[技术]Arizona眼睛模型 [复制链接]

简介 iZZ (4  
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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。 9h0X&1u  
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模型 nhN);R~o"1  
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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。 )z8!f}:De=  
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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. $#|gLVOQ  
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光源 %_
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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。 r&Ca"dI  
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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。 VtOZ%h[#  
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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。 *6U&Qy-M  
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视网膜的散射 Ys8SDlMo  
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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。 .q][? mW3  
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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。 8z5# ]u;  
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脚本 -|Kzo_" v5  

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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： TEsnNi 1  
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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。 2l5KJlfj>k  
余下的脚本计算与屈光度有关的所有参数。 h.K
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分析 zX{.^|  
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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。 X5 ITF)&  
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脚本代码 69#8Z+dw7  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. H(Ms^8Vs~:  
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Dim entity As T_ENTITY VhEMk\  
Dim op As T_OPERATION GD-&_6a  
Dim mat As T_MODELMATERIAL NN 0Q`r,8}  
Dim A As Double H;WY!X$x  
Dim pupilDiam As Double =neL}Fav56  
Dim eID As Long (P6vOo  
Dim parID As Long v
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Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double pJ,@Y>  
Dim tlens As Double, nlens As Double 6Gn4aso
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Dim curv As Double, conic As Double f"&Xr!b.h  
Dim ok As Long lu UYo  
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Sub Main @kD8^,(oH  
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    '用户输入对话框 !D.0 (J  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 JhR W[~  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Uz8hANN0_  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 kReG:  
        OKButton 40,91,90,21 nq`q[KV:  
        CancelButton 190,91,90,21 KO]N%]:&~  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 VGH/X.NJ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 L*]E`Xxd9  
    End Dialog Gg0#H^s( (  
    Dim dlg As UserDialog 9EF~l9`'U  
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    ok = Dialog (dlg) 6*1$8G`$8,  
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    If ok=0 Then    'cancel button was pressed 7S2C/f  
        Print "Execution cancelled." |9NIGg'n  
        End DOL%'k?B  
    End If {^RG% &S  
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    'Assign accommodation and pupil diameter & use defaults if field left empty $T dC/#7  
    If dlg.TextBox1 = "" Then 4u:0n>nJ1  
        A = 0           'Default accommodation 9F_6}.O  
    Else <lFY7'aY  
        A = CDbl(dlg.TextBox1) ~LE[, I:q  
    End If QdDtvJLf  

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    If dlg.TextBox2 = "" Then rpU/s@%L  
        pupilDiam = 4   'Default pupil diameter , Fytk34  
    Else Sr y,@p)  
        pupilDiam = CDbl(dlg.TextBox2)
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    End If 3;BvnD7  
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    Print " " P79R~m`  
    Print "Accommodation = " & A & " Diopters" U'3Fou}  
    Print "Pupil Diameter = " & pupilDiam & " mm" M9V-$ _)  
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    ' Calculate new parameters with accommodation {$TZ}z"DA  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness WV_`1hZX  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens $j`<SxJ>  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )W9_qmYd"  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Yk>8g;<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ^HFo3V }h  
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    tlens = 3.767 + 0.04*A                  'Lens thickness c/$*%J<  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _bQL[eXd  
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    'Adjust parameters to account for accommodation +{&+L0DfH~  
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    '************************************************************************* )q(:eoLDm  
    'Aqueous thickness (Position of Lens) ?N#[<kd  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !"(u_dFw  
    GetCustomElement eID, entity DNho%Xk  
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    parID = FindFullName( "Geometry.Arizona Eye" ) J8h7e}n?  
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    ' Delete any shift(s) in z RO(iHR3cA  
    count = 0 k.>6nho`TV  
    While GetOperationCount(eID)>count zv9MHC &  
        GetOperation eID, count, op <UAP~RH{  
        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count 4Bo<44-,  
            count=count-1 BA`:miH<  
        End If 3B"7VBK{  
        count=count+1 S2}Z&X(  
    Wend "8_,tYAH  
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    'Set new shift in #[,= 1Od(q  
    op.Type = "ShiftZ" :tlE`BIp  
    op.val1 = taq V@Kn24''  
    op.parent = parID 2|s<[V3rP-  
    AddOperation eID, op zze z~bv7:  
    Print "Set aqueous humor thickness = " & taq-0.55 :Fo4O'UC  
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    '************************************************************************* rV U:VL`2  
    'Radius and conic constant of anterior lens )DRkS,I  
    '************************************************************************* Z{#"-UG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6ZTaQPtm  
    GetConic eID, entity, curv, conic _2; ^v`[  
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    SetConic eID, entity, 1/Rant, CCant |I/,F;'  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant A8mlw#`E8b  
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    '************************************************************************* c G*(C
  
    'Radius and conic constant of posterior lens tU(y~)]  
    '************************************************************************* E{I)
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )  /+N|X  
    GetConic eID, entity, curv, conic BMY>a  
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    SetConic eID, entity, 1/Rpost, CCpost Vl4Z_viNH  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost pIvfmIm  
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    '*************************************************************************
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    'Lens thickness (Position of posterior lens surface) 6#O#T;f)  
    '************************************************************************* S$\.4*_H\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CQ$::;  
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    ' Delete any z-shift(s) zw,-.fmM#  
    count = 0 F G3Sk!O6  
    While GetOperationCount(eID)>count )7k&`?Mh  
        GetOperation eID, count, op JxnuGkE0[#  
        If op.Type="ShiftZ" Then -E}>h[;qZ  
            DeleteOperation eID,count d&5c_6oW  
            count=count-1 8,_ -0_^$  
        End If hR!}u}ECd  
        count=count+1 T0YDfo  
    Wend TZ:34\u  
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    'Set new z-shift nW~$ (Qnd  
    op.Type = "ShiftZ" gA{'Q\  
    op.val1 = tlens Yg[ v/[]  
    op.parent = parID 0~qf-x  
    AddOperation eID, op %V31B\]Nz7  
    Print "Set lens thickness = " & tlens %v_IX2'  
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    '************************************************************************* r)OO&. P@j  
    'Lens index of refraction Zd8drT'@#  
    '************************************************************************* ix^gA
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    eID = FindMaterial( "Lens" ) n>br,bQe  
    GetModelMaterial eID, mat sw[oQ!f  
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    mat.Nd = nlens UlnyTz~  
    SetModelMaterial eID, mat KUF$
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    Print "Set lens index of refraction = " & nlens o>@=N2n  
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    '************************************************************************* g})6V  
    'Pupil diameter <b6s&"%=  
    '************************************************************************* Ze#Jhn@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,.[.SU#V  
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    'Adjust pupil diameter (trimming volume inner hole) : #3OcD4  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens {a]pF.^kf  
    parID = FindFullName( "Geometry.Arizona Eye" ) M8\G>0Hc6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) HmhU
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    count = 0 "EN98^ Sl  
    While GetOperationCount(eID)>count 5.O-(eSa0&  
        GetOperation eID, count, op 4g>1Gqv6  
        If op.Type="ShiftZ" Then ]Mn&76fu  
            DeleteOperation eID,count y*}AX%8`e~  
            count=count-1 cT_uJbP+  
        End If $< A8gTJ  
        count=count+1 sk~za  
    Wend U&,r4>V@h>  
    op.Type = "ShiftZ" ^uC"
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    op.val1 = taq-0.01 `@4 2jG}*  
    op.parent = parID Sc%aJ1  
    AddOperation eID, op Uc\|X;nkRk  
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    Print "Set pupil diameter = " & pupilDiam b;Hm\aK  
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    'Update AZ Eye subassembly Description ^Vl^,@  
    eID = FindFullName( "Geometry.Arizona Eye" ) N{ : [/  
    GetEntity eID, entity 9@(O\xr  
    entity.Description = "Accommodation = " & A & "D" 's
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    SetEntity eID, entity C]yvK}  
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    Update nsZDZ/jx  
    Print "DONE!" ^
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End Sub Lv  
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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： 
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Accommodation = 4 Diopters "B3iX@C  
Pupil Diameter = 4 mm ;X+G6F'  
Set aqueous humor thickness = 2.81 hCU)W1q#  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gcX5Q^`a=  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }9MW!Ss  
Set lens thickness = 3.927 {[l'S  
Set lens index of refraction = 1.42672 (nkUeQQN  
Set pupil diameter = 4 !JT<(I2  
DONE! " 7l jc