[技术]Arizona眼睛模型 [复制链接]

简介 z6L>!=  
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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。 TYJnQ2m  
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模型 ~Hyyq-  
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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。 ==e#CSJq  
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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. Cr V2 V)|G  
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光源 &\6`[# bT  
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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。 .olPm3MC  
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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。 VATXsD  
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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。 x9o^9QJh  
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视网膜的散射 n%MYX'0  
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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。 Pguyf2/w  
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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。 sKG~<8M}  
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脚本 X5oW[  
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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： !Bd* L~D  
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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。 o|*|  
余下的脚本计算与屈光度有关的所有参数。 6L6~IX
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分析 cmGj0YUQ1  
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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。 5N3!!FFE  
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脚本代码 feq6!k7  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?o(X0  
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Dim entity As T_ENTITY J0*]6oD!  
Dim op As T_OPERATION ~:b:_ 5"  
Dim mat As T_MODELMATERIAL 5bznM[%xO  
Dim A As Double vyx\N{  
Dim pupilDiam As Double 53+rpU_  
Dim eID As Long ]E8<;t)#  
Dim parID As Long $E_vCB_  
Dim count As Integer lbuW*)  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5iI3u 7Mn1  
Dim tlens As Double, nlens As Double ):\{n8~  
Dim curv As Double, conic As Double .8PO7#  
Dim ok As Long y>cmKE  
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Sub Main B[_bJ *  
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    '用户输入对话框 3(GrDO9^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .s*EV!SE  
        TextBox 220,21,40,21,.TextBox1 'default: 0 [QqNsco)  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 S{)n0/_  
        OKButton 40,91,90,21 Am?Hkh2  
        CancelButton 190,91,90,21 >dm._*M  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Yg,WdVI&@  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ;@Hi*d[  
    End Dialog kRXg."b(  
    Dim dlg As UserDialog bq&S?! =s  
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    ok = Dialog (dlg) pr,1Wp0l  
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    If ok=0 Then    'cancel button was pressed irw
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        Print "Execution cancelled." NlEWm8u  
        End "PScM9)\  
    End If m#K

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    'Assign accommodation and pupil diameter & use defaults if field left empty dQ|Ht[s=  
    If dlg.TextBox1 = "" Then hSKH#NS  
        A = 0           'Default accommodation hYv 6-5_  
    Else Aag)c~D  
        A = CDbl(dlg.TextBox1) /\$|D&e  
    End If ~_j%nJ &2  
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    If dlg.TextBox2 = "" Then YB1DL^:  
        pupilDiam = 4   'Default pupil diameter t\bxd`,  
    Else 9}0Jc(B/x  
        pupilDiam = CDbl(dlg.TextBox2) M-K@n$k  
    End If 3N*C]  
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    Print " " I_I;.Ik  
    Print "Accommodation = " & A & " Diopters" @wg
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    Print "Pupil Diameter = " & pupilDiam & " mm" $#J
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    ' Calculate new parameters with accommodation 0@x$Cp  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness SVWSO  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @%G"i:HZ&  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens sH,)e'0  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )bU")  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens m9w ;a  
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    tlens = 3.767 + 0.04*A                  'Lens thickness NWwtq&pz2  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction /~huTKA}  
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    'Adjust parameters to account for accommodation A?k,}~  
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    '************************************************************************* -?`l<y(  
    'Aqueous thickness (Position of Lens) U9sub6w6  
    '************************************************************************* s:F+bG}|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q09~vFBg  
    GetCustomElement eID, entity =d.W'q|  
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    parID = FindFullName( "Geometry.Arizona Eye" ) afq +;Sh  
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    ' Delete any shift(s) in z }4]x"DfIg  
    count = 0 [y;ZbfMP|o  
    While GetOperationCount(eID)>count <U`Nb) &  
        GetOperation eID, count, op QO1Gq9  
        If op.Type="ShiftZ" Then T\CQ  
            DeleteOperation eID,count Awf=yE:  
            count=count-1 @_ZW
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        End If c;}n=7,>:L  
        count=count+1 B_jI!i{N%o  
    Wend f|1FqL+T]  
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    'Set new shift in b+apNph  
    op.Type = "ShiftZ" s(Bi&C\  
    op.val1 = taq l8us6  
    op.parent = parID O[B_7  
    AddOperation eID, op ,8?*U]}  
    Print "Set aqueous humor thickness = " & taq-0.55 sn`?Foh  
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    '************************************************************************* jN>UW}?  
    'Radius and conic constant of anterior lens x+`3G.  
    '************************************************************************* 2]f.mq_PD  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3
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    GetConic eID, entity, curv, conic #N}}8RL  
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    SetConic eID, entity, 1/Rant, CCant 4tNgK[6M  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant g c=|<(  
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    '************************************************************************* B#
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    'Radius and conic constant of posterior lens oD1=}  
    '************************************************************************* tO3B_zC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) wk/U"@lq  
    GetConic eID, entity, curv, conic aJ;R8(*;\  
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    SetConic eID, entity, 1/Rpost, CCpost iPNsEQ0We  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }gaKO 5  
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    '************************************************************************* uRhH_c-6C  
    'Lens thickness (Position of posterior lens surface) Ll48)P{+}V  
    '************************************************************************* me\)JCZpb{  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Yr0i9Qow  

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    ' Delete any z-shift(s) S@-X?Lu  
    count = 0 1H@F>}DP  
    While GetOperationCount(eID)>count 3e1"5~?'<  
        GetOperation eID, count, op dU n#'<g5  
        If op.Type="ShiftZ" Then [/]3:|  
            DeleteOperation eID,count lR^Qm|  
            count=count-1 ;yrcH+I$_  
        End If )A;<'{t #L  
        count=count+1 =J\7(0Dz4t  
    Wend -W vAmi  
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    'Set new z-shift mt7:`-  
    op.Type = "ShiftZ" EJY:C9W  
    op.val1 = tlens -ZJ:<  
    op.parent = parID "$9ZkADO  
    AddOperation eID, op xSZw,  
    Print "Set lens thickness = " & tlens <h0ptCB  
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    '************************************************************************* ]"_'o~  
    'Lens index of refraction qIp`'.#m  
    '************************************************************************* > xw+2<  
    eID = FindMaterial( "Lens" ) GrIdQi^8  
    GetModelMaterial eID, mat )BDi2: u  
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    mat.Nd = nlens IC~D?c0H:  
    SetModelMaterial eID, mat qxh\umm+2  
    Print "Set lens index of refraction = " & nlens hG)lVo!L4j  
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    '************************************************************************* )I_I?e  
    'Pupil diameter cd#TKmh7re  
    '************************************************************************* SNFz#*
  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Stpho4+/y  
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    'Adjust pupil diameter (trimming volume inner hole) Rwk|

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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" A}# Mrb  
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    ' Adjust pupil location to just in front of the lens (reD  
    parID = FindFullName( "Geometry.Arizona Eye" ) LA5rr}<K  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %yVZ|d*Q  
    count = 0 llJ)u!=5  
    While GetOperationCount(eID)>count __[q`  
        GetOperation eID, count, op L3\{{QOA  
        If op.Type="ShiftZ" Then F9" K  
            DeleteOperation eID,count q\<vCKI-^  
            count=count-1 d=XhOC$  
        End If ~@bKQ>Xw  
        count=count+1 ^4:= b  
    Wend k:.c(_2M  
    op.Type = "ShiftZ" e2Dj%=`EU  
    op.val1 = taq-0.01 dewu@  
    op.parent = parID ]]4E)j8  
    AddOperation eID, op B~IOM  
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    Print "Set pupil diameter = " & pupilDiam R<)uvW_@  
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    'Update AZ Eye subassembly Description Qt$Q/<8U  
    eID = FindFullName( "Geometry.Arizona Eye" ) ?{'Q}%  
    GetEntity eID, entity 1C{~!=6#  
    entity.Description = "Accommodation = " & A & "D" O<*iDd`(e  
    SetEntity eID, entity Ho/5e*X  
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    Update DzEixE-  
    Print "DONE!" JC-L80-  
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End Sub ?/~1z*XUW  
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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： tg:x}n  
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Accommodation = 4 Diopters u/AN| y  
Pupil Diameter = 4 mm q0<g#jK  
Set aqueous humor thickness = 2.81 (|-/S0
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Set anterior lens radius = 10.4 and conic constant = -2.375869 .B@;ch,  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Tm `CA0@  
Set lens thickness = 3.927 =uH`EkY:  
Set lens index of refraction = 1.42672 %K%z<R8  
Set pupil diameter = 4 %`~8j H@  
DONE! :;EzvRy