[技术]Arizona眼睛模型 [复制链接]

简介 j\.\ePmk]  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 D!CuE7}  
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模型 JLH,:2  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 ZMI vzQYI  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. hz~jyH.h_  
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光源 bjYaJtn  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 =Frbhh57  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 6`l7saHXE  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Yl$Cj>FG  
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视网膜的散射 mtn+bV R%  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 aR~Od Ys  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 j1
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脚本 5zBayJh#  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Lc:DJA  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 r06M.r  
余下的脚本计算与屈光度有关的所有参数。 }lzN)e  
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分析 8K/o/  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 tSvklI  
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脚本代码 7berkU
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6b8@6;&LI  
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Dim entity As T_ENTITY 
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Dim op As T_OPERATION 0u"/7OU  
Dim mat As T_MODELMATERIAL r 7mg>3  
Dim A As Double 2iM8V  
Dim pupilDiam As Double |_P-  
Dim eID As Long ]$vJK  
Dim parID As Long GK/Q]}Q8pZ  
Dim count As Integer i;Y@>-[e<  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double +L$,jZqS  
Dim tlens As Double, nlens As Double ", :Ta|  
Dim curv As Double, conic As Double X}5a
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Dim ok As Long (cj3[qq  
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Sub Main 9A4h?/  
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    '用户输入对话框 dWI.t1`i  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r_kw "9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;Q]j"1c  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 B!(t<W8cu  
        OKButton 40,91,90,21 '%m0@5|hCD  
        CancelButton 190,91,90,21 Y)@PGxjz  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .2b) rKo~  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,ZYj8^gF  
    End Dialog {xC C
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    Dim dlg As UserDialog elgCPX&:W  
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    ok = Dialog (dlg) Iy}r'#N  
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    If ok=0 Then    'cancel button was pressed wnE c   
        Print "Execution cancelled." P'Fy,fNg  
        End e<>Lr  
    End If >t"]gQHtx  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 5g-apod  
    If dlg.TextBox1 = "" Then axY-Vj
 
        A = 0           'Default accommodation {tE/Jv $  
    Else bw7!MAXd  
        A = CDbl(dlg.TextBox1) bmAgB}Ior  
    End If [hg|bpEG  
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    If dlg.TextBox2 = "" Then ndm19M8Y|  
        pupilDiam = 4   'Default pupil diameter fJCh  
    Else JXlFo3<  
        pupilDiam = CDbl(dlg.TextBox2) dv0TJ 0%  
    End If eh'mSf^=p  
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    Print " " QD:0iD?  
    Print "Accommodation = " & A & " Diopters" 8-5a*vV,>  
    Print "Pupil Diameter = " & pupilDiam & " mm" x~GV#c  
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    ' Calculate new parameters with accommodation T^a {#B  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness LIH>IpamN  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Z"gllpDr$  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -aNTFt~|[  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c 3@SgfKmk  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  ZW2#'$b  
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    tlens = 3.767 + 0.04*A                  'Lens thickness !9"R4~4  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .bl0w"c^qq  
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    'Adjust parameters to account for accommodation fC3IxlG  
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    '************************************************************************* =] 5;=>(  
    'Aqueous thickness (Position of Lens) V8Q#%#)FHe  
    '************************************************************************* (?\ZN+V)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9L#B"lh  
    GetCustomElement eID, entity pOI+  
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    parID = FindFullName( "Geometry.Arizona Eye" ) -R'p^cMA  
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    ' Delete any shift(s) in z g}^/8rW  
    count = 0 e( ^9fg_SG  
    While GetOperationCount(eID)>count ,:\2Lf  
        GetOperation eID, count, op &up/`8  
        If op.Type="ShiftZ" Then *Kzs(O  
            DeleteOperation eID,count ga^<_;5<  
            count=count-1 0]oQ08  
        End If :=L[kzX  
        count=count+1 pjj 5  
    Wend p>eD{#2  
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    'Set new shift in P'9aZd  
    op.Type = "ShiftZ" J#V`W&\,6  
    op.val1 = taq IVNNiNN*5  
    op.parent = parID CJKH"'u3^  
    AddOperation eID, op j|G-9E  
    Print "Set aqueous humor thickness = " & taq-0.55 , D1[}Lr=K  
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    '************************************************************************* .`'SL''c  
    'Radius and conic constant of anterior lens M<$l&%<`G  
    '************************************************************************* 4\OELU  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3X!~*_iC  
    GetConic eID, entity, curv, conic F[=m|MZb  
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    SetConic eID, entity, 1/Rant, CCant 3+|6])Hi1  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant jATU b-  
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    '************************************************************************* `u>BtAx8  
    'Radius and conic constant of posterior lens rFy9K4D  
    '************************************************************************* <dYk|5AdLF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BWPYHWW}E  
    GetConic eID, entity, curv, conic c&Zm>Qo[  
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    SetConic eID, entity, 1/Rpost, CCpost Lv^j l  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 17i^|&J6}:  
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    '************************************************************************* ?*s!&-KI  
    'Lens thickness (Position of posterior lens surface) GO)rpk9  
    '************************************************************************* W"-nzdAJ5  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) kx=AX*I  
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    ' Delete any z-shift(s) Y+jKP*ri  
    count = 0 kTk?[BK  
    While GetOperationCount(eID)>count Np-D:G  
        GetOperation eID, count, op Ksp;bfe  
        If op.Type="ShiftZ" Then iE
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            DeleteOperation eID,count *tO<wp&  
            count=count-1 ~Op1NE  
        End If ]Cz16e&=2  
        count=count+1 hrL<jcv|  
    Wend ;p_X7N  
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    'Set new z-shift OX`n`+^D  
    op.Type = "ShiftZ" Kmnr}Lp9  
    op.val1 = tlens ^`!Daqk  
    op.parent = parID "QF083$  
    AddOperation eID, op }6bLukv  
    Print "Set lens thickness = " & tlens YiCDV(prT  
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    '************************************************************************* lX4p'R-h  
    'Lens index of refraction `SwnKg  
    '************************************************************************* <di_2hN  
    eID = FindMaterial( "Lens" ) 'AAY!{>  
    GetModelMaterial eID, mat 0/ Ht;(  
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    mat.Nd = nlens 7xc<vl#:q7  
    SetModelMaterial eID, mat ,![=_d  
    Print "Set lens index of refraction = " & nlens ;9PM?Iy[  
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    '************************************************************************* O$H150,Q  
    'Pupil diameter 1;P\mff3Y  
    '************************************************************************* Ax0,7,8y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (6BCFl:/Q<  
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    'Adjust pupil diameter (trimming volume inner hole) |u{QI3#'  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <n\.S  
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    ' Adjust pupil location to just in front of the lens mvgm o  
    parID = FindFullName( "Geometry.Arizona Eye" ) I5L7BTe  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) C'._}\nX  
    count = 0 i-?zwVmn  
    While GetOperationCount(eID)>count +I<Sq_-  
        GetOperation eID, count, op ]K7 64}  
        If op.Type="ShiftZ" Then |&Pl4P  
            DeleteOperation eID,count A,{D9-%  
            count=count-1 vy@Lu cB  
        End If 5 DB>zou   
        count=count+1 9>R|k$`  
    Wend q&E5[/VK:  
    op.Type = "ShiftZ" >t2b?(h/x  
    op.val1 = taq-0.01 Y/0O9}hf  
    op.parent = parID Fw9``{4w  
    AddOperation eID, op &%X J
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    Print "Set pupil diameter = " & pupilDiam 9@Sb! 9h  
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    'Update AZ Eye subassembly Description V@:=}*E  
    eID = FindFullName( "Geometry.Arizona Eye" ) ;n!X% S<z*  
    GetEntity eID, entity i8YgG0[)  
    entity.Description = "Accommodation = " & A & "D" 

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    SetEntity eID, entity g&TCff  
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    Update p^rX.?X  
    Print "DONE!" z[%v_S  
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End Sub _-\s[p5  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： pqN[G=0  
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Accommodation = 4 Diopters 0juIkN#  
Pupil Diameter = 4 mm t!SQLgA  
Set aqueous humor thickness = 2.81 TDIOK  
Set anterior lens radius = 10.4 and conic constant = -2.375869 R0mT/h2  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 -Y=c g;  
Set lens thickness = 3.927 Zk#i9[g9*  
Set lens index of refraction = 1.42672 .eNwC.8i  
Set pupil diameter = 4 8.Ef5-m  
DONE! W4*BR_H&*