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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 giw &&l=_  
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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。 R"t,xM  
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    模型 A[{yCn`tM  
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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。 j-}O0~Jz  
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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. _|I#{jK  
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    光源 }V`"s^  
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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。 ~P **O~  
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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。 AH7}/Rc  
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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。 5e^ChK0Q  
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    图2. 字母F光源的设定方法光 flbd0NB  
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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 iz PDd{[  
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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。 :tg)p+KB  
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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。 z46~@y%k  
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    图5. 视网膜重点采样规格设定
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    脚本 f r6 fj  
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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: cR<fJ[*  
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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。 @lrztM  
    余下的脚本计算与屈光度有关的所有参数。 c<Tf 2]vZE  
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    分析 +a{1)nCXe  
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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。 BUXpC xQ  
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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 j'"J%e]  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. E{P|)`,V  
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    Dim entity As T_ENTITY Z,Dl` w  
    Dim op As T_OPERATION j{+.tIzpq[  
    Dim mat As T_MODELMATERIAL ` 7V]y -  
    Dim A As Double .Vvx,>>D  
    Dim pupilDiam As Double #?- wm  
    Dim eID As Long [?N~s:}  
    Dim parID As Long ^o&. fQ*  
    Dim count As Integer ;+ hH  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M gi,$H  
    Dim tlens As Double, nlens As Double BuXqd[;K%  
    Dim curv As Double, conic As Double LBDjIpR6  
    Dim ok As Long T!)(Dv8@F  
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    Sub Main VQOezQs\  
    '3^'B0 3  
        '用户输入对话框 Ry6@VQ"NLb  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 T'Dv.h  
            TextBox 220,21,40,21,.TextBox1 'default: 0 v O_*yh1  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^WWQI+pk  
            OKButton 40,91,90,21 uiR8,H9*M  
            CancelButton 190,91,90,21 w@w(-F!%l  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'c$+sp ?  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Fd9 [pU  
        End Dialog z1X`o  
        Dim dlg As UserDialog R%[ c;i  
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        ok = Dialog (dlg) {V CWn95Z  
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        If ok=0 Then    'cancel button was pressed -r]W  
            Print "Execution cancelled." 3eQ&F~S  
            End @_}P-h  
        End If G2: agqL/  
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        'Assign accommodation and pupil diameter & use defaults if field left empty p9{mS7R9T  
        If dlg.TextBox1 = "" Then C,|,-CY  
            A = 0           'Default accommodation =fFP5e ['  
        Else d5:c^`  
            A = CDbl(dlg.TextBox1) FXkM#}RgNm  
        End If ,.FxIl ]  
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        If dlg.TextBox2 = "" Then FJ)$f?=Qd  
            pupilDiam = 4   'Default pupil diameter smo~7;  
        Else Yr[\|$H5  
            pupilDiam = CDbl(dlg.TextBox2) 4~Q/"hMSkO  
        End If L) T (<  
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        Print " " ~oY^;/ j  
        Print "Accommodation = " & A & " Diopters" d>qY{Fdz  
        Print "Pupil Diameter = " & pupilDiam & " mm" *u;Iw{.{  
    .U]-j\  
        ' Calculate new parameters with accommodation 1=Z0w +v{  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ji0@P'^;  
    v mk2{f,g  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens nZYBE030  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens TAW/zpps$  
    >tW#/\x{  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &gx%b*;`L0  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens { 9q4)R}G  
    Lt>IX")  
        tlens = 3.767 + 0.04*A                  'Lens thickness @b2aNS<T  
    9p(. A$  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 7J<5f)  
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        'Adjust parameters to account for accommodation XlR@pr6tw  
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        '************************************************************************* cSV aI  
        'Aqueous thickness (Position of Lens) Lw>N rY(Y  
        '************************************************************************* 7hPY_W y  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3)ywX&4"L  
        GetCustomElement eID, entity $-sHWYZ  
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        parID = FindFullName( "Geometry.Arizona Eye" ) =B@2#W#  
    )\$|X}uny&  
        ' Delete any shift(s) in z #AQV(;r7@  
        count = 0 v` 1lxX'*  
        While GetOperationCount(eID)>count oNF6<A(@$  
            GetOperation eID, count, op Ig>(m49d  
            If op.Type="ShiftZ" Then brUF6rQ  
                DeleteOperation eID,count O :Tj"@h  
                count=count-1 TOQP'/   
            End If TuaBm1S{f  
            count=count+1 i=2N;sAl  
        Wend FU4L6n  
    nAdf=D'P  
        'Set new shift in b d!Y\OD  
        op.Type = "ShiftZ" d/~9&wLSb  
        op.val1 = taq R (n2A$  
        op.parent = parID hp|YE'uYT  
        AddOperation eID, op `VguQl_,gA  
        Print "Set aqueous humor thickness = " & taq-0.55 '6%2.[ o  
    ?4T-@~~*`=  
        '************************************************************************* ' S/gmn  
        'Radius and conic constant of anterior lens :^h$AWR^f  
        '************************************************************************* \qJXF|z<K  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G]&qx`TBK  
        GetConic eID, entity, curv, conic nAlQ7 '  
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        SetConic eID, entity, 1/Rant, CCant -aCKRN85  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant FfT`;j  
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        '************************************************************************* Ml-6OvQ7g  
        'Radius and conic constant of posterior lens Uw<nxD/+  
        '************************************************************************* [ub e6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) sK?twg;D*|  
        GetConic eID, entity, curv, conic |M;7>'YNC*  
    )zDCu`  
        SetConic eID, entity, 1/Rpost, CCpost j^RmrOg ,  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost <lJ345Q  
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        '************************************************************************* a/xn'"eli  
        'Lens thickness (Position of posterior lens surface) M kXmA`cP  
        '************************************************************************* E|shs=I  
    SNk=b6`9  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z6MO^_m2  
    J\=*#*rJ1  
        ' Delete any z-shift(s)  K_}K@'  
        count = 0 ]u/sphPe  
        While GetOperationCount(eID)>count )MT}+ai  
            GetOperation eID, count, op jq0O22 -R  
            If op.Type="ShiftZ" Then XC#oB~K'  
                DeleteOperation eID,count LCV(,lu  
                count=count-1 $U-0)4yf  
            End If s_p!43\J  
            count=count+1 S~G ]~gt  
        Wend t\O16O7S  
     &q*Aj17  
        'Set new z-shift QIFgQ0{  
        op.Type = "ShiftZ" -jm Y)(\  
        op.val1 = tlens +R75v)  
        op.parent = parID i SQu#p@  
        AddOperation eID, op |-~Y#]  
        Print "Set lens thickness = " & tlens * kh tJ]=  
    v4 E}D  
        '************************************************************************* @oGcuE  
        'Lens index of refraction goWuw}?  
        '************************************************************************* vtJJ#8a]  
        eID = FindMaterial( "Lens" ) "_?nN"A7  
        GetModelMaterial eID, mat AFt s(  
    ,|/f`Pl  
        mat.Nd = nlens Zx>=tx}  
        SetModelMaterial eID, mat \a3+rN dj  
        Print "Set lens index of refraction = " & nlens Q\0'lQJdy  
    ?:9"X$XR  
        '************************************************************************* V>3X\)qu  
        'Pupil diameter NvX[zqNP_R  
        '************************************************************************* 4s oJ.j8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G=bCNn<  
    :.`2^  
        'Adjust pupil diameter (trimming volume inner hole) u:  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %J-GKpo/S  
    1G`Pmh@  
        ' Adjust pupil location to just in front of the lens ~)M~EX&pK  
        parID = FindFullName( "Geometry.Arizona Eye" ) O^rDHFj,  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) u)Whr@m  
        count = 0 WTiD[u  
        While GetOperationCount(eID)>count `kSZX:=};  
            GetOperation eID, count, op 9;If&uM  
            If op.Type="ShiftZ" Then l;E(I_ i)  
                DeleteOperation eID,count M)(DZ}  
                count=count-1 Rf% a'b  
            End If 0b 54fD=  
            count=count+1 b\,+f n  
        Wend )QJUUn#  
        op.Type = "ShiftZ" &#i"=\d  
        op.val1 = taq-0.01 B`sAk %  
        op.parent = parID 'Z]w^<  
        AddOperation eID, op PQE =D0  
    /g.U&oI]D  
        Print "Set pupil diameter = " & pupilDiam asqV~n  
    `EQL" =)  
        'Update AZ Eye subassembly Description yWf`rF{  
        eID = FindFullName( "Geometry.Arizona Eye" ) y>ktcuML  
        GetEntity eID, entity bW:!5"_{H  
        entity.Description = "Accommodation = " & A & "D" y<.5xq5_3  
        SetEntity eID, entity 1B\WA8  
    -tU'yKhn  
        Update lk=<A"^S  
        Print "DONE!" *yGGBqd  
         lmhLM. 2  
    End Sub dgP3@`YS  
    @E8+C8'  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: :Iz8aQ  
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    Accommodation = 4 Diopters A?0Nm{O;3v  
    Pupil Diameter = 4 mm og>uj>H&  
    Set aqueous humor thickness = 2.81 2+WaA ,   
    Set anterior lens radius = 10.4 and conic constant = -2.375869 2t1ZIyv3 D  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 -7|H}!DFT  
    Set lens thickness = 3.927 iJ|uvPCE  
    Set lens index of refraction = 1.42672 fTX;.M/%   
    Set pupil diameter = 4 8l">cVo]T  
    DONE! .ccp  
     
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