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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 C9+Dw#-f V  
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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。 N>T=L0`  
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    模型 <sF!]R&4  
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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。 rr6"Y&v  
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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. 5[hlg(eb  
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    光源 J2x$uO{Bn  
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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。 n/:Z{  
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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。 $M%}Oz3*  
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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。 %hrsE5k^,  
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    图2. 字母F光源的设定方法光 A` oa|k!U  
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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 ;2 \<M 6  
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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。 I\)N\mov e  
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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。 yzODF>KJ  
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    图5. 视网膜重点采样规格设定
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    脚本 VN1# 8{  
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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: vjY);aQ  
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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。 ~ly`u  
    余下的脚本计算与屈光度有关的所有参数。 GXGN;,7EV  
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    分析 }"!6Xm  
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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。 "`H=AX0  
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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 n C\(+K1%  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. mJU>f-l  
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    Dim entity As T_ENTITY gt(X!iN]  
    Dim op As T_OPERATION N GX-'w  
    Dim mat As T_MODELMATERIAL =Td#2V;0  
    Dim A As Double w;g)Iy6x  
    Dim pupilDiam As Double `XFX`1  
    Dim eID As Long $u(M 4(}  
    Dim parID As Long y?rK5Yos  
    Dim count As Integer Mr@<ZTw  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double @8T Vr2uy  
    Dim tlens As Double, nlens As Double Wl@0TUK  
    Dim curv As Double, conic As Double D"1vw<Ak  
    Dim ok As Long m&;zLBA;  
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    Sub Main @8}-0c  
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        '用户输入对话框 =2GP^vh  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 htNL2N  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Vf#oKPP1  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 98<bF{#0WM  
            OKButton 40,91,90,21 S:"z<O  
            CancelButton 190,91,90,21 &eLQ;<qO*|  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 U[H+87zg  
            TextBox 220,49,40,21,.TextBox2 'default: 4 xP|%rl4  
        End Dialog ]-+.lR%vd9  
        Dim dlg As UserDialog o>QFd x  
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        ok = Dialog (dlg) >"m@qkh  
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        If ok=0 Then    'cancel button was pressed 96([V|5K  
            Print "Execution cancelled." A$$R_3ne  
            End _tWfb}6;Zb  
        End If 9Le/'ovq  
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        'Assign accommodation and pupil diameter & use defaults if field left empty 519:yt   
        If dlg.TextBox1 = "" Then NC[GtAPD3  
            A = 0           'Default accommodation 0YTtA]|`4  
        Else ?Sd~u1w8K  
            A = CDbl(dlg.TextBox1) 1'@lg*^9  
        End If .P0Qs&i  
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        If dlg.TextBox2 = "" Then (qq$y #$  
            pupilDiam = 4   'Default pupil diameter ^QL/m\zq@%  
        Else U{:(j5m  
            pupilDiam = CDbl(dlg.TextBox2) ofJ]`]~VG  
        End If @{$Cv"6769  
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        Print " " # |*,zIYo  
        Print "Accommodation = " & A & " Diopters" V?L$ ys  
        Print "Pupil Diameter = " & pupilDiam & " mm" #B.w7y5*  
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        ' Calculate new parameters with accommodation Xxsnpb>  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )su <Ji*  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^Hhw(@`qf  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens r{N{! "G  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens GVHfN5bTqn  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens _XO)`D~  
    '2q xcco  
        tlens = 3.767 + 0.04*A                  'Lens thickness 94k)a8-!  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +qW w-8  
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        'Adjust parameters to account for accommodation ;h(;(  
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        '************************************************************************* 8UY=}R2C  
        'Aqueous thickness (Position of Lens) ))+9 8iU1s  
        '************************************************************************* 3K20f8g  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) SAxa7B/U2  
        GetCustomElement eID, entity 8KELN(o$ 7  
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        parID = FindFullName( "Geometry.Arizona Eye" ) f[I'j0H%  
    { `|YX_HS  
        ' Delete any shift(s) in z ~FCSq:_  
        count = 0 (l!D=qy  
        While GetOperationCount(eID)>count AqKx3p6  
            GetOperation eID, count, op |I^Jn@Mq:  
            If op.Type="ShiftZ" Then )PoI~km  
                DeleteOperation eID,count jvQ+u L  
                count=count-1 JE:n`l/p  
            End If !}Ou|r4_  
            count=count+1 D>#v 6XI  
        Wend /$.vHt 5nt  
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        'Set new shift in a=T7w;\h  
        op.Type = "ShiftZ" P(i2bbU  
        op.val1 = taq 0N[DV]  
        op.parent = parID ~JRu MP  
        AddOperation eID, op 96E7hp !:  
        Print "Set aqueous humor thickness = " & taq-0.55 iF_r'+j  
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        '************************************************************************* 'e)ze^Jq  
        'Radius and conic constant of anterior lens .q[sk  
        '************************************************************************* = Vr[V@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |3lAye,t)a  
        GetConic eID, entity, curv, conic `L[32B9  
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        SetConic eID, entity, 1/Rant, CCant T2PFE4+Dp  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant IS*"_o<AR  
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        '************************************************************************* d*:qFq_  
        'Radius and conic constant of posterior lens wQuaB6E  
        '************************************************************************* h \cK  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #2'&=?J1r  
        GetConic eID, entity, curv, conic w[vIPlSdS  
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        SetConic eID, entity, 1/Rpost, CCpost WuZ n|j'  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @`*YZq>p  
    Y'H/ $M N  
        '************************************************************************* ^^Q32XC,  
        'Lens thickness (Position of posterior lens surface) 5@rqU(]<  
        '************************************************************************* v%~ViOgL\  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %=O!K>^vt<  
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        ' Delete any z-shift(s) iKH T  
        count = 0 cYn}we}7  
        While GetOperationCount(eID)>count @z JZoJL]J  
            GetOperation eID, count, op >@e%,z  
            If op.Type="ShiftZ" Then 92_H!m/  
                DeleteOperation eID,count ssbyvzQ  
                count=count-1 'n.9qxY;  
            End If 'wq:F?viF  
            count=count+1 F(fr,m3  
        Wend rL/7wa  
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        'Set new z-shift R:m=HS_  
        op.Type = "ShiftZ" 3evfX[V#  
        op.val1 = tlens G'C^C[_W  
        op.parent = parID #@"rp]1xv  
        AddOperation eID, op %D0Ws9:|  
        Print "Set lens thickness = " & tlens /[dAgxL  
    Z'bMIdV  
        '************************************************************************* B&j+fi  
        'Lens index of refraction k8>^dZub  
        '************************************************************************* :2gO) 'cD  
        eID = FindMaterial( "Lens" ) -7VV5W  
        GetModelMaterial eID, mat ~'\u:Imuo  
    boB{Y7gO4  
        mat.Nd = nlens G"sc;nT  
        SetModelMaterial eID, mat ]h$TgX  
        Print "Set lens index of refraction = " & nlens /`@>v$oo  
    <bppu>&  
        '************************************************************************* SP1oBR"3  
        'Pupil diameter ToM*tXj  
        '************************************************************************* [+7X&B  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) T5+b{qA  
    ^P`'qfZ  
        'Adjust pupil diameter (trimming volume inner hole) &g>+tkC  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ub&29Qte  
    }}R!Y)  
        ' Adjust pupil location to just in front of the lens <u/({SZ&  
        parID = FindFullName( "Geometry.Arizona Eye" ) _J;a[Ky+[  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &" n9,$  
        count = 0  Vp4]  
        While GetOperationCount(eID)>count +c_CYkHJ/  
            GetOperation eID, count, op 8}@a?QS(&  
            If op.Type="ShiftZ" Then D8XXm lo  
                DeleteOperation eID,count "!?Ya{  
                count=count-1 PyE<`E  
            End If t4uxon  
            count=count+1 JwVv+9hh  
        Wend +=$G6uR$  
        op.Type = "ShiftZ" DO{4n1-U  
        op.val1 = taq-0.01 w Vmy`OV/  
        op.parent = parID M/;g|J jM  
        AddOperation eID, op Z`M Q+  
    U %l{>*q  
        Print "Set pupil diameter = " & pupilDiam I ]1fH  
    xbA2R4|  
        'Update AZ Eye subassembly Description _?<Fc8F  
        eID = FindFullName( "Geometry.Arizona Eye" ) ]h@:Y]  
        GetEntity eID, entity CB)#; |aDB  
        entity.Description = "Accommodation = " & A & "D" Mq$=zsj  
        SetEntity eID, entity Y [S^&pF  
    &ayoTE^0,  
        Update i[J',  
        Print "DONE!" aR $P}]H  
         p(%x&*)f  
    End Sub VTa8.(i6v  
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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: x #g,l2_!  
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    Accommodation = 4 Diopters AQZ\Kcr  
    Pupil Diameter = 4 mm H R  
    Set aqueous humor thickness = 2.81 =Y0m;-1M  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ESI}+  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 v>R.ou(  
    Set lens thickness = 3.927 ln7.>.F  
    Set lens index of refraction = 1.42672 XF6= xD  
    Set pupil diameter = 4 5N/;'ySAE_  
    DONE! L_|Y_=r."  
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