[技术]Arizona眼睛模型 [复制链接]

简介 *aWh]x9TlU  
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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。 lt:&lIW,3  
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模型 =A'JIssk  
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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。 |ZifrkD=  
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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. M!!vr8}  
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光源 W?E,"z  
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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。 n7Eh!<  
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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。 K8BlEF`  
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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。 rDoMz3[w  
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视网膜的散射 ELMz~vp  
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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。 S[
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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。 cyHbAtl  
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脚本 pG)dF@  
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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： s%Ph  
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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。 ~.U\Y  
余下的脚本计算与屈光度有关的所有参数。 qyKR]%yzi  
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分析 MwSfuP  
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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。 Q7v1xBM  
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脚本代码 Lp|n)29+du  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &1yErGXC  
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Dim entity As T_ENTITY T5T[$%]6  
Dim op As T_OPERATION Da6l=M  
Dim mat As T_MODELMATERIAL \k=%G_W  
Dim A As Double 0 .T5% _/  
Dim pupilDiam As Double #{?RE?nD  
Dim eID As Long 0Db=/sJ>  
Dim parID As Long wEI? 9  
Dim count As Integer ZXiJ5BZ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q\xDAOEL  
Dim tlens As Double, nlens As Double ;Q/1l=Bn  
Dim curv As Double, conic As Double Rx&.,gzj[  
Dim ok As Long N;!!*
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Sub Main *nHMQ/uf  
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    '用户输入对话框 e!w2_6?3  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 I|;zGmg#k  
        TextBox 220,21,40,21,.TextBox1 'default: 0 En&gI`3n  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7o!t/WEEq  
        OKButton 40,91,90,21 .s41Tc5u  
        CancelButton 190,91,90,21 mO]dP;,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 <)sL8G9Y  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ^vxNS[C`;  
    End Dialog e(b$L
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    Dim dlg As UserDialog ]EDCs?,  
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    ok = Dialog (dlg) U-,s/VQ?  
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    If ok=0 Then    'cancel button was pressed 4:b'VHW.  
        Print "Execution cancelled." " L,9.b  
        End l)jP!k  
    End If ?pd/cj^  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 4N7|LxNNl_  
    If dlg.TextBox1 = "" Then %i?v)EW  
        A = 0           'Default accommodation {KEmGHC4R  
    Else o:4#AkS  
        A = CDbl(dlg.TextBox1) }rs>B,=*k  
    End If ]8Xip/uE  
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    If dlg.TextBox2 = "" Then >$ro\/  
        pupilDiam = 4   'Default pupil diameter A =&`TfXu  
    Else mWn0"1C  
        pupilDiam = CDbl(dlg.TextBox2) 1B~Z1w  
    End If q68m*1?y  
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    Print " " TK~KM  
    Print "Accommodation = " & A & " Diopters" d(b~s2\i  
    Print "Pupil Diameter = " & pupilDiam & " mm" STg} Z  
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    ' Calculate new parameters with accommodation #!#s7^%K&  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "*MF
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens M&Ln'BC  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <viC~=k;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens X2:23j<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens _
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    tlens = 3.767 + 0.04*A                  'Lens thickness [U"/A1p  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction [9MbNJt 8~  
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    'Adjust parameters to account for accommodation &"J;  
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    '************************************************************************* Mk+G(4p  
    'Aqueous thickness (Position of Lens) ?Drq!?3PDc  
    '************************************************************************* ~ ^   
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .`v%9-5v  
    GetCustomElement eID, entity 9zIqSjos"  
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    parID = FindFullName( "Geometry.Arizona Eye" ) difX7)\  
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    ' Delete any shift(s) in z Un T\6u  
    count = 0 u3tT=5.D  
    While GetOperationCount(eID)>count Sw5-^2x0'  
        GetOperation eID, count, op kBoQjOV`  
        If op.Type="ShiftZ" Then ~gNFcJuy  
            DeleteOperation eID,count uaU2D-ft"  
            count=count-1 fz2}M:u  
        End If #5'
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        count=count+1 3hUP>F8  
    Wend 1v,R<1)&  
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    'Set new shift in $z 5kA9  
    op.Type = "ShiftZ" M:iH7K  
    op.val1 = taq X:g#&e_  
    op.parent = parID G|8>Q3D  
    AddOperation eID, op y=EVpd  
    Print "Set aqueous humor thickness = " & taq-0.55 F*>#Xr~/  
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    '************************************************************************* /4+(eI7  
    'Radius and conic constant of anterior lens !=a]Awr\  
    '************************************************************************* K' <[kh:cl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) BNI)y@E^X  
    GetConic eID, entity, curv, conic jiLJiYMg  
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    SetConic eID, entity, 1/Rant, CCant 1KBGML-K3  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7\R"RH-  
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    '************************************************************************* MxKTKBxQ  
    'Radius and conic constant of posterior lens 10OkrNQ  
    '************************************************************************* k6RVP:V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2+~gZxHq  
    GetConic eID, entity, curv, conic G43r85LO  
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    SetConic eID, entity, 1/Rpost, CCpost 1<_/Qu>V  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +{I" e,Nk  
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    '************************************************************************* =adHP|S  
    'Lens thickness (Position of posterior lens surface) ftl?x'P%  
    '************************************************************************* yO!M$aOn/  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :2,NKdD  
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    ' Delete any z-shift(s) |g!d[ct]
 
    count = 0 L G5_\sY!  
    While GetOperationCount(eID)>count <'SS IMr  
        GetOperation eID, count, op *h3iAcM8  
        If op.Type="ShiftZ" Then ,-8-Y>[  
            DeleteOperation eID,count }*xjO/Ey  
            count=count-1 ?# _{h  
        End If k,k>w#&  
        count=count+1 U,;796h  
    Wend \]5I atli  
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    'Set new z-shift 7}6CUo  
    op.Type = "ShiftZ" [Z#Sj=z  
    op.val1 = tlens #9!7-!4pW  
    op.parent = parID g<
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    AddOperation eID, op pq&[cA_w  
    Print "Set lens thickness = " & tlens c"Vp5lo0  
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    '************************************************************************* -C3[:g  
    'Lens index of refraction u;c W
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    '************************************************************************* yGAFQ|+  
    eID = FindMaterial( "Lens" ) Y68A+ B.  
    GetModelMaterial eID, mat Xo/H+[;X  
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    mat.Nd = nlens m|{^T/kIbQ  
    SetModelMaterial eID, mat ,qv\Y]  
    Print "Set lens index of refraction = " & nlens  -D'XxOI  
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    '************************************************************************* kmc"`Ogotw  
    'Pupil diameter Y7r;}^+WY  
    '************************************************************************* NjOUe?BQ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) jHn7H)F8  
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    'Adjust pupil diameter (trimming volume inner hole) tkr&Fs"t+  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" gK({InOP  
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    ' Adjust pupil location to just in front of the lens PgT8 1u  
    parID = FindFullName( "Geometry.Arizona Eye" ) 111A e*U  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) H)7v$A,5%  
    count = 0 /]!2k9u\  
    While GetOperationCount(eID)>count igk<]AwxS  
        GetOperation eID, count, op T>rmm7F  
        If op.Type="ShiftZ" Then Q+9:]Bt  
            DeleteOperation eID,count ~i>DF`w$  
            count=count-1 prz COw  
        End If -8Mb~Hfl0  
        count=count+1 U{M3QOF  
    Wend ?{B5gaU9F  
    op.Type = "ShiftZ" nM2<u[{gF  
    op.val1 = taq-0.01 NGl 8*Af
 
    op.parent = parID k)S1Zs~G  
    AddOperation eID, op ~a`[p
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    Print "Set pupil diameter = " & pupilDiam __.MS6"N  
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    'Update AZ Eye subassembly Description qfE0J;e   
    eID = FindFullName( "Geometry.Arizona Eye" ) u*)/e9C  
    GetEntity eID, entity }" vxYB!h3  
    entity.Description = "Accommodation = " & A & "D" *0!p_Hco  
    SetEntity eID, entity J~]@#=,v  
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    Update L4m Vk  
    Print "DONE!" xS/W}-dPv  
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End Sub D~ Y6%9  
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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： S1U0sP@o  
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Accommodation = 4 Diopters ya8p 4N{_  
Pupil Diameter = 4 mm aM;SE9/U  
Set aqueous humor thickness = 2.81 iv *$!\Cd  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @NRN#~S,_]  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 <7\j\`  
Set lens thickness = 3.927 Nbd4>
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Set lens index of refraction = 1.42672 ) bI.K[0^  
Set pupil diameter = 4 1~L;S  
DONE! P|$n