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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 Vjp1RWb  
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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。 p&bROuw<T  
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    模型 C|). ;V&  
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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。 PHXZ=A+  
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    Table 1. AZ眼睛模型的定义
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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. &d+Kg0:  
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    光源 3z)Kz*xr  
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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。 $.PuK~}  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 o-{[|/)Tk  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 7;sj%U^'l  
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    图2. 字母F光源的设定方法光 Z X(z;|l45  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 9S7 kUl{  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 jN>{'TqW4  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 z4+k7a@jn  
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    图5. 视网膜重点采样规格设定
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    脚本 =aj/,Q]  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: W?aI|U1  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 J'fQW<T4wU  
    余下的脚本计算与屈光度有关的所有参数。 `'c_=<&n  
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    分析 'fF;(?  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ]*FVz$>XM  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 7L@K _ZJ  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Tekfw  
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    Dim entity As T_ENTITY H nUYqhZS  
    Dim op As T_OPERATION ?) [EO(D  
    Dim mat As T_MODELMATERIAL C;`XlQG `  
    Dim A As Double w{uuSe  
    Dim pupilDiam As Double a,+@|TJ,i  
    Dim eID As Long %Gj8F4{  
    Dim parID As Long c`WHNky%j  
    Dim count As Integer 1~ t{aLPz  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double k^%B5  
    Dim tlens As Double, nlens As Double ;M#_6Hd?qD  
    Dim curv As Double, conic As Double @@rEs40  
    Dim ok As Long pT1[<X!<s  
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    Sub Main vab@-=%k  
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        '用户输入对话框 * U$!I?  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *gF<m9&  
            TextBox 220,21,40,21,.TextBox1 'default: 0 E)7F\w  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 'd&0Js$^  
            OKButton 40,91,90,21 4e;y G>  
            CancelButton 190,91,90,21 @qjfZH@  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 eKz?"g/j  
            TextBox 220,49,40,21,.TextBox2 'default: 4 HXYRH  
        End Dialog ^Q ps> A(  
        Dim dlg As UserDialog ,4,V4 N  
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        ok = Dialog (dlg) *^wB!{.#  
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        If ok=0 Then    'cancel button was pressed !\#_Jw%y  
            Print "Execution cancelled." )0e2ic/  
            End _s$_Sa ;  
        End If P<2 +L|X?}  
    <ggtjw S  
        'Assign accommodation and pupil diameter & use defaults if field left empty 6uKMCQ=h  
        If dlg.TextBox1 = "" Then -0eq_+oQ  
            A = 0           'Default accommodation npyAJp  
        Else A@D2+fS  
            A = CDbl(dlg.TextBox1) [NIlbjYH  
        End If f%)zg(YlO  
    %#Z/2<_  
        If dlg.TextBox2 = "" Then RQB]/D\BO  
            pupilDiam = 4   'Default pupil diameter )VK }m9Ae  
        Else l?DJJ|>O  
            pupilDiam = CDbl(dlg.TextBox2) 7Irau_  
        End If k@D0 {z  
    1 s*.A6EP"  
        Print " " JwRF(1_sM  
        Print "Accommodation = " & A & " Diopters" ?D)<,  
        Print "Pupil Diameter = " & pupilDiam & " mm" :@xm-.D  
    M9f?q.Bv  
        ' Calculate new parameters with accommodation pdb1GDl0q  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -l-E_6|/W  
    ^*= 85iyo  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens r-IVb&uF b  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens "ZHtR/;  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens C*te^3k>B  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !.<T"8BUpv  
    j! NO|&k  
        tlens = 3.767 + 0.04*A                  'Lens thickness  \^K&vW;  
    q7m6&2$[  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ei3zBS?J)  
    $W42vjr4  
        'Adjust parameters to account for accommodation Grz 3{U  
    (9mMkU=  
        '************************************************************************* F;!2(sPS  
        'Aqueous thickness (Position of Lens) LsGiu9~S  
        '************************************************************************* o1OBwPj  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .LRxP#B  
        GetCustomElement eID, entity -g/hAxb5  
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        parID = FindFullName( "Geometry.Arizona Eye" ) x/MZ(A%D  
    ;C/bJEgdd  
        ' Delete any shift(s) in z PS" .R_"  
        count = 0 QIn/,Yd  
        While GetOperationCount(eID)>count ?Jusl8Sm  
            GetOperation eID, count, op Ti;Ijcq8  
            If op.Type="ShiftZ" Then Lx U={Y0  
                DeleteOperation eID,count _0 snAt^iC  
                count=count-1 hc$@J}`  
            End If aSYs_?&.  
            count=count+1 ]Lqt( c  
        Wend rn:!dV[  
    yWHiw<  
        'Set new shift in i~{ _eQV  
        op.Type = "ShiftZ" 5lJ )(|_  
        op.val1 = taq W;Jx<-#1  
        op.parent = parID L1)@z8]   
        AddOperation eID, op 8Chu"PM%-J  
        Print "Set aqueous humor thickness = " & taq-0.55 V5GkP1L  
    qkP/Nl. u  
        '************************************************************************* dYojm1MQ  
        'Radius and conic constant of anterior lens \H5Jk$*  
        '************************************************************************* N<_Ko+VF  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 2#/p|$;Ec'  
        GetConic eID, entity, curv, conic <<|H=![  
    )06iV  
        SetConic eID, entity, 1/Rant, CCant w.+Eyu_I\  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant lZt(&^T  
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        '************************************************************************* ;ggy5?>Qu  
        'Radius and conic constant of posterior lens vV`|!5x  
        '************************************************************************* bYh9sO/l  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) g.#+z'l  
        GetConic eID, entity, curv, conic |AH@ EI>  
    -lRhz!E]  
        SetConic eID, entity, 1/Rpost, CCpost _NdLcpBT?  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost JK~ m(oQ  
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        '************************************************************************* bn 4 &O  
        'Lens thickness (Position of posterior lens surface) 4W\,y_Q o  
        '************************************************************************* 8!h'j  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^,2c-  
     ?9u4a_x  
        ' Delete any z-shift(s) 0%)5.=6  
        count = 0 ]s|lxqP  
        While GetOperationCount(eID)>count CYB=Uq,  
            GetOperation eID, count, op `:-J+<`  
            If op.Type="ShiftZ" Then H] qq ~bO[  
                DeleteOperation eID,count %f[Ep 3D  
                count=count-1 ?:|YGLaB  
            End If R~B0+:6  
            count=count+1 I Ru$oF}  
        Wend bGh0<r7R  
    fEu9Jk  
        'Set new z-shift 1BD6 l2y  
        op.Type = "ShiftZ" ^w6eWzI  
        op.val1 = tlens ,p,Du F  
        op.parent = parID A"/aGCG0z  
        AddOperation eID, op WhUa^  
        Print "Set lens thickness = " & tlens Xn7 [n  
    .9\Cy4_qSd  
        '************************************************************************* D$_8rHc\A  
        'Lens index of refraction q?VVYZXP  
        '************************************************************************* .w FU:y4r  
        eID = FindMaterial( "Lens" ) ?2~U2Ir]:  
        GetModelMaterial eID, mat oa9)Dv  
    uU+s!C9r  
        mat.Nd = nlens $ WFhBak8  
        SetModelMaterial eID, mat /;UTC)cJ  
        Print "Set lens index of refraction = " & nlens tmxPO e  
    PbUI!Xqe`  
        '************************************************************************* Nz]aaoO4  
        'Pupil diameter ti;%BS  
        '************************************************************************* S_!R^^ySG9  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *Pb.f  
    >1XL;)IL>  
        'Adjust pupil diameter (trimming volume inner hole) )b9I@)C  
    UIw?;:Y  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" mahi7eU P  
    *Yp qq  
        ' Adjust pupil location to just in front of the lens !\w\ ]7 ls  
        parID = FindFullName( "Geometry.Arizona Eye" ) #6FaIq92V  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z`9l<Q/  
        count = 0 :Ba-u  
        While GetOperationCount(eID)>count chwh0J;  
            GetOperation eID, count, op  ,(hY%M&\  
            If op.Type="ShiftZ" Then u-/3(dKt  
                DeleteOperation eID,count er\:U0fr#@  
                count=count-1 `]yKM0 Z  
            End If `1p?*9Ssn  
            count=count+1 }@4| 7  
        Wend v j@V !j?  
        op.Type = "ShiftZ" >\-3P $  
        op.val1 = taq-0.01 y%g`FC   
        op.parent = parID ,yi2O]5e>!  
        AddOperation eID, op 9t\ [N/  
    i~AJ.@ #  
        Print "Set pupil diameter = " & pupilDiam o;'4c  
    K-Y* T}?  
        'Update AZ Eye subassembly Description j) <[j&OWw  
        eID = FindFullName( "Geometry.Arizona Eye" ) ]J~g'">  
        GetEntity eID, entity 7#/|VQX<A  
        entity.Description = "Accommodation = " & A & "D" [b pwg&Oo  
        SetEntity eID, entity W)  
    C_89YFn+  
        Update Bzm. X=U:  
        Print "DONE!" k%a?SU<f  
         $ACe\R/%  
    End Sub {N@Y<=+:  
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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: Uc>LFX& -B  
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    Accommodation = 4 Diopters 4] M =q{  
    Pupil Diameter = 4 mm vD"_X"v  
    Set aqueous humor thickness = 2.81 A9.;>8!u  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 +"G(  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 BfEx'C  
    Set lens thickness = 3.927 i&B?4J)  
    Set lens index of refraction = 1.42672 .k|-Ks|d|  
    Set pupil diameter = 4 A<1l^%i  
    DONE! > fhSaeN  
     
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