[技术]Arizona眼睛模型 [复制链接]

简介 &DQ4=/Z  
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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。 K[>@'P}y  
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模型 P[GX}~_k  
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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。 %*
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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. Xtu`5p_Qv  
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光源 ~d7Wjn$@  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 'W?v.W &  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 DR yESi  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 O? Gl4_y  
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视网膜的散射 B=gsd0^]  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 gF,[u  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 b%[nB  
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脚本 5@UC c  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ;naq-%'Sg  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Ev+HWx~Y  
余下的脚本计算与屈光度有关的所有参数。 'wz\tT^  
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分析 +dCDM1{_a  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 &SjHrOG?  
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脚本代码 so!w!O@@  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. {K45~ha9!m  
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Dim entity As T_ENTITY ?E+:]j_  
Dim op As T_OPERATION .# 6n  
Dim mat As T_MODELMATERIAL MegE--h  
Dim A As Double 3!.H^v?  
Dim pupilDiam As Double fO^e+Mz  
Dim eID As Long '?"t<$b
 
Dim parID As Long j\`EUC  
Dim count As Integer 1p7cv~#95  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double =My}{n[  
Dim tlens As Double, nlens As Double :DdBn.  
Dim curv As Double, conic As Double AV:Xg4UJv  
Dim ok As Long n#+%!HTh  
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Sub Main .3lGX`d{  
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    '用户输入对话框 bBUbw*DF)  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 AT B\^;n.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Q_&}^  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 bQ-Gp;]  
        OKButton 40,91,90,21 CM%|pB/z  
        CancelButton 190,91,90,21 jWH{;V&ZV  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A1T<  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Sl3KpZ  
    End Dialog =\
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    Dim dlg As UserDialog P%zH>K  
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    ok = Dialog (dlg) de> ?*%<  
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    If ok=0 Then    'cancel button was pressed =?/N5O(  
        Print "Execution cancelled." -VS9`7k  
        End j5L)N  
    End If N\9}\Rk@  
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    'Assign accommodation and pupil diameter & use defaults if field left empty <eB<^ &nd  
    If dlg.TextBox1 = "" Then 3@^MvoC  
        A = 0           'Default accommodation slU  
    Else qqncl
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        A = CDbl(dlg.TextBox1) eeuZUf+~]  
    End If bTZ>@~$
 
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    If dlg.TextBox2 = "" Then )^4ko  
        pupilDiam = 4   'Default pupil diameter J+Q+&-a  
    Else M]}l^m>L  
        pupilDiam = CDbl(dlg.TextBox2) 6!P`XTTE  
    End If H@V 7!d  
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    Print " " (+|X<Bl:`  
    Print "Accommodation = " & A & " Diopters" nD7|8,
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    Print "Pupil Diameter = " & pupilDiam & " mm" v`y6y8:>  
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    ' Calculate new parameters with accommodation &!ED# gs  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness HbcOTd)=5  

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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens o4$Ott%Wm  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \[:PykS  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens w{pUUo:<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens XC=%H'p  
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    tlens = 3.767 + 0.04*A                  'Lens thickness >DHp*$y  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction K*
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    'Adjust parameters to account for accommodation [`d$X^<y;  
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    '*************************************************************************
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    'Aqueous thickness (Position of Lens) nSS>\$  
    '************************************************************************* WvujcmOf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }^9]jSq5  
    GetCustomElement eID, entity #?dUv#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !=3Rg-'d1  
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    ' Delete any shift(s) in z 7|YN:7iA  
    count = 0 oK2pM18  
    While GetOperationCount(eID)>count -T7%dLHY  
        GetOperation eID, count, op ;6ky5}z  
        If op.Type="ShiftZ" Then J{`eLmTu  
            DeleteOperation eID,count 98fu>>*G{  
            count=count-1 ` @8`qXg  
        End If 'n0 .#E_  
        count=count+1 1"}cdq.  
    Wend 'B_\TU0 O  
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    'Set new shift in  B$^7h!  
    op.Type = "ShiftZ" 6k"P&AD  
    op.val1 = taq '_dzcN,z  
    op.parent = parID w1r$='*I  
    AddOperation eID, op Rs*vm  
    Print "Set aqueous humor thickness = " & taq-0.55 Po
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    '*************************************************************************
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    'Radius and conic constant of anterior lens z%1{  
    '************************************************************************* +
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C)Jn[/BD  
    GetConic eID, entity, curv, conic +R6a}d/K  
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    SetConic eID, entity, 1/Rant, CCant ,LZX@'5  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F[saP0 *  
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    '************************************************************************* HSN8O@dy  
    'Radius and conic constant of posterior lens
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    '************************************************************************* y,=du  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >xu[q\:"  
    GetConic eID, entity, curv, conic k6"KB  
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    SetConic eID, entity, 1/Rpost, CCpost #eK=  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [mUBHYD7OI  
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    '************************************************************************* FB:<zmwR  
    'Lens thickness (Position of posterior lens surface) aRJcSV  
    '************************************************************************* LZ U$  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) YE}s  
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    ' Delete any z-shift(s) PXz
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    count = 0 T[?6[,.  
    While GetOperationCount(eID)>count _q?<at}y  
        GetOperation eID, count, op 0)!Ll*L!p  
        If op.Type="ShiftZ" Then 1mH%H*#  
            DeleteOperation eID,count tNIlzR-  
            count=count-1 i)ASsYG!  
        End If [zkikZy  
        count=count+1 ~D[?$`x:  
    Wend ]3Dl)[R   
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    'Set new z-shift
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    op.Type = "ShiftZ" 28andfl  
    op.val1 = tlens *[+)7  
    op.parent = parID QHt4",Ij  
    AddOperation eID, op O 5Nb  
    Print "Set lens thickness = " & tlens ?BA^YF  
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    '************************************************************************* 2F`cv1M  
    'Lens index of refraction m~#%Q?_ %  
    '************************************************************************* C\ZkGX  
    eID = FindMaterial( "Lens" ) w}R~C  
    GetModelMaterial eID, mat 5 BtX63  
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    mat.Nd = nlens xI*#(!x"G  
    SetModelMaterial eID, mat wJ<Oo@snm  
    Print "Set lens index of refraction = " & nlens vhu
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    '************************************************************************* ,Gk}"w  
    'Pupil diameter U`|0 jJ  
    '************************************************************************* cbYLU
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &w8)* T  
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    'Adjust pupil diameter (trimming volume inner hole) A'&n5)tb  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" m
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    ' Adjust pupil location to just in front of the lens +>~?m*$  
    parID = FindFullName( "Geometry.Arizona Eye" ) JwnQ0 e  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )
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    count = 0 CSPKP#,B0[  
    While GetOperationCount(eID)>count 6 15s5ZA  
        GetOperation eID, count, op G rmzkNlN  
        If op.Type="ShiftZ" Then xVL5'y1g B  
            DeleteOperation eID,count '})0!g<Y  
            count=count-1 NcPgq?3p  
        End If [+m?G4[  
        count=count+1 G`fC/Le  
    Wend l1U=f]  
    op.Type = "ShiftZ" 5}$b0<em~  
    op.val1 = taq-0.01 u]+~VT1C,3  
    op.parent = parID ml|W~-6l  
    AddOperation eID, op [Y
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    Print "Set pupil diameter = " & pupilDiam ps .]N   
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    'Update AZ Eye subassembly Description &!aAO(g  
    eID = FindFullName( "Geometry.Arizona Eye" ) [[d(jV=*  
    GetEntity eID, entity l!}:|N Yh!  
    entity.Description = "Accommodation = " & A & "D" p Dx-2:}  
    SetEntity eID, entity 1i:|3PA~  
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    Update ae"]\a\&1o  
    Print "DONE!" hQ6a~?f  
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End Sub 0;4t&v7  
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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： r:&`$8$  
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Accommodation = 4 Diopters b^D$jY  
Pupil Diameter = 4 mm -[U1]R  
Set aqueous humor thickness = 2.81 kr$b^"Ku  
Set anterior lens radius = 10.4 and conic constant = -2.375869 /!^&;$A'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 o9xlu.QL{c  
Set lens thickness = 3.927 #ET/=  
Set lens index of refraction = 1.42672 )ZrS{vY  
Set pupil diameter = 4 O=SkAsim  
DONE! &B! o,qp