[技术]Arizona眼睛模型 [复制链接]

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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。 \yqiv"'  
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模型 IO+z: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。 JjwuxZVr O  
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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. 1li`+~L F  
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光源 TcC=_je460  
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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。 rk~/^(!  
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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。 \bg^E>-  
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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。 )sQbDA|p  
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视网膜的散射 5Ql6?UHD  
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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。 L/ZZe5I  
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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。 l
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脚本 2vwT8/  
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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： 8dpVB#]pp,  
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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。 AkF1
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余下的脚本计算与屈光度有关的所有参数。 D&'".N,}  
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分析 bUBuJ  
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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。 H1w;Wb1se  
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脚本代码 >?kt3.IQ!X  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. T4UY%E!0  
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Dim entity As T_ENTITY ]*@7o^4i  
Dim op As T_OPERATION c" l~=1Dr  
Dim mat As T_MODELMATERIAL u&<L
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Dim A As Double Wc)^@f[~<  
Dim pupilDiam As Double d ][E;$  
Dim eID As Long K)k!`du!6  
Dim parID As Long [)a,rrhj  
Dim count As Integer CN >q`[!  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double uIR_p\)  
Dim tlens As Double, nlens As Double 3w-0v"j U  
Dim curv As Double, conic As Double $UH_)Q2#J^  
Dim ok As Long 55AG>j&41
 
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Sub Main =#W{&Te;  
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    '用户输入对话框 Ug9o/I@}C  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >1r>cZn  
        TextBox 220,21,40,21,.TextBox1 'default: 0 %=|I;kI?  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 j/W#=\xz  
        OKButton 40,91,90,21 Z?b. PC/  
        CancelButton 190,91,90,21 v\<`"  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 bi_R.sfK&  
        TextBox 220,49,40,21,.TextBox2 'default: 4 _[<I&^%  
    End Dialog ?GFVV->i  
    Dim dlg As UserDialog gcz1*3)  
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    ok = Dialog (dlg) ZpwB"%e$  
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    If ok=0 Then    'cancel button was pressed @P8q=j}l9  
        Print "Execution cancelled." 8g$ 8]'M^T  
        End ?
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    End If 4(Mt6{q  
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    'Assign accommodation and pupil diameter & use defaults if field left empty IX3r$}4  
    If dlg.TextBox1 = "" Then gDA hl  
        A = 0           'Default accommodation osnDW aN  
    Else h;B'#$_  
        A = CDbl(dlg.TextBox1) Q8P;AN_JS  
    End If 'al-C;Z  
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    If dlg.TextBox2 = "" Then dCc*<S  
        pupilDiam = 4   'Default pupil diameter Hj5b.fB  
    Else D6 M:pIN*  
        pupilDiam = CDbl(dlg.TextBox2) 6I>
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    End If <=0_[M  
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    Print " " ){6;o&CC:  
    Print "Accommodation = " & A & " Diopters" YT-t$QyL  
    Print "Pupil Diameter = " & pupilDiam & " mm" No[>1]ds  
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    ' Calculate new parameters with accommodation QN0Ik
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7%0PsF _  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #-@
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }g`A*y;t  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &^z~wJ,]  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens r<"1$K~Ka  
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    tlens = 3.767 + 0.04*A                  'Lens thickness uD+;5S]us  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +pDuRr  
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    'Adjust parameters to account for accommodation 6-<r@{m$  
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    '************************************************************************* VD1*br^,  
    'Aqueous thickness (Position of Lens) LEk W^Mv  
    '************************************************************************* 4u"O/rt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H1q>UU:  
    GetCustomElement eID, entity thkL<  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 51L:%Af  
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    ' Delete any shift(s) in z G66vzwO  
    count = 0 k8w8I$QEM  
    While GetOperationCount(eID)>count &ts!D!Hj  
        GetOperation eID, count, op }bHdU]$}  
        If op.Type="ShiftZ" Then f\Pd#$3  
            DeleteOperation eID,count q7X/"Dfx  
            count=count-1 |JrG?:n  
        End If Yj;$hV8j(  
        count=count+1 B:Msn)C~  
    Wend 3:S Ex;d+  
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    'Set new shift in In]h+tG?rN  
    op.Type = "ShiftZ" .O~)zMx  
    op.val1 = taq ]2tX'=X  
    op.parent = parID /EWF0XV!  
    AddOperation eID, op 3vmZB2QG  
    Print "Set aqueous humor thickness = " & taq-0.55 {L3lQ8Z  
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    '************************************************************************* y_\vXY'  
    'Radius and conic constant of anterior lens Z~$fTW6g  
    '************************************************************************* w!tQU9+*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) b[H& vp  
    GetConic eID, entity, curv, conic )PR{ia64;<  
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    SetConic eID, entity, 1/Rant, CCant L{osh0  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \9<aCJxN  
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    '************************************************************************* O'o`

  
    'Radius and conic constant of posterior lens t[7YMk  
    '************************************************************************* m &s0Ub  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) :MpIx&  
    GetConic eID, entity, curv, conic o9>r -  
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    SetConic eID, entity, 1/Rpost, CCpost P|c79  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 389T6sP]  
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    '************************************************************************* |Q.t]TR'P  
    'Lens thickness (Position of posterior lens surface) QD q2<  
    '************************************************************************* qH$G_R#)8B  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) &QLCij5:  
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    ' Delete any z-shift(s) $d4eGL2S  
    count = 0 ~%(r47n  
    While GetOperationCount(eID)>count (lT H EiX  
        GetOperation eID, count, op \2pJ ]  
        If op.Type="ShiftZ" Then &
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            DeleteOperation eID,count l8n#sGA%  
            count=count-1 >\[sNCkf  
        End If 
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        count=count+1 A\k@9w\Ll;  
    Wend kR9G;IZ8s  
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    'Set new z-shift DSD#',  
    op.Type = "ShiftZ" hPP+lqY[  
    op.val1 = tlens 5fSDdaO  
    op.parent = parID ,r+=>vre  
    AddOperation eID, op 9^)ochY3  
    Print "Set lens thickness = " & tlens ;"wU+  
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    '************************************************************************* zH}u9IR3`  
    'Lens index of refraction y2o?a6`  
    '************************************************************************* q$0^U{j/  
    eID = FindMaterial( "Lens" ) i=]IUjx<  
    GetModelMaterial eID, mat wnN@aO6g*  
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    mat.Nd = nlens hQ#'_%:  
    SetModelMaterial eID, mat .9S  
    Print "Set lens index of refraction = " & nlens ` L6H2:pf  
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    '************************************************************************* (/Hq8o-Fw  
    'Pupil diameter t? yMuK  
    '************************************************************************* aG?'F`UQ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) wwmMpK}f  
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    'Adjust pupil diameter (trimming volume inner hole) G]=U=9ZI  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 0`3ey*  
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    ' Adjust pupil location to just in front of the lens Oh5(8.<y  
    parID = FindFullName( "Geometry.Arizona Eye" ) e}-uU7O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w(<; $9  
    count = 0 L_=J(H|  
    While GetOperationCount(eID)>count !D7[R'RgY  
        GetOperation eID, count, op =3^YKI  
        If op.Type="ShiftZ" Then [`yiD
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            DeleteOperation eID,count PQlG!  
            count=count-1 BAx)R6kS;  
        End If $Vlfg51ob  
        count=count+1 2sk^A ly  
    Wend uZW ?0W  
    op.Type = "ShiftZ" jgVra*   
    op.val1 = taq-0.01 @L,T/m-HF  
    op.parent = parID >OBuHqC  
    AddOperation eID, op f)vD2_E  
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    Print "Set pupil diameter = " & pupilDiam *;1G+Q#  
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    'Update AZ Eye subassembly Description eN,s#/ip]  
    eID = FindFullName( "Geometry.Arizona Eye" ) GmcxN<  
    GetEntity eID, entity psta&u\ q  
    entity.Description = "Accommodation = " & A & "D" {Ejv8UdA9  
    SetEntity eID, entity m Wsegq4  
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    Update nv2Y6e}dG  
    Print "DONE!" |rq~.cA  
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End Sub +wY3E*hU  
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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： ;KbnaUAS8  
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Accommodation = 4 Diopters k&n7_[]n  
Pupil Diameter = 4 mm FJ!
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Set aqueous humor thickness = 2.81 U-Fr[1I6p  
Set anterior lens radius = 10.4 and conic constant = -2.375869 s^AQJ{X  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 13}=;4O  
Set lens thickness = 3.927 3r%I *  
Set lens index of refraction = 1.42672 'N,x=1R5  
Set pupil diameter = 4 \
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DONE! H]mY6D51"