rays emitted to the sides are reduced to a slightly smaller extent.

a. of Figure 1 where no protective equipment is present. and b. In this case, the backscattered X-rays heading downward have low energy but a large number of photons. In comparison, forward scattered X-rays directed upward have a large energy but a small number of photons. The solid black line indicates the primary X-ray.
c. of Figure 1 where protective equipment is present. and d. shows a box table and a combination case. Figure 1 c. In order to make it easier to see the vicinity of the patient's body 60, the additional shield box 1 and the high-performance table 2 are disassembled and shown as upper and lower parts. In reality, as shown by the small black arrows in the vertical direction, the table and box are in close contact with the patient's body in between.
Figure 1 b. and c. The arrows of the scattered X-rays are both inside the box, so they are the same. Furthermore, the arrows of scattered X-rays indicate d. in the box and c. is the same. Figure 1 d. Looking at the scattered X-ray arrows, we can see the effect of the presence or absence of protective equipment inside and outside the box. Compared to these, d. Outside the box, both the thickness and length are smaller.
Figure 1 d. As shown, the width and length of the upward and lateral arrows outside the box are reduced by the additional shielding box 1. That is, the intensity of emitted scattered X-rays is reduced. The intensity of the scattered X-rays emitted downward is reduced by the highly functional table 2. In particular, the width and length of the upward and downward arrows outside the box are significantly smaller. This is because the upper box top and viewing window and the lower table top have a high shielding ability. That is, the intensity of scattered X-rays emitted above and below the patient's body is significantly reduced by the protective equipment.

First, the effect of reducing scattered X-rays will be explained. The degree of reduction is determined by the specifications (composition, material, and thickness) of the functional material of the protective equipment. The knowledge related to this is explained by the experimental results comparing the shielding materials (comparative Pb plates) of Examples 21 to 23 of Patent Document 1 and the composite absorbent material. This experiment is a transmission X-ray experiment (hereinafter referred to as "JIS test") conducted in accordance with the present invention in accordance with the test criteria of the JIS standard. In this specification, a part of this JIS test result is shown in Example 16.
The X-ray transmittance of a portion where a composite absorbing material having a total thickness (total t) of the functional material portion of 0.4 mm to 0.5 mm is installed on the incident side surface can be evaluated from the above-mentioned JIS test results. According to Example 16 of the present specification, the transmittance of X-rays is approximately 1/50th when the tube voltage is 70 kV compared to the case where no shielding or protective equipment/apparatus is present. Similarly, when the tube voltage is 50 kV, it becomes less than 1/200. On the other hand, when the tube voltage is 70 kV, the X-ray transmittance is approximately 2.5 times lower than when only the Pb shielding material (comparative Pb plate) is used with a thickness of 0.2 mm. Similarly, when the tube voltage is 50 kV, it becomes about 1/9.5.

First, a functional material is placed on the surface of the structural material of the box 1 on the incident side of the scattered X-rays. The shape of box 1 is often a cube. The structural material for box 1 is selected to have a low mass and high strength. Examples of this structural material are aluminum alloys, titanium alloys or high strength plastics. The transparent lead-containing acrylic resin used for the viewing window 6 may be used to form a rectangular shape. Furthermore, the shape of the box 1 made of acrylic resin may be hemispherical instead of square. If the sheet-like composite absorbing material 72 is placed on these surfaces, the intensity of the scattered X-rays transmitted to the sides of the box 1 will be significantly reduced as shown in the JIS test results. Further, the intensity of the forward scattered X-rays, which are transmitted upward except for the periphery of the irradiation field, is significantly reduced. In other words, if the composite absorbing material 72 is placed on the inside surface of the additional shielding box 1, the intensity of the scattered X-rays transmitted upward and sideways will be significantly greater than in the case without the above-mentioned shielding or protective equipment. becomes smaller.

Forward scattered X-rays including small-angle scattered X-rays coming from the periphery of the irradiation field have high energy. Particularly when the energy exceeds 88 KeV and the low reflection attenuation layer is made of Pb, secondary X-rays containing the characteristic X-rays of the K shell are generated, resulting in increased reflection and scattering. That is, although linear attenuation occurs, it cannot be effectively attenuated. As a countermeasure, a line-attenuating material with an atomic number of 83 or higher, such as bismuth (Bi) or uranium (U), is arranged on the surface of the widened box top plate 7 on the incident side of forward-scattered X-rays with high energy. . Thereby, the low reflection attenuation layer can attenuate X-rays with low reflection and scattering. A multilayer absorber is placed on the side opposite to the surface of the low reflection attenuation layer having an atomic number of 83 or more that receives X-ray irradiation. This idea was presented by the inventor as an additional composite absorbent material 73 in the same patent document 3. On the other hand, by increasing the angle of incidence of the viewing window with respect to forward scattered X-rays, a greater shielding ability can be obtained. When the energy is high, the box 1 can attenuate the forward scattered X-rays and absorb the ray energy by the above-described measures.

Next, a functional material is placed on the upper surface of the structural material of the table top plate 7 of the table 2. This structural material is a high strength plastic such as CFRP or an aluminum alloy. In the case of the high-performance table 2, the composite absorbent material 72 is arranged not only on the table top plate 7 but also on the upper surface of the absorbing plate 31 and the aperture plate 36. If the sheet-like composite absorbing material 72 is placed on these surfaces, the intensity of scattered X-rays transmitted below the table, as shown in the JIS test results, will be significantly reduced. Furthermore, the intensity of backscattered X-rays transmitted downward from the periphery of the irradiation field is significantly reduced due to the functions of the slide table 35 and the aperture plate 36. That is, by arranging the composite absorbing material 72 on the upper surface of the high-performance table 2 at various locations, the intensity of the scattered X-rays transmitted downward becomes significantly smaller than in the case without the above-mentioned shielding or protective equipment.

Therefore, in the case of a combination of a box and a table, the intensity of scattered X-rays emitted to the outside in all directions (three directions: upper, side, and lower) can be reduced. Therefore, the effect of combining two protective devices (PD), that is, the high-performance table 2 and the additional shield box 1 when the device is left still, is great.

Next, the effect of the high-performance table 2 on transmitting primary X-rays well will be explained. In the high-performance table 2, most of the primary X-rays are transmitted through free space. That is, since the X-rays are not scattered by an object, there are fewer scattered X-rays generated from the primary X-rays. Further, this table can transmit primary X-rays with high positional accuracy. In the present invention, this phenomenon caused by the high-performance table 2 is referred to as "transmitting primary X-rays well." When the primary X-rays are transmitted well, the image quality of the X-ray receiver becomes clearer. If the image quality of the X-ray receiver is sharp, the X-ray fluoroscope can be used with low primary X-ray energy. If the energy of the primary X-rays is lowered, the intensity of scattered X-rays generated from the patient's body can be further reduced. This synergistic effect can further reduce exposure to scattered X-rays.
In the combined case, this high-transmission feature of the high-performance table 2 increases the transmission rate of the primary X-rays to the X-ray receiver 10. This is the black arrow of the primary X-ray in Figure 1, b. and c. You can see this by comparing.
By combining two protective devices (PD: box and table), the present invention allows primary X-rays to pass through well and reduces the intensity of scattered X-rays in all directions.

(Explanation of bird's eye view of "combination case")
In Example 2, a bird's-eye view of a "combination case" in which the intensity of scattered X-rays in all directions can be reduced by combining two protective devices (PD) will be described. FIG. 2 is a bird's eye view of a combination case of a box and a table. Figure 2 a. is an additional shield box 17 with a built-in FPD, b. indicates the high-performance table 2. Further, b-1 indicates the step 30 of the top plate, b-2 indicates the intermediate step 34, and b-3 indicates the step 40 of the bottom plate.
In FIG. 2, the high-performance table 2 and the additional shield box 1 are shown disassembled and divided into upper and lower parts so that the vicinity of the patient's body 60 can be seen. In reality, as shown by the small black arrows in the vertical direction, the table and box are in close contact with the patient's body in between. Furthermore, the middle stage 34 of b-2 is taken out and shown at the bottom position in FIG. It should be noted that the intermediate stage 34 is actually a removable structure. Both the slide table 35 and the aperture plate 36 in b-2 of FIG. 2 move in the body axis direction.

The additional shield box 1, which is the second protection of the present invention, has a functional material arranged so as to three-dimensionally surround the irradiation field 15 corresponding to the affected area of the patient. The surface of each member constituting the box on the X-ray incident side is coated with a functional material. The operator can visually check the interior from the outside space through the viewing window 6, which is a resin or glass plate with shielding ability. The operator can perform surgery by inserting his arm or arm through the shielding sleeve structure 9 while visually checking the inside. Also, with the exception of patient port 20 and sleeve port 8, there are no openings communicating with external space.
The sleeve structure 9 is made of a flexible functional material such as a lead-containing arm sleeve. This is used by attaching it to the sleeve port 8.
The patient passes through the box axially through the patient port 20. This places the patient's head and body parts in the external space. Further, a flexible shielding sheet 22 with shielding ability attached to the patient port 20 closes the opening between the box and the human body. The excess shielding sheet 22 is rolled up by the holder 23. Power, electrical signals, optical signals, and liquids communicate inside and outside the box through the box without openings by means of the shieldable connection connector 24.
Forward scattered X-rays include small-angle scattered X-rays upward from the irradiation field of the patient's body and its surroundings, and therefore have high energy. If necessary, in this box, a line attenuating material 82 with excellent shielding ability is further attached to the box top plate 3 to shield upward forward scattered X-rays. X-rays scattered to the side from the irradiation field and other parts are shielded by a box body 4 and a viewing window 6 having shielding ability. Further, when the device is left still, the through port is shielded by the sleeve structure 9 and the shielding sheet 22.

The highly functional table 2, which is the first protection of the present invention, is composed of a maximum of three stages: a top board stage 30, an intermediate stage 34, and a bottom board stage 40. A certain level of performance can be achieved even with only one or two stages.
In FIG. 2, in order to make the illustration easier to see, the support rail 45 and the reinforcing beam 46 are not shown on the step 30 of the top plate, but are shown together with the table support 44 on the step 40 of the bottom plate. The middle stage 40 is slid into the support rail 45.
The top plate tier 30 of the high-performance table 2 has the following configuration. These are the table top plate 7, the absorption plate 31, the transmission plate unit 32, the support rail 45, and the reinforcing beam 46. The table top plate 7 supports the weight of the patient's body on which the patient lies. At the center of the axis of the table top plate 7, there is an opening that is long in the body axis direction. The absorption plate 31 is fitted and installed on a support rail 45 below the opening. The absorption plate 31 at a position that may become an irradiation field is removed, and the transmission plate unit 32 is installed. The mesh surface of the transmission plate unit 32 is made of a linear material such as CFPR or Al-based material that has high strength and is difficult to absorb X-rays. A thin film made of CFRP may be used instead of the mesh surface.
In the case of the undertube type, the upper surfaces of the table top plate 7 and the absorption plate 31 are coated with a functional material. The aperture size of the irradiation field in the body axis direction can be adjusted using a slide table 35 and an aperture plate 36, which will be described later. The opening size in the direction perpendicular to the body axis direction can be adjusted using the opening/closing plate 42 and the spacer 33 of the transmission plate unit 32, which will be described later. The load supported by the table top plate 7 is supported by a support rail 45 and a reinforcing beam 46, and finally by a table support stand 44.

The middle stage 34 of the high-performance table 2 is composed of a slide table 35, an aperture plate 36, a slide absorption plate 38, and a drive mechanism thereof. The slide table 35 is a flat plate that is long in the axial direction. There is an opening at a part of the center of the axis, and a slide absorption plate 38 is easily fixed onto the other part. A drive mechanism using a ball screw 37 for the aperture plate 36 is installed inside the slide table 35. A pair of (two) aperture plates 36 can be slid over the opening of the slide table 35 to freely adjust the size of the opening in the axial direction. A slide table 35 installed on the side rollers is slidable in the axial direction, and the position of the opening can be freely adjusted. In this way, the position and size of the aperture in the axial direction of the irradiation field can be adjusted using the slide table 35 and the aperture plate 36.
The bottom plate step 40 of the high-performance table 2 is composed of a bottom plate 41, an opening/closing plate 42, and a fixing/driving mechanism thereof. The opening/closing plate 42 can be opened/closed by controlling the opening angle using a hinge mechanism or the like. During surgery, the opening/closing plate 22 at the irradiation field position is opened. A mechanical device may be attached to the slide table 35, the aperture plate 36, and the opening/closing plate 42.

In the case of the undertube type, the transmission rate of primary X-rays to the X-ray receiver 10 increases due to the ability of the high-performance table 2 to transmit X-rays well.
In addition, in the case of the undertube type, the high-performance table 2 can attenuate and absorb backscattered X-rays downward from the irradiation field 15 of the patient's body and its surroundings using the table top 7 made of a functional material with excellent shielding performance. .
The upper side of the aperture plate 36 is covered with a composite absorbent material 72 and the lower side is covered with a shielding material 81. The slide absorption plate 38 is simply attached and installed at a location other than the opening position of the slide table 35, and the upper side is covered with a composite absorption material 72. Thereby, downward backscattered X-rays can be attenuated and absorbed.
The surface of the opening/closing plate 42 is covered with a shielding material 81 on the outside and a composite absorbent material 72 on the inside. Thereby, downward backscattered X-rays can be attenuated and absorbed.

In Example 1 and Example 2, the method and effects of the "combination case" of the additional shield box and the high-performance table were explained. By combining two protective devices (PD), primary X-rays can pass through well. Furthermore, it is possible to reduce the intensity of scattered X-rays emitted from the patient's body in all directions (in three directions: upward, lateral, and downward) including the periphery of the irradiation field. Therefore, the air dose rate in medical rooms and the like can be reduced. Therefore, the radiation exposure of medical workers and patients can be reduced. Additionally, the protective burden on medical personnel can be reduced.

(Explanation of specific examples of new protective equipment (PI) added during surgery)
In the third embodiment, a specific example of a new protective instrument (PI) added as the third protection will be described. The new PIs to be explained here are the cloth that hangs over the patient's body and the patient's clothing. In general, radiation can be shielded by a material with the same thickness but smaller mass as it approaches the radiation source due to its shape effect. Hereinafter, this will be referred to as the "shape effect of the shielding body." The patient's body is the source of scattered X-rays. Therefore, the position of the hanging cloth and clothing has a large effect in reducing the intensity of scattered X-rays leaking out of the box even if the shield has a small mass.
The patient is asked to wear clothing made of flexible functional material. Using the patient's clothing as a shield is an unconventional idea. Moreover, as mentioned above, clothing can efficiently shield with a small mass due to the shape effect of the shielding body.
FIG. 3 shows an explanatory diagram of a protective device to be worn on a patient's body. Figure 3 a. shows a developed view of the patient's clothing 63. b. shows a state in which the patient's body is wearing clothing 63. c. shows a normal hanging cloth 18. d. shows an installation diagram when a head cover 64, clothing 63, and a normal blanket 18 are used. e. indicates the head cover 64.

Figure 3 a. is an example of a developed view of clothing 63 before being put on. The clothing 63 is often made from a sheet of flexible functional material. Therefore, we avoid sewing complicated shapes. In addition, both the front side and the back side are shaped mainly in straight lines. On the front side and the back side, there are hollowed out portions 39 for the irradiation field through which the primary X-rays are transmitted. The width of the cutout 39 on the back side is large. The clothing 63 has a front part, a back part, and a hand retrieval part 67 that are continuous in one piece.
With the clothing 63, the position of the irradiation field 15 changes to the top, bottom, left and right of the trunk depending on the position of the affected area. Therefore, the clothing 63 can be folded or the wearing position can be shifted. In addition, the size is cut to be larger than the trunk of the human body. The vertical width of the hollowed out part 39 reaches the upper end of the clothing 63. The vertical width of the irradiation field is adjusted to the required size using the cover 70. The clothing 63 has a hand extraction part 67 so that a catheter can be easily inserted into the patient's wrist or arm during a procedure. Further, the clothing 63 can be suspended from the patient's shoulders using two shoulder straps 69. The length of the shoulder strap 69 can be adjusted. The mounting positions of the stoppers 68 on the cover 70, the hand take-out part 67, and the shoulder straps 69 can be easily changed because they are attached using hook-and-loop fasteners or cloth tape.

Figure 3 b. shows a state in which the patient's body is wearing clothing 63. It is preferable that the clothing 63 can cover an area within 40 cm from the edge of the irradiation field 15.
b-1 in FIG. 3 shows how to wear the clothing 63 when the trunk of the body becomes the irradiation field 15. There is no need to fold the clothing 63 when performing X-ray fluoroscopy of organs in the trunk. When performing X-ray fluoroscopy on the abdomen below the stomach, the two shoulder straps 69 are lengthened and the garment 63 is shifted downward when worn.
b-2 in FIG. 3 shows how to wear the clothing 63 when the neck becomes the irradiation field 15. The clothing 63 is pulled up and worn to examine the neck with X-rays. For this purpose, the upper end of the clothing 63 is bent. Also, remove the front and back covers 70. The length of the two shoulder straps 69 is shortened.
When puncturing from the wrist in a catheter technique, the wrist and elbow of the patient's right hand are taken out from the hand removal part 67. After the hand is taken out, the hand-taken part 67 can be secured to clothing 63 with a hook-and-loop fastener using a stopper 68.
Since the clothing 63 is worn on the patient, the patient carries it by himself/herself. Considering the physical burden caused by the patient's weight, the mass of the clothing 63 cannot be made very large. Due to the weight limit that an ordinary person can carry, the weight of the clothing 63 must be at most 20 kg or less. It should be more preferably 15 kg or less, even more preferably 10 kg or less. Therefore, it is difficult to increase the thickness of the material that has the shielding function of the clothing 63 due to mass limitations. If the mass of the clothing 63 is large, the length of the hem should be shortened within a range of 20 cm or more from the edge of the irradiation field 15.

Figure 3 c. is a conventional drapery 18 that is placed over the patient's body. This is a flexible sheet made of functional material. These hanging cloths have a cutout 39 in the area of the irradiation field 15. These hangings have a functional material placed on the surface on the side of incidence of the encapsulated or scattered X-rays. The structure may be made of functional materials as is. Some have a laminated structure in which the surface is treated with resin or the like or laminated.
These draperies on the patient's body can shield scattered X-rays emitted upwardly and laterally from the patient in optimal locations. These blankets cannot shield the downward scattered X-rays. Furthermore, because of the hollowed out portion 39, forward scattered X-rays directed upward from the irradiation field 15 and its surroundings cannot be blocked. Most of the sideward scattered X-rays can be blocked because they pass through the human tissue 60 and these coverings.
As in Example 14, it is preferable that the ordinary hanging cloth 18 can cover an area within 40 cm from the edge of the irradiation field 15. In the case of a commercially available hanging cloth, the length may be longer. An example of a commonly available hanging cloth product is SGB manufactured by Hoshina Seisakusho. The dimensions are 60 cm wide x 100 cm long. Its mass is 3.2 kg with a lead equivalent of 0.25 mmPb. Similarly, it is 5.5 kg for 0.5 mm Pb.
From the viewpoint of limiting the physical load due to the load of the human body, the total mass of the ordinary hanging cloth 18 and clothing 63 must be at most 20 kg or less. Further, the weight should preferably be 15 kg or less, more preferably 10 kg or less.

Figure 3 d. This is an installation diagram when clothing 63 and a normal hanging cloth 18 are used. This figure uses the clothing 63 shown at b-2 in FIG. 3. This is when the affected area is the neck, etc., so see d in Figure 3 . Now, e. of FIG. 3 . A head cover 64 shown in FIG. A typical hanging cloth 18 has a length of 100 cm in the body axis direction. Figure 3 d. In this case, the normal hanging cloth 18 has the longest length. Clothes 63 are the same and 80cm long.

Figure 3 e. is the head cover 64. The head cover 64 is used when the affected neck becomes the irradiation field 15 and the head is within 40 cm from the irradiation field. That is, this is a modification in which the neck of the clothing 63 becomes the irradiation field.
When the separation distance from the irradiation field 15 is short, scattered X-rays that have been scattered multiple times within the patient's body from the head leak into the outside space, increasing the air dose rate. This exposes medical workers to radiation. To reduce radiation exposure to medical personnel, the patient is fitted with a head cover 64 made of a material such as a flexible composite absorbent material.
The head cover 64 is a mask-like headgear, in which the eyes, nose, mouth, etc. are cut out and exposed, and the other parts are covered with a material such as a flexible composite absorbent material. Thereby, emission of scattered X-rays from the head to the outside can be reduced.
Note that when the head becomes the irradiation field 15, the head must necessarily be housed in an additional shield box in which the X-ray receiver 10 is housed.

Ordinary cloths and clothes can shield scattered X-rays generated in the patient's body with a small mass due to the shape effect of the shielding body described above. The combination of these two PIs can reduce the intensity of scattered X-rays. However, since there is a hollowed out portion that allows primary X-rays to pass through, the intensity of scattered X-rays upward and downward from the periphery of the irradiation field cannot be reduced. The role of the additional shield box described above is to shield X-rays scattered upward from the periphery of the irradiation field. Similarly, the role of the high-performance table mentioned above is to shield downward scattered X-rays.
The patient's body bears the weight of clothing and normal draperies. In order to limit the physical load on the human body, the total mass must be at most 20 kg or less. More preferably, the weight is 10 kg or less.
By combining a new protective device (PI) with a protective device (PD) such as a box, the intensity of scattered X-rays inside the box can be reduced. In particular, it has the meaning of reducing the intensity of scattered X-rays leaking laterally during surgery, which will be described later.

(Method and effect of reducing the intensity of X-rays scattered to the side during surgery)
In Example 4, a method and effect of adding a plurality of new protective devices (PI) to the two protective devices (PD) of Example 1 and Example 2 will be explained. The new PI for Example 4 is the patient's usual drape and clothing. The table is the first protection, the box is the second protection, and the new PI is the third protection. By adding a new PI, it is possible to reduce the intensity of scattered X-rays leaking to the outside of the box during surgery.
FIG. 4 is an explanatory diagram showing a method and effect of reducing the intensity of sideward scattered X-rays when a through-port portion of the box and a plurality of PIs are added. The two-dot chain line and arrow in the middle of FIG. 4 distinguish the state before the countermeasure (on the left) and after the countermeasure (on the right). Figure 4 a. From c. indicates the state before the countermeasure is taken, and d in FIG. from f. indicates the status after the measures have been taken. The two-dot chain line and arrow in the middle of Figure 4 distinguish the state before and after the countermeasure. Figure 4 a. and d. is a bird's eye view of each state.

X-rays scattered to the side outside the box are not reduced during surgery compared to above or below. This is due to the fact that there is a penetration port on the side of the box that penetrates human tissue, from which side scattered X-rays leak out of the box. The through ports are the sleeve structure 9 of the sleeve port 8 at the end of the box and the shielding sheet 22 of the patient port 20.

The sleeve structure 9 is an armhole or a glove attached to the sleeve port 8. One typical example of the sleeve structure 9 is a sleeve manufactured by molding a flexible functional material with shielding. The shape of the sleeve is a cone with both ends open. The opening at the base of the sleeve is where it is attached to the short tube of the sleeve port. The tip of the sleeve opens at the wrist size. When left undisturbed, the tip of the sleeve is closed by deflating with rubber. This shields the sleeve port 8 when it is standing still.
On the other hand, shielding sheets 22 are attached to patient ports 20 provided at both ends of the box in the axial direction. The shielding sheet 22 is a one-piece sheet made of a flexible functional material that provides shielding. One end of the shielding sheet 22 is connected to the box. In preparation for surgery, after the box is installed through the patient, the shielding sheet 22 is installed so as to close the remaining space of the patient port 20 as much as possible. This shields the patient port 20 when it is stationary.

When the penetrating ports are left at rest, a flexible structure having a shielding ability is installed to block the penetrating ports. Therefore, when the box is left still, sideward scattered X-rays generated in the patient's body will not leak out of the box. However, during surgery, scattered X-rays leak out of the box through the through port for the following three reasons.

The first reason is that the human body being penetrated moves. At the sleeve port 8, the hands and arms of a medical worker wearing protective gloves during surgery pass through the sleeve structure 9. On top of that, they are working hard to perform medical procedures. Each time this movement occurs, the tip of the sleeve opens. When the tip of the sleeve is opened, scattered X-rays leak out of the box.
The patient's body passes through the patient port 20 during surgery, and a shielding sheet 22 is placed over it. However, the shielding sheet 22 may shift due to movement of the patient. If the position of the shielding sheet 22 is shifted, scattered X-rays will leak out of the box.

The second reason is that human tissue is transparent to X-rays. Body tissues such as the hands and arms of the medical worker or the trunk of the patient's body 60 that pass through the penetration port 20 will block a small percentage of the X-rays. Most of the rest is scattered and some is transmitted. That is, a portion of the incident scattered X-rays leaks out of the box due to transmission and scattering by the body tissue that has penetrated the box.

The third reason is when the shielding ability is insufficient due to the high tube voltage of the X-ray source. The sleeve structure 9 and the shielding sheet 22 are made of a flexible functional material with shielding ability. These materials need to be made of soft material in order to perform delicate medical procedures such as procedures. Both cannot be made thicker due to the operability required for medical practice. That is, there are obvious limits to the shielding ability of these protective devices. These general commercially available products have a thickness of 0.25 mm Pb or less in terms of lead equivalent. However, with this thickness, the shielding ability is generally insufficient when the tube voltage of the X-ray source is, for example, 88 kV or more.

Figure 4 b. and c. 2 shows the remaining space of the through port 20 where scattered X-rays leak. The black hatched areas are candidates for extra space. Figure 4 b. is sleeve port 8, c. indicates patient port 20. Note that among the patient ports 20, c-1. is on the patient's head side, c-2. shows the patient's lower limb side. However, b. of FIG. and c. indicates the entire area of the candidate extra space. However, in practice, in the medical field, efforts are made to block the free space from this situation.
However, during surgery, a surplus space is created and X-rays pass through the human tissue that passes through the surplus space, so the through port 20 cannot completely prevent leakage of X-rays.

Sleeve ports for inserting hands and arms into the sides of the additional shield box are essential for medical professionals to perform procedures inside the box. Additionally, if there is a patient port at the end in the body axis direction, the patient's head and lower limbs can be taken out of the box. This can reduce medical exposure to patients. Moreover, the patient port can eliminate the psychological anxiety of patients due to confinement. Therefore, sleeve ports and patient ports are essential.
Given the existence of these through ports, it is necessary to consider measures to reduce the leakage of scattered X-rays to the sides. The patient's body is the source of scattered X-rays. A possible solution is to place a structure of another shielding material in the narrow space between the patient's body and the through port. However, the distance between the through port of the box and the patient's body is short. It is difficult to place large shielding structures here.
The shielding structure is preferably a plate or film made of metal or resin, which is the simplest structure. Shielding structures that can be placed in this area are patient drapes and patient clothing. Figure 4 e. is a normal hanging cloth 18, f. is dressed 63.
Both are molded sheets of functional material with shielding ability. Furthermore, a hollowed out portion 39 is provided in both of them by cutting out a portion of the irradiation field 15. Therefore, the hanging cloth 18 and clothing 63 cannot strictly shield the scattered X-rays upward and downward from the irradiation field 15.

Figure 4 a. shows the state before taking measures to reduce X-rays scattered laterally outside the box. Figure 4 d. indicates the status after the measures have been taken. Figure 4 a. and d. The arrows around the irradiation field 15 indicate the direction of the scattered X-rays. As in Example 1, the thickness of the arrow indicates the number of photons, and the length indicates the energy of the scattered X-rays. The arrow on the clothing 63 at d-1 in FIG. represents the state after being shielded by clothing 63. The arrow on the hanging cloth 18 in d-2 of FIG. 4 represents the state after the arrow on the clothing 63 is shielded by the ordinary hanging cloth 18.
Figure 4 a. Compare d-1's clothes 63. For d-1, the width of the arrow pointing downward and to the side is smaller. Similarly, the length becomes smaller. This is because the scattered X-rays generated in the patient's body 60 are blocked by the clothing 63.
The clothes 63 in d-1 and the hanging cloth 18 in d-2 in FIG. 4 are compared. The width of the arrow pointing to the side is smaller on the hanging cloth 18 of d-2. Furthermore, the length d-2 is smaller. There is no downward arrow on the hanging cloth 18 in d-2 of FIG. The reason for this is that the cloth does not have the ability to shield downward backscattered X-rays.
On the other hand, a. Compare the top of the hanging cloth 18 of d-2. The upward primary X-ray black arrow does not change significantly in both width and length. The reason for this is that both the clothing 63 of d-1 and the hanging cloth 18 of d-2 have hollowed out portions 39 that cut out the irradiation field 15.

Next, we will explain the shielding ability of parts other than the hollowed out parts of clothing or blankets. If the clothing or blanket is the same sheet-like composite absorbing material as the sample material for the JIS test described in Example 1, the transmittance of scattered X-rays can be estimated. That is, it is assumed that the plate is made of a composite absorbent material with a total thickness of 0.4 to 0.5 mm. The transmittance of scattered X-rays through clothes or blankets is approximately 1/50th when the tube voltage is 70 kV compared to when there is no clothing or cloth. Similarly, when the tube voltage is 50 kV, it becomes less than 1/200. These are clear from the JIS test results shown in Example 16.
Therefore, even within the range of the above-mentioned protective equipment, the scattered X-rays irradiated to the sleeve port 8 position in the additional shield box 1 become small within a certain range. Similarly, the scattered X-rays irradiated to the patient port 20 position become small, and even smaller if the re-scattered radiation inside the box is included.
Therefore, the additional use of the hanging cloth 18 and/or clothing 63 has a great effect in reducing the intensity of the sideward scattered X-rays leaking out of the box.

By combining PD with a new PI (patient's clothing) during surgery, it is possible to reduce the intensity of scattered X-rays leaking to the side from the through port of the box during surgery. By using composite absorption materials for these, scattered X-rays can be absorbed after being attenuated. This reduces the radiation exposure of medical personnel and patients, and also reduces the protective burden on medical personnel.

(Bird's eye view of the case combining a new PI as the third protection)
Figure 5 shows a bird's-eye view of the high-performance table 2 (first protection) and additional shield box 1 (second protection), which are combined with a new PI (regular cover 18 and clothing 63) as the third protection. show. The center part of box 1 in FIG. 5 shows the inside as a perspective view. The scattered X-rays generated in the patient's body 60 are divided and their intensity is reduced. Table 2 shares the lower part. Box 1 serves as an upper part and a side part when the product is left still. Furthermore, composite absorbing materials 72 are placed at various locations to absorb the linear energy of the linearly attenuated X-rays. The normal hanging cloth 18 and the patient's clothes 63 mainly share the side parts during the surgery. The new PI reduces the intensity of scattered X-rays leaking out of the box from the extra space created in the box accessories (sleeve structure 9 and shielding sheet 22) as the human body moves during surgery.
In addition, in FIG. 4, a strip-shaped curtain 54, which will be described later, is attached to the patient port 20 in the lower limb region instead of the shielding sheet 22. The lower limb patient port 20 is spaced from the irradiation field 15 by 40 cm or more, and the dose rate of scattered X-rays at this position is small, so the strip curtain 54 may be used.

The highly functional table 2, which is the first protection, is a medical table that allows X-rays to pass through well and reduces scattering. In the table 2, the primary X-rays pass through the hollow space and then pass through the transmission plate unit 32 made of the mesh of the table top plate 7 or a thin film such as CFRP, and reach the irradiation field 15, which is the affected part of the patient's body 60, without interaction. . The top step 30 includes a table top 7 that supports the weight of the patient and absorbs scattered X-rays from the patient's body. Furthermore, there is the above-mentioned transmission plate unit 32 and absorption plate 31. The intermediate stage 34 can reduce the intensity of backscattered X-rays downward from the periphery of the irradiation field by means of a movable slide table 35 and an aperture plate 36. The opening/closing plate 42 of the step 40 of the bottom plate opens only at the position of the irradiation field 15 by controlling the opening angle. Due to these, the table 2 allows X-rays to pass through well and reduces scattering.

The additional shield box 1 in FIG. 5, which is the second protection, is a box 17 with a built-in FPD installed on the table 2. The box body 4 is divided into two parts. The box 1 has no opening communicating with the external space in any three-dimensional direction, and surrounds the irradiation field 15 with functional materials of a plurality of combinations of different types and thicknesses depending on the dose rate. A line attenuation material 82 with enhanced shielding ability is arranged on the box top plate 3. A medical worker inserts his arm or arm through the sleeve structure 9 and performs medical treatment while visually checking the inside of the box through a viewing window 6 having a shielding ability.
The sleeve structure 9 is located on the side of the box where the viewing window 6 is located and is attached to a sleeve port 8 through the hand and arm of the medical worker. The shielding sheet 22 is located on the side of the box in the body axis direction and is attached to the patient port 20 that penetrates the patient's body. Since extra space is created from these box-attached instruments as the hands and arms of the medical personnel and the patient move during surgery, X-rays scattered to the sides leak out of the box.

Here, new protective equipment (PI), normal hanging cloth 18 and clothing 63, are added as the third protection. A conventional drapery 18 is placed over the patient's body within the box. That is, it is installed so as to surround the upper and lateral sides of the patient's body. The clothing 63 is worn by the patient who is the source of scattered X-rays. The total mass of these is 20 kg or less. More preferably, it is 10 kg or less. These have a hollowed out portion 39 that is cut out to a slightly larger extent in the irradiation field of the affected area in order to transmit the primary X-rays. Therefore, scattered X-rays generated upward and downward from the periphery of the irradiation field cannot be effectively shielded. However, if the shielding of the patient's body 60 is taken into account, the scattered X-rays directed laterally from the periphery of the irradiation field within the box can be effectively shielded. Thereby, the normal hanging cloth 18 and the patient's clothing 63 can reduce the intensity of scattered X-rays leaking to the outside of the box during surgery.

The combination of the above-mentioned high-performance table 2 (first protection), additional shield box 1 (second protection), and PI (third protection) is a composite protective device/instrument (PDITS). The combined PDITS can reduce the intensity of scattered X-rays generated in all directions from the patient's body, including during surgery. By arranging composite absorbing materials at various locations, scattered X-rays can be attenuated and linear energy can be absorbed. In addition to the effect of transmitting X-rays well, this can reduce the air dose rate in a medical room or the like. In other words, it is possible to reduce occupational exposure and protection burden for medical workers. In addition, medical exposure of patients can be reduced.

(A case where a new PI is combined with either a table or a box)
In the sixth embodiment, a case in which a third protection (PI) is combined with either the first protection (table) or the second protection (box), which are protective devices (PD), will be described. Additional protective equipment (API), which will be described later, may be added to the protective equipment (PI), which is the third protection.
As mentioned above, when the first and second protections are combined, it is possible to reduce the intensity of scattered X-rays emitted to the outside in all directions (three directions, upward, side, and downward) when the device is left still. In addition, when the first to third protections are combined, the intensity of scattered X-rays leaking outside the box on the side during surgery can be reduced. When the high-performance table 2 is added to these, the ability to transmit primary X-rays is added.
In the "case in which either is combined" described in Example 6, compared to the two cases described above, a) the ability to reduce the intensity of scattered X-rays in all directions, or b) the ability to reduce the intensity of the primary X-rays, Either or both of the ability to penetrate well is poor.
First, the cases of the first protection and the third protection will be explained. Next, the case of second protection and protection will be explained.

First, consider the case where there is no box 1, which is the second protection, but there is the table 2, which is the first protection, and the normal hanging cloth 18 and clothing 63, which are the third protection. A commercially available ordinary hanging cloth 18 with the largest lead equivalent has a corresponding thickness of 0.5 mm Pb. If two of these are stacked, the thickness will be 1.0 mmPb. Further, the patient is asked to wear clothing 63. Assuming that the physical burden on the patient due to the mass is 20 kg, which is the maximum allowable weight described below, the thickness of both is approximately 2.0 mmPb. This has a corresponding shielding ability as described in Example 17. If the energy of the scattered X-rays generated above and to the sides from the patient's whole body is 50 KeV, the intensity can be reduced to about one-fifteenth of that without shielding. Furthermore, in addition to this, there is also the idea of using a thick hanging cloth 19, which will be described later.
However, around the irradiation field 15 of the hanging cloth and clothing, there is a hollowed out portion 39 through which the primary X-rays are transmitted. There is nothing to block the forward scattered X-rays generated in the irradiation field 15 and directed upward. Further, since the forward scattered X-rays have high energy, the X-rays generated around the irradiation field 15 cannot be shielded by the ordinary cloth 18.
That is, by installing the table 2 as the first protection and the hanging cloth 18 and clothing 63 as the third protection, all directions generated from the patient's body except those directed upward from the periphery of the irradiation field can be prevented. The intensity of scattered X-rays can be reduced within a certain range. However, this simple method is not sufficient to protect medical workers from exposure. In particular, it must be noted that forward scattered X-rays reaching the crystalline lens cannot be reduced much. Therefore, Box 1 is a necessary condition for sufficient shielding of upwardly scattered X-rays.

Next, consider the case where there is no table 2, which is the first protection, but there is box 1, which is the second protection, and the third protection. As a new PI for this third protection, we will consider the case where a commercially available blanket 21 is added to the normal blanket 18 and clothing 63.
Since the bed sheet 21 is placed under the patient, even if the thickness corresponding to the lead equivalent is increased, there is no physical burden on the patient due to its mass. Therefore, it is possible to set the lead equivalent to 1 to 3 mmPb, which corresponds to the thick hanging cloth 19 described later. That is, at 3 mmPb, if the energy of scattered X-rays generated downward from the patient's whole body is 50 KeV, the intensity can be reduced to about 1/60th of that in the case of no shielding.
However, around the irradiation field of the bed sheet 21, there is a hollowed out portion 39 through which the primary X-rays are transmitted. There is nothing to shield the hollowed out portion 39. Further, since there is no table 2, there is no aperture plate 36 below the periphery of the irradiation field 15 that can adjust the position in the body axis direction with high precision. Therefore, backscattered X-rays generated in this region and directed downward cannot be blocked. That is, in addition to the box 1, which is the second protection, and the cloth 18 and clothing 63, which are the third protection, by installing a bed under the patient's body, the irradiation field can be removed from the periphery of the irradiation field, except for those directed downward. The intensity of scattered X-rays generated from the patient's body in all directions can be reduced to a certain extent. This does not change even during surgery. However, this simple method is not sufficient to protect medical workers from exposure. Therefore, the highly functional table 2 is a necessary condition for sufficiently shielding the downwardly scattered X-rays.

Let us consider the ability to transmit primary X-rays well when the second protection and third protection described in the previous section are combined. When a PI sheet 21 is used instead of the high-performance table 2 that is a PD, it is possible to shield X-rays scattered downward except for the periphery of the irradiation field.
However, the sheet 21 cannot be expected to have the effect of increasing the transmission rate of primary X-rays. Even if the sheet 21 were to have a cutout 39 in the area of the irradiation field 15, the effect of good transmission would not be obtained. The reason is that a normal table under the bed scatters the primary X-rays and at the same time re-scatters the scattered X-rays. Further, since there is no aperture plate 36, the irradiation field 15 becomes larger than necessary. Therefore, the presence of a highly functional table 2 is a necessary condition for good transmission of primary X-rays.

(Explanation of specific examples of additional protective equipment (API) added during surgery)
In Example 7, a specific example of an additional protective equipment (API) that is additionally installed as the third protection will be described. The API is a thick wall covering and support structure. As described above, the shape effect of the shielding body means that the closer the position is to the patient's body, the smaller the mass can be used for shielding. Therefore, the position of the thick covering can reduce the intensity of scattered X-rays leaking out of the box with a shielding body having a small mass next to the normal covering and clothing.
FIG. 6 shows an explanatory diagram of a protective device worn on a patient's body. Figure 6 a. shows a state in which the patient's body is wearing clothing 63. b. shows a normal hanging cloth 18. c. indicates a thick hanging cloth 19. d. shows a semi-cylindrical integral support structure 65 that supports the thick drapery 19. e. 1 shows an installation diagram when a garment 63, a normal hanging cloth 18, and a thick hanging cloth 19 supported by a support structure 65 are used. Of these, a. patient's clothing 63 and b. of FIG. The conventional hanging cloth 18 was described in Example 3.

Figure 6 c. is a thick hanging cloth 19. The thick hanging cloth 19 has a functional material disposed on its surface on the side where the X-rays are incident or scattered. The structure of the functional material may be used as it is. A clad-rolled product of these materials may also be used. It is also possible to use a laminated structure in which the surface is treated with resin or the like or laminated.
The thick cloth 19 on the patient's body can shield scattered X-rays emitted upward and laterally from the patient's whole body. Since the thick hanging cloth 19 has the hollowed out portion 39, it cannot block the scattered X-rays upward from the periphery of the irradiation field 15. In order to reduce the area of the hollowed out portion 39, an aperture mechanism such as an XY goniometer type may be attached. Since the X-rays scattered to the side pass through the human tissue 60 and the thick cloth 19, a wide range can be shielded.
The thick hanging cloth 19 is expected to have a greater shielding ability than the ordinary hanging cloth 18. As in the fourteenth embodiment, it is preferable that the thick hanging cloth 19 cover the area within 20 cm from the edge of the irradiation field 15. The thick hanging cloth 19 has a large total thickness (total t) of functional materials of 1 to 3 mm, and has a large mass. However, since the mass is large, the physical load on the patient increases.
From the perspective of limiting the physical load due to the load of the human body, the total mass of the normal hanging cloth 18 and clothing 63 must be at most 20 kg or less. Further, the weight should preferably be 15 kg or less, more preferably 10 kg or less.
When the thick drapery 19 is placed over the patient's body 60, another support structure is required to support its mass. Further, the mass of the thick hanging cloth 19 is determined by the load capacity of the supporting structure 65.

Figure 6 d. shows a semi-cylindrical support structure 65 as an example of the support structure. The support structure 65 is placed on a table and placed over the top of the patient. This has a thick hanging cloth 19 placed thereon to support its mass. Therefore, the mass of the thick hanging cloth 19 is directly loaded onto the table without passing through the patient's body 60.
The skeleton of the support structure 65 is preferably made of the following material. It scatters and absorbs only a small amount of X-rays. Moreover, it is preferable that the density is low and the strength is high. Therefore, hollow shapes made of materials such as metallic titanium and its alloys, metallic aluminum alloys, metallic magnesium alloys, or CFRP are preferable. Hollow shapes include hollow cylinders and square pieces. The support structure 65 may have any shape of frame as long as it can support the mass of the thick hanging cloth 19 placed thereon. The support may be a truss structure, a rigid frame structure, or a portal structure. Figure 6 d. is a support structure 65 having a semi-cylindrical frame. The thick hanging cloth 19 having a large thickness and mass and its support structure 65 are collectively referred to as "additional protective equipment (API)." APIs are also a third type of protection.
By utilizing the support structure 65, the thick hanging cloth 19 can be tolerated even if the weight increase is large. In general, there are many commercially available skeletons that support the weight of a human body. It is technically possible for the frame to withstand a load of 100 kg. However, it is desirable that the thick hanging cloth 19 be portable by a plurality of medical personnel. Here, the transportable mass was considered to be 60 kg. The load capacity of the supporting structure 65 was set to 60 kg. This value becomes the maximum mass of the thick hanging cloth 19. The supporting structure 65 with this specification has a weight of about 10 kg, which is equivalent to a lightweight bicycle.

In Example 17, the X-ray transmittance of a thick hanging cloth with a total thickness of 1 to 4 mm was estimated. This is a simple trial calculation result for the first layer Pb, which is a low reflection attenuation layer of the composite absorbing material. From the results, it is predicted that the transmittance of X-rays of 50 KeV or less of a thick hanging cloth is as follows when compared with a normal hanging cloth with a thickness of 0.45 mm. In the case of total t=1 mm, it is expected to be about 1/15. In the case of total t=2 mm, it is less than 1/1,400. In the case of total t=3 mm, it is less than 1/130,000. Therefore, the transmittance of side scattered X-rays can be reduced by using a thick cloth with a total thickness of 1 to 3 mm. At 80 KeV, the rate of reduction becomes smaller. Incidentally, for this purpose, it seems unnecessary to use a thick hanging cloth with a total thickness of 4 mm.
As mentioned above, a thick hanging cloth with a total thickness of 1 to 3 mm has a large effect in reducing the intensity of sideways scattered X-rays leaking out of the box.

Here, based on the above, the dimensions and mass of the clothes, the normal hanging cloth 18, and the thick hanging cloth 19 will be summarized. It is assumed that one side of the calculated irradiation field is 15 cm. Note that the dimensions of the hollowed out portion are determined for each medical treatment. If the range is 40 cm from both edges of the irradiation field, the total length will be 95 cm. If the length is 20cm, the total length will be 55cm. Based on this information, the approximate dimensions of the clothes and hanging cloth are set. The dimensions of the clothing 63 are 1.2 m wide x 0.8 m long (front and back), and the area is approximately 1 m ² . Assuming that the dimensions of a normal hanging cloth 18 are 0.8 m wide x 1.0 m long, the area is 0.8 m ² . Assuming that the dimensions of the thick hanging cloth 19 are 1.0 m wide x 0.6 m long, the area is 0.6 m ² .
On the other hand, the sample material for the JIS test shown in Example 16 was a sheet-like composite absorbent material 72 with a total thickness of 0.45 mm. The mass of the functional material per unit area is 3.6 to 4.7 kg per cubic meter (kg/m ² ). The mass of the functional material of clothing 63 using this material is 3.6 to 4.7 kg. Further, the mass of the functional material of the normal hanging cloth 18 is 2.9 to 3.8 kg.
From the results of examining the shielding ability of Example 17, the range of the total thickness (total t) of the functional material of the thick hanging cloth 19 used here is preferably 1 mm or more and 3 mm or less. The mass of the functional material per unit area is approximately 10 kg/m ² when total t=1 mm. In the case of 2 mm, it is approximately 20 kg/m ² . In the case of 3 mm, it is approximately 30 kg/m ² . Since the area of the thick hanging cloth 19 is 0.6 m ² , the range of the mass of the functional material is 6 kg or more and 18 kg or less.

Figure 6 e. 1 is an installation diagram in the case of using clothing 63, a normal hanging cloth 18, and a thick hanging cloth 19 supported by a semi-cylindrical integrated support structure 65. This figure uses the clothing 63 shown at b-1 in FIG. This is a case where the affected area is the neck, etc., so e. has a head cover 64 attached. Figure 6 e. In this case, the normal hanging cloth 18 has a length of 100 cm in the body axis direction, which is the largest. Clothes 63 are the same and 80cm long. The thick hanging cloth 19 has the same length of 60 cm and is the smallest in length.

As mentioned above, the range of the mass of the functional material of the thick hanging cloth 19 is 6 kg or more and 18 kg or less. Approximately 10 kg of the support structure 65 is added to this. The total mass of about 20 to 30 kg is supported by the table top plate 7 via a semi-cylindrical support structure 65. The patient's body 60 does not bear these loads.
On the other hand, the patient's body 60 bears the load of the clothing 63 and the normal drapery 18. In order to limit the physical load on the human body, the total mass is preferably 10 kg or less.
By combining a protective device (PD) such as a box with an additional protective instrument (API), it is possible to further reduce the intensity of scattered X-rays leaking laterally from the through port of the box during surgery.

(Description of the structure and attachment mechanism of integrated or split support structures)
Example 8 describes a method of installing an integral or segmented support structure of an API onto a patient's body lying on a table using an attachment mechanism.
As mentioned in Example 7, the combined mass of the thick drapery and support structure is about 20-30 kg. If the mass is within this range, it is possible for multiple medical personnel to install it manually. In the case of manual labor, it is desirable to use a thick cloth made of flexible functional material that is easy to handle.
On the other hand, for single-person handling, it is desirable to use a ready-made attachment mechanism. This may include mechanical equipment. If handled with a ready-made attachment mechanism, a thick-walled drapery in a ready-made shape made of a rigid functional material can be applied. In this case, a transparent lead-containing acrylic resin plate with high strength can be used as the rigid functional material. Here, we considered the case where the thick hanging cloth is installed by being attached to the support structure in advance.

As the transparent lead-containing acrylic resin plate 62 which is a rigid functional material, there is Kyowa Glass-XA manufactured by Kuraray Trading Co., Ltd. The plate thickness of H-22 with a lead equivalent of 1 mmPb is 24 mm. The plate thickness of H-46 with a lead equivalent of 2 mmPb is 50 mm. Since the bending strength is 60 PMa or more, the self-supporting strength is sufficient and no additional supporting structure is required. The transparent lead-containing acrylic resin can be used independently on the table 2. In this case, an opening cutout and its hinge mechanism are installed in advance in the thick hanging cloth 19 at a portion that may be opened during surgery, such as the hand removal portion 67.

FIG. 7 shows the structure and attachment mechanism of the integrated support structure 65 and the split support structure 66. 7A is an integrated type 65. The mounting mechanism a-1 is a lifting type. A-2 is a sliding type. b in FIG. 7 is a split type 66. In FIG. 7B, as an example, a divided support structure 65 with four divisions is drawn. The number of divisions may be larger or smaller as long as it is 2 or more. The mounting mechanism of b-1 is a lifting type. b-2 is a sliding type. In the case of a sliding type, a small recessed guide groove is installed in the table top plate 7 as a guide for sliding the split support structure 66 and the split box 16.
Fig. 7c shows a double-opening support structure that is divided into two parts in the body axis direction. This opens the two-part support structure 66 at a predetermined location on the table 2. In this case, the hinge 51 mechanism that attaches the half-split support structure 66 to the table 2 serves as the attachment mechanism.

The attachment mechanism a-1 and b-1 in FIG. 7 is an overhead crane 58. In the lifting type, the support structure 65 is lifted up by an overhead crane 58, lowered vertically onto the table 2 on which the patient's body lies, and installed at a predetermined position. In the case of b-1, the mass of one split type is small, so the attachment mechanism may be delicate.
The mounting mechanism for a-2 and b-2 is a horizontal carriage 59. In the case of a sliding type, a horizontal carriage 59 is used to move the patient's body onto the table 2 on which it lies. Next, the horizontal cart 59 is lifted up to the height of the upper end of the table top 7. Finally, the support structure 65 is slid horizontally and lowered, and is installed at a predetermined position. Furthermore, the split box 16 can also be placed on the table using the same method.

If there is a mounting mechanism, it can be easily handled even if it has a large mass. When considering the attachment mechanism, the thick hanging cloth 19 can be attached to the support structure 65 in advance. In this case, the thick hanging cloth 19 attached to the support structure 65 is not handled manually, so a rigid functional material may be used.
Although the integrated type has a large mass when installed, it requires less effort to install. Furthermore, a large area is required for storage and handling in a medical room or the like. On the other hand, when installing the split type, the weight is smaller than that of the integrated type. However, the feature is that the area required for storage and handling is small. Another feature is that the patient's body can be accessed from between the divided support structures when unscheduled sampling during surgery becomes necessary.

Here, we devised a mounting mechanism that allows easy installation of the supporting structure and split box using an overhead crane, horizontal carriage, and hinge mechanism. The supporting structure may be of a divided type with small mass and maintenance space. It is also possible to apply a thick covering to the support structure in advance. This attachment mechanism facilitates preparation of additional protective equipment (API) by medical personnel prior to surgery.

(Explanation of the method and effects of the "evolved combination case" with improved operability)
In Example 9, the method and effects of the "evolved combination case" that improves the operability of the box accessories (sleeve structure 9 and shielding sheet 22) shown in Example 2 will be explained.
In Example 7, the configuration and effects of an additional protective device (API) using a thick cloth and a support structure were described. In Example 8, a method for installing an API was described. The API-enhanced protection against side scattered X-rays makes it possible to reduce the protection of the protective device (PD) box accessories. In Example 9, a protective device/instrument (PDITS) was devised based on the concept of improving the operability of the protective equipment attached to the PD while maintaining the same level of protective performance.

In the patient port 20, instead of the shielding sheet 22, a flexible curtain (hereinafter referred to as "strip curtain") 54 with shielding ability and having multiple partitions is installed. In the sleeve port 8, a strip curtain 54 or a gloveless port 53 is installed in place of the sleeve structure 9. These two PIs are collectively referred to as simplified protective equipment (SEPI). By changing to SEPI, we will maintain the same level of protection while increasing the usability for medical personnel.

FIG. 8 is an explanatory diagram of an "evolved combination case" in which protective equipment (PI) is combined. The two-dot chain line and arrow in the middle of FIG. 8 distinguish between the state before (left side) the protective equipment (PI) is combined and the state (right side) after it is combined. Figure 8 a. and e. is a bird's eye view of each.
Here, a. ～d. is the state before compounding. a. A bird's eye view of the conventional FPD built-in box 17, b. is a normal hanging cloth 18, c. is the sleeve structure 9 of the sleeve port 8, d. is the shielding sheet 22 of the patient port 20. On the other hand, e to j of FIG. is the state after compounding. e. is a bird's-eye view of the FPD built-in box 17 after combination; f. is the installation status of the integrated support structure 65; g. is a thick hanging cloth 19, h. is the gloveless port 53 of the sleeve port 8, i. is the strip curtain 54 of the sleeve port 8, j. is the strip curtain 54 of the patient port 20.
Note that d. of FIG. The shielding sheet 22 of the patient port 20 of d-1. is on the patient's head side, d-2. shows the patient's lower limb side. In addition, j. The strip curtain 54 of the patient port 20 of j-1. is on the patient's head side, j-2. shows the patient's lower limb side.

In patient port 20, d. of FIG. Instead of the shielding sheet 22 in j. of FIG. A rectangular curtain 54 is installed. This curtain is made of a flexible shielding sheet with incisions extending through its thickness to create a large number of partitions. The multiple partitions are multiple strip-shaped sheets with a small width in the horizontal direction and a large length in the vertical direction. These suspend from the upper end of patient port 20. Leave the bottom edge free. The appearance of the strip curtain 54 is similar to a line curtain for general household use. From the outside, it looks like a Japanese noren. A noren is a cloth-like sheet that is hung over an entrance door to provide shade or blindness at the front of a store or at the border of a room.
An example of a flexible sheet product used as a raw material is a radiation shielding rubber sheet product number RSL-070 manufactured by Togawa Rubber Co., Ltd. The X-ray shielding ability with a tube voltage of 100 kV is as follows. When the rubber sheet has a thickness of 3 mm, the lead equivalent is approximately 0.38 mmPb. In the case of 5mm, it is about 0.66mmPb.
A strip curtain 54 with multiple partitions normally hangs down and functions as a shield. Also, when using the port, use it so as to close off the extra space between it and the human body. However, if there are a large number of notches in the partition, it is inevitable that gaps will occur between them during surgery, so the shielding ability of the strip curtain 54 is slightly inferior to that of the shielding sheet 22. It is preferable that the rectangular curtains 54 be positioned so as to close the penetrating cuts and used in duplicate. It is more preferable to use three layers. Figure 8 d. and j. The white part is the extra space. This method can reduce leakage of scattered X-rays to the outside of the box.
Since the strip-shaped curtain 54 has a large number of partitions, it can be easily opened by pushing the partition. By replacing the shielding of the penetration part of the patient port 20 with the strip curtain 54, it becomes easier to take the patient's head and lower limbs out of the box. It is highly operable for medical personnel because it does not take time and effort to perform the medical procedure of placing the patient lying down by penetrating the box and closing the free space between the patient port 20 and the patient's body 60.
Moreover, when the strip curtain 54 is used for the patient port 20, the sleeve port 8 on the end face of the box in the body axis direction becomes unnecessary. This is because medical personnel can insert their arms and arms through the strip curtain 54 of the patient port 20.

The strip curtain 54 has a structure of a flexible sheet with notches. Its shielding ability is inferior to that of the shielding sheet 22. In particular, when the distance between the patient port 20 and the irradiation field 15 on the head side is small, there is a concern that the shielding ability thereof may be insufficient. On the body limb side, there is no need to worry about this because the distance from the irradiation field 15 is large. However, in the present invention, the above concerns are eliminated due to the shielding capabilities of the API. The thick hanging cloth 19 has a large ability to reduce the intensity of side-scattered X-rays. Therefore, in the present invention, the strip curtain 54 can also be used in the patient port 20 on the head side.

In sleeve port 8, c. Instead of the sleeve structure 9 of FIG. 8, the strip curtain 54 of FIG. 8i or the strip curtain 54 of FIG. A gloveless port 53 is installed.
The strip curtain 54 has the same structure as the patient port 20 described in the previous section. However, the sleeve port in which this is installed is changed from the oval or round shape shown in Patent Document 3 to a rectangular sleeve port 13. The rectangular curtain 54 is suspended from the upper end of the rectangular sleeve port 13.
The strip curtain 54 has multiple partitions and can be easily opened. By replacing this, it becomes easier to put the skills of medical personnel into the box. First, the act of inserting the hand and arm into the box does not require much effort. Second, the caster can move left and right while keeping their hands and arms in the box. As such, it is highly user-friendly for medical personnel.

The gloveless port 53 is a disk-shaped structure having a large number of radial partitions toward the center formed by notches extending through a round shielding sheet. This is used by attaching it to the sleeve port 8. It is made of flexible functional material, and its function and specifications are the same as the strip curtain. The sleeve port 8 to which this is attached has a round or oval shape. A commercially available product of Glovelessport 53 is a product manufactured by Sunplatec.
Further, when the gloveless port 53 is not used, the round sleeve port is closed by a sealing cover 52 made of the same material as the box body 4. The sealing shielding lid 52 is a disc-shaped lid made of the same material and configuration as the box body 4. A cover can also be used. The sleeve port 8 can be opened and closed by manually operating the sealing cover 52 as an integral part. Additionally, the one-piece unit can be opened and closed up, down, to the left, or to the right using a hinge mechanism. If the sealing cover is divided into two or more parts, it can be opened and closed front to back or left and right. Furthermore, by providing a sensor (or switch) and a drive mechanism, it may be opened and closed by a mechanical device. It is also possible for the surgeon to open and close the sealing cover 52 by himself during surgery using a foot pedal 56 having the same mechanism as the foot-operated stand.
If the sleeve port 8 is closed with the sealing shield lid 52, scattered X-rays leaking from the side to the outside of the box are reduced. Therefore, it is preferable to install a gloveless port 53 with a sealing shielding lid 52 at a position close to the irradiation field 15. The gloveless port 53 can reduce leakage of scattered X-rays to the outside of the box similarly to the strip curtain 54. Since the gloveless port 53 has a large number of partitions, it can be easily opened by a person by pressing the partition. This is highly maneuverable for medical personnel as it can easily pass through the hands and arms.

The shielding ability of the gloveless port 53 is inferior to that of the sleeve structure 9 due to its structure of a circular flexible sheet with notches. In Patent Document 3, the conditions for using the gloveless port are that the energy of scattered X-rays in the box is limited to less than 60 KeV. In the present invention, this limitation is removed due to the shielding capabilities of the API. Therefore, in the present invention, the gloveless port 53 can be used even when the energy of scattered X-rays generated within the patient's body is 60 KeV or more.

In the rectangular sleeve port 13, the strip-shaped curtain 54 is also closed with a closing shielding lid 55. That is, when the strip curtain 54 is not used, the rectangular sleeve port 13 is closed by the closing shielding lid 55. This increases the shielding ability. The closing/shielding lid 55 of this part can be manually operated and opened/closed upward or downward using a hinge mechanism. Furthermore, by providing a sensor (or switch) and a drive mechanism, it may be opened and closed by a mechanical device. The sleeve port may be square or trapezoidal. By closing this shielding lid 55, leakage of scattered X-rays to the sides can be reduced.

In FIG. 8, the direction of the scattered X-rays is indicated by an arrow. Roughly speaking, the thickness of the arrow indicates the number of photons of the scattered X-rays, and the length indicates the energy of the scattered X-rays.
Figure 8 b. d. of FIG. This is the same as on the clothing 63 and on the hanging cloth 18. In contrast, g. shows a new case where a thick hanging cloth 19 is used. Figure 8 b. on the hanging cloth 18 and g. When compared on the thick hanging cloth 19, the width of the arrow pointing to the side becomes even smaller, and the length becomes even smaller. This is the effect of the thick hanging cloth 19. The upward arrow does not change significantly in both width and length compared to the side. This is due to the fact that both have a hollowed out portion 39 that cuts out the portion of the irradiation field 15. Since the hanging cloth does not have the ability to shield backscattered X-rays, a downward arrow was not included.

The adoption of simplified protective equipment (SEPI) is prerequisite for low levels of side-scattered X-rays within the box. By reducing the intensity of side-scattered X-rays inside the box using additional protective equipment (API), the protection performance of combined protective equipment and instruments (PDITS) can be maintained at the same level. Simplified Protective Equipment (SEPI) allows healthcare workers to easily insert their hands and arms into the box.
On the other hand, the determining organs for in vitro exposure are the tissues of the trunk, such as the crystalline lens, thyroid, bones, and reproductive organs. There are no decision-making organs in the hands and arms. For this reason, there are few cases of people wearing exposure dosimeters on their hands and arms. However, exposure dose management should be operated under the principle of ALARA (As Low As Reasonably Achievable). Therefore, regardless of skill, the lower the unnecessary exposure dose, the better. When using SEPI, it is recommended that healthcare workers use protective equipment (PT) such as protective gloves and protective arm covers.

(Bird's eye view of the "evolved combination case" with improved operability)
In Example 10, a bird's-eye view of an "evolved combination case" with improved operability using composite protective devices and instruments (PDITS) will be described. Figure 9 is a bird's eye view. Figure 9 a. is additional shield box 1, b. is high-performance table 2, c. is the patient's clothing 63, d. is a thick hanging cloth 19 and a support structure 66 divided into four parts. Additional protective equipment (API) consists of thick-walled draperies and support structures. Figure 9 d. The thick hanging cloth is an example in which the total t is 2 mm. Here, the mass of the functional material of the thick hanging cloth 19 is about 12 kg. These are operated by the handling mechanism of Example 8 and placed on the table 2, straddling the patient's body 60.
In FIG. 9, the high-performance table 2 and the additional shield box 1 are disassembled and shown in upper and lower parts so that the vicinity of the patient's body 60 can be easily seen. In reality, as shown by the small black arrows in the vertical direction, the table and box are in close contact with the patient's body in between. Also, d. The thick hanging cloth 19 divided into four parts and the divided support structure 66 are shown separately on the right side of the figure, and are joined together by the two-dot chain arrow. Note that d-1 is a case in which a composite absorbent material 72 is used for the thick hanging cloth 19, and d-2 is a case in which a lead-containing acrylic resin plate 62 is used. Figure 9 e. Here, a state in which the thick hanging cloth 19 and the support structure 66 are placed on the patient's body is shown by an imaginary two-dot chain line.

FIG. 9 shows a composite protective equipment/instrument (PDITS) in which additional protective equipment (API) is added to the combination case of the box and table shown in FIG. 2. The API here is a patient's thick hanging cloth 19 supported by a semi-cylindrical support structure 66 divided into four parts perpendicular to the body axis direction. The patient is also wearing clothing 63.
The configuration of FIG. 9 will be roughly described. In FIG. 9, above a patient's body 60 lying on the high-performance table 2, there is a thick hanging cloth 19, which is an API, and a split support structure 66. Furthermore, an additional shield box 1 is installed above (on the outside) to surround the patient's body 60 and the API. Note that the patient is wearing clothing 63. A normal hanging cloth 18 may be used in combination as long as it does not physically affect the patient's load.
A functional material is arranged on the surface of the table top plate 7 of the high-performance table 2. The same applies to the surface of the additional shield box 1 on the X-ray incident side. Scattered X-rays generated in the patient's body 60 are attenuated and absorbed by the following tasks. Here, the table takes care of the bottom part, and the box takes care of the top and side parts. This makes it possible to reduce the intensity of scattered X-rays emitted to the outside in all directions (three directions: upward, lateral, and downward). Furthermore, the highly functional table 2 allows primary X-rays to pass through well.

In addition to the explanation in the previous section, the following three simplified protective equipment (SEPI) have been added. These are the strip curtain 54 of the patient port 20, the strip curtain 54 of the sleeve port 8, and the gloveless port 53 of the sleeve port. These are used to close off the free space between the operator and the patient's body, and shield the free space between the sleeve port 8 and the patient port 20. Moreover, if the closing shielding lid 55 is closed, the opening of the sleeve port 8 can be shielded to the same extent as the shielding ability of the box. The closing shielding lid 55 may be opened and closed by the operator himself during surgery using a mechanical device and a switch (sensor).
By adopting these simplified protective equipment (SEPI), it becomes easier to insert and move the patient's body and the hands and arms of medical personnel into the box, improving the operability of medical procedures by medical personnel during surgery. It gets expensive.

c. of FIG. The patient's clothing 63 shows an example in which a cardiac catheterization procedure is performed assuming that the affected area is the heart. That is, the hollowed out portion 39 of the clothing 63 in the irradiation field region is located on the left side of the patient's trunk. In order to make the mass of the clothing 63 10 kg or less, the total t of the functional material must be 0.8 mm or less. If there is a margin for the intensity of side-scattered X-rays leaking to the sides outside the box, it is desirable that the total t of the clothing 63 be 0.4 to 0.5 mm. In this case, the mass of the functional material of the clothing 63 is approximately 5 kg. These loads are borne by the patient's body 60.
Figure 9 d. The thick hanging cloth 19 is an example in which the total t is 2 mm. The mass of this functional material is approximately 12 kg. The patient's body 60 does not bear the load due to this thick hanging cloth 19. The mass is supported by the table top plate 7 via a semi-cylindrical support structure 66 divided into four parts. The thick hanging cloth 19 is a flexible sheet made of functional material. The thick covering 19 has a cutout 39 at the irradiation field 15.

Clothing 63 exists above, on the sides, and below the patient's body. Thick wall coverings 19 are present above and to the sides of the patient's body. This does not exist below. Both have a cutout 39 at the irradiation field 15.
The total thickness (total t) of the functional materials of the thick hanging cloth 19 and clothing 63 above and on the sides of the patient's body is about 2 mm or more. A composite absorbent material of this thickness has a large shielding capacity. As described in Example 17, the transmittance of X-rays with an effective energy of 50 KeV or less is 1:150 or less when the total t is 2 mm, compared to a normal hanging cloth (total t = 0.45 mm). Therefore, the intensity of scattered X-rays mainly on the sides decreases within the box. However, since there is a cutout 39 in the irradiation field 15 on the upper side, the degree of reduction is smaller than on the side.

In Example 10, an "evolved combination case" was explained in which a protective device (PD) is combined with an additional protective device (API) and a simplified protective device (SEPI). The API that increases the shielding ability is the thick hanging cloth 19 and the support structure 65. SEPI that improves operability is the strip curtain 54 and/or the gloveless port 53. The feature of this case is that by adding and combining API and SEPI, it is possible to improve the operability by medical personnel during surgery while keeping the shielding ability the same as in Example 2.
A thick hanging cloth 19 serving as an additional protective device (API) is supported by the table top plate 7 via a support structure 65 and installed in the box 1 . As a result, X-rays scattered laterally within the box are significantly reduced. In this state, simplified protective equipment (SEPI) can be used for the shielding sheet 22 and the sleeve structure 9 on the box side end face.

(Explanation of "further evolved combination case" with improved operability)
In Example 11, a modification of a "further advanced combination case" in which a plurality of protective devices/instruments (PDITS) are combined to further improve operability will be described. Here, compared to Examples 9 and 10, the shielding of side scattered X-rays inside the box was maximized to maximize the operability of the box by medical personnel. A bird's eye view of this case is shown in FIG. Figure 10 a. is additional shield box 1, b. is the high-performance table 2. c. is a thick hanging cloth 19 made of API and a support structure 66 divided into four parts. d. Shown separately on the right side. 1 shows a gloveless port 53 and its sealing shielding lid 52 attached on the surface of the closing shielding lid 55 of SEPI. Figure 10 c. The total thickness of the thick hanging cloth 19 is different from that in FIG. 9, and is an example in which the total thickness is 3 mm. The mass of the functional material of this thick hanging cloth 19 is about 18 kg. These are operated by the handling mechanism of Example 8 and placed on the table 2, straddling the patient's body 60.

FIG. 10 has roughly the same configuration as FIG. 9, and can reduce the intensity of scattered X-rays in all directions. The main components are as follows. A conventional drapery 18 is placed over the patient's body 60 lying on the table 2. The patient is wearing clothing 63. On the top thereof, there is a thick hanging cloth 19 which is an API and a split support structure 66. A box 1 is installed above the box 1, surrounding the patient's body 60 and the API. Examples of structural materials for box 1 are aluminum alloys, titanium alloys, or high strength plastics, transparent leaded acrylic resins. Further, the shape of the box 1 is often a rectangular shape, but if transparent lead-containing acrylic resin is used, it may be an integral hemispherical shape.
There are two differences from FIG. 9. Firstly, the total thickness of the thick hanging cloth 19 is 3 mm. Second, the rectangular sleeve port 13 to which the strip curtain 54 is attached extends across the entire width of the side of the box.

This case was devised in the present invention because it was found that the shielding ability of a thick hanging cloth with a total thickness of 3 mm was quite high. As described in Example 17, the transmittance of X-rays with an effective energy of 50 KeV or less is 14,000 times lower for a thick cloth with a total thickness of 3 mm than that of a normal cloth (total thickness = 0.45 mm). Becomes 1 or less. This thick blanket alone has a high shielding ability.
On the other hand, the patient is asked to wear clothing 63 with a total t=0.45 mm and a mass of about 5 kg including the functional material. In addition, a normal drapery 18 is used within the range permitted by the physical load of the patient. Note that the mass of the functional material of the normal hanging cloth 18 is about 6 kg. These loads are borne by the patient's body 60. This makes it possible to ensure a total shielding of approximately 1 mm at a position close to the radiation source where the shape of the shielding body is highly effective.
As a result of the above, the intensity of X-rays scattered mainly on the sides within the box is significantly reduced compared to Examples 9 and 10.

In the eleventh embodiment, the rectangular sleeve port 13 is expanded to cover the entire width of the side surface of the box where the viewing window 5 is located, and a strip-shaped curtain 54 is attached thereto. The rectangular sleeve port 13 can be installed on the entire side surface of the box body 4 except for the leg portions that serve as supports. This allows the medical worker to move the entire side surface of the box from side to side without removing his or her arms from the rectangular sleeve port 13. If this is installed throughout the box, the user can insert arms and hands into the box from any position, further increasing operability.

When not in use, the rectangular sleeve port 13 can be shielded by closing the closing shielding lid 55. A gloveless port 53 can also be installed on the plate surface of the closing shielding lid 55. For example, if the tube voltage is 100 kV or more and the intensity of scattered X-rays inside the box is high, the closing shield lid 55 is closed during surgery. Thereby, the rectangular sleeve port 13 can be shielded with the closing shielding lid 55 in the same way as a box. Then, the user opens the sealing cover 52 of the gloveless port 53 and inserts the hand and arm into the box. Thereby, the operator can perform the procedure by inserting his arm and hand into the box while utilizing the shielding provided by the closing shielding lid 55. In FIG. 10, the gloveless port 53 attached on the surface of the closing shielding lid 55 and its closing shielding lid 52 are shown separated on the right side.

There is no accurate information regarding the intensity of X-rays scattered laterally in the body axis direction within the box. It is also possible that the strength differs between the head and lower limbs. However, in areas where there is a distance of 40 cm or more from the edge of the irradiation field 15, such as the lower limbs, the intensity is expected to be low because the patient's body is shielding in the axial direction. At that location, the patient port 20 can also be expanded to the full width of the side of the box for increased maneuverability during preparation. However, it cannot be denied that the scattered X-rays in the space above the patient's body 60 within the box may repeat scattering and leak from the patient port 20 on the side. If the strip curtain 54 attached thereto does not provide sufficient shielding, a patient port cover 61 can be attached to solve the problem.
The patient port lid 61 is a gate-shaped plate-shaped lid that is installed in the patient port 20 and is hollowed out in a semi-cylindrical or portal shape at a portion through which the patient's body is penetrated by a rigid functional material. This is attached to the patient port 20 after the additional shield box 1 is placed over the patient's body 60. The mounting structure may be a sliding type from above, screwing, or magnetic bonding. If the leakage of scattered X-rays from the box to the sides in the body axis direction is large, the patient port lid 61 can reduce the scattered X-rays leaking out of the box.

In Example 11, a ``further advanced combination case'' was explained in which a protective device (PD) is combined with a new PI, an additional protective device (API), and a simplified protective device (SEPI). The API is a thick hanging cloth 19 with a large mass and a support structure 65. SEPI is a strip curtain 54 and/or a gloveless port 53. In Example 11, in which these are combined, the shielding ability is maintained at the same level as Example 10, and the operability by medical personnel during surgery can be further improved.
There are two characteristic SEPIs in the eleventh embodiment related to the gloveless port 53. The first is a strip-shaped curtain 54 that extends to the entire width of the side of the box. The second is a gloveless port 53 installed on the closing shield lid 55 of the strip-type curtain 54. Note that a sealing shielding lid 52 is attached to the gloveless port 53.

(“Further advanced combination case” with improved operability and visibility)
In Example 12, a modification of the "further advanced combination case" in which operability and visibility are improved using transparent lead-containing acrylic resin will be described. In Example 11, which is the basis of this modification, the shielding of side scattered X-rays inside the box was maximized to maximize the operability of the box by medical personnel. Example 11 is a simplified protective device by adding the additional protective equipment (API) described in Examples 7 to 9 to the “case in which a new PI is combined as the third protection” described in Examples 3 to 5. (SEPI) was combined.
In Example 12, protective equipment and appliances made of transparent lead-containing acrylic resin with high visibility were reflected in Example 11 described above. The reflected protective device (PD) is the additional shield box 83 made of acrylic, which is cube-shaped or hemispherical and is integrally or divided into two or more pieces, as described in Example 1. The reflected protective equipment (PI) is a thick acrylic covering 84 that integrates the rigid thick covering described in Example 8 and the support structure. Figure 11 shows a bird's-eye view of protective equipment and equipment (PDITS) that reflects transparent lead-containing acrylic resin with high visibility. In FIG. 11, the additional shield box 83 made of acrylic and the high-performance table 2 are disassembled and shown as upper and lower parts in order to make it easier to see the vicinity of the patient's body 60. A patient body 60 is lying on the table 2. In reality, as shown by the small black arrows in the vertical direction, the table and box are in close contact with the patient's body between them without any gaps.
Note that the explanation of the high-performance table 2 and the new PI will refer to the fifth embodiment and FIG. 5, and the explanation of these itself will be omitted in the twelfth embodiment.

In FIG. 11, the interior of the patient's human body 60 near the center is shown as a perspective view. The PIs visible here are a thick acrylic hanging cloth 84, a regular hanging cloth 18, and the patient's clothes 63. These are called the "three PIs." The thick acrylic hanging cloth 84 is of a four-part type, transparent and highly visible, has a large mass, and has a high shielding ability. This includes a primary X-ray cutout 39 and a hand removal portion 67 as opening cuts. This is installed across the patient's body 60 and slides on the table 2. This mass does not impose a physical burden on the patient's body and is directly loaded onto the table.
A normal cover 18 can be seen on the outside of the clothing 63 inside the thick cover. These also have a primary X-ray cutout part 39 and a hand extraction part 67. The length of the normal hanging cloth 18 in the body axis direction is 100 cm, which is the largest. Clothes 63 are the same and 80cm long. The thick acrylic hanging cloth 84 is the smallest at 60 cm.
The total shielding capacity of these three PIs has a lead equivalent of 3 to 4 mmPb. Therefore, the ability to shield X-rays scattered to the side without the hollowed out portion 39 is high. The intensity of the upwardly scattered X-rays, which are provided by the hollowed out portion 39, can be reduced except for the irradiation field and its surroundings. Scattered X-rays directed upward and downward from the irradiation field and its surroundings are shielded by boxes and tables. That is, the intensity of scattered X-rays in all directions can be reduced.

The additional shield box 83 made of acrylic shown in FIG. 11 is entirely made of transparent lead-containing acrylic resin. Since the structural material is a transparent plate with high strength, the box body 4 and the viewing window 6 are integrated. Since the inside of the box can be seen from all around the table 2, this has high visibility for medical personnel. There are three types of this configuration depending on strength and manufacturing method. It can be molded in one piece, plates glued together, or plates attached to a metal frame. A functional material or line attenuation material 82 and a connection connector 24 are arranged on the ceiling as required. Generally speaking, when increasing the strength of acrylic resin plates, the problem is that the thickness and mass increase. The additional shield box 83 made of acrylic shown in FIG. 11 has a structure in which it is supported and transported by the overhead crane 56 and approaches the patient's body 60 from above. By using these mechanical devices, problems caused by large mass can be overcome. In the case of this configuration, it is not necessary to have a structure with divisions, and an integrated type is preferable. Furthermore, an integral molded type is more preferable.

Simplified protective equipment (SEPI) can be utilized by reducing the intensity of sideways scattered X-rays within the box with three PIs. In FIG. 11, the patient port 20 for installing the SEPI and the rectangular sleeve port 13, which were in FIG. 10, are not present. The SEPI strip-shaped curtain 54 is attached to hang from the lower end of the additional shield box 83 made of acrylic. A strip curtain 54 exists around the entire circumference of the box. It is preferable to increase the length in the vertical direction. The strip curtain 54 is a flexible sheet with a shielding function. Since there are many partitions, a person can easily open the area by pushing. Additionally, medical personnel can move around the entire perimeter of the box without sacrificing their skills. Therefore, it is highly operable for medical personnel during surgery.
As mentioned above, the shielding ability of the strip curtain 54 is not as high as that of other curtains. Therefore, it is necessary to ensure higher shielding ability with the three PIs inside the box. The method of using the strip curtain 54 around the entire circumference can be applied when the intensity of X-rays scattered to the side inside the box can be reduced. The effective energy of the laterally scattered X-rays is 60 KeV or less, preferably 50 KeV or less.

The additional shield box 83 made of acrylic and the strip-shaped curtain 54 all around the circumference are supported and transported by an overhead crane 56 or the like. It approaches the table 2 on which the patient's body 60 lies from above and maintains its position in the air. When approaching, the patient's body 60 is sandwiched between the strip curtains 54. The lower end of the strip-shaped curtain 54 is brought into contact with the upper surface of the table 2 with an extra length. Therefore, by eliminating the extra space between the patient's body 60 and the table 2, the intensity of scattering that leaks laterally during surgery can be reduced.
On the other hand, if the additional shield box 83 made of acrylic is structured to utilize the above-mentioned overhead crane 56, the operability of preoperative preparation work will be improved. This is because there is no need to penetrate the patient's body 60 into the patient port 20.

This protective equipment and equipment (PDITS) uses highly visible transparent lead-containing acrylic resin for both the box body, which also serves as a viewing window, and the thick hanging cloth. This provides high visibility as the medical personnel can see inside the box from all sides.
Additionally, by using three PIs as a third protection to reduce the intensity of X-rays scattered to the sides within the box, the strip curtain 54 can be used all around. This is highly manoeuvrable as the medical personnel can easily insert the arm and move it all around.
Several protective devices and instruments (PDITS) using transparent lead-containing acrylic resin are both highly visible and easy to operate. This makes it possible to reduce the air dose rate in medical rooms, etc., and reduce the occupational exposure and protection burden for medical personnel.

(Method of using the present invention in IVR surgery)
In Example 13, a method of utilizing the present invention in current IVR surgery was investigated. Here, it is confirmed that the present invention can be used without any problems in the current practice of inserting a catheter into the body during IVR surgery.
First, there is a preparatory stage in which a catheter is inserted into a blood vessel or the body through medical procedures such as puncture or incision. At this stage, if the X-ray source is not generating primary X-rays, there is basically no need to assemble protective equipment and instruments for radiation exposure protection. During the preparation stage, it was confirmed that the protective equipment and equipment that had been separated before being assembled could be used without any problems.
Next, it was confirmed as follows that the protective equipment and instruments assembled according to the present invention can be used without any problem in IVR surgery after primary X-rays are generated from an X-ray source.

In the case of cardiac catheterization for vascular system IVR, there are three main locations for inserting the catheter into the artery: the artery in the groin (femoral artery), the artery in the elbow (cubital artery), and the artery in the wrist (radial artery). It is. In recent years, surgical cases of transcatheter aortic valve implantation (TAVI) have been reported. TAVI is a catheter procedure used to replace a narrowed aortic valve with an artificial valve. In TAVI, the catheter is often inserted into the artery in the groin (femoral artery). However, in addition to this, there are left subclavian (below the left shoulder), left suprasternal thoracotomy (left chest), and left intercostal thoracotomy (left chest).
On the other hand, non-vascular IVR involves a procedure in which a lumen such as a bile duct or an abscess is percutaneously punctured with a needle under image guidance, and a drainage tube is then placed. There are also techniques such as tissue biopsy, in which a thick needle is inserted into a parenchymal organ to collect tissue from the organ. Percutaneous interventions into the abdominal cavity often involve a transrectus incision in the abdomen.
Looking at the locations for inserting the above-mentioned catheter, the locations that require only puncture and no incision surgery are the groin, elbow, wrist, and left subclavian region. In addition, open surgery is performed on the left chest and abdomen. Note that the left subclavian and left chest areas are used less frequently.

First, consider the case where there is only puncture and no incisional surgery. In all protective devices of the present invention, the base of the foot is naturally an exposed area. All protective equipment includes clothing 63, regular drapery 18, and thick drapery 19. Furthermore, the protective device has a hand retrieval portion 67 at the wrist and elbow, allowing easy removal. This area is not obstructed by protective equipment during the preparation stage, and medical procedures can be easily performed within the box 1.
The left subclavian part has an API above it. The API slides on the table 2 and retreats, opening the left subclavian part. On top of that, the clothing 63 and the normal hanging cloth 18 are partially opened. This may be handled by making a notch. As mentioned above, the API is provided with the function of sliding on the table 2. Since there are no other objects interfering, the puncture procedure can be performed within box 1 in the area below the left clavicle.

Next, consider the case where there is open surgery. The left chest area is the same procedure as the left subclavian area described above. When X-ray fluoroscopy using high-intensity primary X-rays is used in open surgery, the closing shielding lid 55 of the rectangular sleeve port 13 is closed. After ensuring shielding equivalent to that of the box main body 4, the hand and arm are inserted through the gloveless port 53. In the case of the abdomen, there are some differences from the left subclavian part. The API is retracted by sliding on the table 2 in the direction of the lower limbs, and the abdomen is opened. The incisional surgery is the same as for the left chest. Incisional surgery in the abdominal region is possible within Box 1, since there are no interfering articles. In addition, if it becomes necessary to perform medical treatment with a number of people exceeding the number of people who can approach the box 2 during emergency treatment, etc., the split box 16 can also be slid on the table 2 in the direction of the lower limbs. Evacuate.

Vascular IVR and non-vascular IVR surgeries have no problems with the specifications of the protective devices and instruments of the present invention. The API has a function of sliding on the table 2 in the direction of the head or the lower limbs to retreat. In order to further improve operability, it is preferable that the API be a split support structure 66. Furthermore, if an incisional surgery is to be performed, a split box 16 is preferable, except for special cases. If a larger space is required for medical treatment during open surgery, both the split support structure 66 and the split box 16 are provided with the above-mentioned sliding function. It is more preferable that the API and the split-type box 16 be retracted onto a side-carrying cart 59 attached sideways to the table 2 as shown in FIG.

(Range where the exposure dose within the patient's body increases during IVR)
Example 14 cites Non-Patent Document 2 to explain the range in which the exposure dose within a patient's body increases during IVR. Non-Patent Document 2 shows the exposure doses to major organs in head CT examinations of adults and children using an X-ray CT apparatus with a tube voltage of 120 kV. Although there are examples of measuring patient exposure doses using IVR, there is no evidence of a correlation between the distance from the irradiation field and the exposure dose. The half-value layer in living tissues other than the head does not vary greatly depending on the region. Therefore, Non-Patent Document 2 has been cited here.

Non-Patent Document 2 measures the exposure dose for each distance from the irradiation field during head CT examination. For the measurements, phantoms of an adult woman and a child made of human body equivalent material and sliced into 25 mm thick slices were used. Measurements were taken in a case with protection, in which a lead-containing sheet was wrapped around the outside of the imaging range, and in a case without protection. A glass dosimeter element was inserted at the center of each slice to measure the cumulative dose. The slice thickness, which corresponds to the moving distance per revolution of the X-ray source of the X-ray CT device, is 5 mm, and the imaging range, which is the total moving distance, is 160 mm. The results of the measurement test of Non-Patent Document 2 (hereinafter referred to as "dose measurement results") are shown below.
In addition, in this specification, the results of the Rand phantom of an adult female are cited. It also cited results for cases without protection. The X-ray source during CT examination moves while rotating at high speed. Since one round of CT scanning takes about 1 second, the total measurement time is expected to be about 30 seconds. Although the irradiation field moves sequentially, its total width is thought to be 16 cm. This is approximately equal to 15 cm, which is the full width of a typical IVR irradiation field. Dosimetry results are displayed as distance from the top of the head. Here, the center position of the irradiation field (hereinafter referred to as "irradiation center") corresponding to the isocenter of the IVR was considered to be 8 cm from the top of the head.

In FIG. 6 of Non-Patent Document 2, the dose measurement results for each distance from the irradiation center are shown in a logarithmic graph. Here, the numerical value of the dose (mGy) at the phantom center position was obtained by reading the logarithmic graph. Readings include errors. This is the cumulative dose for 30 seconds. The cumulative dose per minute is twice this value.
The read value was approximately 90 mGy at the irradiation center defined in the present invention. Additionally, the dose was approximately 10 mGy at the 10 cm position from the irradiation center, approximately 2 mGy at the 20 cm position, approximately 0.5 mGy at the 30 cm position, and approximately 0.12 mGy at the 40 cm position. Considering the irradiation center as the incident position, the dose ratio for each distance was calculated. As a result, the cumulative dose is 1/45th of the irradiation center at a position 20cm from the irradiation center, 1/180th of the same at a 30cm position, and 1/450th of the same at a 40cm position.

The above-mentioned dose measurement results will be compared with the JIS test results of Patent Document 1. The results for the tube voltage of 70 kV described in Example 16 and Example 17 are as follows. The dose rate was 2.945 mGy/min for the blank, 0.184 mGy/min after passing through 0.2 mm Pb, and 0.050 mGy/min after passing through the composite absorbing material (No. 3-4).
The dose rate after passing through 0.2 mm of Pb is in the same order as the cumulative dose for 1 minute inside the patient's body at 40 cm from the irradiation center. At a distance of 40 cm from the irradiation center, the dose rate within the patient's body becomes smaller due to linear attenuation due to human tissue. Generally, it is said that the dose rate in human tissue at a position 40 cm away from the edge of the irradiation field in the body axis direction is so small that it is not subject to management. This content is consistent with the phenomenon described above. That is, the scattered X-rays from the whole body have a significant dose rate within a range of 40 cm from the center of irradiation. Preferably, this area is provided with additional shielding as needed.

On the other hand, the half-value layer of X-rays in living tissue where the energy of X-rays is in the range of 60 to 100 KeV is generally said to be about 3 to 4 cm regardless of the location. That is, the five half-value layers are 15 to 20 cm. Ignoring the beam hardening effect, the dose rate becomes 1/32 in the 5 half-value layer. In the above-mentioned dose measurement results, the dose at the 20 cm position is 1/45th of the dose at the irradiation center. These two orders match. Therefore, the above-mentioned dosimetry results generally conform to the half-value layer of biological tissues.
Further, the dose rate at the 20 cm position is in the same order as the dose rate of a blank with a tube voltage of 70 kV in the JIS test. That is, the range within 20 cm from the irradiation center requires shielding equivalent to the blank dose at a tube voltage of 70 kV.

Based on the above study results, the present invention considered the following protective equipment to be added near the patient's body. Significant scattered X-rays of about 0.2 mGy/min are generated from the whole body of the patient within 40 cm from the edge of the irradiation field. Therefore, in this area, the patient's clothing, which is a shield with a total thickness of 0.4 to 0.5 mm, and a normal drapery are installed.
On the other hand, in a range within 20 cm from the edge of the irradiation field, highly scattered X-rays of 3 to 4 mGy/min or more are generated from the patient's body. Therefore, a thick covering cloth with a total thickness of 1 to 3 mm is installed in this area.
Note that the range in the body axis direction described above in this section is the length from the edge of the irradiation field, and an allowance of 7.5 cm, which is half of the assumed dimension of one side of the irradiation field, is added to this.

(Description of composite absorbent material of Patent Document 1)
In Patent Document 1, by the same inventor, a composite absorbent material (CAM) that attenuates scattered X-rays and absorbs ray energy is devised. The CAM is placed on a surface that is irradiated with scattered X-rays from the patient's body. Here, the CAM efficiently attenuates the incident scattered X-rays and then absorbs the ray energy. X-rays disappear by converting their energy into kinetic energy such as photoelectrons.
The composite absorbing material (CAM) 72 is composed of a low reflection attenuation layer and a multilayer absorbing layer. The low reflection attenuation layer is mainly made of lead (Pb) and is disposed in the initial layer of the X-ray incident surface. The multilayer absorption layer behind it is one to three pairs of diffusion absorbers and electron absorbers. A composite absorbing material (CAM) 72 is attached and installed on the incident side surface of a box or table. The total thickness (total t) of the functional material of the 3 to 4 layers of CAM used in the JIS test is 0.3 to 0.6 mm. Even with such a small thickness, CAM can operate if three or more layers with different roles are closely stacked in multiple layers. Here, the CAM attenuates and absorbs scattered X-rays from scatterers such as human tissue and a table.

Pb in the low reflection attenuation layer 80, which is the first layer, attenuates most of the incident X-rays and absorbs ray energy. The multilayer absorption layer 77 aims to efficiently extinguish X-rays using a pair of a diffusion absorber 78 and an electron absorber 79 by utilizing the specific absorption near the K absorption edge of the material in each energy region.
Here, for the purpose of explaining the contents of this section, μ, μen, and μen/μ are shown in Table 1. Here μ is the linear attenuation coefficient. μen is the linear energy absorption coefficient. This phenomenon of linear energy absorption, expressed as μen, is called "electron absorption." This phenomenon is a phenomenon in which scattered X-rays are annihilated and converted into electron kinetic energy. Further, μen/μ is the ratio of μen in μ, and is called the “electron absorption ratio”. This is a dimensionless value of μen divided by μ, expressed as a percentage. Note that Table 1 excerpts and quotes information from the NIST database of Patent Document 1.
Table 1 quotes the energies of three specific monochromatic colors and the numerical values of seven elements. Its energies (KeV) are 80, 50, and 30. Further, the elements are Pb, W, Ba, Sn, Nb, Mo, and Cu.

Here, the diffusing absorber 78 is an element whose electron absorption rate is less than 70% at a specific monochromatic energy in an arbitrary energy range (for example, 80/50/30 KeV). That is, it is an element with μen/μ<70% at a specific monochromatic energy. In Table 1, this is indicated by a frame surrounded by two-dot chain lines.
The electron absorber 79 is an element that absorbs electrons well with an electron absorption ratio of 70% or more at a specific energy when the diffusion absorber 78 is extracted. That is, it is an element with specific monochromatic energy and μen/μ≧70%. This is indicated in Table 1 by a thick dashed frame. As shown in Table 1, the role of the same element changes depending on its energy.

The diffusive absorber 78 emits many secondary X-rays (characteristic X-rays, bremsstrahlung X-rays) in various directions due to specific absorption at the K absorption edge at a specific energy. Along with electron absorption, photons are diffused and pushed back to the adjacent layers. The electron absorber 79 electronically absorbs X-rays in the target energy range, including its secondary X-rays.
The material of the low reflection attenuation layer 80 is mainly Pb. The material of the multilayer absorption layer 77 includes one to three pairs of diffusion absorbers and electron absorbers. For example, at 80 KeV, it is a pair of Sn and Pb. At 50 KeV, it is a pair of Sn and Nb or Mo. At 30 KeV, it is a pair of Nb or Mo and Cu or Fe. For the outermost layer, a flat plate of metal such as Ti or Al, which is a box material, is often used.

FIG. 12 is a configuration diagram of the basic case of the composite absorbent material 72. a. is an overview of the configuration, b. is 2 pairs with a total of 5 layers 74, c. is 3 pairs, total 7 layers 75, d. shows a total of three layers 76 in one pair. Low reflection attenuation layer 80 is Pb in the case of composite absorbing material 72 . In the case of the additional composite absorption material 73, the low reflection attenuation layer 80 is replaced by the linear attenuation material 70 or the low reflection attenuation material 71. Note that the term "pair" refers to the number of pairs of the diffusion absorber 78 and the electron absorber 79 in the multilayer absorption layer 77. In these figures, a pair of diffusion absorber 78 and electron absorber 79 are connected by a dashed line, and a. ～c. The pair numbers in each figure are indicated by (1) to (3). In the figure, example element symbols are shown in parentheses.
An example of a four-layer structure of the composite absorbent material (CAM) 72 is as follows. For example, in the case of flexibility, it is Pb-Sn-Nb-Cu. For example, in the case of rigidity, it is Pb-Sn-Mo-Fe.

(Explanation of JIS test results of Patent Document 1)
Patent Document 1, by the same inventor, reports the measurement results of the dose rate of a composite absorbing material (CAM) through experiments. In Patent Document 1, the transmitted X-ray dose rate of a composite absorbing material having three to five layers in total was measured.
The test method was based on the reverse broad beam conditions (RBB) and narrow beam conditions (NB) of JIS T61331-1 (Protective equipment against diagnostic X-rays). The test specimen was a multilayer test product made by stacking thin plates of pure metal (purity >99.9%) of each element. The dimensions of the test piece are 10 cm long x 10 cm wide. Here, the type of element, the number of its layers, and the thickness of each layer were used as test parameters. The thickness of the first layer Pb (low reflection attenuation layer) of the multilayer test article is either 0.2 or 0.3 mm. Its total thickness is 0.4-0.6 mm. Table 2 shows the material parameters. In addition, the dose rates of a comparative Pb plate and a blank were measured. The tube voltage of the X-ray source was measured in the range of 50 to 110 kV.
In order to compare the measurement results of different tube voltages, transmittance (%) was calculated from the obtained dose rate. The transmittance is a dimensionless value obtained by dividing the dose rate of the multilayer test product/comparison Pb plate by the dose rate of the blank at each tube voltage, and is expressed as a percentage.
For detailed test methods and results, refer to Examples 21 to 23 of Patent Document 1.

Here, among the many test results, we will introduce the results of seven types of multilayer test products and two types of Pb plates for comparison. The multilayer test piece is a test piece in which 3 to 4 layers of Pb, Sn, Nb, and Cu are laminated. The thickness of the initial layer Pb is 0.2 mm in all cases. The total thickness is 0.35-0.50 mm.
Table 2 shows the seven types of multilayer test products and two types of Pb plates for comparison. Table 2 shows the types of elements, their respective thicknesses, total thicknesses, average densities, and total masses. The multilayer test product in Table 2 is No. on the left. 2-3 (47g) has the largest mass. That is, in Table 2, the mass decreases toward the right. No. on the far right. 3-7 (36g) has the smallest mass.

FIG. 13 shows the transmittance (%) of the multilayer test product obtained in the experiment and the Pb plate for comparison. The test piece numbers and material parameters are shown in Table 2. The tube voltage of the X-ray source is shown in a. is 90kV, b. is 70kV, c. is 50kV. All measurement regimes are the result of reverse broad beam conditions (RBB). The transmittance (%) in the figure is shown by a bar graph for the multilayer test article. A comparative Pb board is shown by the line graph. One of them is 0.2 mm Pb, which is indicated by a thick broken line. This is because the thickness of the initial layer Pb of all the multilayer test products to be compared is 0.2 mm. The other 0.3 mm Pb is indicated by a thin two-dot chain line. This is for reference only. Note that c. of FIG. There is no chain double-dashed line for 0.3 mmPb. This is because the dose rate was below the lower limit of quantification and could not be evaluated at a tube voltage of 50 kV.

The results shown in FIG. 13 will be explained. First, a comparison of the X-ray transmittance of a comparative Pb plate (0.2 mm Pb) and a multilayer test product made of a composite absorbing material will be described. At a tube voltage of 90 kV, the X-ray transmittance was 11.9% for 0.2 mm Pb, while the multilayer test product was 4.1% to 6.9%. At a tube voltage of 70 kV, it was 1.4% to 3.0%, compared to 5.9%. At a tube voltage of 50 kV, it was 0.15% to 0.45%, compared to 1.43%. The multilayer test article made of the composite absorbent material has a transmittance reduced to about half or less compared to the Pb initial layer. Moreover, the mass is not more than twice that of the initial layer Pb. The mass of the functional material per unit area of the multilayer test article was 3.6 to 4.7 kg/m ² .

Next, the correlation between each test piece will be explained with reference to FIG. As mentioned above, the bar graph in FIG. 13 is written so that the mass decreases toward the right. The principle of shielding is that shielding performance is proportional to density. In that case, it is natural for the bar graph in FIG. 13 to increase in proportion to the right. However, the bar graph in FIG. 13 has irregularities at specific test piece numbers. The same tendency can be seen for these unevenness at any tube voltage.
At tube voltages of 90 kV and 70 kV, the following two cases have lower transmittance than the nearest left side. That is No. 3-4 (all 4 layers, Cu 0.05 mm, others 0.1 mm) and No. 2-4 (all 3 layers, no Nb, others 0.1 mm). This is expected to include the effect of Sn.
On the other hand, at a tube voltage of 50 kV, there are the following two. That is No. 3-4 and No. 3-6 (all 4 layers, Nb 0.1 mm, others 0.05 mm). No. 2-4 is No. It has been replaced by 3-6. This is expected to include the effect of Nb.
This tendency for unevenness is considered to be an effect of the multilayer absorbent layers of the composite absorbent material. More specifically, it is thought that the effect of electron absorption by a pair of a diffusion absorber and an electron absorber in a specific energy range was demonstrated here.

The X-ray transmittance of the composite absorbent material was reduced to about half or less by adding a multilayer absorbent layer to the initial Pb layer. This is considered to be an effect of the multilayer absorption layer composed of a pair of a diffusion absorber and an electron absorber. The above content was confirmed in the tube voltage range of 50 kV to 90 kV, which corresponds to the effective energy of scattered X-rays generated in the patient's body. That is, the composite absorbing material can effectively reduce the intensity of scattered X-rays generated in the patient's body.

(Explanation of a trial calculation example of the effect of reducing X-ray transmittance by composite absorbing material)
The degree to which scattered X-rays are reduced is determined by the specifications of the functional materials of the protective equipment/equipment. This knowledge is explained by the results of an experiment in which the transmittance of the comparative Pb plate shown in Example 16 and the composite absorbent material were compared.
On the other hand, the ability of the composite absorbing material to attenuate and absorb linear energy depends on the thickness of the initial Pb layer and three parameters of the multilayer absorbing layer. The three parameters of a multilayer absorption layer are the type of element of the constituent material, the number of layers, and the thickness of each layer. This is the specification for the composite absorbent material. Since there are many parameters to specify, it is difficult to quantitatively determine the performance of all combinations. However, on the premise that a composite absorbent material with the same specifications as the JIS test results shown in Example 16 is used for all meat, performance evaluation is possible. However, the effect of the hollowed out part of the protective equipment was ignored in the calculation.

As shown in Example 7, the total mass of clothing and normal draperies should more preferably be 10 kg or less. Due to this mass limitation, the total thickness (total t) of each functional material was considered to be 0.45 mm (approximately 4.3 kg/m ² ). The composition when total t=0.45 mm is No. 1 shown in Table 2 of Example 16 and FIG. 13. 3-4 (0.2mmPb-0.1mmSn-0.1mmNb-0.05mmCu) will be explained as a representative example. On the other hand, due to mass limitations, the total thickness of the functional material of the thick hanging cloth is 4 mm at most. Here, a thick hanging fabric with a total thickness of 1 to 4 mm was studied.
As described above in Examples 4 to 4, the thick covering mainly targets side-scattered X-rays from the patient's body to the sides. As in Patent Document 1, the median value of side scattered X-rays when the tube voltage is 110 kV is 65 KeV. This distribution is not a normal distribution or a bell-shaped distribution, and the number of photons on the high energy side is small. That is, the effective energy is lower than 65 KeV. Generally, the effective energy corresponds to 70% of the tube voltage. Therefore, when the tube voltage is 120 kV, the effective energy is about 84 KeV. Similarly, it is about 77 KeV at 110 kV. Similarly, at 90 kV, it is about 63 KeV. Similarly, at 70 kV, it is about 49 KeV. Similarly, at 50 kV, it is about 35 KeV. Based on these backgrounds, we estimated the performance that a thick hanging cloth should have by comparing it with the results for tube voltages of 50 to 90 kV in Table 2 and Figure 13.

First, the case where total t=0.45 mm will be explained using the test results shown in FIG. The dose rates measured for reference are as shown in RBB in Table 19 of Patent Document 1, 4.980 mGy/min for blank at tube voltage of 90 kV, 0.586 mGy/min for 0.2 mm Pb, and 0.586 mGy/min for No. 3-4 is 0.228 mGy/min. At tube voltage of 70 kV, blank was 2.945 mGy/min, 0.2 mmPb was 0.184 mGy/min, and No. 3-4 is 0.050 mGy/min. At tube voltage of 50 kV, blank was 1.327 mGy/min, 0.2 mmPb was 0.019 mGy/min, and No. 3-4 is 0.002 mGy/min.
In Fig. 13, a comparative Pb plate of 0.2 mm Pb and a No. The transmittance of the composite absorbent material No. 3-4 is as follows. At a tube voltage of 90 kV, they are 11.3% and 4.6%. At a tube voltage of 70 kV, they are 5.4% and 1.7%. At a tube voltage of 50 kV, they are 1.43% and 0.15%. A comparative Pb plate of 0.2 mm Pb corresponds to a shielding material of this thickness. This corresponds to the low reflection attenuation layer (first layer Pb) of the composite absorbing material. Composite absorbent materials add multiple absorbent layers to this.
According to the test results, compared to the case where no shielding or protective equipment/equipment is present, No. The transmittance of 3-4 is less than 1/20 when the tube voltage is 90 kV. Similarly, when the tube voltage is 70 kV, it becomes less than 1/50. Similarly, when the tube voltage is 50 kV, it becomes less than 1/600. Furthermore, compared to the case where there is a shielding material of 0.2 mm Pb, the transmittance of X-rays is less than one-third when the tube voltage is 70 kV. Similarly, when the tube voltage is 50 kV, it becomes about 1/10.

Next, the transmittance performance of a thick hanging cloth whose total thickness (total t) of functional materials is 1 mm to 4 mm is estimated using the formula for X-ray transmission. To simplify the trial calculation, the thickness and linear attenuation coefficient μ are represented only by Pb of the low reflection attenuation layer. In other words, the degree of reduction is determined only by the low reflection attenuation layer (initial layer Pb:Pb-t). Further, μ uses a value equivalent to effective energy. The shielding performance of this composite absorbent material is evaluated by the maintenance side. On the other hand, the shielding performance of the transparent lead-containing acrylic resin plate, which is one of the rigid functional materials, is evaluated as being fair. Based on this assumption, we estimated the performance of thick hanging cloth. Note that there is no reported data for μ between 80 KeV and 50 KeV in the NIST database.

The formula for calculating the X-ray transmission dose is I/I ₀ =Exp(-μt). Here, _I0 is the transmittance on the incident side, I is the transmittance on the output side, t is the thickness (cm) of the initial layer Pb, and μ is the linear attenuation coefficient (1/cm). _I0 is a blank value and is 1.0 (100%). The μ value of Pb was quoted from Table 1 of Example 16. μ (1/cm) is 27.3 at 80 KeV, 90.9 at 50 KeV, and 343 at 30 KeV. The thickness of the initial layer Pb is t=0.2 cm when the total t=4 mm. Transmittance I/I ₀ was calculated using this μ and Pb-t. The calculation results are shown in Table 3.

Here, the trial calculation results in Table 3 will be explained. Note that this result is a guideline value that is simply calculated for the thickness of only the initial layer Pb. The energy (KeV) in Table 3 is effective energy. Here, the results of comparison with the transmittance in the second column of Table 3 where the Pb thickness (Pb-t) is 0.02 cm (0.2 mm Pb) will be explained. The transmittance for each thickness of the thick cloth compared to 0.2 mm Pb, which is equivalent to a normal cloth, is as follows.
When the initial layer Pb thickness is 0.5 mm (total t=1 mm), at 80 KeV it becomes about 1/2 or less. At 50 KeV, it becomes about 1/15 or less. At 30 KeV, it becomes smaller by more than four orders of magnitude.
When the initial layer Pb thickness is 1.0 mm (total t=2 mm), at 80 KeV it becomes about 1/9 or less. At 50 KeV, it becomes about 1/1,400 or less. At 30 KeV, it becomes smaller by more than 11 orders of magnitude.
When the initial layer Pb thickness is 1.5 mm (total t=3 mm), at 80 KeV it becomes about 1/35 or less. At 50 KeV, it becomes about 1/130,000 or less. At 30 KeV, it becomes smaller by more than 19 orders of magnitude.
When the initial layer Pb thickness is 2 mm (total t=4 mm), at 80 KeV it becomes about 1/140th or less. At about 50 KeV, it becomes about 1E+1/7 or less. At 30 KeV, it becomes smaller by more than 26 orders of magnitude.

From the dose measurement results of Example 14, the dose rate in the patient's body by an X-ray source with a tube voltage of 120 kV (effective energy is about 84 KeV) is about 10 mGy at a position 10 cm from the irradiation field. This is approximately 4 mGy/min at the 20 cm position. On the other hand, the dose rate of the blank using the X-ray source in the JIS tests of Patent Document 1 and Example 15 is approximately 7 mGy/min when the tube voltage is 110 kV (approximately 77 KeV). In the case of 90 kV (approximately 63 KeV), it is approximately 5 mGy/min. In the case of 70 kV (approximately 49 KeV), it is approximately 3 mGy/min. That is, the dose rate at the 20 cm position is about 20% smaller than when the effective energy is about 63 KeV, and about 30% larger than when the effective energy is about 49 KeV. When interpreting the dosimetry results from the above-mentioned background, it is expected that the scattered X-rays within the patient's body at a position 20 cm from the irradiation field will have a large number of photons with energy of 50 to 65 KeV. This intensity of scattered X-rays can be reduced by using a composite absorbing material with a total thickness (total t) of 0.4 to 0.5 mm. That is, the thick hanging cloth has the role of reducing scattered X-rays with high intensity within 20 cm from the irradiation field to a level at the 20 cm position that can be shielded by clothing or a normal hanging cloth.
Here, the thick hanging cloth is defined as having the following two roles. That makes the 80 KeV dose rate less than an order of magnitude lower. In addition, the dose rate of 50 KeV should be lower than 2 orders of magnitude. In Table 3, areas corresponding to this definition are indicated by broken lines in Table 3. In Table 3, the initial layer Pb of 0.5 mm, indicated by the dashed line, is on the threshold line. Dose rates with composite absorbing materials are reduced by a factor of less. No. 17 in FIG. 17 of Patent Document 1. According to the result of 1-3, at 77 KeV, it is about 1/2.5. Moreover, at 49 KeV, it becomes about 1/3.5. As a result, the result for the total t=1 mm almost conforms to the above definition. Therefore, it is thought that the necessary thickness for a thick hanging cloth is that the initial layer Pb is 0.5 mm or more (total t=1 mm). However, within the scope of this definition, it seems unnecessary to have an initial layer Pb thickness of up to 2.0 mm (total t=4 mm).

The thick drapery is an additional protective device installed to reduce as much as possible the intensity of the scattered X-rays generated by the patient's body, mainly to the sides. According to the above study results, it is possible to reduce the transmittance of scattered X-rays by using a thick covering with a total thickness of 1 mm (the mass of the functional material per unit area is about 10 kg/m ² ) or more. A preferable range of total thickness (total t) is 3 mm (approximately 30 kg/m ² ) or less. As in Example 14, the thick hanging cloth is placed within 20 cm from the edge of the irradiation field.

(Description of the high-performance table of Patent Document 2)
In Patent Document 2, by the same inventor, a medical table (hereinafter referred to as "high-performance table 2") that transmits X-rays well and eliminates scattering is devised.
The high-performance table 2 supports the weight of the patient, etc., and the primary X-rays pass through the mesh 43 on the step 30 of the top plate and reach the irradiation field 15 without any interaction. By changing the surface material depending on the type or energy of the irradiated X-rays, the generation of scattered X-rays on the bottom plate 41 is reduced, and the table top plate 7 attenuates and absorbs the scattered X-rays from human tissues. do. In addition, the transmitting plate unit 32 on the top plate tier 30, the slide table 35 on the middle tier 34, the aperture plate 36, and the opening/closing plate 42 on the bottom plate tier 40 provide the minimum aperture size necessary for the position of the irradiation field and medical purposes. Adjust to
A bird's-eye view of the high-performance table 2 is shown in FIG. 14 and will be explained. The bird's-eye view in Figure 14 shows the structure divided into three stages: top plate, middle plate, and bottom plate. However, in order to make the illustration easier to see, the support rails 45 and reinforcing beams 46 are shown together with the table support 44 on the bottom plate step 40 instead of on the top plate step 30.

The high-performance table in Patent Document 2 allows primary X-rays to pass through the irradiation field without interacting with substances, limits the irradiation field to the minimum necessary opening size (area), and prevents the generation of further scattered X-rays. suppress. It also attenuates and absorbs scattered X-rays generated downward by the patient's body placed on top of the body. This improves the image quality of the X-ray receiver and reduces the radiation dose rate in a space such as a medical room. Therefore, the exposure dose and radiation protection burden on medical personnel can be reduced.

(Description of additional shield box of Patent Document 3)
In Patent Document 3, by the same inventor, an additional shielding box 1 that reduces radiation exposure and protection load is devised.
The additional shielding box (hereinafter referred to as "box") 1 of Patent Document 3 reduces the intensity of various upwardly and laterally scattered X-rays generated in the patient's body 60. Box 1 has no opening communicating with external space in any three-dimensional direction, and surrounds the irradiation field with functional materials of different combinations of types and thicknesses depending on the dose rate. While viewing the inside of the box through a viewing window with shielding ability, medical personnel insert their hands and arms through the sleeve structure to perform medical procedures. In addition, composite absorbing materials and the like are placed at various locations to absorb the linear energy of the linearly attenuated X-rays.

The additional shield box 1 includes a split box type box 16 and an FPD built-in type box 17. FIG. 15 is an overall configuration diagram of the divided box type box 16. Although FIG. 15 is directed to an X-ray camera type X-ray fluoroscope, Patent Document 3 also devises a device compatible with a C-arm type X-ray fluoroscope. As the above-mentioned option, Patent Document 3 devises a high-dose type additional shielding box when the energy of small-angle scattered X-rays is even higher.

The split box type additional shield box 61 of Patent Document 3 will be explained using the bird's eye view of FIG. 15. The undertube type X-ray receiver 10 can be assembled on site by sandwiching the receiver arm 11 between the box body 4 and the end box 5, so that it can be stored in the box without an opening. The ceiling of the end box 5 is shielded with a plurality of functional materials to prevent X-rays from leaking.

The through port and its protective equipment of Patent Document 3 will be explained. The operator inserts his hand and arm into the box through the sleeve structure 9 and performs the surgery while viewing the inside through the viewing window. The patient passes through the box axially through the patient port 20. This places the patient's head and body parts in the external space. The through ports of box 1 are sleeve port 8 and patient port 20.
A sleeve structure 9 is attached to the sleeve port 8. The sleeve structure 9 is made of a flexible functional material such as a lead-containing arm sleeve.
A shielding sheet 22 is attached to the patient port 20. This closes the opening between the box and the human body. The shielding sheet 22 is made of a flexible functional material with shielding ability. In addition, in Patent Document 3, the shielding sheet 22 is referred to as a "hanging cloth, etc." together with a hanging cloth. Further, the winding device for the shielding sheet 22 is called a cloth holder together with the cloth. In the present invention, the contents of "covering cloth, etc." are strictly classified, and the normal covering cloth 18, the thick covering cloth 19, and the shielding sheet 22 are handled separately. Moreover, the hanging cloth holder of Patent Document 3 is referred to as holder 23 in the present invention.

The additional shield box disclosed in Patent Document 3 allows the operator to perform the procedure in a box that does not have an opening and has a shielding ability. By attenuating and absorbing scattered X-rays generated above and to the sides of a patient's body, the air dose rate in a medical room or the like is reduced. This will reduce unwarranted occupational exposure of medical workers and avoid unnecessary medical exposure of patients' heads, trunks, limbs, etc. In particular, occupational exposure to the operator's head (eye lens) can be significantly reduced. Furthermore, by using protective clothing and protective glasses that are lightweight, it is possible to reduce the burden of radiation protection on medical personnel.

1. Additional shield box 2. Highly functional table 3. Box top plate 4. Box body 6. Peephole 7. Table top plate 8. Sleeve port9. Sleeve structure 10. X-ray receiver13. Square sleeve port 15. Irradiation field 17. Box with built-in FPD 18. Normal hanging cloth 19. Thick hanging cloth 20. Patient port 21. Sheet 22. Shielding sheet 25. Slide table 29. X-ray source 30. Step 31 of the top plate. Absorption plate 32. Transparent plate unit 33. Spacer 34. Middle stage 35. Slide table 36. Aperture plate 38. Slide absorption plate 39. Hollowed out portion 40. Step 42 of the bottom plate. Low reflection scattering opening/closing plate 43. Net (mesh)
44. Table support stand 45. Support rail 46. Reinforcement beam 51. Hinge mechanism 52. Sealing shield lid 53. Gloveless port 54. Strip curtain 55. Closing shield lid 59. Horizontal cart 60. Patient human body 61. Patient port lid 62. Transparent lead-containing acrylic resin plate 63. Clothes 64. Head cover 65. Support structure 66. Split support structure 67. Hand removal part 71. Low reflection attenuation material 72. Composite absorbent material 73. Additional composite absorbent material
77. Multilayer absorbent layer 78. Diffusion absorber 79. Electron absorber 80. Low reflection attenuation layer 81. Shielding material 82. Linear damping material 83. Additional acrylic shield box 84. thick acrylic hanging cloth

Claims (22)

In radiation protection equipment for medical undertube type X-ray fluoroscopy equipment,
The first protection is to install a flat table with a functional material on the top that has the ability to shield the scattered X-rays from the patient placed on top of the table, and the second protection is to allow the scattered X-rays to enter the table. A square-shaped box in which the functional material having a shielding ability is arranged on the surface or inside is installed on the table,
The X-ray receiver is housed in the box without an opening that cannot reduce the transmission of X-rays ,
By surrounding the patient's body in all directions with a structure placed on the surface or inside the functional material capable of shielding ,
A complex protective device/apparatus that is characterized by reducing the intensity of scattered X-rays generated from the patient's body including the periphery of the irradiation field and emitted in all 360-degree directions, up, down, left and right. In radiation protection equipment for medical undertube type X-ray fluoroscopy equipment,
A flat table with a functional material placed on its top surface that has the ability to shield against scattered X-rays, which is the first protection;
In addition to the second protection, a rectangular box in which the functional material with shielding ability is placed on the surface or inside of which scattered X-rays are incident,
Third protection is a cloth worn over the patient's body in which the flexible functional material is arranged on the surface or inside of the incident side of the scattered X-rays, and clothing worn by the patient on the trunk ; Install any one, two or three of the three protective devices worn on patients to protect medical workers from exposure to radiation , including a head cover worn by patients over their heads ;
The X-ray receiver is housed in the box without openings that cannot reduce the transmission of X-rays ,
By surrounding the patient's body in all directions with a structure placed on the surface or inside the functional material capable of shielding ,
Composite protective equipment and instruments that reduce the intensity of scattered X-rays generated from the patient's body during surgery and emitted in all directions. In radiation protection equipment for medical undertube type X-ray fluoroscopy equipment,
A flat table with a functional material placed on its top surface that has the ability to shield against scattered X-rays, which is the first protection;
The third type of protection is to use a combination of any one, two or three of the three protective devices: a cloth with a functional material arranged on or inside the surface where scattered X-rays are incident, clothing, and a head cover;
By surrounding the patient's body in all directions with a structure placed on the surface or inside the functional material capable of shielding ,
A composite device characterized by reducing the intensity of scattered X-rays generated in all directions, excluding those directed upward from the periphery of the irradiation field among the scattered X-rays generated from the patient's body and emitted in all directions. Protective equipment/equipment In radiation protection equipment for medical undertube type X-ray fluoroscopy equipment,
A box in which a functional material is placed that has the ability to shield against scattered X-rays, which is the second protection.
Any 1 to 2 or 3 of the three protective devices, ie, a cloth, clothing, and a head cover, each having a functional material arranged on the surface or inside of which the scattered X-rays are incident, which is the third protection, and the box and A bed sheet is placed below the patient's body at a position between the flat table on which the patient's body is placed and between the patient's body and the table ,
The X-ray receiver is housed in the box without openings that cannot reduce the transmission of X-rays ,
By surrounding the patient's body in all directions with a structure placed on the surface or inside the functional material capable of shielding ,
A compound characterized by reducing the intensity of scattered X-rays generated from a patient's body and emitted in all directions, excluding those directed downward from the periphery of the irradiation field during surgery. Protective equipment and equipment In the composite protective equipment/apparatus of claim 1, claim 2, claim 3 or claim 4,
A thick covering , which is a thick covering with a large thickness and mass and high shielding ability, is made by disposing the functional material having a unit area mass of 10 kilograms per square meter or more inside or on a surface where scattered X-rays are incident. ,
There is a hollowed out part that allows the primary X-rays that have passed through the patient's body to pass through .
placing the patient in a portal-shaped space above the patient's body on the table;
The support structure that supports the mass of the thick cover is installed across the patient's body , and the mass is directly loaded onto the table, without placing any physical strain on the patient due to the load.
By installing additional protective equipment , which is a general term for thick-walled coverings with large thickness and mass and their supporting structures, and adding shielding ability ,
Composite protective equipment and instruments characterized by further reducing the intensity of scattered X-rays generated from the patient's body during surgery. In claim 5, the supporting structure comprises:
The additional protective equipment has a structure that is integrated or divided into two or more parts, and/or the supporting structure is installed after the thick-walled cover is installed, thereby simplifying the installation operation by medical personnel. Features of complex protective equipment and instruments
The composite protective equipment/instrument according to claim 5,
The additional protective device made of a functional material with rigid shielding ability ,
By using an additional protective device consisting of a transparent lead-containing acrylic resin structure with a shielding function, it can be divided into two or more cube-shaped or semi-cylindrical parts .
Composite protective equipment and equipment characterized by reducing the intensity of scattered X-rays generated from the patient's body including the periphery of the irradiation field. In claim 1, claim 2 or claim 4, the box is
The patient 's body passes through the patient port in the body axis direction through the patient port on the end surface of the rectangular box that is the main structure, placing the patient's parts except the vicinity of the irradiation field in the external space.
A flexible shielding sheet with shielding ability is hung from the top of the patient port to close the opening.
A complex protective device/apparatus that is characterized by having no opening and placing the patient's area except for the vicinity of the irradiation field in the external space.
9. The patient port according to claim 8,
There are two or more partitions formed by vertical cuts toward the lower end, and the upper part is a strip-shaped flexible shielding sheet made of a flexible functional material with shielding ability and has multiple partitions. By installing a gate-shaped plate-shaped lid made of a functional material with shielding ability and having a gate-shaped cutout for the penetrating part of the patient's body,
At the same time as reducing scattered X-rays leaking outside the box during surgery,
Composite protective equipment and instruments that simplify pre-surgical preparations for medical personnel
In claim 1, claim 2, or claim 4, the device for operating the inside of the box in the vicinity of the box,
A complex protective device/appliance characterized in that there is one or more flexible sleeve structures attached to sleeve ports on the wall of the box.
In claim 10, a circular or oval sleeve port having a width of a part of a side surface of the box having a viewing window among the sleeve ports,
Installing a circular gloveless port in the form of a sheet of flexible shielding functional material with two or more radial partitions directed towards the center by a through cut, and/or a sleeve of shielding functional material. By installing a circular sealing plate-like lid that seals and shields the port ,
Even when the energy of scattered X-rays from the patient's body is 60 kiloelectron volts or more, the scattered X-rays leaking outside the box during surgery are reduced, and at the same time,
Composite protective equipment and instruments that are characterized by ease of operation by medical personnel during surgery.
In claim 10, among the sleeve ports, a rectangular sleeve port that has a width of a part or all of the side surface of the box where the viewing window is located,
By installing a strip-shaped curtain with a large number of partitions made of strip-shaped flexible shielding sheets suspended from the top, and/or by installing a closing plate-shaped lid made of the above-mentioned functional material with shielding ability ,
At the same time as reducing scattered X-rays leaking outside the box during surgery,
Composite protective equipment and instruments characterized by additional protective equipment that facilitates operations during surgery by medical personnel.
In claim 12, the closing plate-shaped lid of the rectangular sleeve port comprises:
The surface of the board on which scattered X-rays are incident, or the inside of which is placed a functional material that has the ability to shield scattered X-rays, is placed on the side of a square-shaped box with a viewing window that can penetrate the hands and arms of medical personnel. By installing a circular gloveless port, which is a through port , and/or installing a circular sealing plate-like lid that seals and shields the sleeve port ,
Even when the energy of scattered X-rays from the patient's body is 60 kiloelectron volts or more, the scattered X-rays leaking outside the box during surgery are reduced, and at the same time,
Composite protective equipment/instruments characterized by a device that operates internally in close proximity to simplify operation by medical personnel during surgery.
In claim 1, claim 2 or claim 4, the box is
There is a patient port, which is a through port that penetrates the patient's body in the axial direction, on the side end surface in the axial direction of the rectangular box, which is the main structure, and a patient port, which is a through port that penetrates the patient's body in the axial direction. has a sleeve port, which is a penetrating port that passes through the hands and arms of medical personnel.
By blocking the through port with a flexible sheet having shielding ability,
A complex protective device/instrument characterized by further reducing the intensity of scattered X-rays leaking out of the box from the through port during surgery.
The composite protective equipment/instrument according to claim 14,
Adding shielding ability by installing additional protective equipment, which is a general term for a thick hanging cloth with a large thickness and mass and its supporting structure, made of functional material capable of shielding against scattered X-rays, in the box. According to
A complex protective device/instrument characterized by further reducing the intensity of scattered X-rays leaking out of the box from the through port during surgery. In claim 1, claim 2, or claim 4, the device for visually checking the inside of the box in the vicinity of the box,
A composite protective equipment/equipment characterized in that there is a viewing window made of one or more transparent shielded glass plates or shielded resin plates from the ceiling or wall of the box.
The composite protective equipment/instrument according to claim 16 ,
The box in which the viewing window is made the same as the box body,
By creating a transparent box made of a transparent lead-containing acrylic resin structure with a shielding function, it is made of a rectangular or semi-cylindrical shape that is either integrated or divided into two or more parts, and has a shielding function.
A complex protective device/instrument that reduces the intensity of scattered X-rays generated from the patient's body, including the periphery of the irradiation field, and at the same time allows medical personnel to see inside the box without blind spots during surgery. 18. The transparent box according to claim 17 ,
A strip-type curtain with multiple partitions made of strip-shaped flexible shielding sheets is suspended directly from the lower end of the entire circumference.
The transparent box is supported from above and maintained in the air by a transportation means that can move up and down, forward and backward, left and right ,
A patient's body is placed thereon by the conveying means, and maintained in a position where the lower end of the strip-shaped curtain is in contact with the upper surface of a table on which a functional material capable of shielding scattered X-rays is disposed;
The strip-shaped curtain fills the space between the patient's body and the transparent box , and the strip-shaped curtain closes the remaining space that is the gap above the shield that occurs at the part where the human body is penetrated ,
At the same time as reducing scattered X-rays leaking outside the box during surgery,
Complex protective equipment and instruments that are easy to operate by medical personnel
In claim 1, claim 2, claim 3 or claim 4, the functional material is
The first layer on which X-rays are incident is a low reflection attenuation layer made of an element with an atomic number of 82 or higher, and the second and subsequent layers are made up of three or more layers of a multilayer absorbing layer consisting of a pair of a diffuse absorber and an electron absorber. Composite protective equipment/appliances characterized by multi-layered composite absorbent materials
In claim 1, claim 2, or claim 3, the table includes:
A high-performance mesh that suppresses the absorption and scattering of X-rays by the top plate by installing a net made of single elements or compounds of elements with atomic numbers of 14 or less on the top plate, and allowing X-rays to pass through the net. Compounded protective equipment and equipment characterized by the presence of a table
In claim 1, claim 2 or claim 4, the box is
A complex protective device characterized by an additional shielding box in which a device having shielding ability to visually inspect the inside from a nearby or remote location and a device having shielding ability to operate the interior from a nearby or remote location are attached to the box. utensil
In claim 1, claim 2 or claim 4, the box is
The box has a divided structure in which it is divided into two or more parts in the axial direction,
When assembling the divided boxes into one, the receiver arm of the X-ray receiver is assembled into the receiver port on the ceiling of the box,
Closing the opening around the receiver arm where the transmission of X-rays cannot be reduced with an expandable and retractable foldable shielding sheet in which the functional material with shielding ability is placed on the surface or inside;
A complex protective device/equipment characterized by the fact that the X-ray receiver is housed in a box without an opening.