[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 )$x_!=@1  
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。 ;,OfJ'q^  
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模型 &GWkq>  
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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。 !Ngw\@f  
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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. R UTnc  

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光源 J0220 _  
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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。 l!IKUzt)7  
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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。 7uI#L}y  
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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。 PQj<[rY
 
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视网膜的散射 0-2"FdeQU  
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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。 -)w]a{F  
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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。 ]HvZ$  
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脚本 C}CKnkMMD  
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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： R,Ml&4pZ}  
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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。 )mkS5j`5\  
余下的脚本计算与屈光度有关的所有参数。 7U:=~7GH  
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分析 zLek&s&-  
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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。 8B@JFpg^  
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脚本代码 &=-PRza%j  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. If.n(t[M9  
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Dim entity As T_ENTITY xv0M  
Dim op As T_OPERATION $pFk"]=  
Dim mat As T_MODELMATERIAL 'TX M{RGw  
Dim A As Double YsAF{  
Dim pupilDiam As Double %3,xaVN  
Dim eID As Long K+mU_+KRp  
Dim parID As Long @}eNV~ROu  
Dim count As Integer G?[-cNdk  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]_2yiKv&  
Dim tlens As Double, nlens As Double 2X_>vIlEm  
Dim curv As Double, conic As Double K^ 6+Ily  
Dim ok As Long od,tfLw4  
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Sub Main X')S;KW  
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    '用户输入对话框 2nx9#B*/T  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 46dc.Yi  
        TextBox 220,21,40,21,.TextBox1 'default: 0 l;5`0N?QO  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Mdky^;qq3;  
        OKButton 40,91,90,21 *8206[y  
        CancelButton 190,91,90,21 MF|*AB|E  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 KnFQ)sX^  
        TextBox 220,49,40,21,.TextBox2 'default: 4 A`C-sD>  
    End Dialog X2P``YFV{  
    Dim dlg As UserDialog kJeu40oN  
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    ok = Dialog (dlg) Bbs5f@E  
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    If ok=0 Then    'cancel button was pressed cUC17z2D  
        Print "Execution cancelled." `]hCUaV   
        End X X&K=<,Ja  
    End If acP ;(t  
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    'Assign accommodation and pupil diameter & use defaults if field left empty }s6G!v^2""  
    If dlg.TextBox1 = "" Then u#VweXyU  
        A = 0           'Default accommodation r./z,4A`  
    Else Q;@X2JSp  
        A = CDbl(dlg.TextBox1) ?.j,Bq5At  
    End If lrn+d$!@  
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    If dlg.TextBox2 = "" Then Fd}<Uote3  
        pupilDiam = 4   'Default pupil diameter X?kPi&ru  
    Else :o<N!*pT  
        pupilDiam = CDbl(dlg.TextBox2) 1:YAn  
    End If [>wzl"cHW  
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    Print " " &*ZC0V3  
    Print "Accommodation = " & A & " Diopters" RSFJu\0}N  
    Print "Pupil Diameter = " & pupilDiam & " mm" s79q5  
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    ' Calculate new parameters with accommodation {NY]L==H  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 8k%H[Smn:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Lv^a+'  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9Yd-m  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6_Fpca3L  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +&?'KZ+Z_v  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 5(KG=EHj_  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction SUo^c1)G  
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    'Adjust parameters to account for accommodation y 'mlee  
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    '************************************************************************* yX3PUO9  
    'Aqueous thickness (Position of Lens) 6,a%&1_  
    '************************************************************************* %OuX`w=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) m^5s>hUl  
    GetCustomElement eID, entity _>;&-e  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,v|CombIc.  
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    ' Delete any shift(s) in z Bmmb  
    count = 0  JUmw$u  
    While GetOperationCount(eID)>count xa' nJ"f;  
        GetOperation eID, count, op H'D#s;SlR  
        If op.Type="ShiftZ" Then `~0P[>|+  
            DeleteOperation eID,count pEY>A_F  
            count=count-1 +tPx0>p;  
        End If m\/>C|f\  
        count=count+1 P_v0))n{  
    Wend w<v1N  
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    'Set new shift in qjJ{+Rz2  
    op.Type = "ShiftZ" u0wn=Dg  
    op.val1 = taq B<(Pd  
    op.parent = parID OuMco+C  
    AddOperation eID, op T4Xtu
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    Print "Set aqueous humor thickness = " & taq-0.55 Q%+}  
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    '************************************************************************* U8EJC .e&O  
    'Radius and conic constant of anterior lens -*rHB&e  
    '************************************************************************* lt&$8jh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /A0 [_  
    GetConic eID, entity, curv, conic IkiQOk  

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    SetConic eID, entity, 1/Rant, CCant sg+ZQDF{x  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #,7eQaica  
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    '************************************************************************* qPL^zM+  
    'Radius and conic constant of posterior lens #Tup]czO  
    '************************************************************************* 1 ,#{X3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) E]e,cd  
    GetConic eID, entity, curv, conic GU:r vS!  
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    SetConic eID, entity, 1/Rpost, CCpost @47[vhE  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;r gH}r  
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    '************************************************************************* oNiToFbQu  
    'Lens thickness (Position of posterior lens surface) av'd%LZP  
    '************************************************************************* zJz82jMm  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) pESB Il  
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    ' Delete any z-shift(s) IlcNT_ 5a8  
    count = 0 oq=?i%'>  
    While GetOperationCount(eID)>count P%.`c?olbs  
        GetOperation eID, count, op <QYCo1_  
        If op.Type="ShiftZ" Then omXBnzT  
            DeleteOperation eID,count *p""YEN  
            count=count-1 Y1$#KC  
        End If pe\Txg
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        count=count+1 *i=?0M4S  
    Wend "z^BKb5  
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    'Set new z-shift L4\SBO  
    op.Type = "ShiftZ" B rez&3[  
    op.val1 = tlens l9M#]*{  
    op.parent = parID "[%;B0J  
    AddOperation eID, op
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    Print "Set lens thickness = " & tlens @ChN_gd
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    '************************************************************************* 7xLo4  
    'Lens index of refraction se<i5JsSV  
    '************************************************************************* l-DGy#h+z  
    eID = FindMaterial( "Lens" ) )ZS:gD  
    GetModelMaterial eID, mat gi1}5DR  
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    mat.Nd = nlens ^2&O3s
  
    SetModelMaterial eID, mat &*jxI[  
    Print "Set lens index of refraction = " & nlens 1?/5A|?V4+  
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    '************************************************************************* IeRl6r%:  
    'Pupil diameter S(g<<Te  
    '************************************************************************* hN>('S-cq  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) H B::0l<  
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    'Adjust pupil diameter (trimming volume inner hole) 3Ew"[FUs  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 4f@havFIJ  
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    ' Adjust pupil location to just in front of the lens hW0,5>[7%  
    parID = FindFullName( "Geometry.Arizona Eye" ) ?#VP)A  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]ro1{wm!WU  
    count = 0 1A|x$j6m  
    While GetOperationCount(eID)>count e.3sAUHZ-  
        GetOperation eID, count, op "sX[p  
        If op.Type="ShiftZ" Then G/LXUhuif  
            DeleteOperation eID,count #Qtg\X  
            count=count-1 D{,[
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        End If !7O=<  
        count=count+1 NPB,q& Th  
    Wend 9G`FY:(
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    op.Type = "ShiftZ" OH-~  
    op.val1 = taq-0.01 s8f3i\1  
    op.parent = parID q5?
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    AddOperation eID, op ^'C,WZt  
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    Print "Set pupil diameter = " & pupilDiam \,@Yl.,+  
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    'Update AZ Eye subassembly Description ;y?D1o^r8W  
    eID = FindFullName( "Geometry.Arizona Eye" ) [B2>*UPl  
    GetEntity eID, entity 4y]:Gqz~  
    entity.Description = "Accommodation = " & A & "D" g|GvJ)VX  
    SetEntity eID, entity w]o:c(x@  
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    Update ch)Ps2i  
    Print "DONE!" j(@g  
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End Sub v2Qc}o  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： !SO$k%b}!  
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Accommodation = 4 Diopters RAv RNd  
Pupil Diameter = 4 mm V(''p{  
Set aqueous humor thickness = 2.81 Ads<-.R  
Set anterior lens radius = 10.4 and conic constant = -2.375869 :N+#4rtgUY  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 *Lb(urf  
Set lens thickness = 3.927 |`)V^e_  
Set lens index of refraction = 1.42672 n&3iv^  
Set pupil diameter = 4 'n>3`1E,  
DONE! .qqb>7|q  
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