[技术]Arizona眼睛模型 [复制链接]

简介 %9D@W*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。 (&*F`\  
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模型 sMS`-,37u  
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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。 8_,ZJ9l;  
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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. VDPN1+1*  
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光源 r#Fu<so,  
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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。 ZkIQ-;wx  
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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。 ^`!Daqk  
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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+8`.  
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视网膜的散射 I7~|!d6  
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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。
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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。 XJzXxhk2  
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脚本 oSl>%}  
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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： jyGVbno
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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。 Ds87#/Yfv  
余下的脚本计算与屈光度有关的所有参数。 ~{+{pcO}  
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分析 *jK))|%  
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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。 ~qS/90,  
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脚本代码 S |x)7NC  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Y*k<NeDyn  
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Dim entity As T_ENTITY uB1!*S1f  
Dim op As T_OPERATION k^pu1g=6I  
Dim mat As T_MODELMATERIAL A7C+&I!L  
Dim A As Double 2mZ/ 3u  
Dim pupilDiam As Double 6Qb)Uq3}]  
Dim eID As Long [bv@qBL  
Dim parID As Long *?D2gaCta  
Dim count As Integer 2NknC>9(\  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double l~
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Dim tlens As Double, nlens As Double w.aFaR)04  
Dim curv As Double, conic As Double ^,K.)s  
Dim ok As Long
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Sub Main LtztjAm.  
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    '用户输入对话框 z[%v_S  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 6\Vu#r  
        TextBox 220,21,40,21,.TextBox1 'default: 0 _-\s[p5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #L.}CzAz  
        OKButton 40,91,90,21 pqN[G=0  
        CancelButton 190,91,90,21 9'q/&uH  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0juIkN#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 t!SQLgA  
    End Dialog TDIOK  
    Dim dlg As UserDialog iT5SuIv  
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    ok = Dialog (dlg) ,?<h] !aQ  
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    If ok=0 Then    'cancel button was pressed 5?L:8kHsH  
        Print "Execution cancelled." 0~b6wuFl  
        End Gu`Vk/&  
    End If 37-y  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @Q\$dneY  
    If dlg.TextBox1 = "" Then /v)!m&6]>  
        A = 0           'Default accommodation q>(u>z!  
    Else Q(5:~**I  
        A = CDbl(dlg.TextBox1) 0nz@O^*g(  
    End If ,XG|oo-  
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    If dlg.TextBox2 = "" Then _@pf1d$  
        pupilDiam = 4   'Default pupil diameter $;i$k2n:  
    Else m2uML*&O5K  
        pupilDiam = CDbl(dlg.TextBox2) L+rySP  
    End If #D/ }u./  
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    Print " " 9=~H6(m>  
    Print "Accommodation = " & A & " Diopters" w+9C/U;|s  
    Print "Pupil Diameter = " & pupilDiam & " mm" 3b)
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    ' Calculate new parameters with accommodation 0rJ\
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 199hQxib:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @52=3  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8pL>wL &C  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ZYR,8y  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Rc:cVK  
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    tlens = 3.767 + 0.04*A                  'Lens thickness #D LT-G0  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?sf2h:\N  
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    'Adjust parameters to account for accommodation :KV,:13`D  
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    '************************************************************************* B
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    'Aqueous thickness (Position of Lens) ?fa,[r|G  
    '************************************************************************* `b#nC[b6|v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ),p
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    GetCustomElement eID, entity w[YkTv  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~?`9i>3W~  
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    ' Delete any shift(s) in z Q0q)n=i}]  
    count = 0 !/Bw,y ri<  
    While GetOperationCount(eID)>count fv j5[Q  
        GetOperation eID, count, op wO_pcNYZ8  
        If op.Type="ShiftZ" Then 4&]To@>  
            DeleteOperation eID,count iVpA@p   
            count=count-1 BV }(djx  
        End If Qk~0a?#y5  
        count=count+1 mWN1Q<vn,l  
    Wend M~z(a3@[V  
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    'Set new shift in ;!0.Kk 4  
    op.Type = "ShiftZ" APQQ:'>N4~  
    op.val1 = taq {
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    op.parent = parID =JbdsYI(  
    AddOperation eID, op <^*+8{*  
    Print "Set aqueous humor thickness = " & taq-0.55 )Vg{Y [!  
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    '************************************************************************* 3vRLg b  
    'Radius and conic constant of anterior lens y\|-O<8O  
    '************************************************************************* z%}CBTm  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) iB}LnC:  
    GetConic eID, entity, curv, conic :rTKqX&"j  
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    SetConic eID, entity, 1/Rant, CCant MgH1d&R  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @\6nXf  
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    '************************************************************************* s;-78ejj7  
    'Radius and conic constant of posterior lens a_ 9|xI  
    '************************************************************************* mV**9-"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XUQW;H  
    GetConic eID, entity, curv, conic 
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    SetConic eID, entity, 1/Rpost, CCpost x  tYV"  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z/
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    '************************************************************************* RFZU}.*K$  
    'Lens thickness (Position of posterior lens surface) KD%xo/Z.  
    '************************************************************************* j'#jnP*P  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) iL7-4Lv#  
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    ' Delete any z-shift(s) 7,W]zKH  
    count = 0 {FV,j.D  
    While GetOperationCount(eID)>count JK(`6qB>(6  
        GetOperation eID, count, op C;d|\[7Z  
        If op.Type="ShiftZ" Then !7mvyc!'!  
            DeleteOperation eID,count V5e\%  
            count=count-1 Vp(D|}P  
        End If koncWyW  
        count=count+1 o;M.Rt\A  
    Wend p@cfY]<7  
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    'Set new z-shift 0\\ueMj  
    op.Type = "ShiftZ" bxd
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    op.val1 = tlens TZ&4  
    op.parent = parID pW*{Mx  
    AddOperation eID, op  Z;j/K  
    Print "Set lens thickness = " & tlens LaIW,+  
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    '************************************************************************* 2y9:'c|  
    'Lens index of refraction R/ALR
 
    '************************************************************************* x38SSzG:L  
    eID = FindMaterial( "Lens" ) TRs[~K)n  
    GetModelMaterial eID, mat 0%;N9\  
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    mat.Nd = nlens #Acon7Rp  
    SetModelMaterial eID, mat )CC?vV  
    Print "Set lens index of refraction = " & nlens jgo e^f  
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    '************************************************************************* 7af?E)}v  
    'Pupil diameter eW\?eq+ `A  
    '************************************************************************* JYZ2k=zh  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 88Fb1!a5Z  
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    'Adjust pupil diameter (trimming volume inner hole) 8Zcol$XS'  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" i_|9<7a  
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    ' Adjust pupil location to just in front of the lens l 8O"w&  
    parID = FindFullName( "Geometry.Arizona Eye" ) *A~($ZtL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) C-s>1\I  
    count = 0 ]4Nvh\/P9  
    While GetOperationCount(eID)>count 6V'wQqJ  
        GetOperation eID, count, op Zvd ;KGO(a  
        If op.Type="ShiftZ" Then 33=Mm/<m$P  
            DeleteOperation eID,count RpHpMtvNo/  
            count=count-1 ?60>'Xjj  
        End If aqcFY8b '  
        count=count+1 j4E H2v  
    Wend %iK%$  
    op.Type = "ShiftZ" d4jVdOq2  
    op.val1 = taq-0.01 ]*bAF^8i  
    op.parent = parID mDb-=[W5  
    AddOperation eID, op MC4284A5  
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    Print "Set pupil diameter = " & pupilDiam th5,HO~  
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    'Update AZ Eye subassembly Description 9T8
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    eID = FindFullName( "Geometry.Arizona Eye" ) j`>?"1e@x  
    GetEntity eID, entity  5Waw?1GL  
    entity.Description = "Accommodation = " & A & "D" >pgQb9 T+_  
    SetEntity eID, entity l_^T&xq8  
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    Update 6P0y-%[Gk  
    Print "DONE!" TFBYY{Y  
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End Sub @)9REA(
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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： !nec 7  
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Accommodation = 4 Diopters [?;`x&y~y  
Pupil Diameter = 4 mm U5|B9%:&  
Set aqueous humor thickness = 2.81 dVvZu% DFp  
Set anterior lens radius = 10.4 and conic constant = -2.375869 x$~3$E  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &J\B\`  
Set lens thickness = 3.927 bBA$}bv  
Set lens index of refraction = 1.42672 =Nw2;TkB[  
Set pupil diameter = 4 `2>XH:+7F  
DONE! fr
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