[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 g5?r9e  
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。 7 B4w.P,B  
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模型 z0FR33-  
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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。 Vu^Q4Z  
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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. N GX-'w  
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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。 $u(M 4(}  
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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。 mCZF5r  
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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。 uk>q\j  
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视网膜的散射 D~t"9Z\  
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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。 F5om-tzy  
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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。 ~50y-  
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脚本
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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： 96([V|5K  
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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。 0|*UeM  
余下的脚本计算与屈光度有关的所有参数。 071E%
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分析 av|6r#  
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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。 &d &oP  
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脚本代码 $ M[}(m  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. d >wmg*J  
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Dim entity As T_ENTITY 8=zM~v)   
Dim op As T_OPERATION `mHOgS>|  
Dim mat As T_MODELMATERIAL  el*pYI  
Dim A As Double &>wce5uV  
Dim pupilDiam As Double 7T(OV<q;#  
Dim eID As Long 4jyr\=42F'  
Dim parID As Long \w@_(4")Qb  
Dim count As Integer ;JD3tM<  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double
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Dim tlens As Double, nlens As Double yADN_  
Dim curv As Double, conic As Double E?c{02fu  
Dim ok As Long &j
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Sub Main O%Gsk'mo  
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    '用户输入对话框 R4rm>zisVX  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 e7)%=F/)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Lw+1|  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,mBKy
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        OKButton 40,91,90,21 i2%m}S;D9  
        CancelButton 190,91,90,21 +hvIJv ?  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {J6sM$aj  
        TextBox 220,49,40,21,.TextBox2 'default: 4 l1|,Lr  
    End Dialog xvz5\s|b  
    Dim dlg As UserDialog >a`zkl  
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    ok = Dialog (dlg) meVVRFQ2+  
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    If ok=0 Then    'cancel button was pressed +` Y ?-  
        Print "Execution cancelled." 'rq#q)1MT  
        End *e"GQd?  
    End If p31rhe   
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    'Assign accommodation and pupil diameter & use defaults if field left empty elHarey`f  
    If dlg.TextBox1 = "" Then 2;(iTPz +  
        A = 0           'Default accommodation !7a^8   
    Else 'LLQ[JJ=O  
        A = CDbl(dlg.TextBox1) cZX&itVc:  
    End If P+%)0*W  
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    If dlg.TextBox2 = "" Then 0gb]Kjx  
        pupilDiam = 4   'Default pupil diameter n#L2cv~Aj"  
    Else S%gO6&
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        pupilDiam = CDbl(dlg.TextBox2) V1b_z  
    End If gl\$jDC9  
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    Print " " f;XsShxr  
    Print "Accommodation = " & A & " Diopters" Y l3[~S  
    Print "Pupil Diameter = " & pupilDiam & " mm" 4bJ2<j  
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    ' Calculate new parameters with accommodation _(kwD^x6O{  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {Ljl4Sp&  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8\V>6^3CD$  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens +FKP5L
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |ij5c@~&  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens f<Um2YGW  
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    tlens = 3.767 + 0.04*A                  'Lens thickness |b@A:8ss  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction
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    'Adjust parameters to account for accommodation Tvw2py q  
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    '************************************************************************* ieLN;)Iy^  
    'Aqueous thickness (Position of Lens) 1Y"qQp  
    '************************************************************************* ,) jB<`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) E6-(q!"A  
    GetCustomElement eID, entity WuZn|j'  
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    parID = FindFullName( "Geometry.Arizona Eye" ) G`lhvpifG  
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    ' Delete any shift(s) in z VP[!ji9P  
    count = 0 z>g& ?vo2  
    While GetOperationCount(eID)>count Nl)j
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        GetOperation eID, count, op x[@3;_'K  
        If op.Type="ShiftZ" Then @O0vh$3t0  
            DeleteOperation eID,count iKH T  
            count=count-1 uqeWdj*Y  
        End If g UAPjR  
        count=count+1 ~{$'sp0  
    Wend 7Bd_/A($  
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    'Set new shift in #UeU:RJ1  
    op.Type = "ShiftZ" I[IQFka}  
    op.val1 = taq R*G>)YH  
    op.parent = parID a2_IF,p*?  
    AddOperation eID, op oOSyOD  
    Print "Set aqueous humor thickness = " & taq-0.55 (lsod#wEMg  
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    '************************************************************************* ,lYU#Hx*  
    'Radius and conic constant of anterior lens v86`\K*0Y  
    '************************************************************************* *!s?hHv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +Z(VWu6  
    GetConic eID, entity, curv, conic |i}g
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    SetConic eID, entity, 1/Rant, CCant YVp0}m  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !@1!ld  
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    '************************************************************************* ?S:_J!vX{  
    'Radius and conic constant of posterior lens iL' ]du<wk  
    '************************************************************************* ZP/=R<<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic X1D:{S[  
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    SetConic eID, entity, 1/Rpost, CCpost r:Cid*~m  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %d\+(:uu/  
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    '************************************************************************* tV4aUve  
    'Lens thickness (Position of posterior lens surface) ,dMi+c`
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    '************************************************************************* ,OAWGFKOp  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ) hB*Hjh  
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    ' Delete any z-shift(s) q2i~<;Z)9  
    count = 0 :?W:'% (`[  
    While GetOperationCount(eID)>count tJ=zk3BN~  
        GetOperation eID, count, op w2AWdO6  
        If op.Type="ShiftZ" Then }CqIKoX.  
            DeleteOperation eID,count UbH=W(%  
            count=count-1 UeQ%(f  
        End If a8c]B/  
        count=count+1 sxa (  
    Wend " N4]e/.V  
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    'Set new z-shift _%!hk
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    op.Type = "ShiftZ" ~h+3WuOv  
    op.val1 = tlens (E[hl  
    op.parent = parID Us.jyg7_c  
    AddOperation eID, op IW*.B6Hw8  
    Print "Set lens thickness = " & tlens JpiKZG@L  
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    '************************************************************************* \zyGJyy.  
    'Lens index of refraction /V
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    '************************************************************************* ? GW3E  
    eID = FindMaterial( "Lens" ) KguFU  
    GetModelMaterial eID, mat "rJL ^ \r  
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    mat.Nd = nlens !I&Sy]G  
    SetModelMaterial eID, mat }qPo%T  
    Print "Set lens index of refraction = " & nlens 0l*/_;wo  
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    '************************************************************************* R?I3xb  
    'Pupil diameter @DR&e^Zz  
    '************************************************************************* $<PVzW,$o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mQJGKh&Pk  
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    'Adjust pupil diameter (trimming volume inner hole)
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =Y0m;-1M  
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    ' Adjust pupil location to just in front of the lens f^ qQ5N  
    parID = FindFullName( "Geometry.Arizona Eye" ) RJM(+5xQ|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 'Ud5;?
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    count = 0 EbH
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    While GetOperationCount(eID)>count m\=u/Zip  
        GetOperation eID, count, op _i#Z'4?2E  
        If op.Type="ShiftZ" Then ,zaveQ~l  
            DeleteOperation eID,count =|/b[Gd(  
            count=count-1 lhU#/}Z  
        End If ?hYe4tc-#  
        count=count+1 %e(,PL  
    Wend {ar}.U  
    op.Type = "ShiftZ" oGZ9@Y)(T  
    op.val1 = taq-0.01 gu!A:Q  
    op.parent = parID cjk5><}`H7  
    AddOperation eID, op sYzG_*)  
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    Print "Set pupil diameter = " & pupilDiam Mtr~d  
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    'Update AZ Eye subassembly Description [A47OR  
    eID = FindFullName( "Geometry.Arizona Eye" ) [(mq8Nb  
    GetEntity eID, entity |%}?*|-  
    entity.Description = "Accommodation = " & A & "D" qsp,Usu/  
    SetEntity eID, entity "yumc5kt  
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    Update 2_Qzc&"[ 4  
    Print "DONE!" 03PVbDq-  
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End Sub pFuQ!7Uk  
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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： {)M4h?.2  
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Accommodation = 4 Diopters ;&!l2UB%  
Pupil Diameter = 4 mm 2%
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Set aqueous humor thickness = 2.81 uH#NJoRO  
Set anterior lens radius = 10.4 and conic constant = -2.375869 HFazqQ[  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 j.K yPWO  
Set lens thickness = 3.927 Q.Acmht#  
Set lens index of refraction = 1.42672 LuVj9+1 S  
Set pupil diameter = 4 |w5#a_adM  
DONE! `
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