[技术]Arizona眼睛模型 [复制链接]

简介 )Y~q6D K  
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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。 9<<$uf.B  
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模型 M4M 4*o  
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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。 =Z/'|;Vd_x  
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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. &{&lCBN  
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光源 ,Z_nV+l_  
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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。 V]H<:UE  
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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。 DWJ%r"aN  
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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。 $';'MoS  
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视网膜的散射 qa^x4xZM  
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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。 mm#U a/~1u  
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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。 9[T#uh!DC  
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脚本 +*0THol-  
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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： ?2EzNNcS  
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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。 xDADJ>u2K  
余下的脚本计算与屈光度有关的所有参数。 ^D4b\mF  
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分析 /Z2*>7HM8[  
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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。 NlcWnSv  
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脚本代码 /4~RlXf@  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. vMRKs#&8  

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Dim entity As T_ENTITY 4QIvxH  
Dim op As T_OPERATION u]dpA  
Dim mat As T_MODELMATERIAL gX(QRQ  
Dim A As Double MeplM$9  
Dim pupilDiam As Double (/*-M]>  
Dim eID As Long ;4qalxzu  
Dim parID As Long N,[M8n,  
Dim count As Integer I
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double IL
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Dim tlens As Double, nlens As Double \17)=W  
Dim curv As Double, conic As Double {Z?!*Ow  
Dim ok As Long wk
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Sub Main |g;XC^!%=o  
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    '用户输入对话框
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 pwZ &2&|  
        TextBox 220,21,40,21,.TextBox1 'default: 0 5~[Fh2+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 W}=2?vHV=  
        OKButton 40,91,90,21 Sr+1.77}  
        CancelButton 190,91,90,21 "V:UQ<a\  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 n--`zx-['  
        TextBox 220,49,40,21,.TextBox2 'default: 4 rW6w1  
    End Dialog 6w]]KA  
    Dim dlg As UserDialog HE,wEKp  
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    ok = Dialog (dlg) Hd2_Cg FB  
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    If ok=0 Then    'cancel button was pressed ovfw_  
        Print "Execution cancelled." rpXw 8  
        End K 6Gn  
    End If UNAuF8>K  
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    'Assign accommodation and pupil diameter & use defaults if field left empty >C&!# 3  
    If dlg.TextBox1 = "" Then ,}|V'y  
        A = 0           'Default accommodation Q@j:b]Y9  
    Else #UI`G3w<  
        A = CDbl(dlg.TextBox1) j68Gz5;j  
    End If ~,guw7F  
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    If dlg.TextBox2 = "" Then D
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        pupilDiam = 4   'Default pupil diameter kN) pi "  
    Else ]E3g8?L  
        pupilDiam = CDbl(dlg.TextBox2) wGxLs>| 4  
    End If ;
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    Print " " a
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    Print "Accommodation = " & A & " Diopters" rLXn35O  
    Print "Pupil Diameter = " & pupilDiam & " mm" 'qD9kJ`  
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    ' Calculate new parameters with accommodation g ` {0I[  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \ lKQ'_  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =0-qBodbl  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *w6N&  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens g[n8N
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens IpP0|:}  
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    tlens = 3.767 + 0.04*A                  'Lens thickness V:+bq`  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction iUKj:q:  
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    'Adjust parameters to account for accommodation *~"`&
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    '************************************************************************* 4~/6d9f  
    'Aqueous thickness (Position of Lens) ]aR4U`  
    '************************************************************************* D0P% .r"v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) lyPXlt  
    GetCustomElement eID, entity i_@RWka<  
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    parID = FindFullName( "Geometry.Arizona Eye" ) pWp2{G^XB  
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    ' Delete any shift(s) in z vqHJc2yYkZ  
    count = 0 ;n@C(hG  
    While GetOperationCount(eID)>count }X?*o`sW  
        GetOperation eID, count, op LNb![Rq  
        If op.Type="ShiftZ" Then 7AiCQWf9  
            DeleteOperation eID,count pSP_cYa#(#  
            count=count-1 bi[l,  
        End If Ed-gYL^<  
        count=count+1 ZL>V9UWN  
    Wend rifxr4c[X>  
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    'Set new shift in 6b|`[t  
    op.Type = "ShiftZ" &1{k^>oz  
    op.val1 = taq $Da^z[8e  
    op.parent = parID THp `!l  
    AddOperation eID, op |gz,Ip{  
    Print "Set aqueous humor thickness = " & taq-0.55 X A|`wAGP  
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    '************************************************************************* 1sjn_fPz  
    'Radius and conic constant of anterior lens #V6 -*  
    '************************************************************************* #77UKYj2L-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |DD?3#G01  
    GetConic eID, entity, curv, conic m{ fQL  
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    SetConic eID, entity, 1/Rant, CCant
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cZ>W8{G  
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    '************************************************************************* G#:!wI  
    'Radius and conic constant of posterior lens Oy&'zigJ  
    '************************************************************************* <^Tj}5)n  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^Q>*f/.KN  
    GetConic eID, entity, curv, conic F21[r!3  
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    SetConic eID, entity, 1/Rpost, CCpost 6hK"k  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gpWS_Dw9  
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    '************************************************************************* NO^t/(Z  
    'Lens thickness (Position of posterior lens surface) u2]g1XjeG  
    '************************************************************************* DZRxp,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) m!60.  
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    ' Delete any z-shift(s) )yW_O:  
    count = 0 ]F;]<_  
    While GetOperationCount(eID)>count `uA&w}(G  
        GetOperation eID, count, op Mq
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        If op.Type="ShiftZ" Then >` QX xTn  
            DeleteOperation eID,count !d.>r 7w  
            count=count-1 ]4mj 1g&C  
        End If G3+a+=
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        count=count+1 ;|QR-m2/  
    Wend QV$dKjMS  
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    'Set new z-shift K)&XQ`&  
    op.Type = "ShiftZ" ukf\*  
    op.val1 = tlens j#P4Le[t  
    op.parent = parID 9Fx z!-9m  
    AddOperation eID, op t[,T}BCy.  
    Print "Set lens thickness = " & tlens YO$b#  
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    '************************************************************************* $S8
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    'Lens index of refraction kZ-~ ;fBe  
    '************************************************************************* ',`4 U F  
    eID = FindMaterial( "Lens" ) [KI`e  
    GetModelMaterial eID, mat y~c[sW  
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    mat.Nd = nlens ( L\G!pP.  
    SetModelMaterial eID, mat BON""yIC   
    Print "Set lens index of refraction = " & nlens 3dDQz#  
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    '************************************************************************* S aet";pf`  
    'Pupil diameter G>S1Ld'MV  
    '************************************************************************* 8sF0]J[g{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) b%f2"e0g  
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    'Adjust pupil diameter (trimming volume inner hole) >m6,xxTR  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" A|_%'8  
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    ' Adjust pupil location to just in front of the lens {R!TUQ5  
    parID = FindFullName( "Geometry.Arizona Eye" ) *Gh8nQbh  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) A;j$rGx  
    count = 0 #u5;utY:F  
    While GetOperationCount(eID)>count W<N QUf[=  
        GetOperation eID, count, op pD_eo6xX  
        If op.Type="ShiftZ" Then 5`'au61/2  
            DeleteOperation eID,count PSqtZN  
            count=count-1 5YG@[ic  
        End If 2j/1@Z1j=  
        count=count+1 '`~(Fkj  
    Wend OjlB0  
    op.Type = "ShiftZ" X`v79`g_  
    op.val1 = taq-0.01 =
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    op.parent = parID b, **$  
    AddOperation eID, op p C2c(4  
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    Print "Set pupil diameter = " & pupilDiam ~v(M6dz~vk  
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    'Update AZ Eye subassembly Description VDu .L8  
    eID = FindFullName( "Geometry.Arizona Eye" ) ?]:EmP  
    GetEntity eID, entity awSS..g}L  
    entity.Description = "Accommodation = " & A & "D" \%?8jQ'tX  
    SetEntity eID, entity t
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    Update (VXx G/E3  
    Print "DONE!" K-Dk2(x  
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End Sub )"c]FI[}  
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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： ywQ!9 \  
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Accommodation = 4 Diopters =.f +}y  
Pupil Diameter = 4 mm W/Z
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Set aqueous humor thickness = 2.81 voej ~z+  
Set anterior lens radius = 10.4 and conic constant = -2.375869 pGb
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 Zj+}T  
Set lens thickness = 3.927 vD)A)  
Set lens index of refraction = 1.42672 .";tnC!e  
Set pupil diameter = 4 ~SR(K{nf#.  
DONE! vLK\X$4