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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 pBP.x#|  
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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。 ]mXLg:3B  
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    模型 e$uiJNS2  
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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。 JA_BKA  
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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. [mr9(m[F  
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    光源 R &4Z*?S  
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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。 `VL}.h  
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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。 ]UG*r%9  
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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。 NwR}yb6  
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    图2. 字母F光源的设定方法光 W|,V50K  
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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 TSsKfexQ  
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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。 cl*PFQp9j  
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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。 BMIyskl=i  
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    图5. 视网膜重点采样规格设定
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    脚本 (x$9~;<S*d  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: `g1iCF  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 6Ik,zQL  
    余下的脚本计算与屈光度有关的所有参数。 DK&h eVIoZ  
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    分析 sW^a`VM  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 >u(>aV|A  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 9lo [&^<  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. VNtPKtx\  
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    Dim entity As T_ENTITY M}hrO-C  
    Dim op As T_OPERATION w_iamqe,  
    Dim mat As T_MODELMATERIAL Bz`yfl2  
    Dim A As Double fXQiNm[P  
    Dim pupilDiam As Double RP`2)/sMT  
    Dim eID As Long ,s^<X85gp\  
    Dim parID As Long Bfv.$u00p  
    Dim count As Integer J%]D%2vnk`  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #9LzY  
    Dim tlens As Double, nlens As Double d'9:$!oz  
    Dim curv As Double, conic As Double FCc=e{  
    Dim ok As Long 3v!~cC~cI  
    D["MUB4l  
    Sub Main -NBiW6b~  
    vG2b:[W  
        '用户输入对话框 GW2')}g  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U~2`P  
            TextBox 220,21,40,21,.TextBox1 'default: 0 #m8sK(#lo  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 wn11\j&  
            OKButton 40,91,90,21 br,+45:  
            CancelButton 190,91,90,21 ;#G%U!p  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :<~7y.*O{  
            TextBox 220,49,40,21,.TextBox2 'default: 4 $YG1z  
        End Dialog sst,dA V$  
        Dim dlg As UserDialog <Jp1A# %p  
    #rYENR[  
        ok = Dialog (dlg) |@o6NZ<9N  
    ;S/7 h6  
        If ok=0 Then    'cancel button was pressed Jll-X\O`-  
            Print "Execution cancelled." nD,{3B#  
            End *,\` o~  
        End If .%0ne:5  
     9|S`ub'  
        'Assign accommodation and pupil diameter & use defaults if field left empty qSO*$1i  
        If dlg.TextBox1 = "" Then X^@[G8v%  
            A = 0           'Default accommodation ]5v:5:H  
        Else 8Xm@r#Oy5  
            A = CDbl(dlg.TextBox1) cQFR]i  
        End If ZcryAm:I  
    M} .b" ljZ  
        If dlg.TextBox2 = "" Then rvwy~hO"  
            pupilDiam = 4   'Default pupil diameter s!6=|SS7  
        Else ;~sr$6  
            pupilDiam = CDbl(dlg.TextBox2) wh~s Z  
        End If N)43};e  
    wy4q[$.4v  
        Print " " 5su.+4z\  
        Print "Accommodation = " & A & " Diopters" ibF#$&!  
        Print "Pupil Diameter = " & pupilDiam & " mm" iY.eJlfH  
    +|C[-W7Sw  
        ' Calculate new parameters with accommodation Ud3""C5B  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness S>ugRasZ$  
    MMD<I6Iyv  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens H|+tC=]4IZ  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens BQjam+u6  
    (Imp $  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c#q"\"  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens S]yvMj_?  
    DA LQ<iF  
        tlens = 3.767 + 0.04*A                  'Lens thickness Dc FCKji  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mTEVFm  
    'H=weH  
        'Adjust parameters to account for accommodation ~5t?C<wo  
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        '************************************************************************* =FBIrw{w  
        'Aqueous thickness (Position of Lens) bc}dYK3$q  
        '*************************************************************************  0:dB 9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?*K<*wBw#  
        GetCustomElement eID, entity YIDg'a+z  
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        parID = FindFullName( "Geometry.Arizona Eye" ) (G5xkygR9  
    #O</\|aH)i  
        ' Delete any shift(s) in z <-|SIF  
        count = 0 g[!Cj,  
        While GetOperationCount(eID)>count glor+  
            GetOperation eID, count, op L<@&nx   
            If op.Type="ShiftZ" Then [~?M/QI9  
                DeleteOperation eID,count caD5Pod4  
                count=count-1 $GF&x>]]  
            End If #^\}xn" [  
            count=count+1  6`"ZsO  
        Wend #'NY}6cb$  
    A[ 1)!e  
        'Set new shift in +{xG<Wkltz  
        op.Type = "ShiftZ" tQ0=p| T]  
        op.val1 = taq lS3 _Ild  
        op.parent = parID B,0+HoP  
        AddOperation eID, op 3o7xN=N  
        Print "Set aqueous humor thickness = " & taq-0.55 |E|T%i^}./  
    f%1wMOzx  
        '************************************************************************* B*Cb6'Q  
        'Radius and conic constant of anterior lens +UaO<L  
        '************************************************************************* &enlAV'#)O  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) e3rfXhp  
        GetConic eID, entity, curv, conic nh|EZp]  
    -4`sqv ]  
        SetConic eID, entity, 1/Rant, CCant 2))t*9;h  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'WzUu MCx  
    u~)%tL  
        '************************************************************************* y7; 5xF?q  
        'Radius and conic constant of posterior lens s7Qyfe&>  
        '************************************************************************* Wy,"cT  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *cy.*@d  
        GetConic eID, entity, curv, conic T`mEO\f  
    f<=^ 4a  
        SetConic eID, entity, 1/Rpost, CCpost w}b<D#0XC  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost eHROBxH&  
    Deog4Ol"/  
        '************************************************************************* }1\?()rB  
        'Lens thickness (Position of posterior lens surface) a}GAB@YI  
        '************************************************************************* Qf~| S9,  
    |Rk37P {  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) PoY>5  
    "9 u-lcQ\  
        ' Delete any z-shift(s) m^c%]5$  
        count = 0 ty9rH=1  
        While GetOperationCount(eID)>count %)dI2 J^Xf  
            GetOperation eID, count, op %8g$T6E[<2  
            If op.Type="ShiftZ" Then ev*c4^z:s  
                DeleteOperation eID,count ,iohfZz  
                count=count-1 5A;"jp^ Z  
            End If 1 S^'C2/b  
            count=count+1 $;ch82UiX  
        Wend *\C}Ok=  
    yvS^2+jW  
        'Set new z-shift uq]iMz>  
        op.Type = "ShiftZ" 3lyQn "  
        op.val1 = tlens w4`!Te  
        op.parent = parID -D$3!ccX  
        AddOperation eID, op dY 6B%V  
        Print "Set lens thickness = " & tlens frk7^5  
    dkf}),Z F  
        '************************************************************************* oNrEIgaA(+  
        'Lens index of refraction DwTi_8m;  
        '************************************************************************* -aA<.+  
        eID = FindMaterial( "Lens" ) '>"`)-  
        GetModelMaterial eID, mat M44_us  
    2}ag_  
        mat.Nd = nlens kzW\z4f  
        SetModelMaterial eID, mat R+k=Ea&x  
        Print "Set lens index of refraction = " & nlens ~igRg~k:/  
    R<_mK33hd  
        '************************************************************************* uFMs ^^#  
        'Pupil diameter f*UBigk  
        '************************************************************************* W&WB@)ie  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XlE$.  
    gjO *h3`  
        'Adjust pupil diameter (trimming volume inner hole) %+/f'6kR  
    OE5X8DqQe  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" iM4mkCdOO  
    |>M-+@g j  
        ' Adjust pupil location to just in front of the lens aS3P(s L  
        parID = FindFullName( "Geometry.Arizona Eye" ) (Be$$W  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) aA7S'[NjB  
        count = 0 K lPm=  
        While GetOperationCount(eID)>count ::kpl2r\c  
            GetOperation eID, count, op 27}.s0{D  
            If op.Type="ShiftZ" Then wEZqkV  
                DeleteOperation eID,count ~:R4))qpg  
                count=count-1 :Fw *r|  
            End If 6(!,H<bON  
            count=count+1 B/kcb(5v  
        Wend :zRB)hd  
        op.Type = "ShiftZ" k?!TjBKm  
        op.val1 = taq-0.01 ")fOup@ ^a  
        op.parent = parID ,^UcRZ8.H  
        AddOperation eID, op 3 (Gygq#  
    x(exx )w  
        Print "Set pupil diameter = " & pupilDiam 1uK)1%vK  
    }M;sz  
        'Update AZ Eye subassembly Description F Bd+=bx,Z  
        eID = FindFullName( "Geometry.Arizona Eye" ) yz54:q?  
        GetEntity eID, entity M80}3mgP~  
        entity.Description = "Accommodation = " & A & "D" [YL sEo=  
        SetEntity eID, entity &Z;Eu'ia  
    ^!zJf7(+<>  
        Update c80"8r  
        Print "DONE!" D'U\]'.  
         "j *fVn  
    End Sub RlG'|xaT  
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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: s?1-$|*  
    0j-F6a*p'1  
    Accommodation = 4 Diopters Pl`Bd0  
    Pupil Diameter = 4 mm n^g-`  
    Set aqueous humor thickness = 2.81 <v1_F;{n  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 s (l+{b &  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 [346w <  
    Set lens thickness = 3.927 zIX}[l4EW~  
    Set lens index of refraction = 1.42672 ?j},O=JFn  
    Set pupil diameter = 4 Y9lbf_51  
    DONE! 6|>"0[4S  
     
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