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    [技术]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: 2021-10-22
    简介 <xOv0B  
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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。 >_3+s~  
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    模型 'BY{]{SL  
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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。 7O6VnKl  
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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. 2,.%]U  
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    光源 fAMJFHW  
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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。 c5~d^  
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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。 # 3{g6[Y  
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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。 ^<L;"jl%  
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    图2. 字母F光源的设定方法光 -P!_<\q\l  
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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 rN3i5.*/t  
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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。 4 I}xygV  
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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。 U'IJwGRP  
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    图5. 视网膜重点采样规格设定
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    脚本 -OLXRc=  
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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: n ,<`.^  
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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。 \<ohe w  
    余下的脚本计算与屈光度有关的所有参数。 $)OUOv  
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    分析 Iq&S6l <0  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 -BWkPq!  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 A=X2zm>9  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. xJ"CAg|B  
    -"L)<J@gQ?  
    Dim entity As T_ENTITY % I]?xe6  
    Dim op As T_OPERATION f3h&K}x  
    Dim mat As T_MODELMATERIAL R#Z1+&='  
    Dim A As Double hv xvwV1  
    Dim pupilDiam As Double 5- Q`v/w;  
    Dim eID As Long )N QtjB$  
    Dim parID As Long a7G0  
    Dim count As Integer 4_,l[BhsQG  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q?C)5(  
    Dim tlens As Double, nlens As Double #UREFwSL  
    Dim curv As Double, conic As Double -C$Z%I7 0  
    Dim ok As Long lu @#)  
    Y =3:Q%X  
    Sub Main W-Cf#o  
    #&\hgsw/T  
        '用户输入对话框 AR\?bB~`c  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W%]sI n  
            TextBox 220,21,40,21,.TextBox1 'default: 0 [woR9azC  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g0.D36  
            OKButton 40,91,90,21 \K 01 F  
            CancelButton 190,91,90,21 @URLFMFi  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 SEY  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ki6`d?  
        End Dialog }I7/FqrD  
        Dim dlg As UserDialog ?MhRdY  
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        ok = Dialog (dlg) 3mn0  
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        If ok=0 Then    'cancel button was pressed ^o't &  
            Print "Execution cancelled." +P6#7.p`Z  
            End f}bUuQrH-!  
        End If }+`W[h&u  
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        'Assign accommodation and pupil diameter & use defaults if field left empty Yt*M|0bL  
        If dlg.TextBox1 = "" Then *?oQ6g(Nz  
            A = 0           'Default accommodation 6wzF6] @O  
        Else Yfy6o6*:  
            A = CDbl(dlg.TextBox1) |0w'+HaE~N  
        End If ] K7>R0  
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        If dlg.TextBox2 = "" Then =ox#qg.5  
            pupilDiam = 4   'Default pupil diameter  e4NT  
        Else > 3 JU  
            pupilDiam = CDbl(dlg.TextBox2) H<`[,t  
        End If < W,k$|w  
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        Print " " o]#Q6J  
        Print "Accommodation = " & A & " Diopters" TMG:fg&E~  
        Print "Pupil Diameter = " & pupilDiam & " mm" G;Y,C<)0k  
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        ' Calculate new parameters with accommodation ;:*o P(9k  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness }eb%"ZH4|  
    M@Q=!!tQ(  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 6K P!o  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens VO(Ck\i}  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^iubqtT]  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens S^)r,cC  
    *D<S \6=  
        tlens = 3.767 + 0.04*A                  'Lens thickness H'I|tPs  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !U>"H8}dv  
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        'Adjust parameters to account for accommodation J+\F)k>r  
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        '************************************************************************* sNvT0  
        'Aqueous thickness (Position of Lens) RYE::[O7  
        '************************************************************************* |[K7oa~#  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) QC<( rx  
        GetCustomElement eID, entity QY+#Vp<`  
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        parID = FindFullName( "Geometry.Arizona Eye" ) +nuv?QB/  
    ;~]&$2sk  
        ' Delete any shift(s) in z 8tA.d.8  
        count = 0 NG'VlT  
        While GetOperationCount(eID)>count o9wg<LP  
            GetOperation eID, count, op CG9X3%xO%  
            If op.Type="ShiftZ" Then lha )'   
                DeleteOperation eID,count NH 'RU`U)  
                count=count-1 `N(.10~  
            End If T|.Q81.NE  
            count=count+1 10#!{].#x  
        Wend ,zXL8T  
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        'Set new shift in qsvUJU  
        op.Type = "ShiftZ" h| UT/:  
        op.val1 = taq |B`-chK  
        op.parent = parID 18[f_0@ #  
        AddOperation eID, op iqy}|xAU  
        Print "Set aqueous humor thickness = " & taq-0.55 h!K B%4V  
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        '************************************************************************* e!4akKw4wD  
        'Radius and conic constant of anterior lens Qmn5umd=?\  
        '************************************************************************* >.{ ..~"K  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {Y/| 7Cl0  
        GetConic eID, entity, curv, conic Ka_UVKwMro  
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        SetConic eID, entity, 1/Rant, CCant J+IW  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $#RD3#=?u  
    do[K-r  
        '************************************************************************* ~|uCZ.;o  
        'Radius and conic constant of posterior lens On'3K+(_  
        '************************************************************************* J.<eX=<  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i[\[xfk  
        GetConic eID, entity, curv, conic xh-[]Jz(  
    ='VIbE@qC  
        SetConic eID, entity, 1/Rpost, CCpost _5`M( ;hL2  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :W1,s53  
    *<Ddn&_  
        '************************************************************************* )D[ypuM&  
        'Lens thickness (Position of posterior lens surface) V)@MM2,  
        '************************************************************************* 5ef&Ih.3  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tjd"05"@:  
    q#p)E=$  
        ' Delete any z-shift(s) :.35pp,0  
        count = 0 $AXz/fGV  
        While GetOperationCount(eID)>count {?!hUi+  
            GetOperation eID, count, op 19N:9;Ixz  
            If op.Type="ShiftZ" Then b]JN23IS2  
                DeleteOperation eID,count P);Xke  
                count=count-1 8^R>y  
            End If L}21[ N~ky  
            count=count+1 VuPET  
        Wend <khx%<)P  
    :mJM=FeJ  
        'Set new z-shift z9'0&G L  
        op.Type = "ShiftZ" <GNOT"z  
        op.val1 = tlens _yoG<qI  
        op.parent = parID QE#$bCw  
        AddOperation eID, op (C3d<a\:  
        Print "Set lens thickness = " & tlens O ,>&w5   
    z5vryhX_Z  
        '************************************************************************* UpIf t=@P  
        'Lens index of refraction 7S1!|*/ I  
        '************************************************************************* Bjo&  
        eID = FindMaterial( "Lens" ) CYn}wkz  
        GetModelMaterial eID, mat b@X@5SJFW  
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        mat.Nd = nlens %om7h$D =`  
        SetModelMaterial eID, mat B_&PK7vA  
        Print "Set lens index of refraction = " & nlens .lFSFJ??  
    l3afuD :  
        '************************************************************************* ua[\npz5  
        'Pupil diameter !<LS4s;  
        '************************************************************************* qnS7z%H8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) z8!u6odu %  
    i4pJIb  
        'Adjust pupil diameter (trimming volume inner hole) *Qf }4a0  
    YiJu48J  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <R(2 9QN  
    P X0#X=$  
        ' Adjust pupil location to just in front of the lens 6wd]X-G++  
        parID = FindFullName( "Geometry.Arizona Eye" ) wMUnZHd{|  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :I $2[K  
        count = 0 G 6, 8Xwk  
        While GetOperationCount(eID)>count 1CM1u+<iZ  
            GetOperation eID, count, op sWC"^ So  
            If op.Type="ShiftZ" Then ?qbp  
                DeleteOperation eID,count C IDL{i8  
                count=count-1 KCT8Q!\  
            End If I;v`o{  
            count=count+1 V[mQ;:=  
        Wend :A'!u r=\  
        op.Type = "ShiftZ" &f yFUg  
        op.val1 = taq-0.01 bS'r}  
        op.parent = parID a82mC r  
        AddOperation eID, op xY S%dLE"  
    UBVb#FNF  
        Print "Set pupil diameter = " & pupilDiam ul?BKV+3E  
    } 8P}L@q  
        'Update AZ Eye subassembly Description ?>y-5B[K/(  
        eID = FindFullName( "Geometry.Arizona Eye" ) V~_nyjrJM  
        GetEntity eID, entity )1vojp 4Za  
        entity.Description = "Accommodation = " & A & "D" ~ YK <T+  
        SetEntity eID, entity #{M -3  
    (*RybKoaA  
        Update -!0LIr:"  
        Print "DONE!" vO_quQ[.  
         N>R%0m<e  
    End Sub p.9v<I%0  
    <J)A_Kx[57  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: LU{Z  
    X*"K g  
    Accommodation = 4 Diopters *r`Yz}  
    Pupil Diameter = 4 mm 9^^#I ~-  
    Set aqueous humor thickness = 2.81 $dP)8_Z2  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 %D r?.e  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 j0~3[dyqU  
    Set lens thickness = 3.927 `X='g96C1  
    Set lens index of refraction = 1.42672 `0i3"06lr  
    Set pupil diameter = 4 '-IT@}  
    DONE! f}X8|GlBo  
     
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