Background technology
CT equipment is take the area of computer aided imaging device of X ray as human body tomoscan transmission potential, become the Checking and diagnosis armarium of hospital's popularization, CT examination can provide for the surgical operation in the emergency instructive information of most worthy obviously being better than X-ray aspect the demonstration transverse section.China is a country that natural disaster takes place frequently, the frequent occurrence of the natural disasters such as in recent years earthquake, flood, mud-rock flow, and Operation Medical Treatment Clinique, shelter hospital system have been brought into play important function take the characteristics of its fast reserve as earthquake relief work.The development of shelter CT equipment is for field emergency provides strong instrument.
For example disclose a kind of field operations CT shelter among the Chinese patent ZL201210396745.5, described cabin body is the two plank frames that enlarge of manual push-and-pull turnover plate type, described shelter front portion is provided with H type frame, described shelter inside is divided into CT Control Room and CT Scan Room, described CT Control Room is positioned at the shelter front portion, be furnished with image acquisition work station, image processing workstation, medical science display, work chair, film viewer and diagnosis report printer in the CT Control Room, described CT Scan Room is furnished with CT main frame, gantry, scanning bed, CT damping frame and medical film printer.This shelter can load transportation with self-loading and unloading vehicle, possess powerful maneuverability, and inside has CT equipment and effect support equipment facility, can satisfy for shelter hospital CT examination to provide safeguard.
Yet the CT device is take X ray as detection methods, and ionizing radiation has larger harm to human body, and Radiation Exposure must be taked in its working space.Prevent that at fixing inspection chamber wall parcel lead screen layer that X ray penetrates from can effectively prevent the leakage of X ray.Existing CT device is fixed in the inspection chamber of hospital usually, and the lead screen layer thickness adopts unified thickness, and therefore the lead screen layer weight of the CT of row more than equipment is about 2 tons, and this is not have any problem for the fixing inspection chamber in position.
In order to adapt to the demand of open-air medical treatment, shelter CT device needs CT equipment is installed in the shelter, by Automobile Transportation.The haulage vehicle that all adopts load capacity in the prior art directly is loaded in fixing inspection chamber on the truck as Move tool.Yet such mode is very high to the performance requirement of automobile, and because whole shelter system equipment is numerous, conducts oneself with dignity very large, and it is heavy that automobile seems when mobile, and mobility is relatively poor.On the other hand, in order to satisfy flexible user demand, the length over ends of body of vehicle and loading capacity just must limit to some extent, and this restriction is so that vehicle can't carry whole fixing inspection chamber weight, so this is the conflict that exists in the prior art.On the one hand, can consider the number of devices in the body of cabin is reduced, yet the equipment of smaller amounts will reduce the medical services ability of whole medical treatment shelter, that is to say again, the medical services ability will become lowly, can't satisfy the demand of open-air medical treatment.
Therefore, be necessary to study a kind of medical treatment shelter for wild environment, so that its weight reduces, when improving its mobility, keep its medical services ability and level of security, the applicant is through concentrating on studies, a kind of radiation classified protection system of the medical treatment shelter for wild environment has been proposed, to solve the above-mentioned one or more problems that exist in the prior art.
Summary of the invention
Consider at least one the problems referred to above and finished the present invention, and one object of the present invention is to provide a kind of radiation classified protection system of the medical treatment shelter for wild environment.By this system, so that under other equipment can't the prerequisite of weight reduction, can be according to CT radiation of equipment characteristics and environment for use requirement, guaranteeing under the radiation protection prerequisite up to standard, reduce the gross mass of radiation protection shielding layer, thereby reduce the shelter gross weight, improve the maneuverability of vehicle mounted square cabin.Particularly, a kind of radiation classified protection system of the medical treatment shelter for wild environment, this medical treatment shelter is the two large board-like cabin bodies that expand structure of turnover plate type, described shelter inside comprises CT Control Room and CT Scan Room, described CT Control Room is positioned at the shelter front portion, be provided with the CT device in the CT Scan Room, it is characterized in that described radiation classified protection system comprises the different a plurality of stereotypes of thickness that arrange on the shelter sidewall, described a plurality of stereotypes are by following method setting: 1) obtain CT device scattering radiation dose distribution curve; 2) shelter is divided into a plurality of subregions; 3) determine the required thickness H that stereotype is set on the shelter sidewall of every sub regions according to following formula:
In the formula
B represents the greatest irradiation transmittance of every sub regions;
D represents that personnel are to the distance of scanning center;
D
0, d
0Expression is apart from the d of scanning center
0The radiation dose of place's Single Slice Mode is D
0
W represents to provide D
0The condition of scanning of value is all normalizing workloads under the reference conditions;
T represents the personnel at the CT Scan Room external distance scanning center d place factor of persistencing;
θ represent radiant flux with perpendicular to the angle of shield normal to a surface;
4) thickness being set respectively on the shelter sidewall of every sub regions is that the stereotype of H is as shield.
According to a further aspect of the invention, described a plurality of stereotype comprises CT Control Room first area stereotype, CT Control Room second area stereotype, idle regional stereotype, control room observation window zone stereotype, the first room and clear area stereotype, the second room and clear area stereotype, the first inner corridor zone stereotype and zone, the second inner corridor stereotype.
According to a further aspect of the invention, the stereotype thickness H that obtains in the step 3) be multiply by empirical value factor j obtain final stereotype thickness, and the stereotype of this final thickness is arranged on the shelter sidewall of every sub regions.
According to a further aspect of the invention, the span of empirical value factor j is 100%-143%.
According to a further aspect of the invention, the top of described shelter and bottom do not arrange stereotype.
According to a further aspect of the invention, described guard system also comprises computer and radiation measurement assembly, store the greatest irradiation transmittance B of each subregion in the described computer, this radiation measurement assembly is arranged on each position corresponding to subregion greatest irradiation transmittance B, when greatest irradiation transmittance that real-time radiation transmittance that radiation measurement assembly obtains is stored in greater than computer, computer stops the CT device automatically, and sends warning information.
Compared with prior art, beneficial effect of the present invention is: the radiation classified protection system of the medical treatment shelter for wild environment of the present invention is so that under the radiation-resistant prerequisite of safety, the gross weight of medical treatment shelter reduces greatly, and shelter medical services ability is higher, mobility is good, cost.
The specific embodiment
Below in conjunction with accompanying drawing; by preferred embodiment preferred forms of the present invention is described; the specific embodiment here is to explain the present invention; and should not be construed as limitation of the present invention; in the situation that do not break away from spirit of the present invention and essential scope; can make various changes and modifications, these all should be included within protection scope of the present invention.
Embodiment 1
Referring to Fig. 1, wherein show the vehicle-mounted state of the medical treatment shelter that is used for wild environment of the preferred embodiment of the present invention.Referring to Fig. 4, it shows the interior layout schematic diagram after the medical treatment shelter that is used for according to the preferred embodiment of the invention wild environment launches.This medical treatment shelter is the two large board-like cabin bodies that expand structure of turnover plate type, and described shelter inside comprises CT Control Room 31 and CT Scan Room, and described CT Control Room is positioned at the shelter front portion, is provided with CT device 34 in the CT Scan Room.
For medical treatment shelter can be used, the present invention proposes a kind of radiation classified protection system of the medical treatment shelter for wild environment in the open air.This radiation classified protection system comprises the different a plurality of stereotypes of thickness that arrange on the shelter sidewall.Described a plurality of stereotype is by following method setting: 1) obtain CT device 34 scattering radiation dose distribution curves, referring to Fig. 2, wherein show a kind of CT device 34 scattering radiation dose distribution curve charts; 2) shelter is divided into a plurality of subregions; 3) determine the required thickness H that stereotype is set on the shelter sidewall of every sub regions according to following formula:
In the formula
B represents the greatest irradiation transmittance of every sub regions;
D represents that personnel are to the distance (cm) of scanning center;
D
0, d
0Expression is apart from the d of scanning center
0(cm) radiation dose of locating Single Slice Mode is D
0(μ Gy/ layer);
W represents to provide D
0The condition of scanning of value is all normalizing workloads (layer/week) under the reference conditions;
T represents personnel that the CT Scan Room external distance d of scanning center (cm) the locates factor of persistencing;
θ represent radiant flux with perpendicular to the angle of shield normal to a surface;
4) thickness being set respectively on the shelter sidewall of every sub regions is that the stereotype of H is as shield.
Preferably, referring to Fig. 3, described a plurality of subregions comprise CT Control Room first area 1, CT Control Room second area 2, idle zone 3, observation window zone, control room 4, the first room and clear area 5, the second room and clear area 6, zone, the 7 and second inner corridor, zone, the first inner corridor 8.Be understandable that, described a plurality of stereotypes comprise CT Control Room first area stereotype, CT Control Room second area stereotype, idle regional stereotype, control room observation window zone stereotype, the first room and clear area stereotype, the second room and clear area stereotype, the first inner corridor zone stereotype and zone, the second inner corridor stereotype.
Preferably, another embodiment according to the present invention, for so that radiation protection has higher Safety Redundancy amount, the stereotype thickness H that obtains in the step 3) can be multiply by empirical value factor j and obtain final stereotype thickness, and the stereotype of this final thickness is arranged on the shelter sidewall of every sub regions.
Preferably, the span of empirical value factor j is 100%-143%.
Preferably, the top of described shelter and bottom do not arrange stereotype.
Preferably, described guard system also comprises computer and radiation measurement assembly, store the greatest irradiation transmittance B of each subregion in the described computer, this radiation measurement assembly is arranged on each position corresponding to subregion greatest irradiation transmittance B, when greatest irradiation transmittance that real-time radiation transmittance that radiation measurement assembly obtains is stored in greater than computer, computer stops the CT device automatically, and sends warning information.
Be understandable that, because open-air medical treatment shelter in use, is different from the CT Examination Room of hospital, the top of shelter and bottom do not have personnel and exist, and therefore can save the stereotype of this position, so that the overall weight of shelter further reduces, increase the mobility of shelter, and reduced cost.
Embodiment 2
The below will more specifically describe another preferred embodiment of the present invention, more comprehensively to show above-mentioned advantage of the present invention and beneficial effect.
As shown in Figure 4, described CT shelter deployed condition interior layout can further following setting: CT Control Room 31 is positioned at whole cabin anterior (along the transportation direction of advance), CT Scan Room is positioned at whole cabin afterbody, is furnished with scanning bed 33, CT device 34, CT damping frame 35, cabin body dividing plate 37, control room dividing plate 38 and control room observation window 39.For example, CT shelter deployed condition inside dimension be 3900 (L) x5800 (W) x1950 (H) (mm).Be understandable that, these concrete structures and parameter all are adjustable, can not be as any limitation of the invention.Preferably, can also be referring to Chinese patent ZL201210396745.5 about the structure of CT shelter, this patent is by in conjunction with introducing here.
For example, the self-loading and unloading vehicle equipment quality 8T shown in Fig. 1, cabin body assembly (containing H frame, skid, levelling gear) quality is 4.7T, CT machine, air-conditioning and affiliated facility gross mass are 2.4T.
For example, described CT device is selected GE Brivo325 type, and limit conditions of exposure is tube voltage 140KV, tube current 160mA.With personnel's exposure dosage control 5uSv/ week (corresponding to 0.25mSv/) required radiation shield transmittance (B) by formula (1) be calculated as follows:
In the formula
D represents that personnel are to the distance (cm) of scanning center;
D
0, d
0Expression is apart from the d of scanning center
0(cm) radiation dose of locating Single Slice Mode is D
0(μ Gy/ layer);
W represents to provide D
0The condition of scanning of value is all normalizing workloads (layer/week) under the reference conditions;
T represents personnel that the CT Scan Room external distance d of scanning center (cm) the locates factor of persistencing.
For example, when daily inspection amount of described CT machine was 50 person-times, the W value was defined as for 2500 (layer/weeks);
For example, different with frequency according to the time that different places personnel around the described CT machine scanning gantry persistence, determine personnel's factor of persistencing.CT Cabin top and the bilge are all unoccupied, and Radiation Shielding Re design can not considered the protection at the bottom of roof and the car.Can be divided into resident area, inner corridor and idle district around the shelter, for example T value can be defined as respectively 1,1/4,1/16.Be understandable that, W and T value can suitably be adjusted as the case may be.
Utilize described formula (1) to calculate the shelter numerical value of radiation shield transmittance all around, determine required shielding material respective thickness; It is the ray incident angle that this numerical value multiply by oblique fire modifying factor (1+cos θ)/2(θ) after, determine each position stereotype thickness of cabin body.θ represent radiant flux with perpendicular to the angle of shield normal to a surface.
For instance, referring to Fig. 3, according to the layout of shelter hospital, the shelter wall can be divided into 8 zones: be idle district outside the operating room side walls 3; Outside frame and the examinating couch axis side walls 5,6, the left side is the x-ray inspection trolley, band 1mm lead protection, and the right side is the free area, 20m is interior without persistencing personnel; Frame rear side wall 7,8 outer approximately 1 meter are inner corridor.By above condition, in conjunction with the shelter layout dimension, can calculate radiation transmission than (B), as shown in table 1:
Table 1 radiation transmission is than (B) relevant parameter table
According to the result of calculation of radiation transmission in the table 1 than (B), B.3 the radiation shield specification sheet of looking into GBZT180-2006 medical X-ray CT machine room can get the thickness of stereotype.After multiply by oblique fire modifying factor (1+cos θ)/2, rule of thumb be worth factor j and can finally determine each position stereotype thickness of cabin body, as shown in table 2:
Table 2 protective lead plate thickness correction chart
Preferably, process for ease of the cabin body, consist of characteristics and the required shielding bed thickness in each position according to the cabin body, shielding thickness phase near field merged and get the maximum shielding material thickness in this zone, be divided into as shown in Figure 5 each zone, i.e. front, control room 9, side 10, control room observation window 11 inspection chamber antethecas 12, inspection chamber sidewall 13,14 and offside, inspection chamber rear wall are divided into rear flank wall 7 and positive rear wall 8.The weight of the whole stereotype that obtains according to the result of table 2 is at 770.6kg.
Be understandable that, do not satisfy the load-carrying requirement of automobile such as lead screen layer gross mass, the zone can be repartitioned, recomputate.
In sum, beneficial effect of the present invention is: the radiation classified protection system of the medical treatment shelter for wild environment of the present invention is so that under the radiation-resistant prerequisite of safety, the gross weight of medical treatment shelter reduces greatly, and shelter medical services ability is higher, mobility is good, cost.
The invention is not restricted to above-mentioned specific embodiment.Be understandable that, in the situation that do not break away from spirit of the present invention and essential scope, can make various changes and modifications, these all should be included within protection scope of the present invention.