[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 3F$N@K~s  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 9?uU%9r5P  
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模型 _QneaPm%  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 l6N"{iXU  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. PnH5[4&k  
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光源 juQ?k xOB  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 w3M F62:  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 bUe6f,8,  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 {[bB$~7Eu  
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视网膜的散射 \)cbg#v  
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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。 {d%hkbN+{  
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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。 w$aejz`[  
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脚本 Y]Zp[!  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： tcD5"ALJ  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 cRSgP{hy  
余下的脚本计算与屈光度有关的所有参数。 ~n%]u! 6  
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分析 SKo*8r   
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 TlC?
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脚本代码 `~1#X   
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. EV_u8?va  
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Dim entity As T_ENTITY :JK+V2B$H  
Dim op As T_OPERATION  >1q:-^  
Dim mat As T_MODELMATERIAL X3l6b+p  
Dim A As Double ,<;.'r  
Dim pupilDiam As Double \cQ+9e)  
Dim eID As Long `m\ ?gsw7  
Dim parID As Long dZAb':  
Dim count As Integer RggO|s+0;  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Zig3WiD&  
Dim tlens As Double, nlens As Double /KhY,G'Z  
Dim curv As Double, conic As Double v>5TTL~
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Dim ok As Long [pz1f!Wn  
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Sub Main 
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    '用户输入对话框 Hqb-)8 ~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W\O.[7JP  
        TextBox 220,21,40,21,.TextBox1 'default: 0 &7KX`%K"D  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 uC?/p1  
        OKButton 40,91,90,21 $Q`\-  
        CancelButton 190,91,90,21 G4"n`89LK  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 SA~oGgk=P  
        TextBox 220,49,40,21,.TextBox2 'default: 4 &_3o1<  
    End Dialog c  
    Dim dlg As UserDialog 7 ;x to =  
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    ok = Dialog (dlg) 2'8I/>-  
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    If ok=0 Then    'cancel button was pressed C`\yc_b9Pf  
        Print "Execution cancelled." 2Iq*7n:v0  
        End [L?WM>]%  
    End If }LX.gm  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .FvIT]k-  
    If dlg.TextBox1 = "" Then fKa]
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        A = 0           'Default accommodation 8zpTCae^=7  
    Else Yz>8 Nn'_  
        A = CDbl(dlg.TextBox1) $~/x
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    End If Y~UWUF%aK  
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    If dlg.TextBox2 = "" Then kj`h{
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        pupilDiam = 4   'Default pupil diameter wfM|3GS+.  
    Else .WlZT-
  
        pupilDiam = CDbl(dlg.TextBox2) {QIdeB[  
    End If LP}j0)n  
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    Print " " _j]vR  
    Print "Accommodation = " & A & " Diopters" =@.5J'!  
    Print "Pupil Diameter = " & pupilDiam & " mm" "=UhTE  
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    ' Calculate new parameters with accommodation 2XV3f$,H  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness KvlLcE~
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens jk5C2dy  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens qhNYQ/uS  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens - S%8  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens uD4$<rSHb  
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    tlens = 3.767 + 0.04*A                  'Lens thickness f:h<tlob  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction G V%@A  
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    'Adjust parameters to account for accommodation 8o,"G}Hjk  
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    '************************************************************************* 7@ mP;K0  
    'Aqueous thickness (Position of Lens) OyyE0  
    '************************************************************************* S[RVk=A1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 86~q pN  
    GetCustomElement eID, entity 't3nh  
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    parID = FindFullName( "Geometry.Arizona Eye" ) k;vhQ=  
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    ' Delete any shift(s) in z g;!,2,De}  
    count = 0 M;E$ ]Z9  
    While GetOperationCount(eID)>count =T|m#*{.L  
        GetOperation eID, count, op 0zXF{5Up  
        If op.Type="ShiftZ" Then Z|zT%8.8N  
            DeleteOperation eID,count 0[fqF^HEN  
            count=count-1 u]Dds;~"b  
        End If VRz9;=m  
        count=count+1 4"Pf0PD:  
    Wend 2$?j'i!  
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    'Set new shift in `MXGEJF  
    op.Type = "ShiftZ" P>ZIP* Gr  
    op.val1 = taq H)i%\7F5  
    op.parent = parID CI@qT}Y_  
    AddOperation eID, op GD }i=TK  
    Print "Set aqueous humor thickness = " & taq-0.55 )5ISkbsxD  
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    '************************************************************************* 1)ZdkTF@H  
    'Radius and conic constant of anterior lens Eo_;Nc  
    '************************************************************************* mjbV^^>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _~uYNvmg  
    GetConic eID, entity, curv, conic &(rR
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    SetConic eID, entity, 1/Rant, CCant }G1hB#j  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *gN
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    '************************************************************************* };]f 3  
    'Radius and conic constant of posterior lens &BQ%df<y\  
    '************************************************************************* +zSdP2s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @8V~&yqq  
    GetConic eID, entity, curv, conic 3Uni{Z]Q)  
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    SetConic eID, entity, 1/Rpost, CCpost /SQ1i}%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost K"9V8x3Wg  
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    '************************************************************************* o'p[G]NQ1o  
    'Lens thickness (Position of posterior lens surface) RTvzS]  
    '************************************************************************* y7Y g$)sL  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) !gFUC<4bu  
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    ' Delete any z-shift(s) 73kL>u  
    count = 0 ]LZ,>v  
    While GetOperationCount(eID)>count XLsOn(U\&  
        GetOperation eID, count, op o|7 h  
        If op.Type="ShiftZ" Then ob"yz}  
            DeleteOperation eID,count %R LGO&  
            count=count-1 nN!R!tJPa  
        End If j-wz7B  
        count=count+1 Af7&;8pM  
    Wend '.d]n(/lZd  
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    'Set new z-shift ^Ts8nOGMh  
    op.Type = "ShiftZ" 8S7 YVsDz"  
    op.val1 = tlens .?p\=C@C+  
    op.parent = parID ELQc: t -2  
    AddOperation eID, op vP{;'R  
    Print "Set lens thickness = " & tlens \t@4)+s/)  
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    '************************************************************************* lF
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    'Lens index of refraction :_"%o=  
    '************************************************************************* 'K|tgsvgme  
    eID = FindMaterial( "Lens" ) Hnc<)_DF  
    GetModelMaterial eID, mat r&c31k]E  
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    mat.Nd = nlens Y'v;!11#  
    SetModelMaterial eID, mat L
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    Print "Set lens index of refraction = " & nlens D!CuE7}  
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    '************************************************************************* m kHcGB!~  
    'Pupil diameter o!ycVY$yW  
    '************************************************************************* Z@bGLS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &[|P/gj#>  
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    'Adjust pupil diameter (trimming volume inner hole) `<^1Ik[g  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3&z.m/  
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    ' Adjust pupil location to just in front of the lens rYw
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    parID = FindFullName( "Geometry.Arizona Eye" ) 5D%gD
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) UAq%Y8KA  
    count = 0 Y;6%pm$  
    While GetOperationCount(eID)>count #Bgq]6G2  
        GetOperation eID, count, op hpOUz%  
        If op.Type="ShiftZ" Then hCKx%&[^7  
            DeleteOperation eID,count 1xE*quhrh  
            count=count-1 A/#Xr  
        End If #8[iqvE  
        count=count+1 S|?Ht61k  
    Wend mtn+bV R%  
    op.Type = "ShiftZ" gaXKP1m^  
    op.val1 = taq-0.01 JDy;Jb  
    op.parent = parID &33.m
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    AddOperation eID, op {-?8r>  
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    Print "Set pupil diameter = " & pupilDiam ~M4@hG!  
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    'Update AZ Eye subassembly Description ,t=12R]>  
    eID = FindFullName( "Geometry.Arizona Eye" ) pRLs*/Bw  
    GetEntity eID, entity n%YG)5;  
    entity.Description = "Accommodation = " & A & "D" --9Z  
    SetEntity eID, entity wu2C!gyBo  
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    Update Hz6yy*  
    Print "DONE!" ~8 w(M  
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End Sub 3!V$fl0  
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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： OnKPD=<
 
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Accommodation = 4 Diopters ']]&<B}mz  
Pupil Diameter = 4 mm &G"r>,H
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Set aqueous humor thickness = 2.81 [Ifhh2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 4/Bn9F  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 {UR&Y  
Set lens thickness = 3.927 -=A W. Zo  
Set lens index of refraction = 1.42672 ttK`*Ng  
Set pupil diameter = 4 66+y@l1  
DONE! >`@yh-'r  
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