[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 W=v4dy]B  
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。 V`OeJVe  
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模型 a+$WlG/x  
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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。 HC0q_%j  
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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. #%CbZw@hJ9  
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光源 I^iJ^Z]vx  
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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。 }."3&u't  
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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。 d,}fp)  
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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。 vn"2"hPF|  
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视网膜的散射 +Hz});ix<  
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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。 IYm~pXg^0  

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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。 R<VNbm;  
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脚本 $:M*$r^u  
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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： J+f .r|?  
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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。 -<kl d+  
余下的脚本计算与屈光度有关的所有参数。 'Eds0"3  
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分析 >$,A [|R  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 `YTagUq7  
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脚本代码 pKDP1S#<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. s(56aE  
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Dim entity As T_ENTITY OjxaA[$  
Dim op As T_OPERATION Qs2E>C  
Dim mat As T_MODELMATERIAL s(*LV2fa  
Dim A As Double Rd6? ,  
Dim pupilDiam As Double 1qWIku  
Dim eID As Long &7* |rshZ  
Dim parID As Long USz|Rh  
Dim count As Integer 9"m
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double K#bdb  
Dim tlens As Double, nlens As Double )%rGD =2~  
Dim curv As Double, conic As Double ,at"Q$)T  
Dim ok As Long mdxa^#w  
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Sub Main $qkVu  
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    '用户输入对话框 q{v:T}Q|A  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zbHNj(~  
        TextBox 220,21,40,21,.TextBox1 'default: 0 "Y(stRa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :V1ttRW}52  
        OKButton 40,91,90,21 ^VsX9  
        CancelButton 190,91,90,21 Jy&O4g/'5  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 q$)$?"  
        TextBox 220,49,40,21,.TextBox2 'default: 4 P" +!mSe^~  
    End Dialog D<}z7W-
 
    Dim dlg As UserDialog *0>![v  
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    ok = Dialog (dlg) Ay7I_"%  
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    If ok=0 Then    'cancel button was pressed ,~^0AtLv  
        Print "Execution cancelled." 4W7  
        End H/8H`9S$  
    End If :s8^nEK  
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    'Assign accommodation and pupil diameter & use defaults if field left empty *`~ woF  
    If dlg.TextBox1 = "" Then .!uXhF'  
        A = 0           'Default accommodation eQh@.U*S)  
    Else {)j~5m.,/o  
        A = CDbl(dlg.TextBox1) MD(?Wh  
    End If -#0(Jm'  
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    If dlg.TextBox2 = "" Then P{YUW~  
        pupilDiam = 4   'Default pupil diameter W[trsFP1?  
    Else k I{)"  
        pupilDiam = CDbl(dlg.TextBox2) N$1ZA)M  
    End If V+#Sb  
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    Print " " Dqss/vw
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    Print "Accommodation = " & A & " Diopters" y/}[S@4uB  
    Print "Pupil Diameter = " & pupilDiam & " mm" (Fc\*Vn  
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    ' Calculate new parameters with accommodation Ore>j+  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness B|%(0j8  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &)UZ9r`z  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Dq=&K,5;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V_b"^911r  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a!UQ]prT  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ~s.~X5  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction e/+_tC$@p@  
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    'Adjust parameters to account for accommodation @.IGOh  
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    '************************************************************************* a7?z{ssEi  
    'Aqueous thickness (Position of Lens)
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    '************************************************************************* F@m]Imn5Dx  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :H9\nU1  
    GetCustomElement eID, entity +ucj>g1(#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~Mk{
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    ' Delete any shift(s) in z =;9
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    count = 0 &BF97%E2  
    While GetOperationCount(eID)>count  |tK
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        GetOperation eID, count, op M%(B6};J  
        If op.Type="ShiftZ" Then p~(+4uA  
            DeleteOperation eID,count N.\?"n   
            count=count-1 E}^np[u7  
        End If >"LHr&;m&h  
        count=count+1 *\#/4_yB}  
    Wend TcW-pY<N  
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    'Set new shift in d|I_SI1  
    op.Type = "ShiftZ" YUGE>"{  
    op.val1 = taq P{T\zT  
    op.parent = parID y]3`U UvXD  
    AddOperation eID, op o%EzK;Df  
    Print "Set aqueous humor thickness = " & taq-0.55 &,v-AL$:Q  
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    '************************************************************************* AN193o   
    'Radius and conic constant of anterior lens rcq^mPdQ  
    '************************************************************************* EC9bCd-z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) v,T:V#f^  
    GetConic eID, entity, curv, conic QoLp$1O(y  
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    SetConic eID, entity, 1/Rant, CCant .[8! E_  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant C~e&J&zh  
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    '************************************************************************* H1bHQB  
    'Radius and conic constant of posterior lens ON(OYXj  
    '************************************************************************* t`M4@1S"'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) GGM|B}U p  
    GetConic eID, entity, curv, conic <K g=?wb  
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    SetConic eID, entity, 1/Rpost, CCpost ]|JQH  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;C^!T  
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    '************************************************************************* lF*}l  
    'Lens thickness (Position of posterior lens surface) k kZ2Jxvx  
    '************************************************************************* Sb4^* $uz  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .2Q4
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    ' Delete any z-shift(s) <wH"{G3?  
    count = 0 hQeGr2gMq  
    While GetOperationCount(eID)>count &nV/XLpG  
        GetOperation eID, count, op 1;*4yJ2  
        If op.Type="ShiftZ" Then &6feR#~A  
            DeleteOperation eID,count 3# g"Z7/  
            count=count-1 IZ/PZ"n_(  
        End If `w6*(t:T  
        count=count+1 E
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    Wend >^=;b5I2K  
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    'Set new z-shift bmOK8  
    op.Type = "ShiftZ" zAW+!C.  
    op.val1 = tlens C6?({ QB@  
    op.parent = parID f7lt|.p  
    AddOperation eID, op $+k|\+iJ  
    Print "Set lens thickness = " & tlens QkFB\v  
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    '************************************************************************* ~xa yGk  
    'Lens index of refraction 7z2Q!0Sz  
    '************************************************************************* ;tJ}*!z W  
    eID = FindMaterial( "Lens" ) pqCp>BO?O  
    GetModelMaterial eID, mat sck.2-f"  
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    mat.Nd = nlens :[:*kbWN-  
    SetModelMaterial eID, mat tP:ER  
    Print "Set lens index of refraction = " & nlens rNK<p3=7)  
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    '************************************************************************* ]')  
    'Pupil diameter D03QisH=  
    '************************************************************************* B:>>D/O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) zv-9z  
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    'Adjust pupil diameter (trimming volume inner hole) !
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [t6Y,yo&h4  
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    ' Adjust pupil location to just in front of the lens Ueu~803~  
    parID = FindFullName( "Geometry.Arizona Eye" ) qOTo p-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !gm@QO cF  
    count = 0 #AR$'TE#  
    While GetOperationCount(eID)>count +h)1NX;o1  
        GetOperation eID, count, op Ihd{tmr<  
        If op.Type="ShiftZ" Then Pil_zQ4  
            DeleteOperation eID,count ?$Dc>  
            count=count-1 TFNB%|  
        End If 7Y%Si5  
        count=count+1 z41v5rB4  
    Wend
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    op.Type = "ShiftZ" *=}\cw\A  
    op.val1 = taq-0.01
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    op.parent = parID OJ1MV7&  
    AddOperation eID, op 6zp]SPY  
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    Print "Set pupil diameter = " & pupilDiam :'4",  
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    'Update AZ Eye subassembly Description cX#U_U~d  
    eID = FindFullName( "Geometry.Arizona Eye" ) =3Ohy,5L  
    GetEntity eID, entity o3X0c6u

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    entity.Description = "Accommodation = " & A & "D" hK UK#xx  
    SetEntity eID, entity 1d!TU=*  
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    Update 7lx]`u>  
    Print "DONE!" tH(g;flO)  
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End Sub [7\x(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： d f j;e%H  
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Accommodation = 4 Diopters hs*n?vxp3  
Pupil Diameter = 4 mm ,FwJ0V  
Set aqueous humor thickness = 2.81 L%<DLe^P`l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 \b}%A&Ij  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 A[`2Mnj  
Set lens thickness = 3.927 Ki>XLX,er=  
Set lens index of refraction = 1.42672 (sSGJS'X  
Set pupil diameter = 4 !E6QED"  
DONE! PDS?>Jg(  
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