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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 7'g'qUW+~  
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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。 ^.5`jdk  
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    模型 #-b0U[,.  
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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。 T=6fZ;7  
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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. ? +{=>{1  
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    光源 EugQr<sM#  
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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。 i[obQx S94  
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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。 ATq)8Rm\  
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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。 Rv R ,V  
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    图2. 字母F光源的设定方法光 ,VK! 3$;|  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 Xq"@Z  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 H]v"_!(\  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 M XB fX  
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    图5. 视网膜重点采样规格设定
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    脚本 {4u8~whLp  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: hVQ TW[  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 F$a?} }  
    余下的脚本计算与屈光度有关的所有参数。 .;6G?8`  
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    分析 YXC?q  
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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。 ,/ V'(\>  
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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 <.c@l,[.z  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 1iOQ8hD  
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    Dim entity As T_ENTITY ,,+ ~./)  
    Dim op As T_OPERATION Z  Mp  
    Dim mat As T_MODELMATERIAL _E({!t"`  
    Dim A As Double :Uu Py|>  
    Dim pupilDiam As Double gR `:)>  
    Dim eID As Long G$\2@RT9[  
    Dim parID As Long S30@|@fTz  
    Dim count As Integer :sT\-MpQvn  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !oXA^7Th6]  
    Dim tlens As Double, nlens As Double pa0'\  
    Dim curv As Double, conic As Double A=X2zm>9  
    Dim ok As Long C#]%  
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    Sub Main -"L)<J@gQ?  
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        '用户输入对话框 kqYvd]ss  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8.e k_ r  
            TextBox 220,21,40,21,.TextBox1 'default: 0 a$p2I+lX  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5- Q`v/w;  
            OKButton 40,91,90,21 Q ! 5P  
            CancelButton 190,91,90,21 @Yua%n6]#D  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 }K=T B}yY  
            TextBox 220,49,40,21,.TextBox2 'default: 4 &lYKi3}x  
        End Dialog ,j~ R ^j  
        Dim dlg As UserDialog ? C2 bA5 M  
    /*GRE#7S  
        ok = Dialog (dlg) H~~I6D{8  
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        If ok=0 Then    'cancel button was pressed EXz5Rue LV  
            Print "Execution cancelled." tK&.0)*=  
            End LX<c(i  
        End If 6p/gvpZ  
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        'Assign accommodation and pupil diameter & use defaults if field left empty kmM4KP#&|  
        If dlg.TextBox1 = "" Then @URLFMFi  
            A = 0           'Default accommodation t/cj z/]  
        Else ~Z5?\a2Ld  
            A = CDbl(dlg.TextBox1) NF=FbvNe  
        End If eafy5vN[zX  
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        If dlg.TextBox2 = "" Then q>&F%;q1]  
            pupilDiam = 4   'Default pupil diameter pj,.RcH@o  
        Else ;% *e}w0  
            pupilDiam = CDbl(dlg.TextBox2) v>Il #  
        End If ]>@; 2%YvY  
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        Print " " mQ#@"9l%  
        Print "Accommodation = " & A & " Diopters" RIX0AE  
        Print "Pupil Diameter = " & pupilDiam & " mm" v8Ncquv  
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        ' Calculate new parameters with accommodation . iq.H  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 8xmw-s)  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?Gl'-tV  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =S@$"_&  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @6GM)N\{[  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *Kt7"J  
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        tlens = 3.767 + 0.04*A                  'Lens thickness (7 Mn%Jp  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction vnz.81OR  
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        'Adjust parameters to account for accommodation SPsq][5eR  
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        '************************************************************************* {549&]/o  
        'Aqueous thickness (Position of Lens) w0~iGr}P  
        '************************************************************************* CzzG  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `. %;|"xR  
        GetCustomElement eID, entity iyOd&|.  
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        parID = FindFullName( "Geometry.Arizona Eye" ) *6*#"#D  
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        ' Delete any shift(s) in z ?9vBn  
        count = 0 #`GW7(M  
        While GetOperationCount(eID)>count +,>f-kaV  
            GetOperation eID, count, op aJMh>  
            If op.Type="ShiftZ" Then >^:g[6Sj  
                DeleteOperation eID,count o;Zoj}  
                count=count-1 }p t5.'l  
            End If '*>LZo4  
            count=count+1 &X+V}  
        Wend =&"Vf!7YR7  
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        'Set new shift in 5?;'26iC  
        op.Type = "ShiftZ" QVn0!R{  
        op.val1 = taq ^&&dO*0{  
        op.parent = parID DHt 8 f  
        AddOperation eID, op [tMf KO  
        Print "Set aqueous humor thickness = " & taq-0.55 LEhku4U.  
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        '************************************************************************* )[oU|!@  
        'Radius and conic constant of anterior lens Ef,@}S  
        '************************************************************************* @hzQk~Gdi  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xxkP4,(p  
        GetConic eID, entity, curv, conic FZ=6x}QZ  
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        SetConic eID, entity, 1/Rant, CCant 'dWJ#9C  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant YGWb!|Z$  
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        '************************************************************************* oTI*mGR1Z  
        'Radius and conic constant of posterior lens ]Vb#(2<2  
        '************************************************************************* f=K1ZD  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) tEN]0`  
        GetConic eID, entity, curv, conic lR.a3.~  
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        SetConic eID, entity, 1/Rpost, CCpost iLmU|jdE  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost FG#j0#|*  
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        '************************************************************************* u/.s rK!K  
        'Lens thickness (Position of posterior lens surface) R1Pnj  
        '************************************************************************* hsqUiB tc6  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) rG\m]C3E  
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        ' Delete any z-shift(s) &]LwK5SR  
        count = 0 5?O/Aub  
        While GetOperationCount(eID)>count Vj2GK"$v  
            GetOperation eID, count, op =rBFMTllM  
            If op.Type="ShiftZ" Then ,x Tbt4J  
                DeleteOperation eID,count #Ejly2C,  
                count=count-1 d:pp,N~2o  
            End If ]#BXaBVMY  
            count=count+1 Mxd fuFss  
        Wend \B}W(^\wg;  
    (Wx)YI  
        'Set new z-shift JG( <  
        op.Type = "ShiftZ" 8fe"#^"sR  
        op.val1 = tlens pRU6jV 6e)  
        op.parent = parID /yykOvUO  
        AddOperation eID, op 'nT#3/rL  
        Print "Set lens thickness = " & tlens ?1N0+OW   
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        '************************************************************************* tLvli>y@  
        'Lens index of refraction 1)YFEU&]  
        '************************************************************************* ;! 9_5Ar%  
        eID = FindMaterial( "Lens" ) ! 4oIx`  
        GetModelMaterial eID, mat > T-O3/KN  
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        mat.Nd = nlens F}AbA pTv  
        SetModelMaterial eID, mat J,D{dYLDD  
        Print "Set lens index of refraction = " & nlens T^nX+;:|  
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        '************************************************************************* 9{TOFjsF  
        'Pupil diameter I"!gzI`Sd  
        '************************************************************************* [e}]K:  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) bv+e'$U3  
    I L\mFjZ'  
        'Adjust pupil diameter (trimming volume inner hole) SRD&Uf0M  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" yBe/UFp+  
    =#V11j  
        ' Adjust pupil location to just in front of the lens (mD]}{>  
        parID = FindFullName( "Geometry.Arizona Eye" ) %om7h$D =`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B_&PK7vA  
        count = 0 sY6'y'a95  
        While GetOperationCount(eID)>count ('lnQD.Hd  
            GetOperation eID, count, op !6%G%ZG@3-  
            If op.Type="ShiftZ" Then ZF t^q /pw  
                DeleteOperation eID,count q@sH@-z4]  
                count=count-1 z<fEJN  
            End If x$Oz0[  
            count=count+1 ' " tieew  
        Wend :RQ[(zD]  
        op.Type = "ShiftZ" #NE^f2  
        op.val1 = taq-0.01 sy`s$E d!  
        op.parent = parID BdKtpje  
        AddOperation eID, op u#,]>;  
    :$tW9*\KY  
        Print "Set pupil diameter = " & pupilDiam ^0&] .m  
    Yo(B8}?0!  
        'Update AZ Eye subassembly Description Sy'>JHx  
        eID = FindFullName( "Geometry.Arizona Eye" ) >YfOR%mS4  
        GetEntity eID, entity 4eEs_R  
        entity.Description = "Accommodation = " & A & "D" =_H39)|T  
        SetEntity eID, entity OZ" <V^"`  
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        Update <S}qcjG  
        Print "DONE!" LF~#4)B  
         )q^vitkjup  
    End Sub q"Md)?5N  
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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: gQEV;hCO  
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    Accommodation = 4 Diopters '=H^m D+gl  
    Pupil Diameter = 4 mm 9y5 \4&v  
    Set aqueous humor thickness = 2.81 uJ`&hX  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 3XnXQ/({  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 #'8PFw\zw  
    Set lens thickness = 3.927 8Vn6* Xn  
    Set lens index of refraction = 1.42672 }j?S?=;m=  
    Set pupil diameter = 4 *X\c $ =*  
    DONE! 5);#\&B  
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    QQ:2987619807 !{Y#<tG]  
     
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