[技术]Arizona眼睛模型 [复制链接]

简介 G.2ij%Zz  
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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。 *B7+rd  
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模型 jseyT#2  
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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。 >#}MDwKZD  
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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. Mg H,"G  
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光源 >[ r TUn;  
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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。 T+z]ztO  
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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。 BJI}gm2y  
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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。 7XKPC+)1ya  
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视网膜的散射 D}|PBR  
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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。 FLI\SF<  
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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。 +0U{CmH  
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脚本 >$=-0?.  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： cstSLXD  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 6e,|HV  
余下的脚本计算与屈光度有关的所有参数。 :34#z.O  
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分析 L/1zG/@  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。  ,lX5-1H  
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脚本代码 &V7@ TZ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. :TU;%@7  
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Dim entity As T_ENTITY ,L#Qy>MOb  
Dim op As T_OPERATION sBP.P7u  
Dim mat As T_MODELMATERIAL \u@4eBAV  
Dim A As Double CW*Kd
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Dim pupilDiam As Double [:gPp)f,  
Dim eID As Long ;-p1z% u  
Dim parID As Long xW@y=l Cu  
Dim count As Integer yM$@*od  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double DQ7+  
Dim tlens As Double, nlens As Double O]{3aMs!Y  
Dim curv As Double, conic As Double S,Q!Xb@  
Dim ok As Long "&jA CI  
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Sub Main QC7Ceeh]4  
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    '用户输入对话框 WP,Ll\K)7  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _DPWp,k<~  
        TextBox 220,21,40,21,.TextBox1 'default: 0 n1OxT"tD  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ;,T3C:S?  
        OKButton 40,91,90,21 c$?(zt;  
        CancelButton 190,91,90,21 VW^6qf/,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Cz=HxU80J  
        TextBox 220,49,40,21,.TextBox2 'default: 4 zfvMH"1  
    End Dialog X._skq  
    Dim dlg As UserDialog A4RA5N/}  
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    ok = Dialog (dlg) oBZ\mk L  
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    If ok=0 Then    'cancel button was pressed j8p</gd  
        Print "Execution cancelled." <a/TDW  
        End UObI&*2  
    End If #/fh_S'Z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~B!O X  
    If dlg.TextBox1 = "" Then d-e6hI4b  
        A = 0           'Default accommodation Mf
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    Else *a_U2}N
 
        A = CDbl(dlg.TextBox1) -2NXQ+m ;  
    End If SMHQo/c r  
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    If dlg.TextBox2 = "" Then 2=Sv#  
        pupilDiam = 4   'Default pupil diameter eF]`?AeWQ  
    Else H&K(,4u^  
        pupilDiam = CDbl(dlg.TextBox2) S/YT V  
    End If g)7~vm2/,
 
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    Print " "  lJaR,,  
    Print "Accommodation = " & A & " Diopters" HUF],[N  
    Print "Pupil Diameter = " & pupilDiam & " mm" u{#}Lo>B #  
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    ' Calculate new parameters with accommodation zrt\]h+  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2$=U#!OtU  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens L%G/%*7;c  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,(d\!T/]'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ? yL3XB>  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens }DH3_M!  
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    tlens = 3.767 + 0.04*A                  'Lens thickness a=(D`lQ8  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L$R"?O7  
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    'Adjust parameters to account for accommodation aYTVY
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    '************************************************************************* KGsS2  
    'Aqueous thickness (Position of Lens) 50
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    '************************************************************************* k'O^HMAn!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) \o-9~C\c*  
    GetCustomElement eID, entity a%\6L  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ]=X6* E*/E  
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    ' Delete any shift(s) in z %6A."sePO  
    count = 0 Po(Y',xI[  
    While GetOperationCount(eID)>count x`7Ch3`4}  
        GetOperation eID, count, op 3y&N}'R(F  
        If op.Type="ShiftZ" Then X`-7: !+  
            DeleteOperation eID,count R]dN-'U  
            count=count-1 %:yp>nm  
        End If w'Y(doY,  
        count=count+1 ~_l@ _P5yz  
    Wend 12{F  
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    'Set new shift in 9jwcO)p^  
    op.Type = "ShiftZ" c@SNbY4}%  
    op.val1 = taq '6^+|1  
    op.parent = parID Z;=h=  
    AddOperation eID, op Zv[D{  
    Print "Set aqueous humor thickness = " & taq-0.55 ]~a;tF>Fw  
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    '************************************************************************* qq Vjx?bKe  
    'Radius and conic constant of anterior lens \[\4= !
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    '************************************************************************* Iax-~{B3AY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @wvgMu  
    GetConic eID, entity, curv, conic F747K);_  
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    SetConic eID, entity, 1/Rant, CCant 6XP>qI,AJ  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant w\V1pu^6@  
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    '************************************************************************* s<z`<^hRe  
    'Radius and conic constant of posterior lens ON(OYXj  
    '************************************************************************* Dx)>`yJk$;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) GGM|B}U p  
    GetConic eID, entity, curv, conic <K g=?wb  
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    SetConic eID, entity, 1/Rpost, CCpost ]|JQH  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost
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    '************************************************************************* V8w7U:K  
    'Lens thickness (Position of posterior lens surface) %w
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    '************************************************************************* R"wBDWs  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *|gY7Av*  
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    ' Delete any z-shift(s) J#>)+  
    count = 0 O'Mo/ u1-  
    While GetOperationCount(eID)>count 1'NJ[ C`  
        GetOperation eID, count, op }}
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        If op.Type="ShiftZ" Then ;\]&k  
            DeleteOperation eID,count bUzo>fm_  
            count=count-1 1 5heLnei  
        End If pD@:]VP  
        count=count+1 TdU'L:<4l  
    Wend 0dTHF})m  
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    'Set new z-shift "|Ke/0rGB  
    op.Type = "ShiftZ" /IxoS  
    op.val1 = tlens cv{icz,%w  
    op.parent = parID f7lt|.p  
    AddOperation eID, op $+k|\+iJ  
    Print "Set lens thickness = " & tlens vh$If0  
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    '************************************************************************* ~xa yGk  
    'Lens index of refraction 7z2Q!0Sz  
    '************************************************************************* ;tJ}*!z W  
    eID = FindMaterial( "Lens" ) NR>&1aRbyb  
    GetModelMaterial eID, mat HUFm@?  
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    mat.Nd = nlens 9xN`  
    SetModelMaterial eID, mat *g*~+B :  
    Print "Set lens index of refraction = " & nlens n2(`O^yd7C  
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    '************************************************************************* 2/iBk'd  
    'Pupil diameter 1!%T<!A.  
    '************************************************************************* @+6cKP  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) u?F^gIw  
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    'Adjust pupil diameter (trimming volume inner hole) MpVZL29)  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .iV-Y*3<  
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    ' Adjust pupil location to just in front of the lens O[|_~v:^  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;=UkTn}N?l  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e#AmtheZR  
    count = 0 +h)1NX;o1  
    While GetOperationCount(eID)>count Ihd{tmr<  
        GetOperation eID, count, op Pil_zQ4  
        If op.Type="ShiftZ" Then F-XL  
            DeleteOperation eID,count }*P?KV (  
            count=count-1 M9QYYo@  
        End If (Fj"<  
        count=count+1 IkuE|  
    Wend nK)hv95i_  
    op.Type = "ShiftZ" V}MRdt7  
    op.val1 = taq-0.01 9'=ZxV  
    op.parent = parID gF2,Jm@"6  
    AddOperation eID, op =D`:2k~ ,  
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    Print "Set pupil diameter = " & pupilDiam M1q_gHA  
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    'Update AZ Eye subassembly Description 7.*Mmx~]=  
    eID = FindFullName( "Geometry.Arizona Eye" ) d3]<'B:nb  
    GetEntity eID, entity Ftdx+\O_i&  
    entity.Description = "Accommodation = " & A & "D" 2xBYJoF(  
    SetEntity eID, entity 7fC:'1]G  
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    Update g_JSg
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    Print "DONE!" G-TD9Og
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End Sub b(Yxsy{U  
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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： n= q7*<l  
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Accommodation = 4 Diopters } 4ZWAzH  
Pupil Diameter = 4 mm -br): }f  
Set aqueous humor thickness = 2.81 @Hl+]arUh  
Set anterior lens radius = 10.4 and conic constant = -2.375869 1pz-jo,2'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &bigLe  
Set lens thickness = 3.927 y7Nd3\v [\  
Set lens index of refraction = 1.42672 AqT}^f
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Set pupil diameter = 4 PVSz%"
 
DONE! C;%1XFzM