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    [分享]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: 2020-12-09
    简介 z7$}#)Z7  
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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。 n K0hTQ  
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    模型 a#6,#Q"  
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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。 8Y]}Gb!  
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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. zh hGqz[K  
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    光源 \c'%4Ao  
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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。 gtl;P_  
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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。 012:BZR  
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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。 2@OBeR  
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    图2. 字母F光源的设定方法光 ge@reGfsB1  
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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 Z@8MhJ  
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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。 W=(MsuirO  
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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。 o4U]lK$  
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    图5. 视网膜重点采样规格设定
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    脚本 /,-h%gj  
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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: ye56-T  
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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。 1 NB2y[  
    余下的脚本计算与屈光度有关的所有参数。 )+VHt  
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    分析 AD0ptHUBa  
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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。 i,C0o   
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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 M^!C?(Hx^x  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. & bp#1KR)  
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    Dim entity As T_ENTITY MxFt;GgE8  
    Dim op As T_OPERATION qBf wN1  
    Dim mat As T_MODELMATERIAL _3-RoA'UZr  
    Dim A As Double 2D\x-!l/  
    Dim pupilDiam As Double rQ 9?N^&!%  
    Dim eID As Long (xjoRbU*  
    Dim parID As Long wliGds  
    Dim count As Integer #3 }5cC8_  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  <Hq6]\<  
    Dim tlens As Double, nlens As Double mgJ]@s}9  
    Dim curv As Double, conic As Double ui0J}DM  
    Dim ok As Long \#IJ=+z   
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    Sub Main BWqik_  
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        '用户输入对话框 \.XT:B_  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QSl:=Q'  
            TextBox 220,21,40,21,.TextBox1 'default: 0 24.7S LXO  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `2Z4#$.  
            OKButton 40,91,90,21 3> n2  
            CancelButton 190,91,90,21 kHz+ ZY<?  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 c1Fru  
            TextBox 220,49,40,21,.TextBox2 'default: 4 *_<SWTE  
        End Dialog YFC0KU  
        Dim dlg As UserDialog Wfi:wCqZG  
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        ok = Dialog (dlg) { c6DT  
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        If ok=0 Then    'cancel button was pressed tq4"Q BIKh  
            Print "Execution cancelled." ouu-wQ|(mM  
            End xC=3|,U  
        End If X=*Yzz}  
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        'Assign accommodation and pupil diameter & use defaults if field left empty y5Z<uwXc  
        If dlg.TextBox1 = "" Then  8E.5k@  
            A = 0           'Default accommodation }tl8(kjm  
        Else 0|wKR|zW  
            A = CDbl(dlg.TextBox1) Np5/lPb1  
        End If ,_TH@0{   
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        If dlg.TextBox2 = "" Then D KMbs   
            pupilDiam = 4   'Default pupil diameter k7Be'E BKG  
        Else <*~BG)b  
            pupilDiam = CDbl(dlg.TextBox2) Cs6zv>SR  
        End If u\Erta`  
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        Print " " X<@y*?D9D  
        Print "Accommodation = " & A & " Diopters" sWpRX2{5,  
        Print "Pupil Diameter = " & pupilDiam & " mm" JE8p5WaR  
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        ' Calculate new parameters with accommodation `hQ!*f6  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^r?sgJ  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens HnKF#<  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens V]CK'   
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yg]nS<K~4  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 07G*M ]  
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        tlens = 3.767 + 0.04*A                  'Lens thickness R y*I~<m  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "n2xn%t{  
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        'Adjust parameters to account for accommodation l7r N  
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        '************************************************************************* JNA}EY^2I.  
        'Aqueous thickness (Position of Lens) M$5%QM}  
        '************************************************************************* +h\W~muR  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <=GzK:4L  
        GetCustomElement eID, entity @gVyLefS6g  
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        parID = FindFullName( "Geometry.Arizona Eye" ) q.hc%s2?  
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        ' Delete any shift(s) in z HDae_.  
        count = 0 j/`qd(=B  
        While GetOperationCount(eID)>count A1s=;qr  
            GetOperation eID, count, op NcY0pAR*  
            If op.Type="ShiftZ" Then x#}eC'Q  
                DeleteOperation eID,count N=?kEX O  
                count=count-1 tEs[zo+DR-  
            End If (A<sFw?  
            count=count+1 L|xen*O  
        Wend 3x;y}:wQa  
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        'Set new shift in u g$\&rM>  
        op.Type = "ShiftZ" dmMr8-w  
        op.val1 = taq r(xlokpnb6  
        op.parent = parID V;+$/>J`vB  
        AddOperation eID, op f8_UIdM7  
        Print "Set aqueous humor thickness = " & taq-0.55 z%gtV'  
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        '************************************************************************* nJ0eZBgB]  
        'Radius and conic constant of anterior lens $(mdz)Cfy  
        '************************************************************************* {*r$m>HpM  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) E1 gTrMo  
        GetConic eID, entity, curv, conic ~9'4w-Sy  
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        SetConic eID, entity, 1/Rant, CCant 7(+ZfY~w"  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant  3usA  
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        '************************************************************************* rZCAj  
        'Radius and conic constant of posterior lens WuQ<AS=   
        '************************************************************************* ~ z&A  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Am`A[rV0  
        GetConic eID, entity, curv, conic )B5gs%u]  
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        SetConic eID, entity, 1/Rpost, CCpost I)/7M}t`  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %oKc?'L0  
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        '************************************************************************* {-]HYk  
        'Lens thickness (Position of posterior lens surface) GyM%vGl 3  
        '************************************************************************* 5i-;bLm  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) |[7$) $  
    1,!\7@<CT  
        ' Delete any z-shift(s) 92ww[+RQ@  
        count = 0 6@*;Wk~  
        While GetOperationCount(eID)>count 4bjp*1*]  
            GetOperation eID, count, op 2o}G<7r  
            If op.Type="ShiftZ" Then ph (k2cb  
                DeleteOperation eID,count l*MUDT@M8\  
                count=count-1 Gqb-3n gH  
            End If GYmBxX87  
            count=count+1 9nAK6$/  
        Wend SJ_cwYwI$  
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        'Set new z-shift &UH z  
        op.Type = "ShiftZ" DH*|>m&  
        op.val1 = tlens uB"m!dL  
        op.parent = parID .vF< 3p|  
        AddOperation eID, op )7mJ+d[  
        Print "Set lens thickness = " & tlens ,$ret@.H  
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        '************************************************************************* L"<Eov6  
        'Lens index of refraction ;pK"N:|  
        '************************************************************************* CKw)J}z  
        eID = FindMaterial( "Lens" ) L k+1r8  
        GetModelMaterial eID, mat 5kZ yiC*  
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        mat.Nd = nlens a8P 6-)W  
        SetModelMaterial eID, mat QHz76i!=>  
        Print "Set lens index of refraction = " & nlens 7%}}m&A7h  
    \-id[zKb  
        '************************************************************************* )cBV; E<  
        'Pupil diameter U4pvQE.m<  
        '************************************************************************* qz SI cI  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #e|kA&+8M  
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        'Adjust pupil diameter (trimming volume inner hole) 5i&V ~G  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?kefRev<#h  
    n=MYv(Pp}  
        ' Adjust pupil location to just in front of the lens 4 V*)0?oYE  
        parID = FindFullName( "Geometry.Arizona Eye" ) 3`q`W9  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) `W S  
        count = 0 DQQjx>CK  
        While GetOperationCount(eID)>count $X]v;B)J|  
            GetOperation eID, count, op \{mJO>x  
            If op.Type="ShiftZ" Then EmoU7iy  
                DeleteOperation eID,count d0,F'?.0|  
                count=count-1 dPX>A4wp  
            End If 0R%58,R  
            count=count+1 ,gD i)]  
        Wend E #]%e^  
        op.Type = "ShiftZ" {<8#T`I  
        op.val1 = taq-0.01 bJ}+<##  
        op.parent = parID tTamFL6  
        AddOperation eID, op ]gk1h=Y~h  
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        Print "Set pupil diameter = " & pupilDiam @SB+u+mOS  
    DZZt%n8J  
        'Update AZ Eye subassembly Description )j*qGsOg  
        eID = FindFullName( "Geometry.Arizona Eye" ) LvdMx]*SSr  
        GetEntity eID, entity y>PbYjuIU  
        entity.Description = "Accommodation = " & A & "D" "G(/MT^C  
        SetEntity eID, entity 1nmWL0  
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        Update aoX$,~oI5  
        Print "DONE!" 6*Qpq7Ml  
         Rgu^> ~   
    End Sub = 0Sa  
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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: xn[di-L F  
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    Accommodation = 4 Diopters A/aQpEb%  
    Pupil Diameter = 4 mm #1k,t  
    Set aqueous humor thickness = 2.81 T]`" Xl8  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 WLb7]rCTp  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 j=4>In?x  
    Set lens thickness = 3.927 `6su_8Hno  
    Set lens index of refraction = 1.42672 2Mp;/b!  
    Set pupil diameter = 4 _>I5Ud8(-  
    DONE! LPF?\mf ^4  
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