[技术]Arizona眼睛模型 [复制链接]

简介 .K;*uq:0  
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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。 jHTaG%oh  
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模型 D("['`{  
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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。 a{el1_DIGK  
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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. q$~S?X5\  
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光源 "EQ}xj  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 |4x&f!%m  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ?^5W.`Y2i  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 hFs0qPVY  
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视网膜的散射 Et# }XVCJ  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 C7eaioW$  
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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。 MoO jM&9  
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脚本 ]'DtuT?Z  
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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： I^0bEwqZ~  
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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。 @fPiGu`L  
余下的脚本计算与屈光度有关的所有参数。 I`p44}D3  
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分析 V?0|#=_mE  
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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。 e8--qV#<  
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脚本代码 }eULcgRG  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. qf(!3  
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Dim entity As T_ENTITY gj$gqO`B  
Dim op As T_OPERATION H:a
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Dim mat As T_MODELMATERIAL P;mmK&&  
Dim A As Double p+#uPY1#  
Dim pupilDiam As Double #eR*|W7o  
Dim eID As Long yngSD`b_P  
Dim parID As Long J:M^oA'N:>  
Dim count As Integer kplyZ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double fW <qp  
Dim tlens As Double, nlens As Double &HT PeB  
Dim curv As Double, conic As Double 11%^K=dq  
Dim ok As Long i*nNu-g  
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Sub Main V:2|l!l*  
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    '用户输入对话框 y~]>J^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 pc:~_6S  
        TextBox 220,21,40,21,.TextBox1 'default: 0 C(xdiQJh  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^Me__Y  
        OKButton 40,91,90,21 $*`fn{2  
        CancelButton 190,91,90,21 \;$j "i&  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 CP["N(fF  
        TextBox 220,49,40,21,.TextBox2 'default: 4 coyy T  
    End Dialog ^W3xw[{  
    Dim dlg As UserDialog eiJ $}\qJL  
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    ok = Dialog (dlg) L&.9.Ll  
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    If ok=0 Then    'cancel button was pressed 87r#;ND  
        Print "Execution cancelled." `:R8~>p  
        End $
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    End If v>;6pcp[F  
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    'Assign accommodation and pupil diameter & use defaults if field left empty FJ}/g ?  
    If dlg.TextBox1 = "" Then z;2kKQZm  
        A = 0           'Default accommodation BQ2DQ7
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    Else q: ?6  
        A = CDbl(dlg.TextBox1) nH/V2>Lm  
    End If zxT&K|  
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    If dlg.TextBox2 = "" Then Xj.6A,}^  
        pupilDiam = 4   'Default pupil diameter " q0lh  
    Else :>\i  
        pupilDiam = CDbl(dlg.TextBox2) mj{TqF  
    End If kOs_]  
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    Print " " v0apEjT  
    Print "Accommodation = " & A & " Diopters" o/)]z
 
    Print "Pupil Diameter = " & pupilDiam & " mm" z|<6y~5,  
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    ' Calculate new parameters with accommodation j_j~BXhIS  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (w6024~  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [yW0U:m  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens OLXG0@  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ovvR{MTc  
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    tlens = 3.767 + 0.04*A                  'Lens thickness R]/3`X9!d>  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction -V%"i,t  
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    'Adjust parameters to account for accommodation 5.q2<a :  
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    '************************************************************************* ;1'X_tp  
    'Aqueous thickness (Position of Lens) +ZQ
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    '************************************************************************* }N&}6U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) si.ZTG9m  
    GetCustomElement eID, entity 4%Z!*W*  
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    parID = FindFullName( "Geometry.Arizona Eye" ) %-/[.DYt  
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    ' Delete any shift(s) in z 0r*E$|
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    count = 0 Fw)#[  
    While GetOperationCount(eID)>count _)"-zbh}{  
        GetOperation eID, count, op bqWo*>l  
        If op.Type="ShiftZ" Then !D!~4h)  
            DeleteOperation eID,count ;}@.E@s%'  
            count=count-1 F>dB@V-  
        End If c>6dlWTqX  
        count=count+1 MX2]Q  
    Wend #^|y0:  
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    'Set new shift in ]bLI!2Kr  
    op.Type = "ShiftZ" 3CL/9C>  
    op.val1 = taq 4>-'wMW")  
    op.parent = parID :PE{2*  
    AddOperation eID, op 'y[74?1  
    Print "Set aqueous humor thickness = " & taq-0.55 #>iBu:\J  
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    '************************************************************************* _kg<KD=P  
    'Radius and conic constant of anterior lens Q,9"/@:c,  
    '************************************************************************* -d1 YG[1|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) kVz9}Xp"  
    GetConic eID, entity, curv, conic *:gx1wd  
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    SetConic eID, entity, 1/Rant, CCant n=J~Rssp  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant VHyH't_&s  
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    '************************************************************************* 8eq*q   
    'Radius and conic constant of posterior lens 1j"G~TM  
    '*************************************************************************  DA]<30w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) uatY:GSR  
    GetConic eID, entity, curv, conic q!iTDg*$  
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    SetConic eID, entity, 1/Rpost, CCpost FjR/_GPo6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @6h,#8#  
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    '************************************************************************* fIe';a  
    'Lens thickness (Position of posterior lens surface) ])OrSsV}  
    '************************************************************************* diHK  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XuS3#L/3p  
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    ' Delete any z-shift(s) qW+'#Jh@TV  
    count = 0 4PK/8^@7)>  
    While GetOperationCount(eID)>count Cm@rXA/  
        GetOperation eID, count, op _|+}4 ap  
        If op.Type="ShiftZ" Then m';j#j)w  
            DeleteOperation eID,count bpP-wA^Hd  
            count=count-1 I
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        End If -&q@|h'  
        count=count+1 ;>hRj!  
    Wend @=_4i&]$  
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    'Set new z-shift 3bYPi^  
    op.Type = "ShiftZ" pPL)!=o!  
    op.val1 = tlens m.F}9HI%hN  
    op.parent = parID 43wm_4C!H  
    AddOperation eID, op >AK9F. _z  
    Print "Set lens thickness = " & tlens {E=BFs  
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    '************************************************************************* o8_))  
    'Lens index of refraction 5PY4PT=G  
    '************************************************************************* /cHUqn30a  
    eID = FindMaterial( "Lens" ) OSoIH`tA  
    GetModelMaterial eID, mat Me 5Xd|  
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    mat.Nd = nlens R7\T.;8+  
    SetModelMaterial eID, mat A1Ru&fd!  
    Print "Set lens index of refraction = " & nlens M$u.lI  
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    '************************************************************************* 5Ve`j,`=<  
    'Pupil diameter K_
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    '************************************************************************* t=nZ1GZyM  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) L|hELWru  
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    'Adjust pupil diameter (trimming volume inner hole) 5ENU}0W  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" niA>afo  
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    ' Adjust pupil location to just in front of the lens ^>wlj  
    parID = FindFullName( "Geometry.Arizona Eye" ) o$QC:%[#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) knn9s0'Q  
    count = 0 *@I/TX'\rY  
    While GetOperationCount(eID)>count ]l7rM"  
        GetOperation eID, count, op E3hXs6P  
        If op.Type="ShiftZ" Then |)VNf.aJZ  
            DeleteOperation eID,count ="p,~ivrz  
            count=count-1 *iX PG9XZ  
        End If {x,d9I  
        count=count+1 n\ 'PNB  
    Wend !C(U9p. 0  
    op.Type = "ShiftZ" mE\)j*Nnv  
    op.val1 = taq-0.01 8]K+,0m6  
    op.parent = parID z0H+Or  
    AddOperation eID, op )O],$\u  
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    Print "Set pupil diameter = " & pupilDiam BT)PD9CN(  
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    'Update AZ Eye subassembly Description s%QCdU ]  
    eID = FindFullName( "Geometry.Arizona Eye" ) |.z4
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    GetEntity eID, entity `pb=y}  
    entity.Description = "Accommodation = " & A & "D" cYgd1  
    SetEntity eID, entity kyi"U A82  
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    Update ."Kp6s`k  
    Print "DONE!" DHg)]FQ/  
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End Sub {SF'YbY  
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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： MQe|\SMd  
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Accommodation = 4 Diopters Nwj M=GG  
Pupil Diameter = 4 mm G#Kw6
 
Set aqueous humor thickness = 2.81 x4i&;SP0  
Set anterior lens radius = 10.4 and conic constant = -2.375869 W|Cs{rBc?  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 uZTbJ3$$  
Set lens thickness = 3.927 XU<XK9EA  
Set lens index of refraction = 1.42672 nx(jYXVT  
Set pupil diameter = 4 bt*  
DONE! rf^u&f