[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 X|-v0 f  
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。 fz<|+(_>J  
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模型 fw:7Q7 qo  
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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。 lnS\5J  
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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. PEX26==  
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光源 Yn I
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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。 .*RB~c 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。 DU/9/ I?~  
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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。 c ,h.`~{  
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视网膜的散射 dl*_ m3T  
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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。 aJK-O"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。 Z #.GI  
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脚本 T!m42EvIvE  
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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： ^#a#<8Jz  
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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。 #W>x\  
余下的脚本计算与屈光度有关的所有参数。 &_Cxv8  
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分析 vbr~<JT=  
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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。 bh=
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脚本代码 ]}nu9z<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. RtW4n:c  
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Dim entity As T_ENTITY Nbgp_:{  
Dim op As T_OPERATION H"Q(2I  
Dim mat As T_MODELMATERIAL 06PhrPVa!\  
Dim A As Double C$KaT3I  
Dim pupilDiam As Double qJ\X~5{  
Dim eID As Long iP~sft6  
Dim parID As Long I?f"<5[0  
Dim count As Integer !&@2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double CMC?R,d  
Dim tlens As Double, nlens As Double D"`%|`O  
Dim curv As Double, conic As Double -(6eVI  
Dim ok As Long >=4sPF)  
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Sub Main b0r,h)R  
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    '用户输入对话框 <$"7~i/X  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b2a'KczV  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }=Hf?';m  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Sv.KI{;v$  
        OKButton 40,91,90,21 r`?&m3IOP
 
        CancelButton 190,91,90,21 E2>im>
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 vad|Rpl  
        TextBox 220,49,40,21,.TextBox2 'default: 4 %0NLRfp  
    End Dialog F?!FD>L{`  
    Dim dlg As UserDialog 8r2XGR  
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    ok = Dialog (dlg) !?yxh/>lM  
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    If ok=0 Then    'cancel button was pressed 4#TnXxL  
        Print "Execution cancelled." eT;AAGql  
        End ;_x2Ymw  
    End If t$aVe"uM  
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    'Assign accommodation and pupil diameter & use defaults if field left empty G?>qd}]y0L  
    If dlg.TextBox1 = "" Then |d5ggf.w  
        A = 0           'Default accommodation CP}0Ri)  
    Else Q?Wr7  
        A = CDbl(dlg.TextBox1) P~&O4['<  
    End If Gj6<s./  
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    If dlg.TextBox2 = "" Then x]H3Y3  
        pupilDiam = 4   'Default pupil diameter yxqTm%?y  
    Else QT_Srw@  
        pupilDiam = CDbl(dlg.TextBox2) Xe)Pg)J1  
    End If bC6X?m=  

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    Print " " VIetcs  
    Print "Accommodation = " & A & " Diopters" y*_K=}pk  
    Print "Pupil Diameter = " & pupilDiam & " mm" '=$TyiU  
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    ' Calculate new parameters with accommodation x 96}#0'  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xOhRTxic  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ;.\g-`jb  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ACgt" M.3F  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (WJV.GcP1  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens X!o@f$  
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    tlens = 3.767 + 0.04*A                  'Lens thickness eVTO#R*'|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction cY{I:MA+h@  
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    'Adjust parameters to account for accommodation <8$Md4r  
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    '************************************************************************* P>|Ef~j  
    'Aqueous thickness (Position of Lens) >;m{{nj  
    '************************************************************************* ^[0"vtb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Vw7WK  
    GetCustomElement eID, entity iW'_R{)T  
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    parID = FindFullName( "Geometry.Arizona Eye" ) QJQJR/g  
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    ' Delete any shift(s) in z _n7%df  
    count = 0 rj}(muM,R  
    While GetOperationCount(eID)>count FbmsN)mv!%  
        GetOperation eID, count, op m!;G/s*  
        If op.Type="ShiftZ" Then _$!`VA%  
            DeleteOperation eID,count *aI~W^N3  
            count=count-1 J, r Xx:  
        End If ]/a g*F  
        count=count+1 }H5/3be  
    Wend _;#9!"&  
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    'Set new shift in {b[
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    op.Type = "ShiftZ" <vL}l:r  
    op.val1 = taq ghX:"vV{n  
    op.parent = parID .3(;9};  
    AddOperation eID, op l`*( f9Q  
    Print "Set aqueous humor thickness = " & taq-0.55 Xh`"  
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    '************************************************************************* pG~'shD~Dn  
    'Radius and conic constant of anterior lens 4AuH1m)<  
    '************************************************************************* w?*jdwh,'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) db'K!M)  
    GetConic eID, entity, curv, conic eJW[ ]!  
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    SetConic eID, entity, 1/Rant, CCant Fk aXA.JE  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant UP?D@
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    '************************************************************************* 6A.P6DW  
    'Radius and conic constant of posterior lens >r=6A   
    '*************************************************************************  J+lGh9G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) z$66\/V']  
    GetConic eID, entity, curv, conic T30Zk*V  
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    SetConic eID, entity, 1/Rpost, CCpost svqvG7  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Nkx0CG*  
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    '************************************************************************* s+'XQs^{aj  
    'Lens thickness (Position of posterior lens surface) ,&[7u9@  
    '************************************************************************* i_NJ -K  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]H>+m 9  
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    ' Delete any z-shift(s) z|Ap\[GS  
    count = 0 R2CQXhiJ  
    While GetOperationCount(eID)>count ?d~]Wd!z  
        GetOperation eID, count, op z(rK^RT  
        If op.Type="ShiftZ" Then >IBTBh_ka  
            DeleteOperation eID,count F(;jM(  
            count=count-1 l1|~
 
        End If #cO+<1  
        count=count+1 /z
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    Wend ld95[cTP  
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    'Set new z-shift TOrMXcn!/  
    op.Type = "ShiftZ" _F^$aZt?e  
    op.val1 = tlens McP~}"!^  
    op.parent = parID Li]k7w?H  
    AddOperation eID, op 6< >SHw  
    Print "Set lens thickness = " & tlens Co[n--@C  
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    '************************************************************************* DRp&IP<  
    'Lens index of refraction ZL=N[XW4'  
    '************************************************************************* +YuzpuxjJ  
    eID = FindMaterial( "Lens" ) M!#AfIyB  
    GetModelMaterial eID, mat wA631kr  
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    mat.Nd = nlens @C=M UT-!  
    SetModelMaterial eID, mat XGhw
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    Print "Set lens index of refraction = " & nlens 
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    '************************************************************************* QLn+R(r  
    'Pupil diameter Je@kiE  
    '************************************************************************* L1{T ?aII  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) rnH}#u+  
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    'Adjust pupil diameter (trimming volume inner hole) r6MB"4xd  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 9x[ U$B  
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    ' Adjust pupil location to just in front of the lens 1}nm2h1 I  
    parID = FindFullName( "Geometry.Arizona Eye" ) B4^`Sw  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 79wLT\&  
    count = 0 U!0E_J  
    While GetOperationCount(eID)>count hiN/S|JN8y  
        GetOperation eID, count, op BGzO!s*@j  
        If op.Type="ShiftZ" Then ?@DNsVwb  
            DeleteOperation eID,count [
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            count=count-1 Cg
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        End If qv uxhzF  
        count=count+1 `m, Ki69.  
    Wend q]XHa,"  
    op.Type = "ShiftZ" A9;0y jae  
    op.val1 = taq-0.01 ;cLUnsB\  
    op.parent = parID K$ AB} Fvc  
    AddOperation eID, op iadkH]w  
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    Print "Set pupil diameter = " & pupilDiam ]u0Jd#@  
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    'Update AZ Eye subassembly Description i-.c=M  
    eID = FindFullName( "Geometry.Arizona Eye" ) c3#q0Ma  
    GetEntity eID, entity e9:P9Di(b  
    entity.Description = "Accommodation = " & A & "D" ]"h=Qc  
    SetEntity eID, entity (bvoF5%  
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    Update AerFgQi
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    Print "DONE!"
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End Sub %t[K36,p  
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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： vYdlSe=6G  
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Accommodation = 4 Diopters :1MMa6  
Pupil Diameter = 4 mm c3W BALdh  
Set aqueous humor thickness = 2.81 kcY,vl  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]7vf#1i<  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 $:;%bjSI  
Set lens thickness = 3.927 Bm}iU~(Z`  
Set lens index of refraction = 1.42672 `< Yf{'*  
Set pupil diameter = 4 mgcN(n1  
DONE! q% EC  
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