[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 <C\snB  
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。 XW6>;:4k  
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模型 `gq@LP"o  
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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。 9)p VDS  
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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. =iy%;>I`  
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光源 =
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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。 oB8u[!  
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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。 E1:{5F5/  
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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。 ;5 cg<~t  
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视网膜的散射 ,qJ/Jt$A  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 A P><l@  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 g$eb@0$  
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脚本 TFWV(<  
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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： TI:-Y@8  
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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。 x
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余下的脚本计算与屈光度有关的所有参数。 a6"Pe07t  
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分析 hZ-No  
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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。 : 'M$:ZJ  
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脚本代码 ,tv P"@d  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. s2)a8<  
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Dim entity As T_ENTITY `s(T(l  
Dim op As T_OPERATION P31}O2 Nh  
Dim mat As T_MODELMATERIAL DSad[>Uj],  
Dim A As Double ^il'
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Dim pupilDiam As Double x|n2,3%  
Dim eID As Long mR:G,XytxM  
Dim parID As Long ,TaaXI  
Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  UN[rW0*  
Dim tlens As Double, nlens As Double SU9qF73Y  
Dim curv As Double, conic As Double o:jLM7$=  
Dim ok As Long B ?96d'A  
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Sub Main bIt%KG{PY6  
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    '用户输入对话框 f.cIhZF  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 % \Nfj)9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 E]V:@/(M'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7H~StdL/>  
        OKButton 40,91,90,21 1a4 [w  
        CancelButton 190,91,90,21 j+NOT`&  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 T:IKyb  
        TextBox 220,49,40,21,.TextBox2 'default: 4 IM),cOp=  
    End Dialog B;?)   
    Dim dlg As UserDialog #jn6DL@[{  
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    ok = Dialog (dlg) H5uWI  
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    If ok=0 Then    'cancel button was pressed JPW+(n|g  
        Print "Execution cancelled." Y,z15i3j?  
        End /H&:  
    End If 0@z=0}0Z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty nAv@^G2  
    If dlg.TextBox1 = "" Then *#{[9d  
        A = 0           'Default accommodation .q#2 op  
    Else YFgQ!\&59  
        A = CDbl(dlg.TextBox1) VXlTA>a }  
    End If )]~'zOE_  
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    If dlg.TextBox2 = "" Then z%5i^P  
        pupilDiam = 4   'Default pupil diameter [4B.;MS(  
    Else Wo&10S w  
        pupilDiam = CDbl(dlg.TextBox2) N
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    End If } <; y,4f  
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    Print " " +ou5cQ^  
    Print "Accommodation = " & A & " Diopters" MFO}E!9`q  
    Print "Pupil Diameter = " & pupilDiam & " mm" a.QF`J4"'  
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    ' Calculate new parameters with accommodation }3 NGMGu$  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness l&cYN2T b  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens uSp=,2)  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens %cJ]Ds%V  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zB`)\
 
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens zS*GYE(l^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness rSDS9Vf(  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction KY$
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    'Adjust parameters to account for accommodation +*-u_L\'  
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    '************************************************************************* g(m3 &  
    'Aqueous thickness (Position of Lens) w.exLC  
    '************************************************************************* P<yd  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tAH,3Sz( /  
    GetCustomElement eID, entity |mvy@
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    parID = FindFullName( "Geometry.Arizona Eye" ) 4hwU
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    ' Delete any shift(s) in z ?h4-D:!$L  
    count = 0 Rg~ ~[6G>  
    While GetOperationCount(eID)>count VKRj 1LXz  
        GetOperation eID, count, op I;kKY  
        If op.Type="ShiftZ" Then k6-.XW  
            DeleteOperation eID,count xgP/BK2"  
            count=count-1 3#vhQ*xU  
        End If RkP g&R;i  
        count=count+1 7KU/ 1l9$9  
    Wend :FOMRrf7.  
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    'Set new shift in .hW_P62\#  
    op.Type = "ShiftZ" gf2<dEff  
    op.val1 = taq DP`$gd  
    op.parent = parID Xao 0cb.R  
    AddOperation eID, op aLapb5VV  
    Print "Set aqueous humor thickness = " & taq-0.55 I8 Ai_^P  
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    '************************************************************************* Z'iXuI49  
    'Radius and conic constant of anterior lens >e
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    '************************************************************************* WMfu5x7e4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;\yY*  
    GetConic eID, entity, curv, conic Wi]Mp7b  
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    SetConic eID, entity, 1/Rant, CCant zTb!$8D"g  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gd3~R+Kd  
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    '************************************************************************* F/;uN5{o  
    'Radius and conic constant of posterior lens {2?o:  
    '************************************************************************* yZFm<_9>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) D hy  
    GetConic eID, entity, curv, conic .zf#S0y%(  
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    SetConic eID, entity, 1/Rpost, CCpost j]i:~9xKW  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }Jkz0JY~  
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    '************************************************************************* o#Q0J17i?  
    'Lens thickness (Position of posterior lens surface) L2:v#c()#)  
    '************************************************************************* 3n-~+2l  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N3 qtq9{  
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    ' Delete any z-shift(s) 2:0'fNX
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    count = 0 ??Zh$^No:  
    While GetOperationCount(eID)>count +$
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        GetOperation eID, count, op 6rlafISvO  
        If op.Type="ShiftZ" Then >g8H  
            DeleteOperation eID,count kd^CZ;O  
            count=count-1 k fS44NV  
        End If ab4(?-'-  
        count=count+1 K~Lh'6  
    Wend lJHV c"*/  
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    'Set new z-shift 5*QNE!  
    op.Type = "ShiftZ" Ul#||B .c{  
    op.val1 = tlens 2u
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    op.parent = parID nRq@hk  
    AddOperation eID, op !#P|2>>u  
    Print "Set lens thickness = " & tlens 1"k"<{%  
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    '************************************************************************* .9X
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    'Lens index of refraction LlAMtw"  
    '************************************************************************* .*+?]  
    eID = FindMaterial( "Lens" ) wWV`k  
    GetModelMaterial eID, mat QRbiO  
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    mat.Nd = nlens *3 .+19Q  
    SetModelMaterial eID, mat =ZdP0l+V=k  
    Print "Set lens index of refraction = " & nlens \ci'Cbn\o  
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    '************************************************************************* D=*3Xd  
    'Pupil diameter rXR=fj= 2  
    '************************************************************************* {=n-S2%  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m]t`;lr<  
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    'Adjust pupil diameter (trimming volume inner hole) &~`Ay4hq  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" y"4Nw]kU  
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    ' Adjust pupil location to just in front of the lens Th&-n%r9K  
    parID = FindFullName( "Geometry.Arizona Eye" ) .{,
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Bn>"lDf,  
    count = 0 L
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    While GetOperationCount(eID)>count Jv*[@ -.k  
        GetOperation eID, count, op Fy(-.S1  
        If op.Type="ShiftZ" Then h>>KH*dQ  
            DeleteOperation eID,count xb`,9.a7  
            count=count-1 |ymw
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        End If 8}9B*m  
        count=count+1 Ww8<f$  
    Wend QkMK\Up  
    op.Type = "ShiftZ" Y`$dtg {  
    op.val1 = taq-0.01 Z)=S. )  
    op.parent = parID JBY`Y]V3  
    AddOperation eID, op 3q +C8_:  
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    Print "Set pupil diameter = " & pupilDiam IK#W80y  
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    'Update AZ Eye subassembly Description 6:Eu[PE~w  
    eID = FindFullName( "Geometry.Arizona Eye" ) p6=L
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    GetEntity eID, entity ""LCyKu   
    entity.Description = "Accommodation = " & A & "D" U;%I" p`Z/  
    SetEntity eID, entity D|zlC,J,  
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    Update 3=r#=u5z  
    Print "DONE!" WO=X*One  
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End Sub
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如果屈光度是4，光瞳直径是4，则会输出如下数据： v]`}T/n  
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Accommodation = 4 Diopters 6]`XW0{C  
Pupil Diameter = 4 mm -Ucj|9+(a  
Set aqueous humor thickness = 2.81 uK_Q l\d  
Set anterior lens radius = 10.4 and conic constant = -2.375869 e+Qq a4  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 vAeh#V~#  
Set lens thickness = 3.927 cT8b$P5w  
Set lens index of refraction = 1.42672 iR k
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Set pupil diameter = 4 w.tQ)x1h  
DONE! 3I|&}+Z6  
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