[技术]Arizona眼睛模型 [复制链接]

简介 6VW&An[6r  
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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。 n' &:c}zKO  
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模型 RAPR-I;{  
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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。 HZKqGkE  
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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. %d3qMnYu  
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光源 )CKPzNf  
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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。 .]24V!J(1w  
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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。 h8'
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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。 jnho*,X  
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视网膜的散射 }LeizbU  
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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。 pr-=<[ d  
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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。 2+s#5K&i  
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脚本 \:y oS>G  
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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： \w#)uYK{i_  
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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。 !:baG]Y  
余下的脚本计算与屈光度有关的所有参数。 tzJ7wXRr  
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分析 z>]P_E~`}  
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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。 4g+Dp&U  
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脚本代码 /L{V3}[j  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. };Pdn7;1G:  
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Dim entity As T_ENTITY 45Hbg  
Dim op As T_OPERATION cS#
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Dim mat As T_MODELMATERIAL X{Ij30Bmv  
Dim A As Double o4U0kiI@  
Dim pupilDiam As Double *[Im].  
Dim eID As Long ,J(shc_F  
Dim parID As Long ]$~\GE^  
Dim count As Integer 0@yw#.j  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double w~4T.l#1  
Dim tlens As Double, nlens As Double #(7^V y&  
Dim curv As Double, conic As Double ULH<FDot  
Dim ok As Long
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Sub Main (}m2}  
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    '用户输入对话框 %0Ibi  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 IFsh"i  
        TextBox 220,21,40,21,.TextBox1 'default: 0 W#&BU-|2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ',Y`\X  
        OKButton 40,91,90,21 p~WX\;  
        CancelButton 190,91,90,21 !?)aZ |r  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 E(F?o.b  
        TextBox 220,49,40,21,.TextBox2 'default: 4 zJ)`snN|  
    End Dialog .WLwAL  
    Dim dlg As UserDialog }_=h]|6t  
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    ok = Dialog (dlg) ZZ>F ^t  
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    If ok=0 Then    'cancel button was pressed osn ,kD*  
        Print "Execution cancelled." wEZieHw  
        End 0YZ66VN!  
    End If J@A^k1B  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ^+w1:C5  
    If dlg.TextBox1 = "" Then (3WK2IM^  
        A = 0           'Default accommodation vd
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    Else xwub-yz  
        A = CDbl(dlg.TextBox1) []doLt;J  
    End If ka@yQ
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    If dlg.TextBox2 = "" Then T_[5 ZYy  
        pupilDiam = 4   'Default pupil diameter 4C[kj  
    Else @6M>x=n5  
        pupilDiam = CDbl(dlg.TextBox2) fu iTy72  
    End If rgo!t028^  
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    Print " " 8
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    Print "Accommodation = " & A & " Diopters" q'9;  
    Print "Pupil Diameter = " & pupilDiam & " mm" H#M;TjR  
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    ' Calculate new parameters with accommodation %%9T-+T  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H2'djZ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens >y+?Sz!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens JkI|Ojmm/  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Wr@q+Whq  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J| 1!4R~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness k*OHI/uiow  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction v%kl*K`*  
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    'Adjust parameters to account for accommodation i|0!yID0@  
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    '************************************************************************* L#WGOl  
    'Aqueous thickness (Position of Lens) IH`7ou{  
    '************************************************************************* \O]kf>nC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) - _~\d+>w  
    GetCustomElement eID, entity qT01@Bku  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 21my9Ui]  
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    ' Delete any shift(s) in z i*8j|  
    count = 0 OnyAM{$g  
    While GetOperationCount(eID)>count )=cJW(nfP  
        GetOperation eID, count, op b81cq,  
        If op.Type="ShiftZ" Then ol~ tfS  
            DeleteOperation eID,count 'J)9#  
            count=count-1 (1[Z#y[  
        End If ,."wxP2u  
        count=count+1 !hE F.S  
    Wend a5(9~.9  
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    'Set new shift in QVah4wFL*.  
    op.Type = "ShiftZ" efuiFN;  
    op.val1 = taq |[p]])
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    op.parent = parID {{)pb>E  
    AddOperation eID, op 2km0  
    Print "Set aqueous humor thickness = " & taq-0.55 3EH@tlTl  
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    '************************************************************************* 'UTMEN&  
    'Radius and conic constant of anterior lens VF+g+~  
    '************************************************************************* '3~m},0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s@g
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    GetConic eID, entity, curv, conic '*EKi  
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    SetConic eID, entity, 1/Rant, CCant %zR5q  Lb  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WqS$C;]%  
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    '************************************************************************* \tA
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    'Radius and conic constant of posterior lens VA`VDUG,  
    '************************************************************************* ;Zc0
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) CtUAbR  
    GetConic eID, entity, curv, conic ].Ra=^q  
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    SetConic eID, entity, 1/Rpost, CCpost w
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;kZJnN"y  
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    '************************************************************************* />uE)R$  
    'Lens thickness (Position of posterior lens surface) e.Q'l/g  
    '************************************************************************* r9<#R=r)}J  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -S&d5(
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    ' Delete any z-shift(s) 'Tskx  
    count = 0 69t6lB#;!  
    While GetOperationCount(eID)>count Q'Uv5p"X  
        GetOperation eID, count, op I0;gTpt9  
        If op.Type="ShiftZ" Then jaIcIc=Pf  
            DeleteOperation eID,count 7mn&w$MS4:  
            count=count-1 K,+z^{Hvh  
        End If XsSDz}dg  
        count=count+1 `Gx 5=Bm;  
    Wend "Y"`'U=v  
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    'Set new z-shift 9H53H"5q  
    op.Type = "ShiftZ" JUJrtKS  
    op.val1 = tlens o#D'"Tn!  
    op.parent = parID d7uS[tKqg  
    AddOperation eID, op [#AI!-  
    Print "Set lens thickness = " & tlens ,Ww.W'#P  
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    '************************************************************************* WpMm%G~'4t  
    'Lens index of refraction P,#l~\  
    '************************************************************************* uTdz$Nh  
    eID = FindMaterial( "Lens" ) KI].T+I  
    GetModelMaterial eID, mat .&Sjazk0XO  
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    mat.Nd = nlens \Hq=_}]F  
    SetModelMaterial eID, mat vrh2}biCR  
    Print "Set lens index of refraction = " & nlens ~wcp&D
 
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    '************************************************************************* mi@uX@
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    'Pupil diameter =AF;3  
    '************************************************************************* WopA7J,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) bn=7$Ax  
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    'Adjust pupil diameter (trimming volume inner hole) ty@D3l  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" B-|C%~fe  
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    ' Adjust pupil location to just in front of the lens ]w]:9w  
    parID = FindFullName( "Geometry.Arizona Eye" ) ACI.{`SrQ=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %][zn$aa|  
    count = 0 dV^ck+
 
    While GetOperationCount(eID)>count SPvKq=,
 
        GetOperation eID, count, op +xU=7
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        If op.Type="ShiftZ" Then <2LUq@Pg  
            DeleteOperation eID,count r jnf30  
            count=count-1 RF~c/en  
        End If 0&3zBL%Bo  
        count=count+1 %+(fdk-k+  
    Wend +JB*1dz>8  
    op.Type = "ShiftZ" I]
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    op.val1 = taq-0.01 oJc7az  
    op.parent = parID aCyn9Y$=  
    AddOperation eID, op dd@ D s  
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    Print "Set pupil diameter = " & pupilDiam qg*xdefQ%  
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    'Update AZ Eye subassembly Description aq9Ej]1b  
    eID = FindFullName( "Geometry.Arizona Eye" ) ApcE)mjpc  
    GetEntity eID, entity I@1VX5  
    entity.Description = "Accommodation = " & A & "D" /1hcw|cfC  
    SetEntity eID, entity w-Q=oEt  
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    Update z:0
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    Print "DONE!" ("=B,%F_  
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End Sub 3)l<'~"z<  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 9 vNz yh\  
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Accommodation = 4 Diopters iH-(_$f;  
Pupil Diameter = 4 mm cejD(!MKe  
Set aqueous humor thickness = 2.81 iP?lP= M  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2p*L~! iM  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 b^<7@tY  
Set lens thickness = 3.927 //#]CsFiP  
Set lens index of refraction = 1.42672 xz}=C:s
 
Set pupil diameter = 4 \~T&C5  
DONE! 8>:u%+C1c