[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 "J+L]IC?AD  
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。 8b]4uI<  
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模型
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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。 <#?dPDMG.*  
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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. iu8Q &Us0P  
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光源 Bc }o3oc  
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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。 WJONk_WAc  
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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。 &}e>JgBe0  
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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。 o[_,r]%+D  
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视网膜的散射 hO$Gx*e$  
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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。 "Tser*i )  
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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。 q&>fKSnKs  
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脚本 KO8{eT9d  
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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： 7O*Sg2B  
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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。 <bhGpLh-E  
余下的脚本计算与屈光度有关的所有参数。 Q]TZyk  
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分析 ),`jMd1`  
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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。 BZ.l[LMp  
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脚本代码 +|dLR*s  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b`+yNf  
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Dim entity As T_ENTITY FNraof @Oy  
Dim op As T_OPERATION 4Us,DS_/  
Dim mat As T_MODELMATERIAL ~ i+XVo  
Dim A As Double ~;$QSO\2h  
Dim pupilDiam As Double ?Ybq]J\q  
Dim eID As Long h@O\j
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Dim parID As Long ?m~1b_@A{  
Dim count As Integer F5:xrcyC  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double jRiMWolLv  
Dim tlens As Double, nlens As Double Cx~;oWZ  
Dim curv As Double, conic As Double s'N<  
Dim ok As Long REU&8J@k&?  
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Sub Main OHAU@*[lM  
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    '用户输入对话框 0U%tjYk(  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 EMe1!)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 FXT^r3  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 DRRQ]eK0  
        OKButton 40,91,90,21 ,S dj"C  
        CancelButton 190,91,90,21 H0OO+MCe  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #]1jvB  
        TextBox 220,49,40,21,.TextBox2 'default: 4 %-fXa2  
    End Dialog M .6BFC  
    Dim dlg As UserDialog y-H9fWi8Y&  
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    ok = Dialog (dlg) Zl9  
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    If ok=0 Then    'cancel button was pressed qm/>\4eLt  
        Print "Execution cancelled." e}{#VB<  
        End AEj%8jh  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty {ly<%Q7j  
    If dlg.TextBox1 = "" Then M __S)  
        A = 0           'Default accommodation CzreX3i  
    Else whw+  
        A = CDbl(dlg.TextBox1) 7&P70DO  
    End If y,rdyt  
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    If dlg.TextBox2 = "" Then j|[$P4w}U  
        pupilDiam = 4   'Default pupil diameter _(m455HZ  
    Else $'>iNMtK{p  
        pupilDiam = CDbl(dlg.TextBox2) yph@H!@  
    End If r<(UN@T}  
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    Print " " C=Fu1H
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    Print "Accommodation = " & A & " Diopters" CIo`;jt
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    Print "Pupil Diameter = " & pupilDiam & " mm" !jB}}&Ii  
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    ' Calculate new parameters with accommodation g*FHZM*N9  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `2+TN  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #"r_ 3  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens D0bpD  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens *B@#A4f"  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens d,i4WKp  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @kDY c8 t9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction a(fiW%eFb  
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    'Adjust parameters to account for accommodation c^H#[<6p  
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    '************************************************************************* b(U5n"cdA  
    'Aqueous thickness (Position of Lens) R(_WTs9x4  
    '************************************************************************* .#tA .%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) K~-V([tWg  
    GetCustomElement eID, entity 9i_@3OVl  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 4Hyp]07  
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    ' Delete any shift(s) in z m7A3i<6p  
    count = 0 <x<qO=lq  
    While GetOperationCount(eID)>count kda*rl~c  
        GetOperation eID, count, op )~$ejS  
        If op.Type="ShiftZ" Then rcLF:gd]E  
            DeleteOperation eID,count i,RbIZnJ  
            count=count-1 VFq\{@- %  
        End If BUi,+NdIk  
        count=count+1 NODg_J~T  
    Wend ,=@WE>ip  
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    'Set new shift in I WT|dA >  
    op.Type = "ShiftZ" k'F*uS  
    op.val1 = taq 4R01QSbd  
    op.parent = parID Wo9=cYC)  
    AddOperation eID, op `T%nGVl>\  
    Print "Set aqueous humor thickness = " & taq-0.55  iSX:H;  
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    '************************************************************************* v?nGAn  
    'Radius and conic constant of anterior lens eUu<q/FUMj  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (?T{^Hg  
    GetConic eID, entity, curv, conic Um-Xb'R*]V  
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    SetConic eID, entity, 1/Rant, CCant $i3`cX)g  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant P?8$VAkj  
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    '************************************************************************* f@Ve,i  
    'Radius and conic constant of posterior lens Z
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    '************************************************************************* U CFw+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ':\bn:;  
    GetConic eID, entity, curv, conic ??hKsjNAm0  
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    SetConic eID, entity, 1/Rpost, CCpost 4/SltWU  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N/2WUp  
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    '************************************************************************* =b6G' O[  
    'Lens thickness (Position of posterior lens surface) %6V=G5+W  
    '************************************************************************* ,&O&h2=  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Mac:E__G  
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    ' Delete any z-shift(s) >N~jlr|  
    count = 0 "6%qi qt  
    While GetOperationCount(eID)>count t08[3Q&  
        GetOperation eID, count, op ^6CPC@B1  
        If op.Type="ShiftZ" Then :Xx7':5  
            DeleteOperation eID,count c~\^C_  
            count=count-1 kMa|V0  
        End If 9(a*0H  
        count=count+1 ady SwB  
    Wend {@" F/G+  
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    'Set new z-shift 5!6iAS+I  
    op.Type = "ShiftZ" dleLX%P  
    op.val1 = tlens d(Yuz#Qcrh  
    op.parent = parID sv\=/F@n  
    AddOperation eID, op ~dsx|G?p  
    Print "Set lens thickness = " & tlens 6UPGE",u  
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    '************************************************************************* _Mh..#)`[  
    'Lens index of refraction r6:nYyF$)v  
    '************************************************************************* Bq
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    eID = FindMaterial( "Lens" ) TPZ^hL>ao  
    GetModelMaterial eID, mat gp{Z]{io  
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    mat.Nd = nlens =NRiro  
    SetModelMaterial eID, mat fL&e^Q  
    Print "Set lens index of refraction = " & nlens RHt~:D3*  
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    '************************************************************************* 0+rBGk  
    'Pupil diameter bU4\Yu   
    '************************************************************************* H Mfhe[A?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _oU~S$hO  
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    'Adjust pupil diameter (trimming volume inner hole) 3-![%u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &e4EZ  
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    ' Adjust pupil location to just in front of the lens R <u\ -  
    parID = FindFullName( "Geometry.Arizona Eye" ) t$uj(y>  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) lYrW"(2  
    count = 0 yMb.~A^$J  
    While GetOperationCount(eID)>count ,fs>+]UY3  
        GetOperation eID, count, op Hg[AulNna  
        If op.Type="ShiftZ" Then sQ82(N7l  
            DeleteOperation eID,count dM5N1$1,  
            count=count-1 }M(
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        End If YtT:\#D  
        count=count+1 B o[aiT  
    Wend P76QHBbl  
    op.Type = "ShiftZ" %e=UYBj"  
    op.val1 = taq-0.01 9q<?
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    op.parent = parID _8?r!D#P;s  
    AddOperation eID, op YYd!/@|N5  
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    Print "Set pupil diameter = " & pupilDiam u|&a!tOf2  
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    'Update AZ Eye subassembly Description !~f!O"n)3r  
    eID = FindFullName( "Geometry.Arizona Eye" ) g _u  
    GetEntity eID, entity 4--[.j*W  
    entity.Description = "Accommodation = " & A & "D" fh}j)*K8  
    SetEntity eID, entity OQsF$%*  
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    Update ^:m7Qd?Z[  
    Print "DONE!" N1z:9=(I  
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End Sub 'Y-Y By :  
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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： E#+|.0*!s  
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Accommodation = 4 Diopters 5!d'RBO   
Pupil Diameter = 4 mm C%kIxa)  
Set aqueous humor thickness = 2.81 1"} u51  
Set anterior lens radius = 10.4 and conic constant = -2.375869 +S}/6dg  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 *Q2}Qbu  
Set lens thickness = 3.927 NT [~AK9M  
Set lens index of refraction = 1.42672 i}e OWi  
Set pupil diameter = 4 g E;o_~  
DONE! THDyb9_g  
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