[分享]Arizona眼睛模型 [复制链接]

简介 ^>k[T.  
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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。 ze,HNFg@>  
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模型 )+cP8$n6L  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 3G5i+9Nt.L  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. vco:6Ab$  
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光源 bU_9GGG|  
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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。 Xg.\B1d  
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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。 Mb?6c y[  
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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。 (x?A#o>%  
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视网膜的散射 #sNa}292"  
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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。 <\Y>y+$3  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 oPre$YT}h  
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脚本 f+L )x  

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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： G7zfyw}W  
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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。 LH<--#K  
余下的脚本计算与屈光度有关的所有参数。 5#WZXhlc}  
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分析 mN~;MR;  
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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。 SM0
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脚本代码 d{9jd{ _#G  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Yxi.A$g  
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Dim entity As T_ENTITY '4N[bRCn  
Dim op As T_OPERATION i,b>&V/Y$  
Dim mat As T_MODELMATERIAL (8H "'  
Dim A As Double nFxogCn
 
Dim pupilDiam As Double *B@<{x r  
Dim eID As Long kk^KaD4dA  
Dim parID As Long  ) VJ|  
Dim count As Integer -+O8v;aC'  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double srg#<oH|{c  
Dim tlens As Double, nlens As Double eQzSWn[  
Dim curv As Double, conic As Double +F+jC9j(<  
Dim ok As Long #gi&pR'$  
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Sub Main t'R&$;z@b  
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    '用户输入对话框 ii{5z;I]X  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Eepy%-\  
        TextBox 220,21,40,21,.TextBox1 'default: 0 U_oMR$/Z  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 gIRFqEz@o  
        OKButton 40,91,90,21 F<G.!Y8!&  
        CancelButton 190,91,90,21 MUVp8!*@  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 okr'=iDg  
        TextBox 220,49,40,21,.TextBox2 'default: 4 H-0deJ[>  
    End Dialog bha_bj  
    Dim dlg As UserDialog L3i\06M  
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    ok = Dialog (dlg) udW, P  
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    If ok=0 Then    'cancel button was pressed MhJq~G p  
        Print "Execution cancelled." ]Alu~Dw  
        End 0'aZ*ozk  
    End If X~n Kuo  
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    'Assign accommodation and pupil diameter & use defaults if field left empty `Mp]iD{  
    If dlg.TextBox1 = "" Then l3(k  
        A = 0           'Default accommodation %~$4[,=  
    Else 3$WK%"%T  
        A = CDbl(dlg.TextBox1) N[
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    End If X @r5^A[9  
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    If dlg.TextBox2 = "" Then 21w<8:Vg  
        pupilDiam = 4   'Default pupil diameter ,!bOzth2>K  
    Else ?Tb'J`MO  
        pupilDiam = CDbl(dlg.TextBox2) B/pNM81(  
    End If G}] ZZ  
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    Print " " @(Q4  
    Print "Accommodation = " & A & " Diopters" Gz^g!N[  
    Print "Pupil Diameter = " & pupilDiam & " mm" ib uA~\5  
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    ' Calculate new parameters with accommodation $"x(:  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness gy~M]u{  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens $c  f?`k  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens dI'C[.zp[  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \h_hd%'G  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (?q]E$ @  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 0*q~(.>a  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction NL2n\%n  
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    'Adjust parameters to account for accommodation E/AM<eN  
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    '************************************************************************* Fv e,
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    'Aqueous thickness (Position of Lens) ~+^,o_hT  
    '************************************************************************* G{ F>=z"(l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7|65;jm+  
    GetCustomElement eID, entity EYG&~a>L*  
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    parID = FindFullName( "Geometry.Arizona Eye" ) UDuKG\_J<y  
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    ' Delete any shift(s) in z x{Gih
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    count = 0 zCPjuS/~ Q  
    While GetOperationCount(eID)>count C:gE   
        GetOperation eID, count, op
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        If op.Type="ShiftZ" Then KLAnW#  
            DeleteOperation eID,count +$8hTi,  
            count=count-1 "B)DX*-\?  
        End If :UFf6T?  
        count=count+1 |%zhwDQ.  
    Wend t}NxD`8  
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    'Set new shift in w)DO"Z7  
    op.Type = "ShiftZ" nb?bx{M  
    op.val1 = taq .[K{;^>  
    op.parent = parID vP&*(WfO)  
    AddOperation eID, op zIRa%%.i<  
    Print "Set aqueous humor thickness = " & taq-0.55 ilFM+x@  
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    '************************************************************************* zXVQLz5  
    'Radius and conic constant of anterior lens 9x{T"'  
    '************************************************************************* $Q]`+:g*}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +wT,dUin_<  
    GetConic eID, entity, curv, conic \gIdg:"02  
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    SetConic eID, entity, 1/Rant, CCant iAup',AZg  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant li NPXS+  
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    '************************************************************************* B[b'OtH  
    'Radius and conic constant of posterior lens ,0#OA*0B  
    '************************************************************************* @JN%P}4)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )  FcfN]!  
    GetConic eID, entity, curv, conic UP,0`fh(y  
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    SetConic eID, entity, 1/Rpost, CCpost G)b]uX  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost T5Pc2
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    '************************************************************************* >@]E1Qfe  
    'Lens thickness (Position of posterior lens surface) :5@7z9 >  
    '************************************************************************* Lg9ktRKK  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1 4(?mM3   
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    ' Delete any z-shift(s) )xTp7YnZ;  
    count = 0 S0p]:r";x  
    While GetOperationCount(eID)>count %tQIKjsVaY  
        GetOperation eID, count, op 2hU4g e?6  
        If op.Type="ShiftZ" Then b\^Sz{  
            DeleteOperation eID,count }14.
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            count=count-1 q{KRM\ooYs  
        End If fI"`[cA"]  
        count=count+1 V|b?H6Q  
    Wend  hA/FK  
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    'Set new z-shift {/B) YR  
    op.Type = "ShiftZ" I-;JDC?  
    op.val1 = tlens 5HOhk"  
    op.parent = parID (y(V,kXwa8  
    AddOperation eID, op i37W^9 R  
    Print "Set lens thickness = " & tlens =YPWt>\a}  
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    '************************************************************************* EH4WR/x  
    'Lens index of refraction Z39^nGO  
    '************************************************************************* gB
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    eID = FindMaterial( "Lens" ) w(mn@Qc  
    GetModelMaterial eID, mat ^Jc~G~x4*  
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    mat.Nd = nlens F}.Af=<Q  
    SetModelMaterial eID, mat "I_T  
    Print "Set lens index of refraction = " & nlens 7a@V2cr@  
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    '************************************************************************* CWC*bkd5a  
    'Pupil diameter 's&Vg09D,  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ]~a!O  
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    'Adjust pupil diameter (trimming volume inner hole) QjZ}*p  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" YK}(
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    ' Adjust pupil location to just in front of the lens x`B:M7+\  
    parID = FindFullName( "Geometry.Arizona Eye" ) Tri.>@-u  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) [Q^kO;  
    count = 0 br'~SXl  
    While GetOperationCount(eID)>count <GoE2a4Va  
        GetOperation eID, count, op M{nz~W80  
        If op.Type="ShiftZ" Then `5!7Il  
            DeleteOperation eID,count lg!1q8  
            count=count-1 A;Zg:  
        End If ef,6>xv  
        count=count+1 Z;%qpsq  
    Wend f_z2d+  
    op.Type = "ShiftZ" =}Cb?C[;  
    op.val1 = taq-0.01 RNi&OG(  
    op.parent = parID 59EAqz[:  
    AddOperation eID, op RmzK?muk  
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    Print "Set pupil diameter = " & pupilDiam xRaYm  
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    'Update AZ Eye subassembly Description x,p|n  
    eID = FindFullName( "Geometry.Arizona Eye" ) kxf'_Nzy  
    GetEntity eID, entity -Mv`|odY/  
    entity.Description = "Accommodation = " & A & "D" +;*])N%q  
    SetEntity eID, entity F92n)*[  
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    Update }[75`pC~O  
    Print "DONE!" ;9prsvf  
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End Sub ~xHr/:  
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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： c)$/Uu  
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Accommodation = 4 Diopters &"L3U  
Pupil Diameter = 4 mm g`1*p|  
Set aqueous humor thickness = 2.81 g@1MImc'!  
Set anterior lens radius = 10.4 and conic constant = -2.375869 M8g=t[\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 <'gCIIa2  
Set lens thickness = 3.927 O %)+ w  
Set lens index of refraction = 1.42672 H=wmN0s{<  
Set pupil diameter = 4 G=b`w;oL:  
DONE! mBnC]$<R  
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