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    [分享]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: 2020-12-09
    简介 %YhM?jMW  
    2b`3"S  
    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。 XoO#{7a  
    $QbaPmHW  
    模型 SZ*Nr=X  
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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。 $vQ#ah/k  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ~dpU D F  
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    光源 vp#AD9h1  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 x KZLXQ'e-  
    (C=.&',P  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 SMMsXH  
    |v[0(  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 7v8V0Gp  
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    图2. 字母F光源的设定方法光 z3\WcW7|  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 *T+Bjj;w  
    `ecIy_O3P&  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 S*5hO) C  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 'DDlX3W-  
    %O=U|tuc$  
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    图5. 视网膜重点采样规格设定
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    脚本 ^ |xSU_wa  
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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: S1!X;PP/  
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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。 GmONhh(k  
    余下的脚本计算与屈光度有关的所有参数。 T&ECGF;Y/  
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    分析 ;VL v2J*  
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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。 us_o{  
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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 sM4Qu./  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. FLqF!N\G  
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    Dim entity As T_ENTITY `Wes!>Vh!  
    Dim op As T_OPERATION fpDx)lQ  
    Dim mat As T_MODELMATERIAL RSK~<Y@]q{  
    Dim A As Double nO ^m  
    Dim pupilDiam As Double A<1:vV  
    Dim eID As Long .[@TC@W  
    Dim parID As Long 5`!Bj0Uf  
    Dim count As Integer udEJo~u  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d>RoH]K4  
    Dim tlens As Double, nlens As Double =J2cX`  
    Dim curv As Double, conic As Double 61XLL/=P  
    Dim ok As Long P  -O& X  
    \~LwlOo%R  
    Sub Main aB=&XGV9  
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        '用户输入对话框 B8f BX!u/  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 MRI`h.  
            TextBox 220,21,40,21,.TextBox1 'default: 0 I 3ZlKI  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \$g,Hgp/<  
            OKButton 40,91,90,21 !XJvhsKXy  
            CancelButton 190,91,90,21 ^`HP&V  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9AA_e ~y  
            TextBox 220,49,40,21,.TextBox2 'default: 4 }o'WR'LX  
        End Dialog _3;vir%)  
        Dim dlg As UserDialog +1te8P*  
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        ok = Dialog (dlg) r Ljb'\<*  
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        If ok=0 Then    'cancel button was pressed =SY`Xkj[  
            Print "Execution cancelled." "-WEUz  
            End ib-)T7V`  
        End If e hgUp =  
    >" z$p@7  
        'Assign accommodation and pupil diameter & use defaults if field left empty oZ /z{`  
        If dlg.TextBox1 = "" Then vmY 88Kx&S  
            A = 0           'Default accommodation LdPA`oI3j  
        Else 68!W~%?pR  
            A = CDbl(dlg.TextBox1) iE}Lw&x  
        End If .$rt>u,8<  
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        If dlg.TextBox2 = "" Then |})7\o  
            pupilDiam = 4   'Default pupil diameter /'ukeK+'  
        Else BJL*Dih m[  
            pupilDiam = CDbl(dlg.TextBox2) )J"*[[e  
        End If /Cl=;^)  
    #guq/g$  
        Print " " &|LP>'H;  
        Print "Accommodation = " & A & " Diopters" -!ARVf *  
        Print "Pupil Diameter = " & pupilDiam & " mm" uQ_s$@brI  
    ?kF_C,k/>N  
        ' Calculate new parameters with accommodation Mqk[+n  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xc&&UKd  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens bo]= *  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens L+]|-L`S  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7/UdE:~]*=  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Vi5&%/Y  
    *.2[bQL@v  
        tlens = 3.767 + 0.04*A                  'Lens thickness +Y9n@`  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0\X'a}8Bu  
    @Q%g#N  
        'Adjust parameters to account for accommodation (U GmbRf&  
    7XDze(O5  
        '************************************************************************* f'-) 3T  
        'Aqueous thickness (Position of Lens) AgU 7U/yk  
        '************************************************************************* 2\'5LL3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) gT=RJB  
        GetCustomElement eID, entity %(v<aEQtt  
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        parID = FindFullName( "Geometry.Arizona Eye" ) efnj5|JSV  
    -AX[vTB  
        ' Delete any shift(s) in z NW*qw q  
        count = 0 }8\"oA6  
        While GetOperationCount(eID)>count -y1t;yU.L  
            GetOperation eID, count, op Jemb0Qv  
            If op.Type="ShiftZ" Then |-'.\)7:  
                DeleteOperation eID,count mm@)uV<\  
                count=count-1 X"z!52*3]  
            End If ,x. 2kb  
            count=count+1 |AS`MsbI9  
        Wend rQ!X  
    F,l%SQCyj  
        'Set new shift in r!,/~~m T  
        op.Type = "ShiftZ" ~H+W[r}  
        op.val1 = taq 4-dV%DgC  
        op.parent = parID |!=KLJUA  
        AddOperation eID, op SA'c}gP  
        Print "Set aqueous humor thickness = " & taq-0.55 kl90w  
    1}$GVb%i  
        '************************************************************************* M^$liS.D  
        'Radius and conic constant of anterior lens $kM8E@x2  
        '************************************************************************* Z%uDz3I\Q"  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) i H^Gv*  
        GetConic eID, entity, curv, conic O@gHx!L  
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        SetConic eID, entity, 1/Rant, CCant .bT|:Q~@{  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (fYrb# ]!y  
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        '************************************************************************* =rrbS8To=  
        'Radius and conic constant of posterior lens \1p_6U7  
        '************************************************************************* p 7YfOUo k  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) npW1Z3n  
        GetConic eID, entity, curv, conic \s[/{3  
    @Q=P6Rz {S  
        SetConic eID, entity, 1/Rpost, CCpost h{sY5d'D  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost b)eKa40Z  
    *Y@)t* -a  
        '************************************************************************* M]Y72K^  
        'Lens thickness (Position of posterior lens surface) 9b0M'x'W5  
        '************************************************************************* njk1x  
    ,3zF_y(*Y  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4G%!t`? q  
    l^F%fIRp)  
        ' Delete any z-shift(s) 2`o}neF{  
        count = 0 G|p3NhLgO=  
        While GetOperationCount(eID)>count gyI(O>e  
            GetOperation eID, count, op W:8*Z8?7  
            If op.Type="ShiftZ" Then ;,8bb(j  
                DeleteOperation eID,count nVTCbV  
                count=count-1 tkG0xRH  
            End If ;gh#8JkI  
            count=count+1 f|*vWHSM  
        Wend Y{ho[%  
    S[b)`Wi D  
        'Set new z-shift J#0oL_xY#  
        op.Type = "ShiftZ" `FP)-^A8  
        op.val1 = tlens da[u@eNrnX  
        op.parent = parID [\ M=w7  
        AddOperation eID, op RsYn6ozb  
        Print "Set lens thickness = " & tlens )TceNH  
    1GnT^u y/  
        '************************************************************************* JeR8Mb  
        'Lens index of refraction b[^=GF>e  
        '************************************************************************* D<rO:Er?*a  
        eID = FindMaterial( "Lens" ) UC,43 z  
        GetModelMaterial eID, mat -$(,&qyk  
    ^KU:5Bn  
        mat.Nd = nlens $XqfwlUu/4  
        SetModelMaterial eID, mat \(a9rZ9  
        Print "Set lens index of refraction = " & nlens jb' hqz  
    zfE;)K^"  
        '************************************************************************* IED7v  
        'Pupil diameter :\@WY  
        '************************************************************************* $X %GzrN  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ZhKYoPIq  
    ExDH@Lb  
        'Adjust pupil diameter (trimming volume inner hole) q|,I\H5}  
    "`DCXn#mB  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" X[8m76/V  
    =|n NC  
        ' Adjust pupil location to just in front of the lens }Po&6^  
        parID = FindFullName( "Geometry.Arizona Eye" ) "D7*en  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =5EG}@  
        count = 0 Bv $;yR  
        While GetOperationCount(eID)>count YMG{xGPtM  
            GetOperation eID, count, op } XCHoB  
            If op.Type="ShiftZ" Then \oPW  
                DeleteOperation eID,count w \pD'1e  
                count=count-1 rMqWXGl`(  
            End If `LL#Aia  
            count=count+1 ^;B vd!  
        Wend "4LYqDe  
        op.Type = "ShiftZ" SX|b0S,  
        op.val1 = taq-0.01 q('O@-HA  
        op.parent = parID A'qJke=  
        AddOperation eID, op b/oJ[Vf  
    ;$(a+?  
        Print "Set pupil diameter = " & pupilDiam s4lkhoN\t  
    |_a E~_  
        'Update AZ Eye subassembly Description Yt2_*K@rC  
        eID = FindFullName( "Geometry.Arizona Eye" ) ,U2 /J  
        GetEntity eID, entity -MoI{3a  
        entity.Description = "Accommodation = " & A & "D" J%EbJ5p<QF  
        SetEntity eID, entity PdJtJqA8h\  
    =35^k-VS  
        Update noa?p&Y1m  
        Print "DONE!" V@<tIui$  
         @! ^c@  
    End Sub 3> -/sii  
    .Xh^L  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Afo(! v  
    #ldNWwvRGj  
    Accommodation = 4 Diopters yInW?3  
    Pupil Diameter = 4 mm or\ 2)  
    Set aqueous humor thickness = 2.81 e2;19bj&  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 / O6n[qj|  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 $@+\_f'bU>  
    Set lens thickness = 3.927 md_aD  
    Set lens index of refraction = 1.42672 "EF: +gi#"  
    Set pupil diameter = 4 `4}zB#3  
    DONE! ZU7e1VaZM  
    "m0>u,HmI  
    ,d<wEB?\`  
    QQ:2987619807 Y(78qs1w  
     
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