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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 &6Wim<*  
     9mv6  
    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。 )A;jBfr  
    FP6Jf I8  
    模型 IgF#f%|Q  
    )/v`k>E  
    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。 a'G[ !"  
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    Table 1. AZ眼睛模型的定义
    K!88 Nox(  
    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. toox`|  
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    光源 t1l4mdp  
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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。 1rmN)  
    N jA\*M9  
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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。 \?k"AtL  
    KU0;}GSNX}  
    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。 wB*}XJah  
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    图2. 字母F光源的设定方法光 0[OlJMVf  
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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 e]d\S] 5  
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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。 6FI`0j=~  
    ]n|lHZR  
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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。 NEMC  
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    图5. 视网膜重点采样规格设定
    I#t# %!InH  
    脚本 htqC~B{1E  
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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: x@"`KiEUs  
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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。 a`QKN rA2  
    余下的脚本计算与屈光度有关的所有参数。 \M-$|04Qt  
    ,Z]4`9c  
    分析 Q-S5("  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 h`p9H2}0  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 p[gq^5WuC  
    N]@e7P'9F  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. V\><6v  
    ~bk+JK- >  
    Dim entity As T_ENTITY !F*CEcB  
    Dim op As T_OPERATION 8:(e~? f6  
    Dim mat As T_MODELMATERIAL <DM:YWNa  
    Dim A As Double wrt^0n'r)c  
    Dim pupilDiam As Double 79(Px2H2  
    Dim eID As Long _:,U$W  
    Dim parID As Long _LSf )  
    Dim count As Integer -7l)mk  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double cn!Y7LVr  
    Dim tlens As Double, nlens As Double L%O( I  
    Dim curv As Double, conic As Double p^QB^HEV  
    Dim ok As Long )OcG$H NK  
    o5eFLJ6  
    Sub Main v/lQ5R1  
    (|<.7K N  
        '用户输入对话框 u~a@:D/F{G  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 UKxeN[fv  
            TextBox 220,21,40,21,.TextBox1 'default: 0 J deGQ  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 s\dF7/b  
            OKButton 40,91,90,21 c 7uryL  
            CancelButton 190,91,90,21 DN;An0 {MK  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  Enj],I  
            TextBox 220,49,40,21,.TextBox2 'default: 4 /?P="j#u  
        End Dialog &-0 eWwMW  
        Dim dlg As UserDialog HN tl>H  
    S7 Tem:/  
        ok = Dialog (dlg) D#,P-0+%  
    w_!]_6%{b  
        If ok=0 Then    'cancel button was pressed v(tr:[V  
            Print "Execution cancelled." Pa !r*(M)C  
            End 6+[7UH~pm^  
        End If q9&d24|  
    KzC`*U[  
        'Assign accommodation and pupil diameter & use defaults if field left empty mT2Fn8yC1  
        If dlg.TextBox1 = "" Then UF00K1dbz  
            A = 0           'Default accommodation _:tisr{  
        Else z2lEHa?w  
            A = CDbl(dlg.TextBox1) UE9r1g`z  
        End If C}{$'#DV2  
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        If dlg.TextBox2 = "" Then Wg+fT{[f|  
            pupilDiam = 4   'Default pupil diameter {~ngI<  
        Else n3kYVAgF  
            pupilDiam = CDbl(dlg.TextBox2) wz P")}[0  
        End If }~RH!Q1  
    ~\z\f} w  
        Print " " w<]Wg^dyQ  
        Print "Accommodation = " & A & " Diopters" b}[W[J}`  
        Print "Pupil Diameter = " & pupilDiam & " mm" YbrsXp"  
    zF[>K4  
        ' Calculate new parameters with accommodation f`j RLo*L  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness  ? h$>7|  
    vO)nqtw  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3'WS6B+  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens H[{ch t h  
    @"m? #  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens =y/VrF.bV  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens sGCV um}  
    ~ 0x9`~  
        tlens = 3.767 + 0.04*A                  'Lens thickness ;Vad| -  
    &OiJJl[9  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction '%>$\Lv  
    B%L0g.D"  
        'Adjust parameters to account for accommodation 'lU9*e9  
    IdlW[h3`[  
        '************************************************************************* v |XEC[F  
        'Aqueous thickness (Position of Lens) shlL(&Py  
        '************************************************************************* 8yH) 8:w  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) +x!V;H(  
        GetCustomElement eID, entity $zTjh~ 9  
    zX!zG<<K  
        parID = FindFullName( "Geometry.Arizona Eye" ) EV@xUq!x .  
    tF)aNtX4^  
        ' Delete any shift(s) in z /R< Q~G|\  
        count = 0 J}coWjw`q  
        While GetOperationCount(eID)>count R4"g? e  
            GetOperation eID, count, op |/g\N, ]  
            If op.Type="ShiftZ" Then TZq']Z)#  
                DeleteOperation eID,count _wg6}3  
                count=count-1 EY(@R2~#J  
            End If ti'a^(  
            count=count+1 ;fhFv&`mE  
        Wend \)ac,i@fy  
    @fp(uu  
        'Set new shift in e jwFQ'wTx  
        op.Type = "ShiftZ" Got5(^'c  
        op.val1 = taq G1Cn[F;e  
        op.parent = parID ;b$(T5  
        AddOperation eID, op S2" p(  
        Print "Set aqueous humor thickness = " & taq-0.55 :<s)QD  
    -\j}le6;c  
        '************************************************************************* =F ZvtcCa  
        'Radius and conic constant of anterior lens 9[|Ql  
        '************************************************************************* [t /hjm"$  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zQ}:_  
        GetConic eID, entity, curv, conic +"a . ,-f!  
    +GWeu0b(~  
        SetConic eID, entity, 1/Rant, CCant @7%nMTZ@&v  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant POc< G^  
    Gu&?Gn oc  
        '************************************************************************* Nl7"|()e  
        'Radius and conic constant of posterior lens >U9*  
        '************************************************************************* pHY~_^B4&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7vV3"uns  
        GetConic eID, entity, curv, conic .8CR \-  
    JPgV7+{b[  
        SetConic eID, entity, 1/Rpost, CCpost {3C~cK{  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost g^1M]1.f  
     x9 <cT'  
        '************************************************************************* )k3zOKZ;  
        'Lens thickness (Position of posterior lens surface) "-vm=d~\  
        '************************************************************************* }@}jwi)l  
    w/N.#s^  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Fp-d69Npo  
    &-9wU Z  
        ' Delete any z-shift(s) (eN\s98)/  
        count = 0 vI#\ Qe  
        While GetOperationCount(eID)>count ;|b D@%@  
            GetOperation eID, count, op 7[:9vY  
            If op.Type="ShiftZ" Then K3TMTY<p  
                DeleteOperation eID,count DVRE;+Jt  
                count=count-1 b3x!tuQn  
            End If cxrUk$f  
            count=count+1 `RfhxzI  
        Wend z:|4S@9  
    ) ]U-7  
        'Set new z-shift x\!Qe\lE  
        op.Type = "ShiftZ" '6fMF#X4F  
        op.val1 = tlens "a;JQ:  
        op.parent = parID "W|Sh#JF  
        AddOperation eID, op IC/'<%k  
        Print "Set lens thickness = " & tlens 4)-LlYS_d<  
    YrjF1hJ  
        '************************************************************************* y:D|U!o2V  
        'Lens index of refraction xRJv_=dT  
        '************************************************************************* Txfu%'2)e  
        eID = FindMaterial( "Lens" ) B+wSLi(  
        GetModelMaterial eID, mat |SZRO,7x  
    q/?#+d  
        mat.Nd = nlens ;4Y@xS2M  
        SetModelMaterial eID, mat g ` 6Xrf  
        Print "Set lens index of refraction = " & nlens ;c_X ^"d  
    n!&DLB1z  
        '************************************************************************* 8k]'P*9ulz  
        'Pupil diameter N0sf V  
        '************************************************************************* r@H<@Vuc  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (+38z)f  
    y|nMCkuX  
        'Adjust pupil diameter (trimming volume inner hole) Xp{+){Iu  
    b"t!nfgo  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Ja| ! fT  
    hJ>{`Tw  
        ' Adjust pupil location to just in front of the lens R>To L  
        parID = FindFullName( "Geometry.Arizona Eye" ) T#Qn\ 8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) eR D?O  
        count = 0 Z[yQKy  
        While GetOperationCount(eID)>count "6lf~%R"  
            GetOperation eID, count, op q[nX<tO  
            If op.Type="ShiftZ" Then C+cSy'VIK!  
                DeleteOperation eID,count d3+pS\&IX?  
                count=count-1 ~C{d2i  
            End If Lf&p2p?~c  
            count=count+1 !,+peMy  
        Wend ,o]"G[Jk  
        op.Type = "ShiftZ" m\__Fl  
        op.val1 = taq-0.01 .ZFs+8qU>  
        op.parent = parID gd R wh  
        AddOperation eID, op } '.l'%  
    \Q|1I  
        Print "Set pupil diameter = " & pupilDiam t]#y} V  
    4iBp!k7  
        'Update AZ Eye subassembly Description G\?fWqx  
        eID = FindFullName( "Geometry.Arizona Eye" ) { ,/mQ3  
        GetEntity eID, entity 7@$Hua,GY  
        entity.Description = "Accommodation = " & A & "D" En&ESW N  
        SetEntity eID, entity GN /]^{D  
    p\wE})mu  
        Update r;t0+aLc*  
        Print "DONE!" L@2T  
         %'nM!7w@I  
    End Sub 6n]fr9f  
    ( YF`#v6  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: F``$}]9KHD  
    ~z$vF  
    Accommodation = 4 Diopters 1D&Q{?RM  
    Pupil Diameter = 4 mm TggM/ @k  
    Set aqueous humor thickness = 2.81 YQvN;W  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 y5 $h  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ='q:Io?T  
    Set lens thickness = 3.927 qYBoo]}a  
    Set lens index of refraction = 1.42672 +N: K V}K  
    Set pupil diameter = 4 yjaX\Wb[z[  
    DONE! 6e(|t2^  
    G4vXPx%a8  
    Wp`wIe6  
    QQ:2987619807 QU_O9 BN  
     
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