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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 n79DS(t  
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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。 $'I$n  
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    模型 ck4T#g;=  
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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。 fSQ3 :o  
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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. uN? O*h/(  
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    光源 ?#{2?%_  
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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。 ]@j"0F/`  
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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。 GXv o't@N  
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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。 q0KXuMK  
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    图2. 字母F光源的设定方法光 _-yF9g"I  
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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 j/`qd(=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。 vS,G<V3B  
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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。 VA&OI;=ri  
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    图5. 视网膜重点采样规格设定
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    脚本 }SvWC8  
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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: # *aGzF  
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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。 j &[WE7wf  
    余下的脚本计算与屈光度有关的所有参数。 %Fm;LQa ]  
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    分析 =&g}Y  
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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。 {3p7`h~  
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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 t=\[J+  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Mh/>qyS *2  
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    Dim entity As T_ENTITY #1hz=~YO  
    Dim op As T_OPERATION byxehJ6[V  
    Dim mat As T_MODELMATERIAL o0+BQ&A)s*  
    Dim A As Double <XcMc<h~  
    Dim pupilDiam As Double ``)1`wx$  
    Dim eID As Long $m0x8<7nu  
    Dim parID As Long |l\/ {F  
    Dim count As Integer 7a_n\]t465  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double fy-Z{  
    Dim tlens As Double, nlens As Double v.&*z48  
    Dim curv As Double, conic As Double {gHscj;SM  
    Dim ok As Long ]f @LhC1x  
    nZ+5@( *  
    Sub Main yl+)I  
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        '用户输入对话框 Dj&bHC5%  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 csA.3|rv  
            TextBox 220,21,40,21,.TextBox1 'default: 0 dX}dO)%m{  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b2kbuk]  
            OKButton 40,91,90,21 v?=VZ~`O(  
            CancelButton 190,91,90,21 q@Yt`$VTN  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 JkDZl?x5  
            TextBox 220,49,40,21,.TextBox2 'default: 4 H D ^~4\%  
        End Dialog !w\;Q8irN  
        Dim dlg As UserDialog f]65iE?x  
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        ok = Dialog (dlg) . pEeR  
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        If ok=0 Then    'cancel button was pressed 9s6lt#?b  
            Print "Execution cancelled." T.N7`  
            End 2j BE+k"M  
        End If XFAt\g  
    TUYl><F5v=  
        'Assign accommodation and pupil diameter & use defaults if field left empty #;\;F PuZ  
        If dlg.TextBox1 = "" Then w3UJw  
            A = 0           'Default accommodation rX d2[pp  
        Else ^`5Yxpz  
            A = CDbl(dlg.TextBox1) eL4@% ]o  
        End If g' U^fN  
    ri V/wN9C  
        If dlg.TextBox2 = "" Then Y[]t_o)  
            pupilDiam = 4   'Default pupil diameter  ,qqV11P]  
        Else 0|vWwZq  
            pupilDiam = CDbl(dlg.TextBox2) hRcJ):Wyb  
        End If 9+|,aG s  
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        Print " "  +6-!o,(  
        Print "Accommodation = " & A & " Diopters" =W^L8!BE'  
        Print "Pupil Diameter = " & pupilDiam & " mm" 2 ~'quA  
    f TtMmz  
        ' Calculate new parameters with accommodation  Q'M Ez  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OB@t(KNx*P  
    .HJHJ.Js8X  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens &y+*3,!n8  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5-po>1g'  
    @= 9y5r  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens BJr Nbo;T  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a-5$GvG  
    0~+:~$VrT  
        tlens = 3.767 + 0.04*A                  'Lens thickness e-t`\5b;  
    9xp ;$14  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction F+r6/e6a  
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        'Adjust parameters to account for accommodation 0P >dXd)T  
    :HQ/vVw'"9  
        '************************************************************************* xq*yZ5:5Jo  
        'Aqueous thickness (Position of Lens) )ISTb  
        '************************************************************************* h:90K  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #<3\}*/  
        GetCustomElement eID, entity %c{)'X  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 0~+ k  
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        ' Delete any shift(s) in z |sAg@kM  
        count = 0 ,' B=eY,  
        While GetOperationCount(eID)>count [RuY'  
            GetOperation eID, count, op e /Y+S;a  
            If op.Type="ShiftZ" Then -lEh}r  
                DeleteOperation eID,count N`MQHQ1  
                count=count-1 ~`.%n7  
            End If J n/=v\K@  
            count=count+1 \}W.RQ^3  
        Wend $ 7!GA9Bn  
    mYX) =B{  
        'Set new shift in c5pG?jr+d  
        op.Type = "ShiftZ" (5 hu W7v  
        op.val1 = taq u>#'Y+7  
        op.parent = parID (#lS?+w)  
        AddOperation eID, op OwUbm0)h^V  
        Print "Set aqueous humor thickness = " & taq-0.55 X=~QE}x  
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        '************************************************************************* ^u{$$.&  
        'Radius and conic constant of anterior lens &|eQLY #l  
        '************************************************************************* ,Nh X%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 1uMdgrJRR  
        GetConic eID, entity, curv, conic !}?]&[N=  
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        SetConic eID, entity, 1/Rant, CCant o~p^`5#  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4G ?k31,k  
    !hUyX}{`j  
        '************************************************************************* g=Jfp$*[  
        'Radius and conic constant of posterior lens *fZ'#C~x  
        '************************************************************************* 2t<CAKBB  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K~R{q+  
        GetConic eID, entity, curv, conic 6yqp<D0SP)  
    8qveKS]vZ  
        SetConic eID, entity, 1/Rpost, CCpost \)*qW[C$a  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >{Djx  
    iDr0_y*t  
        '************************************************************************* C.O-iBVe#  
        'Lens thickness (Position of posterior lens surface) *d 4D9(  
        '************************************************************************* pm+[,u!i  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) d|3[MnU[a  
    #q%/~-Uk  
        ' Delete any z-shift(s) NT'Yh  
        count = 0 l]gf T&  
        While GetOperationCount(eID)>count Tec6]  :  
            GetOperation eID, count, op X@rAe37h+  
            If op.Type="ShiftZ" Then NG ~sE&,7  
                DeleteOperation eID,count KC'{>rt7  
                count=count-1 va\cE*,@ns  
            End If -[z;y73]t  
            count=count+1 dL>ZL1.$  
        Wend A7se#"w  
    %|Vq"MW,I  
        'Set new z-shift XQ>m8K?\d  
        op.Type = "ShiftZ" *&s_u)b  
        op.val1 = tlens lOZZ-  
        op.parent = parID Jh1fM`kB5K  
        AddOperation eID, op A]1](VQ)4  
        Print "Set lens thickness = " & tlens Flsf5 Tr0  
    ZC"p^~U_e[  
        '************************************************************************* H`sV\'`!}  
        'Lens index of refraction 0:nyOx(;  
        '************************************************************************* Nsb13mlY  
        eID = FindMaterial( "Lens" ) 'tekne  
        GetModelMaterial eID, mat L,$9)`j  
    ;IyQqP#,<  
        mat.Nd = nlens p)`JVq,H/B  
        SetModelMaterial eID, mat G 9;WO*  
        Print "Set lens index of refraction = " & nlens :7gIm|2"]  
    L fhd02  
        '************************************************************************* 5K0Isuu>>  
        'Pupil diameter $P$OWp?b  
        '************************************************************************* t5S S]  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) N]3XDd|q  
    ^VD14V3  
        'Adjust pupil diameter (trimming volume inner hole) ;TYkJH"  
    8WMC ~  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" s&4Y+dk93  
    yfj<P/aA+  
        ' Adjust pupil location to just in front of the lens czafBO6  
        parID = FindFullName( "Geometry.Arizona Eye" ) 3LG)s:p$/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) qbjRw!2?w  
        count = 0 9kcAMk1K  
        While GetOperationCount(eID)>count &W1c#]q@r  
            GetOperation eID, count, op !^w+<p  
            If op.Type="ShiftZ" Then "Mth<%i  
                DeleteOperation eID,count 3/iGSG`  
                count=count-1 278 6tZF,  
            End If @AJt/wPk  
            count=count+1 >354O6  
        Wend K:mb$YJ&  
        op.Type = "ShiftZ" {=TD^>?  
        op.val1 = taq-0.01 <3'r&ks  
        op.parent = parID 8@ b83  
        AddOperation eID, op xRb-m$B}L  
    ws@;2?%A  
        Print "Set pupil diameter = " & pupilDiam n<MH\.!tM  
    CZ|R-ky6p  
        'Update AZ Eye subassembly Description s {!F@^a  
        eID = FindFullName( "Geometry.Arizona Eye" ) dI3U*:$X  
        GetEntity eID, entity EI'(  
        entity.Description = "Accommodation = " & A & "D" f5AK@]4G  
        SetEntity eID, entity )]'?yS"  
    (V*ggii@  
        Update tR1 kn&w  
        Print "DONE!" :WE(1!P@  
         !RV}dhI  
    End Sub 1 Nv_;p.{  
    : -OHD#>%  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: |dXmg13( -  
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    Accommodation = 4 Diopters bX8Bn0#a+  
    Pupil Diameter = 4 mm ~)ls.NXI  
    Set aqueous humor thickness = 2.81 fDf:Jec`[  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 0GEK xV\F  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 /_v@YB!0  
    Set lens thickness = 3.927 @wb V@  
    Set lens index of refraction = 1.42672 (h%!Kun  
    Set pupil diameter = 4 sa{X.}i%E  
    DONE! ~!\n  
     
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