[技术]Arizona眼睛模型 [复制链接]

简介 X{\>TOk  
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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。 v5i
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模型 )`yxJ;O@$  
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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。 #ebT$hf30  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 6tB-  
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光源 &e@2zfl7  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 E8J`7sa  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 lidzs<W-fW  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 \Xc6K!HJM  
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视网膜的散射 96T.xT>&  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 %/b?T]{  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 su/l'p'  
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脚本 ]WR+>)ERb  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： p#hs8xz  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 DvHcT]l>5  
余下的脚本计算与屈光度有关的所有参数。 Z0g3> iItM  
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分析 =($RT  
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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。 PN[ `p1F  
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脚本代码 0? (  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ]c]rIOTN  
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Dim entity As T_ENTITY akHcN]sa2  
Dim op As T_OPERATION eU'DQp*  
Dim mat As T_MODELMATERIAL 8M*[RlUJB  
Dim A As Double EQ'iyXhEe  
Dim pupilDiam As Double }tv%  
Dim eID As Long 1OK,r`   
Dim parID As Long -hj@^Auf  
Dim count As Integer MKLntX  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /2pf*\u  
Dim tlens As Double, nlens As Double |F[E h ~  
Dim curv As Double, conic As Double +gqtW86  
Dim ok As Long >;kCcfS3ct  
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Sub Main -jnx0{/  
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    '用户输入对话框 5A/8G}'XZ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 g^@Kx5O\  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {i y[8eLg  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 pV{MW#e  
        OKButton 40,91,90,21 ,0%P3  
        CancelButton 190,91,90,21 l?v`kAMR
 
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :L#t?~  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (G $nN*rlu  
    End Dialog {Ak{ ct\t  
    Dim dlg As UserDialog 6*cG>I.Z  
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    ok = Dialog (dlg) rq?:I:0  
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    If ok=0 Then    'cancel button was pressed J/S 47J~  
        Print "Execution cancelled." xO)vn\uJ  
        End 0&T0Ls#4  
    End If vKN"o* q  
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    'Assign accommodation and pupil diameter & use defaults if field left empty )j(13faW|  
    If dlg.TextBox1 = "" Then yE[ -@3v  
        A = 0           'Default accommodation :Y/i%#*1  
    Else HKr")K%  
        A = CDbl(dlg.TextBox1) 6}wXNTd  
    End If <6^MVaD  
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    If dlg.TextBox2 = "" Then EM]~yn!+  
        pupilDiam = 4   'Default pupil diameter ?#?[6t  
    Else Dz/I"bZLC  
        pupilDiam = CDbl(dlg.TextBox2) Sp$~)f'  
    End If Z*S 9pkWcF  
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    Print " " m<)0XE6w  
    Print "Accommodation = " & A & " Diopters" l<5O\?Vo]  
    Print "Pupil Diameter = " & pupilDiam & " mm" N|hNh$J[  
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    ' Calculate new parameters with accommodation Qb}7lm{r  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OrP-+eg  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens BE. v+'c"  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )R$+dPu>  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens C{>@b:]p  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $G/h-6+8  
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    tlens = 3.767 + 0.04*A                  'Lens thickness jqxeON  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }&#R-eQT  
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    'Adjust parameters to account for accommodation w"d~R   
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    '************************************************************************* !GI*R2<W
 
    'Aqueous thickness (Position of Lens) 2KVMQH`B9  
    '************************************************************************* x&9}] E^<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2%4dA$H#4w  
    GetCustomElement eID, entity mqgA  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Eyi^N0  
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    ' Delete any shift(s) in z cPA-EH  
    count = 0 >I
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    While GetOperationCount(eID)>count '9^+J7iO(+  
        GetOperation eID, count, op <>/0;J1<  
        If op.Type="ShiftZ" Then j<H`<S  
            DeleteOperation eID,count ]oB-qfbH  
            count=count-1 nEu,1  
        End If ?B ;+,  
        count=count+1 /Am,5X.  
    Wend 0<*R 0  
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    'Set new shift in 1gk{|keh  
    op.Type = "ShiftZ" O="
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    op.val1 = taq j`jF{k b  
    op.parent = parID V`xZ4 i%L  
    AddOperation eID, op 5&a4c"fU  
    Print "Set aqueous humor thickness = " & taq-0.55 T0BFit6  
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    '************************************************************************* 0S8v41i6  
    'Radius and conic constant of anterior lens _mVq9nBEf  
    '************************************************************************* =9$hZ c  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ; (I(TG  
    GetConic eID, entity, curv, conic $YuVM  
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    SetConic eID, entity, 1/Rant, CCant =" Q5Z6W  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant tDj~+lmdN  
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    '************************************************************************* Ny|2Fcs  
    'Radius and conic constant of posterior lens S9kagiFX\  
    '************************************************************************* 0'u2xe  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2qV.`d  
    GetConic eID, entity, curv, conic ~lO^C  
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    SetConic eID, entity, 1/Rpost, CCpost P,5gaT)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Zp'c>ty=  

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    '************************************************************************* *L_+rJj,  
    'Lens thickness (Position of posterior lens surface) !Ra.DSL  
    '************************************************************************* (iM*Y"Y  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Hq9yu*!u  
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    ' Delete any z-shift(s) W*A-CkrO  
    count = 0 bxX[$q  
    While GetOperationCount(eID)>count V,t&jgG*  
        GetOperation eID, count, op / J 3  
        If op.Type="ShiftZ" Then 5Y
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            DeleteOperation eID,count Fw,'a  
            count=count-1 i'Vrx(y3  
        End If }{"a}zOl  
        count=count+1 
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    Wend /C)mx#h]  
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    'Set new z-shift E?%SOU<  
    op.Type = "ShiftZ" =TImx.D:  
    op.val1 = tlens {m1=#*  
    op.parent = parID &t.9^;(  
    AddOperation eID, op >q+o MrU  
    Print "Set lens thickness = " & tlens 'iy &%?  
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    '************************************************************************* paFiuQ  
    'Lens index of refraction &8VB{S>r  
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    eID = FindMaterial( "Lens" ) 'N1_:$z@(  
    GetModelMaterial eID, mat R5O{;/w  
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    mat.Nd = nlens Z^t"!oY  
    SetModelMaterial eID, mat 6ww4ZH?j  
    Print "Set lens index of refraction = " & nlens .iK{=L/(y  
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    '************************************************************************* aXi5~,Ks_  
    'Pupil diameter + 3+^J?N  
    '************************************************************************* K/oC+Z;K  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) CKJ9YKu{W  
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    'Adjust pupil diameter (trimming volume inner hole) E]zTd$v6  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" CXC,@T  
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    ' Adjust pupil location to just in front of the lens C.SGm  
    parID = FindFullName( "Geometry.Arizona Eye" ) ?.E ixGzI^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )  ByP  
    count = 0 K9JW&5Q  
    While GetOperationCount(eID)>count r{DR$jD  
        GetOperation eID, count, op jKFypIZ4  
        If op.Type="ShiftZ" Then C>%2'S^.b  
            DeleteOperation eID,count c%2C\UB
  
            count=count-1 qJq49}2  
        End If 8Ar5^.k  
        count=count+1 W<Ms0  
    Wend M%dJqwH5{
 
    op.Type = "ShiftZ" 1pe eecE  
    op.val1 = taq-0.01 ` VL`8
  
    op.parent = parID 4F_*,
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    AddOperation eID, op j$Tto
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    Print "Set pupil diameter = " & pupilDiam 9uk}r; %9  
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    'Update AZ Eye subassembly Description p
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    eID = FindFullName( "Geometry.Arizona Eye" ) ]"'$i4I{R  
    GetEntity eID, entity N[$bP)h7  
    entity.Description = "Accommodation = " & A & "D" u,<#z0R|;$  
    SetEntity eID, entity _D%aT6,G+(  
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    Update ,sEu[m  
    Print "DONE!" 5<o8prtB  
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End Sub .~#<>  
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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： #:rywz+  
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Accommodation = 4 Diopters {J`Zl1_q  
Pupil Diameter = 4 mm 0IHcyb  
Set aqueous humor thickness = 2.81 *ea%KE":  
Set anterior lens radius = 10.4 and conic constant = -2.375869 21
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 I!IWmU6FN  
Set lens thickness = 3.927 CXqU<a&  
Set lens index of refraction = 1.42672 R~40,$e{  
Set pupil diameter = 4 fIOI  
DONE! u&)+~X