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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 l{kum2DT  
    R+P1 +5  
    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。 UF?qL1w  
    ]@_*O$  
    模型 DRal{?CH  
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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。 *S7<QyVh  
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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. F6yMk%  
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    光源 *!vwW T  
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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。 xM[m(m  
    2WqjNqx)6  
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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。 )A,M T i  
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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。 wgY: W:y'N  
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    图2. 字母F光源的设定方法光 [$$i1%c%Z<  
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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  `i;f  
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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。 n' &:c}zKO  
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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。 @w?hX K=  
    ^Yul|0*J  
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    图5. 视网膜重点采样规格设定
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    脚本 T@Mrbravc  
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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: e-Mei7{%  
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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。 c<Fr^8  
    余下的脚本计算与屈光度有关的所有参数。 h8'`g 0  
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    分析 EZypqe):/C  
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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。 OlI|.~  
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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 u7L&cx  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. gaV>WF  
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    Dim entity As T_ENTITY X;'H@GU0  
    Dim op As T_OPERATION Ce_k&[AJF  
    Dim mat As T_MODELMATERIAL pr-=<[ d  
    Dim A As Double bf@H(gCW=  
    Dim pupilDiam As Double t\S=u y  
    Dim eID As Long -aPRL HR  
    Dim parID As Long K,j'!VQA4g  
    Dim count As Integer $\Oc]%  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double owQSy9Az  
    Dim tlens As Double, nlens As Double *!NxtB!LC  
    Dim curv As Double, conic As Double /F@CrNFb(  
    Dim ok As Long <<w*_GM  
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    Sub Main }ff+RGxLIG  
    5Q7Z$A1a 9  
        '用户输入对话框 [3D*DyQt  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 TsVU^Z%W  
            TextBox 220,21,40,21,.TextBox1 'default: 0 u'`eCrKT*  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 l$Y*ii  
            OKButton 40,91,90,21 p?-qlPl  
            CancelButton 190,91,90,21 _TntZv.?  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 zCji]:  
            TextBox 220,49,40,21,.TextBox2 'default: 4 N2 4J!L  
        End Dialog y~Z7sx0  
        Dim dlg As UserDialog WIKSz {"=/  
    "o)jB~ :L  
        ok = Dialog (dlg) Y#[xX2z9  
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        If ok=0 Then    'cancel button was pressed *q;u%; 4  
            Print "Execution cancelled." )sN}ClgJ  
            End q{Ao j  
        End If 9$f%  
    ij5|P4Eka  
        'Assign accommodation and pupil diameter & use defaults if field left empty 4ibOVBG:*,  
        If dlg.TextBox1 = "" Then fDjJdRS"  
            A = 0           'Default accommodation ;&c9!LfP  
        Else (h"-#q8$  
            A = CDbl(dlg.TextBox1) UMUG~P&@  
        End If WeZ?L|&%w0  
    .fAHP 5-  
        If dlg.TextBox2 = "" Then T].Xx`  
            pupilDiam = 4   'Default pupil diameter dk/f_m  
        Else >=1Aa,_tc  
            pupilDiam = CDbl(dlg.TextBox2) uN&UYJ' B  
        End If XFSHl[uS1  
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        Print " " # Rhtaq9  
        Print "Accommodation = " & A & " Diopters" K2{6{X=  
        Print "Pupil Diameter = " & pupilDiam & " mm" ',Y`\X  
    p~WX\;   
        ' Calculate new parameters with accommodation !?)aZ |r  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i^@hn>s$  
    *b7evU *1  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens m<sCRWa-  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &G!~@\tMg  
    @>*r2=#14  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <!=:{&d%  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens BdB9M8fM  
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        tlens = 3.767 + 0.04*A                  'Lens thickness & LhQr-g  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mWF\h>]|.  
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        'Adjust parameters to account for accommodation CC)Mws+2  
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        '************************************************************************* @ 3rJ$6W  
        'Aqueous thickness (Position of Lens) f}EsS  
        '************************************************************************* -H F1c  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) D@%!|:  
        GetCustomElement eID, entity b ,x$wP+  
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        parID = FindFullName( "Geometry.Arizona Eye" ) tIk$4)ZAl  
    @HE<\Z{ KI  
        ' Delete any shift(s) in z cx[[K.  
        count = 0 lS|F&I5j  
        While GetOperationCount(eID)>count xb2j |KY7  
            GetOperation eID, count, op `(r0+Qx  
            If op.Type="ShiftZ" Then [0D.+("EW  
                DeleteOperation eID,count 1HLU &  
                count=count-1 d ATAH}r&  
            End If 9* P-k.Bl  
            count=count+1 5Y 7 %Z  
        Wend W=y9mW|p/  
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        'Set new shift in X4L@|"ZI  
        op.Type = "ShiftZ" Gd`s01GKQ  
        op.val1 = taq &14xYpD<  
        op.parent = parID 558!?kx$  
        AddOperation eID, op wlQ @3RN>  
        Print "Set aqueous humor thickness = " & taq-0.55 85q!FpuH  
    3:<[;yo  
        '************************************************************************* >`^;h]Q  
        'Radius and conic constant of anterior lens #r,!-;^'p  
        '************************************************************************* fZ(k"*\MZ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 7Y)i>[u3  
        GetConic eID, entity, curv, conic Wngc(+6O&  
    p0D@O_ :5  
        SetConic eID, entity, 1/Rant, CCant ju!V1ky  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant W6RjQ1  
    9VMk?   
        '************************************************************************* <E:_9#Z0sc  
        'Radius and conic constant of posterior lens %jJIR88  
        '************************************************************************* _C=01 %/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Nxt`5kSx=  
        GetConic eID, entity, curv, conic fymmA faR  
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        SetConic eID, entity, 1/Rpost, CCpost x_9#:_S'  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost s )Xz}QPK.  
    /z(d!0_q|v  
        '************************************************************************* Q3'P<"u  
        'Lens thickness (Position of posterior lens surface) 5~$WSL?O)  
        '************************************************************************* Y-,S_59  
    3[@:I^q  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,."wxP2u  
    !hE F.S  
        ' Delete any z-shift(s) a5(9~. 9  
        count = 0 YV'B*arIA  
        While GetOperationCount(eID)>count ?BbEQr  
            GetOperation eID, count, op t~$8sG\  
            If op.Type="ShiftZ" Then 3BAQ2S}  
                DeleteOperation eID,count '$VP\Gj.  
                count=count-1 $h}w: AV:  
            End If T+S\'f\  
            count=count+1 ]bbP_n8  
        Wend 8bf@<VTO_  
    D~TlG@Pq  
        'Set new z-shift wv=U[:Y  
        op.Type = "ShiftZ" '@zMZc!  
        op.val1 = tlens Bc`L ]<  
        op.parent = parID Urol)_3X  
        AddOperation eID, op n<F3&2w  
        Print "Set lens thickness = " & tlens HG)$ W  
    n'?]_z<  
        '************************************************************************* WEoD ?GLS8  
        'Lens index of refraction =iB$4d2  
        '************************************************************************* 6W~JM^F  
        eID = FindMaterial( "Lens" ) 8Q0/kG  
        GetModelMaterial eID, mat *^XMf  
    I}|E_U1Qj  
        mat.Nd = nlens Iu(]i?Y  
        SetModelMaterial eID, mat 99%R/m  
        Print "Set lens index of refraction = " & nlens NBAOVYK  
    ` +)Bl%*  
        '************************************************************************* ~@e=+Z  
        'Pupil diameter %s;5  
        '************************************************************************* A'"J'q*t  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 9!0-~,o  
    ?T,a(m<i {  
        'Adjust pupil diameter (trimming volume inner hole) |+Z-'k~Q  
    ~S<}q6H.  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" yr*~?\  
    W"\+jHF"  
        ' Adjust pupil location to just in front of the lens muDOY~.  
        parID = FindFullName( "Geometry.Arizona Eye" ) |QQ(1#d  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) NCYOY  
        count = 0 k^#*x2b  
        While GetOperationCount(eID)>count  Y=H_U$  
            GetOperation eID, count, op gc b8eB ,  
            If op.Type="ShiftZ" Then E_P,>f  
                DeleteOperation eID,count Hq&MePl[  
                count=count-1 9|NF)~Q}'  
            End If ')iyD5/4  
            count=count+1 %|ioNXMu  
        Wend PG @C5Rnu  
        op.Type = "ShiftZ" 2Ky|+s[`[  
        op.val1 = taq-0.01 vg1E@rH|}  
        op.parent = parID &'/bnN +R  
        AddOperation eID, op ]vw%J ^7:a  
    _bv9/#tR  
        Print "Set pupil diameter = " & pupilDiam %`s1 Ocvp  
    ) % gU  
        'Update AZ Eye subassembly Description +:/.\3v71  
        eID = FindFullName( "Geometry.Arizona Eye" ) 0LTsWCUQ6e  
        GetEntity eID, entity AmUH]+5KT  
        entity.Description = "Accommodation = " & A & "D" 9)n3f^,Oj*  
        SetEntity eID, entity X|4Kdi.r@  
    %fXgV\xY  
        Update R <&U]%FD  
        Print "DONE!" 31F^38  
         tItI^]w2s  
    End Sub +S1h~@c:B  
    V<U9Pj^?^  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: MRHRa  
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    Accommodation = 4 Diopters T?1e&H%USV  
    Pupil Diameter = 4 mm d_ &~^*>  
    Set aqueous humor thickness = 2.81 "y ;0}9]n1  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 YWDd[\4  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 l {\k\Q!4  
    Set lens thickness = 3.927 _Om5w p=:  
    Set lens index of refraction = 1.42672 R$">  
    Set pupil diameter = 4 ?}S~cgL -  
    DONE! a,:Nlr3  
    /<J5?H  
    sD6vHX%  
    QQ:2987619807 <AHdz/N  
     
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