[技术]Arizona眼睛模型 [复制链接]

简介 9fs-|E[5  
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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。 %t6-wWM97  
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模型 RcJtVOrd  
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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。 DC/Cz
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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. RhB)AUAj  
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光源 `YwJ.E  
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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。 [aA@V0l  
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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。 j[R.UB3J  
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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。 rp"5176  
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视网膜的散射 #C.  
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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。 )qMbk7:v\  
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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。 %x{kd8>u!  
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脚本 -n[(0n3c  
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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： $+n6V2^K)7  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 d8agM/F*/  
余下的脚本计算与屈光度有关的所有参数。 .QKyB>s  
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分析 Ng!d6]  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 o<3$|`S&  
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脚本代码 ,>b>I#{  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. *-5N0K<kQ  
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Dim entity As T_ENTITY m }HaJ  
Dim op As T_OPERATION %>=6v}f,+  
Dim mat As T_MODELMATERIAL 9NU0K2S  
Dim A As Double Y2 J-`o$5  
Dim pupilDiam As Double B1!xr-kC  
Dim eID As Long m#8PX$_  
Dim parID As Long /; Bmh=  
Dim count As Integer J+E,UiZU  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double O8bxd6xb  
Dim tlens As Double, nlens As Double EV{Ys}3M  
Dim curv As Double, conic As Double [H<TcT8  
Dim ok As Long kUS]g r~i  
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Sub Main 4%ooJi|)  
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    '用户输入对话框 u)<s*jk  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 RfTGTz@H  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9!uiQ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 CKK}Z;~:  
        OKButton 40,91,90,21 ]nB|8k=J  
        CancelButton 190,91,90,21 A|+QUPD  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 '-RacNY  
        TextBox 220,49,40,21,.TextBox2 'default: 4 RhHm[aN  
    End Dialog 7LVG0A2>7  
    Dim dlg As UserDialog BXYH&2]Q  
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    ok = Dialog (dlg) I@9'd$YY  
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    If ok=0 Then    'cancel button was pressed ySmbX  
        Print "Execution cancelled." [DM0'4  
        End OQKeU0v  
    End If @0@ZlHwM  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 8;DDCop 8L  
    If dlg.TextBox1 = "" Then ?![[la+f  
        A = 0           'Default accommodation kzRJzJquP  
    Else 6j<!W+~G  
        A = CDbl(dlg.TextBox1) ciS,  
    End If rYr*D[m]  
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    If dlg.TextBox2 = "" Then /gZyl|kdy  
        pupilDiam = 4   'Default pupil diameter @GFB{ ;=  
    Else , [|aWT%9  
        pupilDiam = CDbl(dlg.TextBox2) MWh Y&I+  
    End If 3J+2#ML  
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    Print " " !o /=,ZIx  
    Print "Accommodation = " & A & " Diopters" |R0f--;  
    Print "Pupil Diameter = " & pupilDiam & " mm" Q# B0JT1  
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    ' Calculate new parameters with accommodation f 5v&4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 9aJIq{`E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ai/|qYf  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3x0t[{l  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens sF{aG6u
 
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    tlens = 3.767 + 0.04*A                  'Lens thickness wfmM`4Y   
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction U-I,Q+[C[^  
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    'Adjust parameters to account for accommodation G@k]rwub  
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    '************************************************************************* Jay"  
    'Aqueous thickness (Position of Lens) `5IrV&a  
    '************************************************************************* vQljxRtW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?;ok9Y  
    GetCustomElement eID, entity T-e
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    parID = FindFullName( "Geometry.Arizona Eye" ) $^ws#}j  
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    ' Delete any shift(s) in z t*gZcw5 r  
    count = 0 4o*i(W  
    While GetOperationCount(eID)>count f4"UI-8;n  
        GetOperation eID, count, op .:$(o&  
        If op.Type="ShiftZ" Then Ktq4b%{  
            DeleteOperation eID,count {%R^8  
            count=count-1 X7},|cmD_  
        End If DiFYVR<@  
        count=count+1 V*giF`gq  
    Wend R~\R>\  
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    'Set new shift in QqA=QTZ}  
    op.Type = "ShiftZ" (~GQncqa  
    op.val1 = taq uuC [
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    op.parent = parID .^Sglo  
    AddOperation eID, op ubcB<=xb  
    Print "Set aqueous humor thickness = " & taq-0.55 -&1(~7  
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    '************************************************************************* v675C#l(  
    'Radius and conic constant of anterior lens .XJ'2yKof  
    '************************************************************************* H7zN|NdNw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {&=+lr_h?  
    GetConic eID, entity, curv, conic Q(bOar5  
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    SetConic eID, entity, 1/Rant, CCant 8xPt1Sotq[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ]r Uj<[O  
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    '************************************************************************* 6"Uu;Q  
    'Radius and conic constant of posterior lens t'n@yX_  
    '************************************************************************* vK',!1]y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 5\+*ml  
    GetConic eID, entity, curv, conic Xs0)4U  
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    SetConic eID, entity, 1/Rpost, CCpost }[AaI #  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost XF!L.'zH  
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    '************************************************************************* 2XP }:e  
    'Lens thickness (Position of posterior lens surface) g#5R||r  
    '************************************************************************* 4p
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7v5]%%E/  
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    ' Delete any z-shift(s) ingG  
    count = 0 a(gXvgrf[  
    While GetOperationCount(eID)>count (RddR{mX  
        GetOperation eID, count, op cQ8[XNa  
        If op.Type="ShiftZ" Then +:S`]  
            DeleteOperation eID,count Cv**iW  
            count=count-1 Gv-VDRS  
        End If 7(Fas(j3  
        count=count+1 w*F[[*j@.  
    Wend B7%K}|Qg  
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    'Set new z-shift & l>nzJ5?  
    op.Type = "ShiftZ" 4V@%Y,:ee  
    op.val1 = tlens d_9 Cm@  
    op.parent = parID gv*b`cl  
    AddOperation eID, op eZ'8JU]  
    Print "Set lens thickness = " & tlens ] ZV[}7I.  
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    '************************************************************************* +A}t_u3<  
    'Lens index of refraction +_5*4>MC  
    '************************************************************************* lw@Yn>eza  
    eID = FindMaterial( "Lens" ) q0.!T0i  
    GetModelMaterial eID, mat sscbf  
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    mat.Nd = nlens =7 l uV_5  
    SetModelMaterial eID, mat 3#7V1  
    Print "Set lens index of refraction = " & nlens qG9a!sj   
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    '************************************************************************* JipNI8\r  
    'Pupil diameter Z/Rp?Jz\j/  
    '************************************************************************* pN9!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) y``\^F  
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    'Adjust pupil diameter (trimming volume inner hole) <ToS&  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y{} ub]i  
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    ' Adjust pupil location to just in front of the lens `B%%2p&  
    parID = FindFullName( "Geometry.Arizona Eye" ) Mu3G/|t(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m$vq%[/#  
    count = 0 )N.3Q1g-  
    While GetOperationCount(eID)>count s)-An(Uw  
        GetOperation eID, count, op )D8op;Fn  
        If op.Type="ShiftZ" Then +( LH!\
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            DeleteOperation eID,count _^iY;&  
            count=count-1 q5f QTV  
        End If j7}mh  
        count=count+1 j.=:S;  
    Wend 6n9/`D!  
    op.Type = "ShiftZ" 9g6$"',H  
    op.val1 = taq-0.01 v "l).G?  
    op.parent = parID 2S8;=x}/  
    AddOperation eID, op }B0[S_mw  
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    Print "Set pupil diameter = " & pupilDiam lR?y tIY  
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    'Update AZ Eye subassembly Description fFJ7Y+^  
    eID = FindFullName( "Geometry.Arizona Eye" ) tA(oD4H9  
    GetEntity eID, entity 9\8ektq}Z  
    entity.Description = "Accommodation = " & A & "D" ]it. R-  
    SetEntity eID, entity ZqclmCi  
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    Update [ja^Bhu  
    Print "DONE!" }a"=K%b<\  
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End Sub [UwQi!^-O  
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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： vHi%UaD-y  
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Accommodation = 4 Diopters mm>l:M TF  
Pupil Diameter = 4 mm @b(@`yz.a  
Set aqueous humor thickness = 2.81 ilL%  
Set anterior lens radius = 10.4 and conic constant = -2.375869 h0F=5| B  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 gSFZ>v*6  
Set lens thickness = 3.927 =z. hJu  
Set lens index of refraction = 1.42672 ?`+VWa[,e  
Set pupil diameter = 4 .$\-{)  
DONE! %n$f#Ml_r