[技术]Arizona眼睛模型 [复制链接]

简介 a2N4Jg@  
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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。 6$^dOJ_"  
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模型 GBsM?A:  
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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。 &BDdJwE  
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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. .}l&lj
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光源 vAMr&[  
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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。 Z'I0e9Jw  
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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。 t846:Z%[  
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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。 d@72z r  
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视网膜的散射 9w! G  
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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。 uF=xo`=|  
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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。 An%V>a-[  
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脚本 rpNe8"sh  
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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： O<x53MN^  
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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。 Ht'jm(  
余下的脚本计算与屈光度有关的所有参数。 2.K"+%  
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分析 X&<#3n  
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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。 p ?HODwZ  
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脚本代码 6L6
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. DT=!  
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Dim entity As T_ENTITY &\C{,:[  
Dim op As T_OPERATION >Q~"/-bN)  
Dim mat As T_MODELMATERIAL IpxFME%!  
Dim A As Double f-\l<o(  
Dim pupilDiam As Double BX),
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Dim eID As Long y(RbW_ ?  
Dim parID As Long Hc@Z7eQ3^  
Dim count As Integer 2#Au6BvX  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double B(MO!GNg=  
Dim tlens As Double, nlens As Double Dz&4za+{  
Dim curv As Double, conic As Double ubhem(p#  
Dim ok As Long OD"eB?  
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Sub Main !UUh7'W4u  
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    '用户输入对话框 |k'I?:'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 e<^tY0rR&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <,0&Ox  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mId{f  
        OKButton 40,91,90,21 ji(S ?^  
        CancelButton 190,91,90,21 "VWxHRVg4M  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 e7L;{+XI  
        TextBox 220,49,40,21,.TextBox2 'default: 4 nX Qz  
    End Dialog nWZrB s _  
    Dim dlg As UserDialog d1j v>tu  
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    ok = Dialog (dlg) !*%3um  
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    If ok=0 Then    'cancel button was pressed vS<;:3  
        Print "Execution cancelled." #G#gB   
        End %h%r6EB1F  
    End If A|>a Gy  
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    'Assign accommodation and pupil diameter & use defaults if field left empty % wRJ"T`Tt  
    If dlg.TextBox1 = "" Then t*Q12Q  
        A = 0           'Default accommodation 4 qW)R{%  
    Else F{T|lTl  
        A = CDbl(dlg.TextBox1) :OI!YR%"  
    End If v;K\#uc_  
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    If dlg.TextBox2 = "" Then `%ymg8^  
        pupilDiam = 4   'Default pupil diameter NHc+QMbou(  
    Else dy`~%lX?  
        pupilDiam = CDbl(dlg.TextBox2) EoY#D'[  
    End If T  |j^  
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    Print " " w-nkf M~  
    Print "Accommodation = " & A & " Diopters" FpRK^MEkG  
    Print "Pupil Diameter = " & pupilDiam & " mm" 2N,*S   
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    ' Calculate new parameters with accommodation OC\C^Yh*U  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness :,VyOmf  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Ra*9d]N@  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \aW5V:?  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Tf0#+6 1>  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Y2$%%@  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Z=H fOC  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction OQsH,'
  
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    'Adjust parameters to account for accommodation i'EXylb  
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    '************************************************************************* er<~dqZ}]  
    'Aqueous thickness (Position of Lens) d~_OWCg`  
    '************************************************************************* }M~AkJL  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3?}SXmA'@  
    GetCustomElement eID, entity FP\[7?ZLn  
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    parID = FindFullName( "Geometry.Arizona Eye" ) QWP_8$Q  
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    ' Delete any shift(s) in z G37_ `C  
    count = 0 FQ4rA 4  
    While GetOperationCount(eID)>count kB:R-St  
        GetOperation eID, count, op IWQ8e$N  
        If op.Type="ShiftZ" Then _6[NYv$"  
            DeleteOperation eID,count ><DE1tG  
            count=count-1 Gce_gZH7{  
        End If [lJ[kr*7  
        count=count+1 EagI)W!s[  
    Wend U--ER r8  

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    'Set new shift in C/$IF M<  
    op.Type = "ShiftZ" 1GNAx\(  
    op.val1 = taq }l2JXf55  
    op.parent = parID &S{F"z  
    AddOperation eID, op /[-hJ=<Yb  
    Print "Set aqueous humor thickness = " & taq-0.55 bC{~/ JP  
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    '************************************************************************* {!4%Z9G  
    'Radius and conic constant of anterior lens I[|I\tW  
    '************************************************************************* mU_O64  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n#R!`*[  
    GetConic eID, entity, curv, conic S,v`rmI  
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    SetConic eID, entity, 1/Rant, CCant =
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant I F@M  
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    '************************************************************************* ^q
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    'Radius and conic constant of posterior lens | jkmh6  
    '************************************************************************* t&oNJq{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @PI\.y_w  
    GetConic eID, entity, curv, conic bM'AD[  
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    SetConic eID, entity, 1/Rpost, CCpost Q9'p2@Z  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~:@H6Ke[  
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    '************************************************************************* )<|TEp4r-  
    'Lens thickness (Position of posterior lens surface) B?M+`;  
    '************************************************************************* eOb`uyi  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) gM*s/,;O"  
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    ' Delete any z-shift(s) JjmL6(*ui  
    count = 0 RD4)NN6y5}  
    While GetOperationCount(eID)>count A_.QHUjpx  
        GetOperation eID, count, op zxh"@j$?  
        If op.Type="ShiftZ" Then EI;\of2,  
            DeleteOperation eID,count V#~.Jg7  
            count=count-1 7I|%GA_  
        End If EDo (  
        count=count+1 DHAWUS6  
    Wend TU/J]'))C  
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    'Set new z-shift VPHCPGrk  
    op.Type = "ShiftZ" #^9;<@M  
    op.val1 = tlens (Ka#6   
    op.parent = parID l;.BlHyu  
    AddOperation eID, op R+K[/AA  
    Print "Set lens thickness = " & tlens {OOt+U!  
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    '************************************************************************* @I&"P:E0F;  
    'Lens index of refraction +[ItkfSod!  
    '************************************************************************* ;i9CQ0e?  
    eID = FindMaterial( "Lens" ) wL
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    GetModelMaterial eID, mat 9)">()8  
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    mat.Nd = nlens }]I?vyQ#V  
    SetModelMaterial eID, mat $ZS9CkN  
    Print "Set lens index of refraction = " & nlens HhL%iy1  
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    '************************************************************************* f2wW2]Fg  
    'Pupil diameter aW"!bAdx`,  
    '************************************************************************* F(<8:`N;G  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) sD8S2  
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    'Adjust pupil diameter (trimming volume inner hole) ^NDX4d;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =@2V#X]M*  
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    ' Adjust pupil location to just in front of the lens /<0D E22  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) E: GJ$I  
    count = 0 (5~C _Y  
    While GetOperationCount(eID)>count PAHlj,n)  
        GetOperation eID, count, op 9$&e~^&B  
        If op.Type="ShiftZ" Then 8-
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            DeleteOperation eID,count "NU".q  
            count=count-1 D,\=zX;  
        End If d 4]%Wdvf  
        count=count+1 $VWzv4^:  
    Wend ImY.HB^&  
    op.Type = "ShiftZ" ^d80\PXz  
    op.val1 = taq-0.01 M N#C2 qz  
    op.parent = parID PQ}%}S7:  
    AddOperation eID, op bZ.N7X PH  
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    Print "Set pupil diameter = " & pupilDiam *Xoscc  
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    'Update AZ Eye subassembly Description n*Vd<m;w  
    eID = FindFullName( "Geometry.Arizona Eye" ) N;'HR)  
    GetEntity eID, entity #OWs3$9  
    entity.Description = "Accommodation = " & A & "D" @@83PJFid  
    SetEntity eID, entity ,
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    Update N@6OQ:,[F  
    Print "DONE!" P/Kit?kngS  
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End Sub m> (h_j  
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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： Wk\@n+Q{]  
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Accommodation = 4 Diopters YM`pNtQ  
Pupil Diameter = 4 mm @b\ S.  
Set aqueous humor thickness = 2.81 5xDN&su  
Set anterior lens radius = 10.4 and conic constant = -2.375869 i ,pN1_-
 
Set posterior lens radius = -4.424557 and conic constant = -3.081019 TE%#$q  
Set lens thickness = 3.927 RX5.bVp eE  
Set lens index of refraction = 1.42672 {|Ki^8h/p  
Set pupil diameter = 4 45sxF?GSwL  
DONE! DBJA}Cw