[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 J3K!@m_\  
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。 _G`kj{J  
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模型 :#+VH_%N  
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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。 N5g!,
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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. :sJVklK  
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光源 b,s T[!X[  
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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。 ;Lz96R@}  
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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。 1{_;`V  
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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。 z`'{l{  
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视网膜的散射 ]M#_o]  
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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。 SxH b76 ;  
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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。 ]Z6==+mCP  
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脚本 P6@(nGgK<  
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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： 6Xbo:#  
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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。 tWT@%(2~0  
余下的脚本计算与屈光度有关的所有参数。 |]*]k`o<)  
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分析 G?v]p~6  
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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。 ^1nQDd*  
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脚本代码 fIWOo >)D  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. EA) K"C  
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Dim entity As T_ENTITY {d|e@`"T  
Dim op As T_OPERATION Db3#;  
Dim mat As T_MODELMATERIAL BUvE~l.,|  
Dim A As Double xJlf}LEyF  
Dim pupilDiam As Double -
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Dim eID As Long OTwIR<_B+  
Dim parID As Long qy|[V   
Dim count As Integer Ti:PKpc  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2)cq!Zv  
Dim tlens As Double, nlens As Double rY yB"|  
Dim curv As Double, conic As Double 41dB4Td5t  
Dim ok As Long jJc:%h$|2  
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Sub Main u]RI,3Z  
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    '用户输入对话框 vM5yiHI(jb  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }JPLhr|d^  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $S Kax#[  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 s aY;[bz}  
        OKButton 40,91,90,21 _/xA5/V  
        CancelButton 190,91,90,21 g4z*6L,u  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 N=%4V  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ;@/^hk{A  
    End Dialog #O<,  
    Dim dlg As UserDialog {Qv Whf  
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    ok = Dialog (dlg) Pnl+.?  
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    If ok=0 Then    'cancel button was pressed !:BmDX[<n  
        Print "Execution cancelled." ~[a6  
        End ?E +[  
    End If Z/G`8|A  
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    'Assign accommodation and pupil diameter & use defaults if field left empty n[+$a)$8  
    If dlg.TextBox1 = "" Then |[./jg"  
        A = 0           'Default accommodation @'IRh9  
    Else h[*:\P`  
        A = CDbl(dlg.TextBox1) e2F{}N  
    End If +PAb+E|,  
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    If dlg.TextBox2 = "" Then P z< \q
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        pupilDiam = 4   'Default pupil diameter yX7P5c.   
    Else  :d)y  
        pupilDiam = CDbl(dlg.TextBox2) +%sMd]$,n  
    End If \Dlmrke  
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    Print " " to,\sc  
    Print "Accommodation = " & A & " Diopters" O n/q&h5  
    Print "Pupil Diameter = " & pupilDiam & " mm" (pv6V2i  
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    ' Calculate new parameters with accommodation +Hd'*'c  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {J~VB~('  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7ILb&JQ!%{  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -4Hf5!  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]L6[vJHx  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +d!"Zy2|B  
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    tlens = 3.767 + 0.04*A                  'Lens thickness )=TS)C4  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction O_4j"0  
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    'Adjust parameters to account for accommodation 5}Z_A?gy  
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    '************************************************************************* K#;EjR4H  
    'Aqueous thickness (Position of Lens) ^~`t q+  
    '************************************************************************* 8," 5z_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nnZM{<!hF  
    GetCustomElement eID, entity ;%^T*?t  

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    parID = FindFullName( "Geometry.Arizona Eye" ) wA< Fw )  
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    ' Delete any shift(s) in z 0#:St  
    count = 0 3[Z7bhpV  
    While GetOperationCount(eID)>count L %20tm  
        GetOperation eID, count, op W[B;;"ro  
        If op.Type="ShiftZ" Then Z/oP?2/Afh  
            DeleteOperation eID,count w%?6s3
 
            count=count-1 AQgagE^  
        End If  WfH4*e  
        count=count+1 !n3J6%b9y/  
    Wend 1X-fiQJe  
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    'Set new shift in (W'3Zv'f  
    op.Type = "ShiftZ" |Ye%HpTTv  
    op.val1 = taq M/evZ?uis  
    op.parent = parID aTFT'(O,  
    AddOperation eID, op iM_Zn!|@\  
    Print "Set aqueous humor thickness = " & taq-0.55 q[
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    '************************************************************************* Yq0jw&v  
    'Radius and conic constant of anterior lens T:0#se  
    '************************************************************************* }ZB:nnG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) r0:I  
    GetConic eID, entity, curv, conic &O\$=&, h  
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    SetConic eID, entity, 1/Rant, CCant \9%RY]TK3  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9-hVlQ~|  
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    '************************************************************************* (( {4)5}  
    'Radius and conic constant of posterior lens :>o2UH  
    '************************************************************************* Sr4/8BZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) uTvck6  
    GetConic eID, entity, curv, conic |#J!oBS!  
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    SetConic eID, entity, 1/Rpost, CCpost 859ID8F  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost us>$f20T  
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    '************************************************************************* Ja%(kq[v  
    'Lens thickness (Position of posterior lens surface) A[Pz&\@  
    '************************************************************************* 0Q5fX}  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) eGk`Z>  
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    ' Delete any z-shift(s) &vV_,$  
    count = 0 jQi)pVT^  
    While GetOperationCount(eID)>count :FWo,fq?:{  
        GetOperation eID, count, op 7#9yAS+x(  
        If op.Type="ShiftZ" Then <69Uq8GI  
            DeleteOperation eID,count .TKKjS%8  
            count=count-1 @ZtDjxN &  
        End If I1fUV72  
        count=count+1 R^=[D#*]>  
    Wend "Oq>i9v;|$  
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    'Set new z-shift +@jX|  
    op.Type = "ShiftZ"  HV\l86}  
    op.val1 = tlens PNG!q}(c  
    op.parent = parID rh$q]  
    AddOperation eID, op obtXtqew  
    Print "Set lens thickness = " & tlens vj4n=F,Z  
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    '************************************************************************* K-,8~8[  
    'Lens index of refraction ylPDM7Ka  
    '************************************************************************* Hl b%/&  
    eID = FindMaterial( "Lens" ) 6U[bAp  
    GetModelMaterial eID, mat 9,>u,  
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    mat.Nd = nlens !R"iV^?V  
    SetModelMaterial eID, mat k+`e0Jago  
    Print "Set lens index of refraction = " & nlens %eQw\o,a  
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    '************************************************************************* #b5V/)K  
    'Pupil diameter AD4Ot5  
    '************************************************************************* i2Cw#x0s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Nlk'  
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    'Adjust pupil diameter (trimming volume inner hole) \A=:6R%Qb  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 1k?k{Ri  
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    ' Adjust pupil location to just in front of the lens 3PgiV%]  
    parID = FindFullName( "Geometry.Arizona Eye" ) 0 V3`rK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =#K$b *#  
    count = 0 $pGdGV\H  
    While GetOperationCount(eID)>count N_eZz#);  
        GetOperation eID, count, op KL4vr|i,  
        If op.Type="ShiftZ" Then k.("<)  
            DeleteOperation eID,count C,#FH}  
            count=count-1 i!DO  
        End If c]!Yb-  
        count=count+1 N;.}g*_+}  
    Wend m[%
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    op.Type = "ShiftZ" Yk!TQY4  
    op.val1 = taq-0.01 >nOU 8  
    op.parent = parID w|0w<K  
    AddOperation eID, op [(PD2GO+  
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    Print "Set pupil diameter = " & pupilDiam XLxr@1   
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    'Update AZ Eye subassembly Description j& ~`wGM  
    eID = FindFullName( "Geometry.Arizona Eye" ) y8|?J\eRy  
    GetEntity eID, entity .uwD;j +#  
    entity.Description = "Accommodation = " & A & "D" 'mR9Uqq\  
    SetEntity eID, entity :UDT! 5FNO  
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    Update k7\ ,No}  
    Print "DONE!" AHl1{* [  
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End Sub /swNhDQ"o  
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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： [9>h! khs  
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Accommodation = 4 Diopters GfMCHs   
Pupil Diameter = 4 mm !&b wFO>P  
Set aqueous humor thickness = 2.81 9/_F  
Set anterior lens radius = 10.4 and conic constant = -2.375869 e )?~  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 d9kN@W  
Set lens thickness = 3.927 3HI-G.]hC  
Set lens index of refraction = 1.42672 ;R x Rap  
Set pupil diameter = 4 kvo V?<!  
DONE! x{.+i'  
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