[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ie)1h  
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。 y[@j0xlO  
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模型 w4MMo  
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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。 ; 7v7V  
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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. =jv$ 1  
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光源 4C9"Q,o%&  
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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。 bvu<IXX=2  
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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。 !#4HGjPI  
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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。 ,,#rv-*  
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视网膜的散射 D&6Qk&>  
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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。 6V6g{6W,/  
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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。 #`)-$vUv^f  
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脚本 KPe.AK,8  
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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： qg:I+"u  
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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。 Vyq<T(5  
余下的脚本计算与屈光度有关的所有参数。 *k]S{]Y  
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分析 $AhX@|?z  
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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。 3[i!2iL.  
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脚本代码 ~dr1Qi#j?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. SFgIY]  
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Dim entity As T_ENTITY U7%pOpO!  
Dim op As T_OPERATION ~teW1lMu(  
Dim mat As T_MODELMATERIAL Vg~ kpgB
 
Dim A As Double (E(:F[.S  
Dim pupilDiam As Double !;!~5"0~"  
Dim eID As Long J9c3d~YW  
Dim parID As Long tskODM0Zf  
Dim count As Integer EAXU{dRV  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double C|@k+^S  
Dim tlens As Double, nlens As Double ftuQ"Ds  
Dim curv As Double, conic As Double +F&]BZ  
Dim ok As Long %FFm[[nxI  
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Sub Main ;C3?Ic  
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    '用户输入对话框 SWd[iD  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^J~4~!  
        TextBox 220,21,40,21,.TextBox1 'default: 0 QLU;.&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 NG!Q< !Y  
        OKButton 40,91,90,21 J15T!_AW<  
        CancelButton 190,91,90,21 6="&K_Q7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
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        TextBox 220,49,40,21,.TextBox2 'default: 4 HMd)64(  
    End Dialog q=i<vcw  
    Dim dlg As UserDialog !TZ/PqcE  
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    ok = Dialog (dlg) oxXW`C<  
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    If ok=0 Then    'cancel button was pressed x i,wL0{  
        Print "Execution cancelled." z9O/MHT[w  
        End A0u:Fm{E  
    End If Z=8CbS).  
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    'Assign accommodation and pupil diameter & use defaults if field left empty :Fp
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    If dlg.TextBox1 = "" Then u3brb'Y+  
        A = 0           'Default accommodation 7]zZha4X  
    Else >F_Ne)}qTQ  
        A = CDbl(dlg.TextBox1) DC7}Xly(  
    End If K -1~K  
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    If dlg.TextBox2 = "" Then &YKzK)@  
        pupilDiam = 4   'Default pupil diameter Q9zpX{JT  
    Else zNJyF;3  
        pupilDiam = CDbl(dlg.TextBox2) vqZM89xY  
    End If tah%jRfT&  
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    Print " " "*\3.`Kd  
    Print "Accommodation = " & A & " Diopters" j&GK
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    Print "Pupil Diameter = " & pupilDiam & " mm" Dy@NgHe  
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    ' Calculate new parameters with accommodation &b
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )pa|uH+N  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens /loNOutw  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Vs"Q-?  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0EU4irMa  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  +@7R,8  
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    tlens = 3.767 + 0.04*A                  'Lens thickness KL~sEli  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s>I}-=.(Q  
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    'Adjust parameters to account for accommodation ?=rh=#  
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    '************************************************************************* L-dKZ8Q  
    'Aqueous thickness (Position of Lens) 2Jv4l$$;*  
    '************************************************************************* S-|$sV^cG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4q8%!\A+  
    GetCustomElement eID, entity
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    parID = FindFullName( "Geometry.Arizona Eye" ) \vQ (  
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    ' Delete any shift(s) in z ')RK(I  
    count = 0 5UyK
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    While GetOperationCount(eID)>count pl&GFf o  
        GetOperation eID, count, op +?
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        If op.Type="ShiftZ" Then gk%ye&:f  
            DeleteOperation eID,count =&GV\ju  
            count=count-1 ABGL9;.8  
        End If O0RQ}~$'m  
        count=count+1 xw Qkk  
    Wend v8N1fuP}  
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    'Set new shift in &LYZQ?|  
    op.Type = "ShiftZ" 8/v_uEG  
    op.val1 = taq PeaD]  
    op.parent = parID tWIhbt  
    AddOperation eID, op kfV}w,  
    Print "Set aqueous humor thickness = " & taq-0.55 t-/^O  
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    '************************************************************************* G>"[nXmcu  
    'Radius and conic constant of anterior lens _`58G#z  
    '************************************************************************* ?'r[P03  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) '/?&Gol-  
    GetConic eID, entity, curv, conic Ycm1
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    SetConic eID, entity, 1/Rant, CCant q~C6+  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant YQJ_t@0C  
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    '************************************************************************* **"sru;@=  
    'Radius and conic constant of posterior lens uIBV1Qz  
    '************************************************************************* &bb*
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V qf}(3K0  
    GetConic eID, entity, curv, conic r@aFB@  
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    SetConic eID, entity, 1/Rpost, CCpost O^GTPYW  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost x($1pAE   
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    '************************************************************************* +dRTHz  
    'Lens thickness (Position of posterior lens surface) fpUX @b  
    '************************************************************************* ~mU#u\r(*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) APya&TG  
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    ' Delete any z-shift(s) 6|9fcIh]B  
    count = 0 ;|c,  
    While GetOperationCount(eID)>count nr}H;wB  
        GetOperation eID, count, op $!t!=  
        If op.Type="ShiftZ" Then LT!4pD:a  
            DeleteOperation eID,count 4Q.70  
            count=count-1 3D3K:K!FK  
        End If y g7z?AZ  
        count=count+1 v,s]:9f`\>  
    Wend %pdfGM9g  
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    'Set new z-shift
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    op.Type = "ShiftZ" . 2WZb_B  
    op.val1 = tlens mGX;JOjZ  
    op.parent = parID : f
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    AddOperation eID, op ) Ez=#dIq  
    Print "Set lens thickness = " & tlens ~lMsD~$sO  
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    '************************************************************************* N4r`czoj  
    'Lens index of refraction v^pE=f*/  
    '************************************************************************* na~ r}77o  
    eID = FindMaterial( "Lens" ) `8Gwf;P1  
    GetModelMaterial eID, mat _-^@Jx[
 
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    mat.Nd = nlens '#XP:nqFkK  
    SetModelMaterial eID, mat 7dLPy[8";t  
    Print "Set lens index of refraction = " & nlens FD8aO?wvg  
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    '************************************************************************* I".r`$XZ  
    'Pupil diameter tG6 o^  
    '************************************************************************* VFyt9:
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) h0!j;fn  
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    'Adjust pupil diameter (trimming volume inner hole) tNtP+v-{  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" s%Z3Zj(,8(  
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    ' Adjust pupil location to just in front of the lens TJCoID7a8  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3Z`oI#-x  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4aGHks8Z,\  
    count = 0 ~-,<`VY  
    While GetOperationCount(eID)>count 1iz\8R:0  
        GetOperation eID, count, op  oo2VT  
        If op.Type="ShiftZ" Then \KG{ 11  
            DeleteOperation eID,count :R_(+EK1  
            count=count-1 R+5x:mpHy  
        End If X(/W|RY{@  
        count=count+1 \jC}>9  
    Wend E*[X\70  
    op.Type = "ShiftZ" W}KtB1J  
    op.val1 = taq-0.01 =oSv=xY  
    op.parent = parID RS$e^_W  
    AddOperation eID, op @]~\H-8  
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    Print "Set pupil diameter = " & pupilDiam f9!wO';P6  
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    'Update AZ Eye subassembly Description Iu%S><'+  
    eID = FindFullName( "Geometry.Arizona Eye" ) m'Wz0b^BO  
    GetEntity eID, entity nF05p2Mh  
    entity.Description = "Accommodation = " & A & "D" b"p,~{  
    SetEntity eID, entity ?QZ\KY  
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    Update m(?M]CH(A  
    Print "DONE!" 5pz%DhjLo  
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End Sub v50=D/&w  
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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： ppS,9e-  
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Accommodation = 4 Diopters "GgK,d}%  
Pupil Diameter = 4 mm }9jy)gF*e  
Set aqueous humor thickness = 2.81 Ig]Gg/1G  
Set anterior lens radius = 10.4 and conic constant = -2.375869 nx=Zl:Q}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 w$pBACX  
Set lens thickness = 3.927 5PG%)xff*  
Set lens index of refraction = 1.42672 T0
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Set pupil diameter = 4 JhIgqW2  
DONE! oC"c%e8  
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