Patent ID: 11904188
Assignee: BEIJING RAYER SHIWEI MEDICAL RESEARCH CO., LTD
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A fully-spherical radiation therapy system, comprising a multi-degree-of-freedom robot, a linear accelerator and a double-image-guided positioning mechanism, wherein
the double-image-guided positioning mechanism comprises four ray sources and two ray detectors, and the four ray sources comprise a first ray source, a second ray source a third ray source and a fourth ray source;
an intersection of two beams emitted by the first ray source and the second ray source is a low-level treatment center, and a first actual projection and a second actual projection are generated on the two ray detectors;
an intersection of two beams emitted by the third ray source and the fourth ray source is a high-level treatment center, two actual projections are generated on the two ray detectors and then are converted into a first virtual projection and a second virtual projection, respectively;
a plurality of treatment nodes with the low-level treatment center as a spherical center and a plurality of treatment nodes with the high-level treatment center as a spherical center form a fully-spherical treatment space;
the multi-degree-of-freedom robot carries the linear accelerator, the multi-degree-of-freedom robot forms a spherical treatment space above and on two sides of a patient around the low-level treatment center and forms a spherical treatment space below and on two sides of the patient around the high-level treatment center;
the two ray detectors are each flat-panel detectors;
a beam emitted by a ray source corresponding to the low-level treatment center image-guided positioning mechanism is perpendicular to an actual projection plane of a corresponding flat-panel detector so that an orthographically projected X-ray image is generated;
a beam emitted by a ray source corresponding to the high-level treatment center image-guided positioning mechanism is not perpendicular to an actual projection plane of a corresponding flat-panel detector so that an obliquely projected X-ray image is generated; and
the obliquely projected X-ray image is converted to a virtual imaging plane to obtain an orthographically projected virtual X-ray image, (x1,y1) represents a coordinate point on a coordinate system of an oblique projection plane x1py1, and (x1,y1) is converted to a corresponding coordinate point (x2,y2) on a coordinate system of a virtual orthographic projection plane x2py2 through following formulas:, y
    2
   
   =
   
    
     d
     *
     
      y
      1
     
     ⁢
     cos
     ⁢
     γ
    
    
     d
     -
     
      
       y
       1
      
      ⁢
      sin
      ⁢
      γ
     
    
   
  
  ,
   
  and
 

 
  
   
    x
    2
   
   =
   
    
     
      
       
        (
        
         d
         
          d
          -
          
           
            y
            1
           
           ⁢
           sin
           ⁢
           γ
          
         
        
        )
       
       2
      
      ⁢
      
       (
       
        
         x
         1
         2
        
        +
        
         
          (
          
           
            y
            1
           
           ⁢
           cos
           ⁢
           γ
          
          )
         
         2
        
       
       )
      
     
     -
     
      y
      2
      2
     
    
   
  
  ;
 

wherein γ represents an included angle between a plane of the coordinate system of the oblique projection plane and a plane of the coordinate system of the virtual orthographic projection plane and d represents a distance from a central point of an emission source of an X-ray tube to a central point of a corresponding flat-panel detector.