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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 6$kqaS##  
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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。 3Dng 1}  
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    模型 $*e2YQdLo  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 Yw^m  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Y$Z x,  
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    光源 ~Sj9GxTe  
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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。 vHyC;4'  
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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。 11o.c;  
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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。 3EJj9}#x"'  
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    图2. 字母F光源的设定方法光 OLyf8&AU@  
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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 K"|l@Q[  
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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。  _zY# U9  
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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。 Cn,d?H  
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    图5. 视网膜重点采样规格设定
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    脚本 @$ne{2J3  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 8EW_V$>R  
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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。 CDsSrKhx  
    余下的脚本计算与屈光度有关的所有参数。 Z InpMp  
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    分析 &5\iM^  
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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。 7?#J~.d5  
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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 uZNTHD  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. %'b M){  
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    Dim entity As T_ENTITY joFm]3$;  
    Dim op As T_OPERATION V3&RJ k=b  
    Dim mat As T_MODELMATERIAL [)H&'5 +F  
    Dim A As Double y&6FybIz  
    Dim pupilDiam As Double WffQ:L?  
    Dim eID As Long <f ZyAa3}  
    Dim parID As Long 9Vg?{v!yn  
    Dim count As Integer S=MEG+Ad  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Njxv4cc  
    Dim tlens As Double, nlens As Double /Gd=n  
    Dim curv As Double, conic As Double ~5NXd)2+Ks  
    Dim ok As Long $mu^G t  
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    Sub Main R cAwrsd  
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        '用户输入对话框 Lb!Fcf|h  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 | z9*GY6RU  
            TextBox 220,21,40,21,.TextBox1 'default: 0 . k#U]M  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 '9laa=H%8  
            OKButton 40,91,90,21 2y//'3[  
            CancelButton 190,91,90,21 r /YMLQ  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 y`VyQWW  
            TextBox 220,49,40,21,.TextBox2 'default: 4 vq0Vq(V=  
        End Dialog q8FTi^=Kb  
        Dim dlg As UserDialog aT{_0m$G10  
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        ok = Dialog (dlg) v_<rNc,z-s  
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        If ok=0 Then    'cancel button was pressed *T- <|zQ  
            Print "Execution cancelled." )Lk639r  
            End HguT"%iv  
        End If Vy6qbC-Kt  
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        'Assign accommodation and pupil diameter & use defaults if field left empty 6 hw=  
        If dlg.TextBox1 = "" Then oQLq&zRH`f  
            A = 0           'Default accommodation &TnS4O  
        Else \RNNg  
            A = CDbl(dlg.TextBox1) A}BVep@D  
        End If _Us#\+]_:  
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        If dlg.TextBox2 = "" Then O [\i E5+$  
            pupilDiam = 4   'Default pupil diameter aAZZ8V  
        Else cm&nd'A't  
            pupilDiam = CDbl(dlg.TextBox2) PxTwPl  
        End If <Q3oT  
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        Print " " } K7#Q  
        Print "Accommodation = " & A & " Diopters" +Jlay1U&  
        Print "Pupil Diameter = " & pupilDiam & " mm" yg `j-9[8  
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        ' Calculate new parameters with accommodation X@'u y<tI-  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ye\rB\-  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens c-x,fS"&W  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens bbtGXfI+SB  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens J}*,HT*  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens H7?Vybg~  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 7yG#Z)VE  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "$~':) V"  
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        'Adjust parameters to account for accommodation 0m7Y>0wC6T  
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        '************************************************************************* S$f9m  
        'Aqueous thickness (Position of Lens) #Z}Rf k(~  
        '************************************************************************* w ~.f  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 45=bGf#  
        GetCustomElement eID, entity aFc1|.Nm  
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        parID = FindFullName( "Geometry.Arizona Eye" ) }^4Xv^dW>g  
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        ' Delete any shift(s) in z ?# Mr  
        count = 0 d)B@x`  
        While GetOperationCount(eID)>count bADnW4N`6;  
            GetOperation eID, count, op H;D>|q  
            If op.Type="ShiftZ" Then Av @b!iw+  
                DeleteOperation eID,count Jz?j[  
                count=count-1 \@-@Y  
            End If _ftI*ni:<  
            count=count+1 ~fBtQGdX  
        Wend +ylTGSZS  
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        'Set new shift in n?oW< &  
        op.Type = "ShiftZ" 1da@3xaF  
        op.val1 = taq JBD7h5|Lc  
        op.parent = parID _geWE0 E  
        AddOperation eID, op A]y`7jJ  
        Print "Set aqueous humor thickness = " & taq-0.55 'QG xd!4  
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        '************************************************************************* 68bQ;Dv  
        'Radius and conic constant of anterior lens Q0$8j-1I  
        '************************************************************************* :fKl]XO  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) V @rI`~$  
        GetConic eID, entity, curv, conic ,4 hJT  
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        SetConic eID, entity, 1/Rant, CCant pb^i^tA+A  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 2^XGGB0  
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        '************************************************************************* iz5CAxm  
        'Radius and conic constant of posterior lens 9*$t!r{B@  
        '*************************************************************************  ,t}vz 7  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) cD@(/$wt  
        GetConic eID, entity, curv, conic qsL) }sC^8  
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        SetConic eID, entity, 1/Rpost, CCpost 1pQn8[sc@  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost E"\/ M  
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        '************************************************************************* \:R%4w#Jv  
        'Lens thickness (Position of posterior lens surface) t4{rb, }W  
        '************************************************************************* #XK2Ien)Z  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) D@C-5rmq  
    $r@ =*(  
        ' Delete any z-shift(s) z,|r*\dw  
        count = 0 BW-`t-,E;  
        While GetOperationCount(eID)>count /{|EAd{  
            GetOperation eID, count, op Usg K  
            If op.Type="ShiftZ" Then 85lCj-cs  
                DeleteOperation eID,count Z/Eb:  
                count=count-1 u,F nAh?"  
            End If >d~WH@o`G  
            count=count+1 ]&?Y~"{cD  
        Wend 6\L0mcXR!  
    _a_7,bk5  
        'Set new z-shift 0YaA`  
        op.Type = "ShiftZ" @*>@AFnf\Z  
        op.val1 = tlens _AYXc] 4%  
        op.parent = parID b6W2^tr-  
        AddOperation eID, op "ZHW2l Mf  
        Print "Set lens thickness = " & tlens _4TH4~cY  
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        '************************************************************************* -g)9R%>-  
        'Lens index of refraction $m7?3/YG  
        '************************************************************************* )64@2 ~4y  
        eID = FindMaterial( "Lens" ) a-y+@#;2_  
        GetModelMaterial eID, mat dG@"!!,  
    LY6;.d$J  
        mat.Nd = nlens vQ<90Z xqB  
        SetModelMaterial eID, mat f5F@^QXQ  
        Print "Set lens index of refraction = " & nlens l6(-I Tb  
    '[J<=2&  
        '************************************************************************* whonDG4WP  
        'Pupil diameter .tkT<o-u<J  
        '************************************************************************* lW<PoT  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m7&O9?X  
    -yR.<KnL  
        'Adjust pupil diameter (trimming volume inner hole) A3vUPWdDk  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" d\%WgH  
    Y^36>1.:  
        ' Adjust pupil location to just in front of the lens 79nG|Yj|\  
        parID = FindFullName( "Geometry.Arizona Eye" ) U;bK!&Z  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6}75iIKi  
        count = 0 <$6QDfa#  
        While GetOperationCount(eID)>count ^BUYjq%(`  
            GetOperation eID, count, op =81@ o,1w  
            If op.Type="ShiftZ" Then F&])P- !3  
                DeleteOperation eID,count 0~HKiH-  
                count=count-1 6``'%S'#  
            End If wx\v:A  
            count=count+1 @lCJ G!u  
        Wend  e`d%-9  
        op.Type = "ShiftZ" [v$0[IuY,  
        op.val1 = taq-0.01 "oWwc zzO  
        op.parent = parID !E,A7s  
        AddOperation eID, op !h(|\" }  
    V~S0hqW[  
        Print "Set pupil diameter = " & pupilDiam kgy:Q'  
     ]E_h  
        'Update AZ Eye subassembly Description S5KEXnjm  
        eID = FindFullName( "Geometry.Arizona Eye" ) HODz*pI  
        GetEntity eID, entity V?Z.\~  
        entity.Description = "Accommodation = " & A & "D" >RPd$('T  
        SetEntity eID, entity \ W?R  
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        Update Ob}?zl@  
        Print "DONE!" 9Rn? :B~W:  
         3 N7[.I>A  
    End Sub 0`)iIz  
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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: b3S.-W{p.  
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    Accommodation = 4 Diopters {g2@6ct  
    Pupil Diameter = 4 mm fBgEnz/  
    Set aqueous humor thickness = 2.81 nt;haeJ  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 _$wmI/_J M  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 <EPj$::  
    Set lens thickness = 3.927 &ZghMq~  
    Set lens index of refraction = 1.42672 NB\{'  
    Set pupil diameter = 4 CNQC^d\ h  
    DONE! B.g[c97  
     
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