Background technology
CT equipment is to be the area of computer aided imaging device of human body tomoscan transmission potential with the X ray, inspection and the diagnostic medical device of hospital's popularization have been become, CT examination obviously is being better than the X-ray sheet aspect the demonstration transverse section, and the instructive information of most worthy can be provided for the surgical operation in the emergency treatment treatment.China is a country that natural disaster takes place frequently, the frequent generation of natural disasters such as earthquake in recent years, flood, mud-rock flow, and field medicine institute, shelter hospital system are that important function has been brought into play in earthquake relief work with the characteristics of its fast reserve.The development of shelter CT equipment is for field emergency provides strong tool.
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 work for the treatment of station, 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 the inspection means with the X ray, and ionizing radiation has bigger harm to human body, and the radiation protection measure 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 C T 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 inspection chamber of fixed-site.
In order to adapt to the demand of open-air medical treatment, shelter CT device needs CT equipment is installed in the shelter, is transported by automobile.The haulage vehicle that all adopts the heavy amount 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, and it is very big to conduct oneself with dignity, 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 makes vehicle can't carry whole fixing inspection chamber weight, so this is a pair of contradiction 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 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 shelter CT system for wild environment, make its weight reduce, when improving its mobility, keep its medical services ability and level of security, the applicant is through concentrating on studies, a kind of vehicle-mounted shelter CT system 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 vehicle-mounted shelter CT system for wild environment.By this system, make 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 shelter.Particularly, a kind of vehicle-mounted shelter CT system for wild environment, comprise transport vehicle, shelter and suitable shape radiation classification guard system, this shelter is the two big 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 furnished with the image acquisition work station in the CT Control Room, image work for the treatment of station, the medical science display, work chair, film viewer and diagnosis report printer, be provided with the CT device in the CT Scan Room, described suitable shape radiation classification guard system comprises the different a plurality of stereotypes of thickness that arrange on the shelter sidewall, and 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 each subregion according to following formula:
In the formula
B represents the greatest irradiation transmittance of each subregion;
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 on the shelter sidewall of each subregion respectively 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, first room and clear area stereotype, second room and clear area stereotype, the first inner corridor zone stereotype and zone, 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 each subregion.
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 the position of each subregion greatest irradiation transmittance B correspondence, when real-time radiation transmission that radiation measurement assembly obtains during than the greatest irradiation transmittance of storing 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 vehicle-mounted shelter CT system for wild environment of the present invention makes that the gross weight of shelter reduces greatly under the radiation-resistant prerequisite of safety, and shelter medical services ability is higher, and mobility is good, and cost reduces.
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; under the situation that does 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 shelter CT system schematic that is used for wild environment of the preferred embodiment of the present invention.Referring to Fig. 4, it shows the interior layout sketch map after the shelter that is used for wild environment according to the preferred embodiment of the invention launches.This shelter is the two big 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.Be furnished with image acquisition work station, image work for the treatment of station, medical science display, work chair, film viewer and diagnosis report printer in the CT Control Room 31.
For shelter can be used, the present invention proposes a kind of vehicle-mounted shelter CT system for wild environment in the open air.This radiation protecting systems comprises transport vehicle, shelter and suitable shape radiation classification guard system.Suitable shape radiation classification guard 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 each subregion according to following formula:
In the formula
B represents the greatest irradiation transmittance of each subregion;
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 on the shelter sidewall of each subregion respectively 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, first room and clear area 5, 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, first room and clear area stereotype, second room and clear area stereotype, the first inner corridor zone stereotype and zone, second inner corridor stereotype.
Preferably, another embodiment according to the present invention, in order to make radiation protection have higher safe amount of redundancy, 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 each subregion.
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 the position of each subregion greatest irradiation transmittance B correspondence, when real-time radiation transmission that radiation measurement assembly obtains during than the greatest irradiation transmittance of storing in greater than computer, computer stops the CT device automatically, and sends warning information.
Be understandable that, because vehicle-mounted shelter CT system in use, be 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, make the overall weight of shelter further reduce, increase the mobility of shelter, and reduced cost.
Embodiment 2
Below another preferred embodiment of the present invention will be described more specifically, 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 front portion, cabin (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 for use, 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.Top, CT shelter cabin and the bilge are all unoccupied, and the protection at the bottom of roof and the car can not be considered in the radiation shield design.Can be divided into resident area, inner corridor and idle district around the shelter, for example T value can be defined as 1,1/4,1/16 respectively.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 X ray examination car, band 1mm lead protection, and the right side is the free area, does not have the personnel that persistence in the 20m; Frame rear side wall 7,8 outer about 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, constitute 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 each zone as shown in Figure 5, 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 radiation classification guard system 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 as lead screen layer gross mass, the zone can be repartitioned, recomputate.
In sum, beneficial effect of the present invention is: the vehicle-mounted shelter CT system for wild environment of the present invention makes that the gross weight of shelter reduces greatly under the radiation-resistant prerequisite of safety, and shelter medical services ability is higher, and mobility is good, and cost reduces.
The invention is not restricted to above-mentioned specific embodiment.Be understandable that under the situation that does 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.