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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 Sx\]!B@DSu  
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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。 )_NO4`ejs/  
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    模型 ,=N.FS  
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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。 u-C)v*#L  
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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. -{+}@?  
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    光源 KGpA2Nx  
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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。 v.ui!|c  
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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。 o? $.fhD   
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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。 UY 2OZ& &  
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    图2. 字母F光源的设定方法光 .>nRzgo  
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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 4H<lm*!^  
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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。 V470C@  
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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。 $tS}LN_!  
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    图5. 视网膜重点采样规格设定
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    脚本 IaXeRq?<  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: &8 x-o,  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 ?I@W:#>o  
    余下的脚本计算与屈光度有关的所有参数。 r0gJpttDl  
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    分析 RdML3E  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 xF44M]i  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 K6)j0 ]K1  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. UZsH9 o  
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    Dim entity As T_ENTITY abLnI =W`  
    Dim op As T_OPERATION xK\d4 "  
    Dim mat As T_MODELMATERIAL j,dR,Nd  
    Dim A As Double (*)hD(C5  
    Dim pupilDiam As Double ^]-6u:J!  
    Dim eID As Long ,nB5/Lx  
    Dim parID As Long NTI+  
    Dim count As Integer igR";OQk  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double FG*r'tC~r  
    Dim tlens As Double, nlens As Double A$:U'ZG_  
    Dim curv As Double, conic As Double >&5DsV.B  
    Dim ok As Long 0=E]cQwh  
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    Sub Main s}% M4  
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        '用户输入对话框 `lt"[K<  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2V;PYI  
            TextBox 220,21,40,21,.TextBox1 'default: 0 OH(waKq2I  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -p XSSa;O9  
            OKButton 40,91,90,21 ?m? ::RH  
            CancelButton 190,91,90,21 Ak"m 85B  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r? E)obE  
            TextBox 220,49,40,21,.TextBox2 'default: 4 <?4V  
        End Dialog 3x'|]Ns  
        Dim dlg As UserDialog C&rkvM8  
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        ok = Dialog (dlg) b?QoS|<e?  
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        If ok=0 Then    'cancel button was pressed &@Be2!%'9K  
            Print "Execution cancelled." 'u |c  
            End HqT#$}rv  
        End If <;Zmjeb+#  
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        'Assign accommodation and pupil diameter & use defaults if field left empty l&Q`wR5e  
        If dlg.TextBox1 = "" Then *.d)OOpLo  
            A = 0           'Default accommodation l3I:Q^x@  
        Else i5Yb`Z[Y  
            A = CDbl(dlg.TextBox1) #Kex vP&*  
        End If y ~!Zg}o  
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        If dlg.TextBox2 = "" Then Ks`J([(W&  
            pupilDiam = 4   'Default pupil diameter xBi' X  
        Else XXn67sF/  
            pupilDiam = CDbl(dlg.TextBox2) *]/zc1Q4M  
        End If 54R#W:t  
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        Print " " A!WKnb_`  
        Print "Accommodation = " & A & " Diopters" uH- l%17  
        Print "Pupil Diameter = " & pupilDiam & " mm" "Nbq#w\  
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        ' Calculate new parameters with accommodation qL3;}R  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .jT#:_  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens dufu|BL|}  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens e_ANUll1  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3>`mI8 $t  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .Una+Z  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 9BBmw(M}  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ""F5z,'  
    7XLtN "$$  
        'Adjust parameters to account for accommodation Y}|X|!0x  
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        '************************************************************************* PB`Y g  
        'Aqueous thickness (Position of Lens) {~"/Y@&]R  
        '************************************************************************* /,&<6c-Q@W  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) qCpp6~]Um  
        GetCustomElement eID, entity 9YQb &  
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        parID = FindFullName( "Geometry.Arizona Eye" ) O6a<`]F  
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        ' Delete any shift(s) in z <~'"<HwtK  
        count = 0 `WFw3TI  
        While GetOperationCount(eID)>count Pz|>"'  
            GetOperation eID, count, op s6v ;  
            If op.Type="ShiftZ" Then cyv`B3}  
                DeleteOperation eID,count {Y=WW7:Qx  
                count=count-1 1&evG-#<:  
            End If @oY~..d`  
            count=count+1 A_ N;   
        Wend 2E/"hQw  
    )E@.!Ut4o  
        'Set new shift in Ln<`E|[29  
        op.Type = "ShiftZ" lC("y' ::  
        op.val1 = taq cr?Q[8%t1  
        op.parent = parID L Mbn  
        AddOperation eID, op ex9g?*Q  
        Print "Set aqueous humor thickness = " & taq-0.55 Ou!2 [oe@M  
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        '************************************************************************* 2 %@4]  
        'Radius and conic constant of anterior lens #TX/aKr:  
        '************************************************************************* Cc' 37~6~P  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) OSWYGnZg  
        GetConic eID, entity, curv, conic m=A(NKZ   
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        SetConic eID, entity, 1/Rant, CCant ," Wr"  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant i,E{f  
    aS{n8P6vW  
        '************************************************************************* &<5zqsNJ\a  
        'Radius and conic constant of posterior lens )=Z>#iH1  
        '************************************************************************* 3<Zq ]jk?n  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7BjJhs  
        GetConic eID, entity, curv, conic "9P>a=Y  
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        SetConic eID, entity, 1/Rpost, CCpost C]eSizS.  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :W:K:lk  
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        '************************************************************************* E$:*NSXj  
        'Lens thickness (Position of posterior lens surface) $@Rxrx_@M  
        '************************************************************************* YEs&  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) uK#4(eY=W  
    X_ cV%#  
        ' Delete any z-shift(s) EXwo,?I  
        count = 0 a 3b/e8c  
        While GetOperationCount(eID)>count $L>@Ed<  
            GetOperation eID, count, op /vde2.|  
            If op.Type="ShiftZ" Then  |`f$tj  
                DeleteOperation eID,count 6C^ D#.S  
                count=count-1 ,p@y] cr  
            End If #*uL)2nR  
            count=count+1 .hP D$o  
        Wend ,j}6? Q  
    *_{j=sd  
        'Set new z-shift z^q0/'  
        op.Type = "ShiftZ" VT%NO'0  
        op.val1 = tlens TJpD{p}  
        op.parent = parID OwUhdiG  
        AddOperation eID, op ,I$`-$_'  
        Print "Set lens thickness = " & tlens vNY{j7l/W  
    %@ODs6 R0  
        '************************************************************************* f ue(UMF~  
        'Lens index of refraction AGO+p(6d=g  
        '************************************************************************* N/'b$m5= S  
        eID = FindMaterial( "Lens" ) JEwa &  
        GetModelMaterial eID, mat p8H'{f\G  
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        mat.Nd = nlens u+e{Mim  
        SetModelMaterial eID, mat *74MWF@IY  
        Print "Set lens index of refraction = " & nlens 5 +YH.4R  
    D|L9Vs`  
        '************************************************************************* fZzoAzfv2  
        'Pupil diameter Oo8VeRZ  
        '************************************************************************* `$<.pOm  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <8i//HOE  
    ]z;I _-  
        'Adjust pupil diameter (trimming volume inner hole) `?qF$g9u~  
    4 Y9`IgQ  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $Sx'sA2  
    k&q;JyUi  
        ' Adjust pupil location to just in front of the lens K5VWt)Z#  
        parID = FindFullName( "Geometry.Arizona Eye" ) 7P5)Z-K[  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z1f8/?`W  
        count = 0 K.nHii   
        While GetOperationCount(eID)>count f:,DWw`B  
            GetOperation eID, count, op [{,T.;'<j  
            If op.Type="ShiftZ" Then 4Zddw0|2  
                DeleteOperation eID,count 82qoGSD.  
                count=count-1 fS:&Ak ];  
            End If y`5 9A  
            count=count+1 #PW9:_BE  
        Wend FP`b>E qOH  
        op.Type = "ShiftZ" v2\FA(BPn  
        op.val1 = taq-0.01 _QE qk@ql  
        op.parent = parID G1tY)_-8[  
        AddOperation eID, op y0.'?6k  
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        Print "Set pupil diameter = " & pupilDiam c?*=|}N  
    Z'W =\rl  
        'Update AZ Eye subassembly Description :T$|bc  
        eID = FindFullName( "Geometry.Arizona Eye" ) S-b/S5  
        GetEntity eID, entity zOIDU  
        entity.Description = "Accommodation = " & A & "D" $am$ EU?s  
        SetEntity eID, entity beGa#JH,  
    EhvX)s  
        Update e@ 07  
        Print "DONE!" b<ZIWfs  
         uEP*iPLD@  
    End Sub P%VSAh\|n  
    }W8;=$jr  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: (Q!}9K3  
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    Accommodation = 4 Diopters v^NIx q}U  
    Pupil Diameter = 4 mm \fd v]f  
    Set aqueous humor thickness = 2.81  RVmh6m  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 /NFj(+&g+  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 , WYPU  
    Set lens thickness = 3.927 LEf^cM=>  
    Set lens index of refraction = 1.42672 u@M,qo`  
    Set pupil diameter = 4 0<@KG8@hI;  
    DONE! ~<5!?6Yt  
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    QQ:2987619807 U&OJXJd j  
     
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