[技术]Arizona眼睛模型 [复制链接]

简介 .v1rrH?  
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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。 5jNBt>.0  
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模型 E=s`$ A  
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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。 {##A|{$3%  
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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. 3;:xEPb._6  
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光源 <Isr  
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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。 MeplM$9  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 }f-rWe{gs>  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 :cC`w
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视网膜的散射 .FMF0r>l  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 5~[Fh2+  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ,*lK4?v  
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脚本 _%L3?PpF"  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 0>?mF]M  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 fsmH];"GD  
余下的脚本计算与屈光度有关的所有参数。 ?t
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分析 LnyA5T  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 )eG&"3kFe!  
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脚本代码 Ux<h` s  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Ebk@x=
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Dim entity As T_ENTITY A
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Dim op As T_OPERATION Pb`sn5;  
Dim mat As T_MODELMATERIAL 0y1t
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Dim A As Double 50Jr(OeU<  
Dim pupilDiam As Double w##Fpv<m  
Dim eID As Long g!QumRF  
Dim parID As Long tw(2V$J  
Dim count As Integer 7xcYM  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tsa6: D  
Dim tlens As Double, nlens As Double u,]yd*  
Dim curv As Double, conic As Double G?g7G,|d  
Dim ok As Long S:j0&*  
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Sub Main g[n8N
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    '用户输入对话框 0jS/U|0  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 lt]U?VZ   
        TextBox 220,21,40,21,.TextBox1 'default: 0 !6%mt}h  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 OH(+]%B78  
        OKButton 40,91,90,21 \r2qH0B  
        CancelButton 190,91,90,21 /6fPC;l  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ) jvkwC  
        TextBox 220,49,40,21,.TextBox2 'default: 4 aD^MoB3  
    End Dialog (l,o UBRr  
    Dim dlg As UserDialog _aGdC8%[  
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    ok = Dialog (dlg) S.j
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    If ok=0 Then    'cancel button was pressed #(H_w4  
        Print "Execution cancelled." +u2Co_FJ&  
        End LKZI@i)  
    End If &|4Uo5qS=Z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty d7P @_jO6  
    If dlg.TextBox1 = "" Then ,+RO 5n  
        A = 0           'Default accommodation L_r &'B  
    Else {Vm36/a  
        A = CDbl(dlg.TextBox1) >KPJ74R  
    End If i=D,T[|>a  
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    If dlg.TextBox2 = "" Then &1{k^>oz  
        pupilDiam = 4   'Default pupil diameter $Da^z[8e  
    Else @FV;5M:I  
        pupilDiam = CDbl(dlg.TextBox2) yd~fC:_ ]  
    End If {;E/l(HNI  
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    Print " " /z5lxS@#  
    Print "Accommodation = " & A & " Diopters" GP$Y4*y/  
    Print "Pupil Diameter = " & pupilDiam & " mm" OKVYpf  
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    ' Calculate new parameters with accommodation %np#Bv-L  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ar|[D7Xrq\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,LZ:y1z'V-  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens x,dv~QU  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens l'T0<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 81cmG`G7  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ArYF\7P  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction o}A #-  
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    'Adjust parameters to account for accommodation Ak Tw?v'  
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    '************************************************************************* ;l()3;  
    'Aqueous thickness (Position of Lens) 0Q>|s_  
    '************************************************************************* a`*WpP\+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) WZ&@ JB  
    GetCustomElement eID, entity F*}Q^%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) h\d($Ki  
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    ' Delete any shift(s) in z zDyeAxh4  
    count = 0 ZPao*2xz  
    While GetOperationCount(eID)>count #\BI-zt  
        GetOperation eID, count, op k+$4?/A  
        If op.Type="ShiftZ" Then G3+a+=
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            DeleteOperation eID,count ;|QR-m2/  
            count=count-1 \STvBI?  
        End If p0y?GNQ  
        count=count+1 K)&XQ`&  
    Wend W;dzLgc  
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    'Set new shift in [V, ;X  
    op.Type = "ShiftZ" lMez!qx,=  
    op.val1 = taq 43=-pyp  
    op.parent = parID dY@Tt&k8E  
    AddOperation eID, op 0DIM]PS  
    Print "Set aqueous humor thickness = " & taq-0.55 \BaN5+
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    '************************************************************************* NoZ4['NI\  
    'Radius and conic constant of anterior lens ?{,)XFck  
    '************************************************************************* h_G|.7!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0C+yq'D~[  
    GetConic eID, entity, curv, conic HcVs(]tIW  
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    SetConic eID, entity, 1/Rant, CCant , )pt_"-XA  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant k`mrRs  
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    '************************************************************************* <VR&=YJ  
    'Radius and conic constant of posterior lens h;Ud
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    '************************************************************************* GdeR#%z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zw0 r i6  
    GetConic eID, entity, curv, conic n;^k
 
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    SetConic eID, entity, 1/Rpost, CCpost ilcy/  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost | ,l=v`/  
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    '************************************************************************* Doc'7P  
    'Lens thickness (Position of posterior lens surface) pD_eo6xX  
    '************************************************************************* r]EZ)qp^@  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) MY*>)us\  
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    ' Delete any z-shift(s) C+]q  
    count = 0 f.84=epv  
    While GetOperationCount(eID)>count p9}c6{Wp  
        GetOperation eID, count, op _E<O+leWf  
        If op.Type="ShiftZ" Then dms:i)L2  
            DeleteOperation eID,count y#Za|nt  
            count=count-1 2N8sq(LK{  
        End If ;7^j-6  
        count=count+1 fRa-bqQ  
    Wend vQTQS[
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    'Set new z-shift C`~4q<W'  
    op.Type = "ShiftZ" 2:HP5  
    op.val1 = tlens $s(4?^GP  
    op.parent = parID dYew7  
    AddOperation eID, op iMeRQYW  
    Print "Set lens thickness = " & tlens nK%/tdq  
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    '************************************************************************* Or#+E2%1E  
    'Lens index of refraction Gp3nR<+  
    '************************************************************************* L1!hF3G  
    eID = FindMaterial( "Lens" ) &0 )xvZ  
    GetModelMaterial eID, mat #b"5L2D`y'  
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    mat.Nd = nlens C(1A8  
    SetModelMaterial eID, mat wI]R+.  
    Print "Set lens index of refraction = " & nlens z2nUul(2  
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    '************************************************************************* vD)A)  
    'Pupil diameter .";tnC!e  
    '************************************************************************* ~SR(K{nf#.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) vLK\X$4  
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    'Adjust pupil diameter (trimming volume inner hole) 71<PEawL  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" NtA|#"^  
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    ' Adjust pupil location to just in front of the lens oA3W {  
    parID = FindFullName( "Geometry.Arizona Eye" ) j zmSFKg*  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) K,C$J I  
    count = 0 k.
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    While GetOperationCount(eID)>count ~q]|pD"\K|  
        GetOperation eID, count, op 3e!Yu.q:  
        If op.Type="ShiftZ" Then Puth8$  
            DeleteOperation eID,count 5Ckk5b  
            count=count-1 4z0R\tjT  
        End If F3Ak'h{Ay  
        count=count+1 C@UJOB  
    Wend K7[AiU_I  
    op.Type = "ShiftZ" DtJTnvG~B  
    op.val1 = taq-0.01 QC\g%MVG  
    op.parent = parID rMXOwkE  
    AddOperation eID, op ghJ,s|lH  
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    Print "Set pupil diameter = " & pupilDiam #EQx
  
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    'Update AZ Eye subassembly Description ;oY(I7  
    eID = FindFullName( "Geometry.Arizona Eye" ) \Sq"3_m4T  
    GetEntity eID, entity 74}eF)(me  
    entity.Description = "Accommodation = " & A & "D" B~_,>WG  
    SetEntity eID, entity mOz&6T<|  
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    Update HV$9b~(  
    Print "DONE!" .cH{WZ  
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End Sub Kixr6\  
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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： h[-d1bKwS  
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Accommodation = 4 Diopters 1|l)gfc
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Pupil Diameter = 4 mm $xUzFLh=`  
Set aqueous humor thickness = 2.81 dY4k9
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Set anterior lens radius = 10.4 and conic constant = -2.375869 ni"$[8U  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 6
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Set lens thickness = 3.927 6m-:F.k1(  
Set lens index of refraction = 1.42672 zU4V^N'  
Set pupil diameter = 4 ax72ehL}  
DONE! Mf;|z0UX