[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 xF|P6GXg  
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。 Z*r;"WHB  
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模型 E(t:F^z&D  
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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。 r(qAe{  
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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. ~\4`tc  
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光源 gN"Abc  
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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。 9hoTxWpmy  
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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。 -TL `nGF  
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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。 V* :Q~ ^  
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视网膜的散射 6:PQkr  
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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。 z'iAj  
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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。 gW0{s[}T  
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脚本 g7>p,  
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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： bKAR}JM&  
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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。 _6Ex}`fyJ  
余下的脚本计算与屈光度有关的所有参数。 IdY\_@$ v  
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分析 :#yjg1aej  
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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。 _dg2i|yP<  
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脚本代码 \1^qfw  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. C`)n\?:Sth  
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Dim entity As T_ENTITY 627
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Dim op As T_OPERATION M@R_t(&=  
Dim mat As T_MODELMATERIAL *{/L7])gm  
Dim A As Double  'Dh+v3O  
Dim pupilDiam As Double X?B9Z8  
Dim eID As Long O&ur|&v  
Dim parID As Long rSGt`#E-s.  
Dim count As Integer M=HP!hn  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p_K``JE  
Dim tlens As Double, nlens As Double !i"Z  
Dim curv As Double, conic As Double d&!ZCq#_e  
Dim ok As Long $d@_R^]X  
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Sub Main zVSbEcr,C~  
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    '用户输入对话框 ig]
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *58`}]  
        TextBox 220,21,40,21,.TextBox1 'default: 0 j|WuOZm\0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 M*& tVG  
        OKButton 40,91,90,21 =*ZQGM3w  
        CancelButton 190,91,90,21 c5jd q[0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 d8Keyi8[  
        TextBox 220,49,40,21,.TextBox2 'default: 4 5LPyPL L  
    End Dialog {95z\UE}  
    Dim dlg As UserDialog z / YF7wrx  
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    ok = Dialog (dlg) f/_RtOSw  
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    If ok=0 Then    'cancel button was pressed L}>XH*  
        Print "Execution cancelled." Wq4>!|  
        End P^1+;dL,D  
    End If evbqBb21b  
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    'Assign accommodation and pupil diameter & use defaults if field left empty pi'w40!:  
    If dlg.TextBox1 = "" Then FIB 9W@oao  
        A = 0           'Default accommodation uk8vecj  
    Else ZTq"SQ>ym  
        A = CDbl(dlg.TextBox1) L(a){<c  
    End If #i#4h<R  
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    If dlg.TextBox2 = "" Then ~|LlT^C  
        pupilDiam = 4   'Default pupil diameter =bVaB<!  
    Else "`sr#  
        pupilDiam = CDbl(dlg.TextBox2) ac/=%om8u  
    End If "IK QFt'  
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    Print " " 8veYs`  
    Print "Accommodation = " & A & " Diopters" Jgf73IX[  
    Print "Pupil Diameter = " & pupilDiam & " mm" {}vB#!  

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    ' Calculate new parameters with accommodation kJ;fA|(I  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Nb))_+/  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens s'&/8RR  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens qqm7p ,j  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }RGp)OFY&  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -Qs4s  
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    tlens = 3.767 + 0.04*A                  'Lens thickness *3S./C}  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1>JUI5 {  
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    'Adjust parameters to account for accommodation L*A9a  
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    '************************************************************************* De^GWO.?bT  
    'Aqueous thickness (Position of Lens) W!$aK)]4u  
    '************************************************************************* 0;*1g47\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vm3B>ACJ  
    GetCustomElement eID, entity R7/"ye:7J  
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    parID = FindFullName( "Geometry.Arizona Eye" ) qusX]Tstz  
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    ' Delete any shift(s) in z ]Zfg~K(  
    count = 0 G~oGBq6Gz  
    While GetOperationCount(eID)>count 6cCC+*V{  
        GetOperation eID, count, op qOyg&]7  
        If op.Type="ShiftZ" Then {x3"/sF  
            DeleteOperation eID,count .t/XW++  
            count=count-1 D[.;-4"_  
        End If *x^W`i   
        count=count+1 `@8QQB  
    Wend ail%#E8  
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    'Set new shift in 93zoJiLRf  
    op.Type = "ShiftZ" 3y}0J @  
    op.val1 = taq K._tCB:  
    op.parent = parID d

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    AddOperation eID, op a$f$C
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    Print "Set aqueous humor thickness = " & taq-0.55 ={Bcbj{  
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    '************************************************************************* 1^G*)Qn5Df  
    'Radius and conic constant of anterior lens .xRJ )9q  
    '************************************************************************* Z J:h]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?v]EXV3  
    GetConic eID, entity, curv, conic gO0X-fN8  
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    SetConic eID, entity, 1/Rant, CCant CzP?J36W^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant &E0d{2  
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    '************************************************************************* oy I8}s:  
    'Radius and conic constant of posterior lens ?a~59!u  
    '************************************************************************* )aW;w|#n  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0dv# [  
    GetConic eID, entity, curv, conic P
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    SetConic eID, entity, 1/Rpost, CCpost ]8)nIT^EP  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost XBd/,:q
  
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    '************************************************************************* @dl{.
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    'Lens thickness (Position of posterior lens surface) [TUy><Z  
    '************************************************************************* dQD YN_  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4Wz@^7|V5  
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    ' Delete any z-shift(s) +Y7"!wYR>  
    count = 0 W@R\m=e2  
    While GetOperationCount(eID)>count ]L/h,bVI1  
        GetOperation eID, count, op (*{Y#XD{  
        If op.Type="ShiftZ" Then -+^E5  
            DeleteOperation eID,count q~*9A-MH  
            count=count-1 ~b.C[s  
        End If 1P(5+9"s  
        count=count+1 ~p9nAACU  
    Wend ?P<8Zw
 
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    'Set new z-shift $a^YJY^_  
    op.Type = "ShiftZ" qmNgEz%  
    op.val1 = tlens ]njObU)[zr  
    op.parent = parID J2rw4L  
    AddOperation eID, op )f#raXa5+  
    Print "Set lens thickness = " & tlens 5F#Q1gP-  
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    '************************************************************************* WCK;r{p%I  
    'Lens index of refraction W{pyU\  
    '************************************************************************* -4 ~(*  
    eID = FindMaterial( "Lens" ) >=G-^z:  
    GetModelMaterial eID, mat YVcFCl  
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    mat.Nd = nlens @FC|1=+  
    SetModelMaterial eID, mat g^ @9SU  
    Print "Set lens index of refraction = " & nlens iUNlNl ?  
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    '************************************************************************* [1OX:O|  
    'Pupil diameter R07 7eX  
    '************************************************************************* X~m*`UH  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) azEN_oUV  
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    'Adjust pupil diameter (trimming volume inner hole) [^oTC;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" FU;b8{Y  
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    ' Adjust pupil location to just in front of the lens 3aD\J_  
    parID = FindFullName( "Geometry.Arizona Eye" ) Y9YE:s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) oqLM-=0<}  
    count = 0 ,C4gA(')K  
    While GetOperationCount(eID)>count [SnnOqWw  
        GetOperation eID, count, op ^oykimYI-  
        If op.Type="ShiftZ" Then <oFZFlY@  
            DeleteOperation eID,count ~"eQPTd  
            count=count-1 A6ar@$MZ  
        End If I.C,y\  
        count=count+1 y(^hlX6gQ  
    Wend FLWQY,  
    op.Type = "ShiftZ" U|[+M@F_L  
    op.val1 = taq-0.01 mpsi{%gA  
    op.parent = parID `5J`<BPs  
    AddOperation eID, op M/!5r  
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    Print "Set pupil diameter = " & pupilDiam ';HNQe?vT  
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    'Update AZ Eye subassembly Description A>0wqT  
    eID = FindFullName( "Geometry.Arizona Eye" ) WF'Di4   
    GetEntity eID, entity `~~.0QC  
    entity.Description = "Accommodation = " & A & "D" G<dWh.|`=  
    SetEntity eID, entity pwu8LQ3b{O  
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    Update P~6QRm  
    Print "DONE!" -XbO[_Wf  
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End Sub ceKR?%8s  
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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： HU~,_m  
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Accommodation = 4 Diopters [,@gSb|D?  
Pupil Diameter = 4 mm IJ#G/<ZJZ  
Set aqueous humor thickness = 2.81 mVSaC  
Set anterior lens radius = 10.4 and conic constant = -2.375869 |._9;T-Yde  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 0=WZ 8|R  
Set lens thickness = 3.927 %.NOQ<@W  
Set lens index of refraction = 1.42672 ;usv/8  
Set pupil diameter = 4 5.]eF$x2  
DONE! ('9LUFw\  
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