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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 :"y7Weh  
    !)l%EJngL  
    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。 nEa'e5 lg  
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    模型 ozxK?AMgG  
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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。 ~8n~4  
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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. =4w^)'/  
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    光源 hD9' `SQ  
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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。 66Cj=n5  
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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。 tp,mw24  
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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。 y1jGf83  
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    图2. 字母F光源的设定方法光 [> aoDJ  
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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 v#YS`];B  
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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。 f4\p1MYQ  
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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。 X0r#,u  
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    图5. 视网膜重点采样规格设定
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    脚本 ,h)T(  
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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: Xy(SzJ %  
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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。 xYkgNXGs5  
    余下的脚本计算与屈光度有关的所有参数。 NcY0pAR*  
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    分析 fKK-c9F   
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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。 R.WsC bU  
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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 }W>[OY0^A  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. #o |&MV_j  
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    Dim entity As T_ENTITY hZ /  
    Dim op As T_OPERATION <cS7L0h  
    Dim mat As T_MODELMATERIAL u B%^2{uU  
    Dim A As Double lIc9, |FL  
    Dim pupilDiam As Double &DhA$o"'  
    Dim eID As Long $(mdz)Cfy  
    Dim parID As Long {*r$m>HpM  
    Dim count As Integer E1 gTrMo  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~9'4w-Sy  
    Dim tlens As Double, nlens As Double Ch&]<#E>`  
    Dim curv As Double, conic As Double 7(+ZfY~w"  
    Dim ok As Long  3usA  
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    Sub Main rZCAj  
    WuQ<AS=   
        '用户输入对话框 ~ z&A  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Am`A[rV0  
            TextBox 220,21,40,21,.TextBox1 'default: 0 )B5gs%u]  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G?1V~6  
            OKButton 40,91,90,21 I)/7M}t`  
            CancelButton 190,91,90,21 %oKc?'L0  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  G#n)|p  
            TextBox 220,49,40,21,.TextBox2 'default: 4 T9v#Jb6  
        End Dialog GyM%vGl 3  
        Dim dlg As UserDialog 5i-;bLm  
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        ok = Dialog (dlg) |DS@90}  
    !!X9mI|2|  
        If ok=0 Then    'cancel button was pressed "?(Fb_}i  
            Print "Execution cancelled." ITY!=>S-  
            End v?"ee&Y6  
        End If [?6D1b[  
    Z/UVKJm>:  
        'Assign accommodation and pupil diameter & use defaults if field left empty MxA'T(Ay  
        If dlg.TextBox1 = "" Then g<tTZD\g  
            A = 0           'Default accommodation 0guc00IN  
        Else `V2j[Fz  
            A = CDbl(dlg.TextBox1) ~g6[ [  
        End If tSLl'XeN  
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        If dlg.TextBox2 = "" Then { RX|  
            pupilDiam = 4   'Default pupil diameter hg/&[/eodm  
        Else 9NXiCP9A  
            pupilDiam = CDbl(dlg.TextBox2) Zd/~ *ZA  
        End If NGZ>:  
    NJ!#0[@C  
        Print " " q x }fn/:  
        Print "Accommodation = " & A & " Diopters" bjX$idL  
        Print "Pupil Diameter = " & pupilDiam & " mm" i4C b&h^  
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        ' Calculate new parameters with accommodation _ShJ3\,K  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Y]0y -H  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens zQfxw?~A  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens m;1 exa  
    q)i(wEdUZ  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens YAG3PWmD  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2 ~'quA  
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        tlens = 3.767 + 0.04*A                  'Lens thickness  Q'M Ez  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .HJHJ.Js8X  
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        'Adjust parameters to account for accommodation 5-po>1g'  
    ;$;/#8`>  
        '************************************************************************* dAt[i \S  
        'Aqueous thickness (Position of Lens) H<?yG->  
        '************************************************************************* 0~+:~$VrT  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) e-t`\5b;  
        GetCustomElement eID, entity 9xp ;$14  
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        parID = FindFullName( "Geometry.Arizona Eye" ) oABPGyv  
    ^: j:;\;  
        ' Delete any shift(s) in z mmK_xu~f28  
        count = 0 'FXZ`+r|  
        While GetOperationCount(eID)>count EZW?(%b>H  
            GetOperation eID, count, op N^at{I6C  
            If op.Type="ShiftZ" Then .r"?w  
                DeleteOperation eID,count KrzM]x  
                count=count-1 ~'mhC46d  
            End If y~ LVK8  
            count=count+1 ,FO|'l  
        Wend bm?TMhC  
    AV! cCQ  
        'Set new shift in gC 4#!P  
        op.Type = "ShiftZ" $^>vJk<  
        op.val1 = taq -lEh}r  
        op.parent = parID k]sT'}[n  
        AddOperation eID, op ~`.%n7  
        Print "Set aqueous humor thickness = " & taq-0.55 J n/=v\K@  
    \}W.RQ^3  
        '************************************************************************* $ 7!GA9Bn  
        'Radius and conic constant of anterior lens mYX) =B{  
        '************************************************************************* -]%@,L^@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C3gz)!3  
        GetConic eID, entity, curv, conic %9M49 s  
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        SetConic eID, entity, 1/Rant, CCant M?lr#} d  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {D< ?.'  
    ny}utO  
        '************************************************************************* ".IhV<R  
        'Radius and conic constant of posterior lens O:)@J b2  
        '************************************************************************* G= e[TR)i  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) "Q4{6FH+mB  
        GetConic eID, entity, curv, conic qMOD TM~+  
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        SetConic eID, entity, 1/Rpost, CCpost 471}'3  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -`&;3 7  
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        '************************************************************************* uyIA]OtyN  
        'Lens thickness (Position of posterior lens surface) jT',+   
        '************************************************************************* va<pHSX&I@  
    =j-{Mxb3  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .+sIjd  
    $-73}[UA 4  
        ' Delete any z-shift(s) g;T`~  
        count = 0 ML-g"wv  
        While GetOperationCount(eID)>count >E3OYa?G  
            GetOperation eID, count, op we3t,?`rk7  
            If op.Type="ShiftZ" Then 10(N|2'q  
                DeleteOperation eID,count mDUS9>  
                count=count-1 3( kZfH~  
            End If Y!zlte|P  
            count=count+1 =9-c*bL  
        Wend Q>$v~v?9  
    PR0]:t)E  
        'Set new z-shift gqd#rjtfz  
        op.Type = "ShiftZ" T28#?Lp6]  
        op.val1 = tlens RWYA`  
        op.parent = parID &CgD smJo#  
        AddOperation eID, op :M16ijkx  
        Print "Set lens thickness = " & tlens b.(^CYYQ  
    I6+5mv\  
        '************************************************************************* fqxMTTg@  
        'Lens index of refraction +FI]0r  
        '************************************************************************* nM#\4Q[}Jh  
        eID = FindMaterial( "Lens" ) lU maNZ  
        GetModelMaterial eID, mat hdzaU&w  
    G8VWx&RE  
        mat.Nd = nlens L-yC'C  
        SetModelMaterial eID, mat *P>F# ~X  
        Print "Set lens index of refraction = " & nlens <>cajQ@  
    }/|1"D  
        '************************************************************************* <#sK~G  
        'Pupil diameter %y'#@%kO:S  
        '************************************************************************* 38 F8(QU{  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 70@:!HI]  
    zKo,B/Ke4  
        'Adjust pupil diameter (trimming volume inner hole) P:G^@B3^  
    CKK8 o9W  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 7y!{lr=n  
    8Pq|jK "  
        ' Adjust pupil location to just in front of the lens _:J! |'  
        parID = FindFullName( "Geometry.Arizona Eye" ) r?{tBju^  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e([}dz  
        count = 0 \RJ428sxn  
        While GetOperationCount(eID)>count [1Rs~T"  
            GetOperation eID, count, op tG'c79D\  
            If op.Type="ShiftZ" Then 2]|+.9B  
                DeleteOperation eID,count &0'BCT  
                count=count-1 dXZV1e1b&#  
            End If 5Jd,]~KAP  
            count=count+1 1:?Wv DN=  
        Wend b@Fa| >"_  
        op.Type = "ShiftZ" B|tP3<  
        op.val1 = taq-0.01 ral0@\T  
        op.parent = parID -70Ut 4B  
        AddOperation eID, op 7+fFKZFKF  
    |2Q;SaI^\  
        Print "Set pupil diameter = " & pupilDiam MOXDR  
    278 6tZF,  
        'Update AZ Eye subassembly Description mU;TB%#)  
        eID = FindFullName( "Geometry.Arizona Eye" ) >354O6  
        GetEntity eID, entity  1r$q $\  
        entity.Description = "Accommodation = " & A & "D" J}BS/Tr}=  
        SetEntity eID, entity _|3n h;-m  
    o`G@Je_}x  
        Update xRb-m$B}L  
        Print "DONE!" ^j@,N&W:lG  
         \\_Qv  
    End Sub *+5AN306  
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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: koFY7;_<?  
    )!'SSVaRs  
    Accommodation = 4 Diopters OX!9T.j  
    Pupil Diameter = 4 mm 9k1n-po  
    Set aqueous humor thickness = 2.81 Lf3:' n  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Pl U!-7  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 z"|^Y|`m  
    Set lens thickness = 3.927 C;_10Rb2ut  
    Set lens index of refraction = 1.42672 Eg>MG87  
    Set pupil diameter = 4 6tVB}UKs  
    DONE! m3,i{  
     
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