[技术]Arizona眼睛模型 [复制链接]

简介 1`II%mf[  
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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。 qZQm*q(jM  
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模型 `zs@W  
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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。 5m;pHgkb  
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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. -8:O?]+Q/  
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光源 +=`w  
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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。 F0m[ls$  
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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。 O[ans_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。 T~>&m~} +  
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视网膜的散射 X7aj/:fXe  
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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。 RXPl~]k#i  
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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。 XF4NRs  
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脚本 oRn5blj  
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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： P.|g4EdND  
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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。 Io;26F""  
余下的脚本计算与屈光度有关的所有参数。 Z=?qf$.}  
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分析 g.EKdvY"%H  
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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。 [h :FJ  
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脚本代码 TLzcQ|  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. %hzNkyD)Y  
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Dim entity As T_ENTITY XN'X&J  
Dim op As T_OPERATION |B*`%7{+  
Dim mat As T_MODELMATERIAL =7("xz%  
Dim A As Double I=`efc]T  
Dim pupilDiam As Double \-s'H:
 
Dim eID As Long X"G3lG  
Dim parID As Long LYiz:cQh  
Dim count As Integer (au7wI{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 785Y*.p  
Dim tlens As Double, nlens As Double ?9H.JR2s%  
Dim curv As Double, conic As Double vCNYqa)m:  
Dim ok As Long QO~T
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Sub Main ph1veD<ZZ  
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    '用户输入对话框 ^coJ"[D  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \+w -{"u$  
        TextBox 220,21,40,21,.TextBox1 'default: 0 CD0SXNi"zH  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Ec]cCLB  
        OKButton 40,91,90,21 @{n2R3)k B  
        CancelButton 190,91,90,21 kR-5RaW  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 j&?NE1D>I  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *o[*,1Pw  
    End Dialog K`1\3J)  
    Dim dlg As UserDialog yyHr. C  
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    ok = Dialog (dlg) L7*~8Y  
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    If ok=0 Then    'cancel button was pressed gasl%&  
        Print "Execution cancelled." MhB kr{8  
        End R\=y/tw0H  
    End If HgX4RSU  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Hca)5$yL  
    If dlg.TextBox1 = "" Then ji2if.t@  
        A = 0           'Default accommodation [XQoag;!  
    Else ;z7iUke0%  
        A = CDbl(dlg.TextBox1) vexQP}N0  
    End If ]IkjZ=  
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    If dlg.TextBox2 = "" Then 6q8qq/h)  
        pupilDiam = 4   'Default pupil diameter fD|ox  
    Else +kl@`&ga  
        pupilDiam = CDbl(dlg.TextBox2) [w~1e)D  
    End If Nr7MSFiL  
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    Print " " rC<m6  
    Print "Accommodation = " & A & " Diopters" rq6(^I  
    Print "Pupil Diameter = " & pupilDiam & " mm" (N43?iv(  
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    ' Calculate new parameters with accommodation ]0dp^%  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness }EOn=*  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !=0N38wA  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Y6fU;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ")(1z@  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Fu m1w  
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    tlens = 3.767 + 0.04*A                  'Lens thickness &ze'V , :  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction w];t]q|  
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    'Adjust parameters to account for accommodation D9c8#k9Y.  
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    '************************************************************************* e[n T'e  
    'Aqueous thickness (Position of Lens) z/rN+  ,  
    '************************************************************************* m.EWYO0XQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }kXF*cVg  
    GetCustomElement eID, entity E<&VK*{zcO  
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    parID = FindFullName( "Geometry.Arizona Eye" ) oChcEx%  
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    ' Delete any shift(s) in z it>FG9hVo  
    count = 0 Jp5~iC2d  
    While GetOperationCount(eID)>count {q8V
 
        GetOperation eID, count, op ~Cj+6CrT  
        If op.Type="ShiftZ" Then <6n(a)L1  
            DeleteOperation eID,count UXa3>q>  
            count=count-1 K$' J:{yY  
        End If =UNzjmP503  
        count=count+1 +5)
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    Wend 59T:{d;~  
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    'Set new shift in `t ZvIy*  
    op.Type = "ShiftZ" ycCEXu2F  
    op.val1 = taq zc,fJM  
    op.parent = parID U#,2et6  
    AddOperation eID, op  O,xU+j~)  
    Print "Set aqueous humor thickness = " & taq-0.55 tM]qR+  
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    '*************************************************************************  }e9:2  
    'Radius and conic constant of anterior lens O-bC+vB]M  
    '************************************************************************* D,1S-<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &Cdk%@Tj]B  
    GetConic eID, entity, curv, conic Y@^MU->+  
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    SetConic eID, entity, 1/Rant, CCant T
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $N5}N\C:a  
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    '*************************************************************************  +<AX 0(  
    'Radius and conic constant of posterior lens {Sd{|R_  
    '************************************************************************* ~XQN4Tv-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) =1yU& PJ  
    GetConic eID, entity, curv, conic Y R#_<o  
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    SetConic eID, entity, 1/Rpost, CCpost nY}Ep\g  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (+bk +0  
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    '************************************************************************* #$X_,P|D  
    'Lens thickness (Position of posterior lens surface) f#/v^Ql*  
    '************************************************************************* &kRkOjuk  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) j$A~3O<e"  
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    ' Delete any z-shift(s) t#}/VnSQ  
    count = 0 K )1K ]  
    While GetOperationCount(eID)>count z)yxz:E  
        GetOperation eID, count, op ix$?/GlL  
        If op.Type="ShiftZ" Then "F}anPY  
            DeleteOperation eID,count 0b~5i-zM/  
            count=count-1 8GV$L~i  
        End If q9yY%  
        count=count+1 @B*?owba>  
    Wend !YsLx[+  
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    'Set new z-shift P0DvZV8  
    op.Type = "ShiftZ" kOx2P(UAEx  
    op.val1 = tlens m(XcPb  
    op.parent = parID M8:gHjwsx  
    AddOperation eID, op kiZA$:V8  
    Print "Set lens thickness = " & tlens tlQ3BKp  
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    '************************************************************************* 6|rqsk  
    'Lens index of refraction TJp(  
    '************************************************************************* 73rr"> 9#0  
    eID = FindMaterial( "Lens" ) ul>$vUbyf  
    GetModelMaterial eID, mat 2r,K/'  
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    mat.Nd = nlens =Qp~@k=2  
    SetModelMaterial eID, mat 2W~,,$ G  
    Print "Set lens index of refraction = " & nlens x'+lNlv  
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    '************************************************************************* QR
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    'Pupil diameter %f#3;tpC8  
    '************************************************************************* e$45OL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) q4|TwRx
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    'Adjust pupil diameter (trimming volume inner hole) r,A750P^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 2N9 BI-a  
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    ' Adjust pupil location to just in front of the lens "$;=8O5O  
    parID = FindFullName( "Geometry.Arizona Eye" ) <}pqj3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) L8Z[Ly+_  
    count = 0 s3W35S0Q3  
    While GetOperationCount(eID)>count z0t6}E<VIR  
        GetOperation eID, count, op UsNr$MO {  
        If op.Type="ShiftZ" Then E#URTt:&>  
            DeleteOperation eID,count |)}F}~&  
            count=count-1 Yi1_oe  
        End If sT?Qlj'Zd  
        count=count+1 |g}! F-  
    Wend Y [0S  
    op.Type = "ShiftZ" C=t:0.:PJ  
    op.val1 = taq-0.01 u 3wF)B{  
    op.parent = parID /x"gpKwsB  
    AddOperation eID, op qN1(mxa.?  
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    Print "Set pupil diameter = " & pupilDiam :=UiEDN@  
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    'Update AZ Eye subassembly Description @sO*O4os>  
    eID = FindFullName( "Geometry.Arizona Eye" ) 72GXgah  
    GetEntity eID, entity f\!*%xS;  
    entity.Description = "Accommodation = " & A & "D" 57'=Qz52  
    SetEntity eID, entity :+|b7fF  
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    Update ?"$W=*P\o  
    Print "DONE!" ?C(Z\"IX  
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End Sub `o8b\p\zn  
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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： h `d(?1  
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Accommodation = 4 Diopters f#pT6  
Pupil Diameter = 4 mm &THM]3:  
Set aqueous humor thickness = 2.81 .7ESPr  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Q*+@"tk<  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 IJ3[6>/M0  
Set lens thickness = 3.927 YES!?^}  
Set lens index of refraction = 1.42672 a5{CkM&,(  
Set pupil diameter = 4 _-H uO/  
DONE! 46o3F"