[分享]Arizona眼睛模型 [复制链接]

简介 a{{g<<H  
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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。 rj6#
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模型 ew"v{=X  
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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。 IpP~Uz  
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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. rk)##)  
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光源 Z!U)I-x&  
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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。 @:KJYm[  
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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。 4C FB"?n0  
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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。 :]J Ye*  
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视网膜的散射 Offu9`DiZ  
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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。 _cu:aktf2  
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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。 QcgfBsv96  
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脚本 F+@5C:<?  
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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： :H c0b=  
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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。 \|K;-pL  
余下的脚本计算与屈光度有关的所有参数。 !H ~<  
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分析 G#?Sfn O0  
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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。 s&NX@  
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脚本代码 &9Xhl''  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Z.M,NR  
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Dim entity As T_ENTITY ~j<+k4I~  
Dim op As T_OPERATION ezMI\r6  
Dim mat As T_MODELMATERIAL IV)<5'v  
Dim A As Double P><o,s"v  
Dim pupilDiam As Double PTEHP  
Dim eID As Long _vZ"4L+Iw+  
Dim parID As Long W16,Alf:  
Dim count As Integer LU9A#  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 'z$
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Dim tlens As Double, nlens As Double !=N"vD*  
Dim curv As Double, conic As Double 39=1f6I1  
Dim ok As Long 65Cg]Dt71  
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Sub Main phgm0D7
 
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    '用户输入对话框 ,%)6jYHRw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 yfm^?G|sW  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $5*WLG&AK  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a|?4)
 
        OKButton 40,91,90,21 h}xeChw]  
        CancelButton 190,91,90,21 m o:D9  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 lgb?)=  
        TextBox 220,49,40,21,.TextBox2 'default: 4 d.P\fPSD  
    End Dialog Rb{U+/gq  
    Dim dlg As UserDialog O/<K!;(@?  
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    ok = Dialog (dlg) V#`fs|e;y  
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    If ok=0 Then    'cancel button was pressed #cCL.p"]  
        Print "Execution cancelled." Q_Gi]M9  
        End dX)GPC-D7  
    End If /;
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    'Assign accommodation and pupil diameter & use defaults if field left empty uxzze~_+C  
    If dlg.TextBox1 = "" Then E~_]Lfs)  
        A = 0           'Default accommodation 8f3vjK'  
    Else J52 o g4l  
        A = CDbl(dlg.TextBox1) sUU{fNC6|  
    End If lHhUC16>  
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    If dlg.TextBox2 = "" Then k0Uyf~p~  
        pupilDiam = 4   'Default pupil diameter )kkhJI*v  
    Else afb+GA!  
        pupilDiam = CDbl(dlg.TextBox2) Qu]z)";7  
    End If ,Bal  

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    Print " " F  3'9u#
 
    Print "Accommodation = " & A & " Diopters" wV^V]c?U  
    Print "Pupil Diameter = " & pupilDiam & " mm" zBe8,, e  
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    ' Calculate new parameters with accommodation G3{=@Z1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |K|h+fgG6*  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens T9879[ZU\  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [mPjP%{=@  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?|ZTaX6A  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens as>L[jyG/  
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    tlens = 3.767 + 0.04*A                  'Lens thickness b/Xbs0q  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction PfZ+PqS  
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    'Adjust parameters to account for accommodation xQp|;oW;z  
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    '************************************************************************* C|o`k9I#  
    'Aqueous thickness (Position of Lens) QQV~?iW{~  
    '************************************************************************* {4-[r#R<M  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) b@2J]Ay E*  
    GetCustomElement eID, entity A4]s~Ur  
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    parID = FindFullName( "Geometry.Arizona Eye" ) {je-I9%OK  
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    ' Delete any shift(s) in z &zuG81F6  
    count = 0 Kk{<@v)  
    While GetOperationCount(eID)>count V}zEK0n(6  
        GetOperation eID, count, op D2,z)O%VK  
        If op.Type="ShiftZ" Then I'@Ydt2  
            DeleteOperation eID,count jr`Ess  
            count=count-1 6HlePTf8  
        End If Usta0Ag  
        count=count+1 b?j< BvQ  
    Wend %bdjBa}  
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    'Set new shift in ? mhs$g>  
    op.Type = "ShiftZ" tu5*Qp\  
    op.val1 = taq m{7(PHpw  
    op.parent = parID bl'z<S, '  
    AddOperation eID, op 5A4&+rdU  
    Print "Set aqueous humor thickness = " & taq-0.55 Y9`5G%  
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    '************************************************************************* UDL RCS8i  
    'Radius and conic constant of anterior lens :Pv*,qHE  
    '************************************************************************* c-Pw]Ju  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \{EpduwZ  
    GetConic eID, entity, curv, conic "XT"|KF|D  
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    SetConic eID, entity, 1/Rant, CCant 5
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >B>CB3U  
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    '************************************************************************* U.@*`Fg  
    'Radius and conic constant of posterior lens IO/4.m-aN#  
    '************************************************************************* @e'5E^
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) E(i[o?  
    GetConic eID, entity, curv, conic 0V!l,pg  
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    SetConic eID, entity, 1/Rpost, CCpost R9!Uo  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost hbcuK&  
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    '************************************************************************* yu;SH[{Wi  
    'Lens thickness (Position of posterior lens surface) G\a8B#hg  
    '************************************************************************* 2mq$H_  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XB[<;*Iz  
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    ' Delete any z-shift(s) 1U,1)<z~u  
    count = 0 RO3oP1@B  
    While GetOperationCount(eID)>count (4%YHS8  
        GetOperation eID, count, op /o2P+Xr8"  
        If op.Type="ShiftZ" Then q}FVzahv  
            DeleteOperation eID,count OK{xuX8u  
            count=count-1 =GXu 5 8  
        End If +L=*:e\j  
        count=count+1 0W%@gs5d
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    Wend u@3y&b  
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    'Set new z-shift $ F S_E
 
    op.Type = "ShiftZ" Gx 72  
    op.val1 = tlens e9E\% p  
    op.parent = parID _aPh(qprc  
    AddOperation eID, op wI5Yn h  
    Print "Set lens thickness = " & tlens uZi.HG{<)  
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    '************************************************************************* 1+7GUSIb  
    'Lens index of refraction I_q~*/<h  
    '************************************************************************* $@i"un;  
    eID = FindMaterial( "Lens" ) 2
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    GetModelMaterial eID, mat emW:C-/h/@  
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    mat.Nd = nlens _|''{kj(  
    SetModelMaterial eID, mat
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    Print "Set lens index of refraction = " & nlens Oi} T2I  
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    '************************************************************************* BtY%r7^o  
    'Pupil diameter tW;:-  
    '************************************************************************* **>/}.%?K  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #pHs@uvO  
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    'Adjust pupil diameter (trimming volume inner hole) vEG'HOP  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" )RsM!}  
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    ' Adjust pupil location to just in front of the lens 3u33a"nL8  
    parID = FindFullName( "Geometry.Arizona Eye" ) LG]3hz9^9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z* <y5  
    count = 0 ?tg  y|  
    While GetOperationCount(eID)>count *{o UWt  
        GetOperation eID, count, op -]:GL>b  
        If op.Type="ShiftZ" Then 6/ `.(fL1  
            DeleteOperation eID,count KL'zXkS  
            count=count-1 ]h9!ei [  
        End If X_$a,"'~)  
        count=count+1 eb|i3.  
    Wend w-$[>R[hw  
    op.Type = "ShiftZ" #;#3%?  
    op.val1 = taq-0.01 \/|)HElKR  
    op.parent = parID +!0eu>~_&  
    AddOperation eID, op s4H2/E
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    Print "Set pupil diameter = " & pupilDiam l =IeJh  
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    'Update AZ Eye subassembly Description rbqo"g`  
    eID = FindFullName( "Geometry.Arizona Eye" ) 4l8BQz}sb  
    GetEntity eID, entity
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    entity.Description = "Accommodation = " & A & "D" y/c%+Ca/  
    SetEntity eID, entity F&;   
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    Update W >
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    Print "DONE!" ->lu#;A5  
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End Sub vf~`eT  
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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： SNT5Amz!  
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Accommodation = 4 Diopters YH:8<O,{-  
Pupil Diameter = 4 mm k6\^p;!Y  
Set aqueous humor thickness = 2.81 ]|:uU  
Set anterior lens radius = 10.4 and conic constant = -2.375869 =sOo:s
 
Set posterior lens radius = -4.424557 and conic constant = -3.081019 @o
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Set lens thickness = 3.927 f*xpE`&  
Set lens index of refraction = 1.42672 (!?K7<Jv  
Set pupil diameter = 4 >P. 'CU  
DONE! dv N<5~  
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