[技术]Arizona眼睛模型 [复制链接]

简介 Je?V']lm  
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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。 \64
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模型 }B]FHpi  
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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。 AV8TP-Ls+  
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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. 5hD
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光源 r@n%  
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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。 n*;mFV0s  
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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。 Wh4lz~D\@  
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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。 Bq2}nDP  
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视网膜的散射 lX7#3ti:  
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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。 I~mw\K{.3M  
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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。 )lW<:?k  
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脚本 fmSA.z  
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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： )<~b*^kl\  
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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。 oF3#]6`;/  
余下的脚本计算与屈光度有关的所有参数。 %8$wod6  
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分析 {uhw ^)v  
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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。 "%Rx;xw|  
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脚本代码 D)!k  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. xAoozDj  
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Dim entity As T_ENTITY *.K}`89T  
Dim op As T_OPERATION c(eu[vj:  
Dim mat As T_MODELMATERIAL GEvif4  
Dim A As Double a-kU?&* y  
Dim pupilDiam As Double <vj&e(D^  
Dim eID As Long bGSgph  
Dim parID As Long ;PbyR}s  
Dim count As Integer QX8N p{g-  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double k r/[|.bq  
Dim tlens As Double, nlens As Double dFS+O;zE\  
Dim curv As Double, conic As Double *D9QwQ _|  
Dim ok As Long H-S28%.  
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Sub Main a1j6-p  
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    '用户输入对话框 +^%F8GB  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {X<tUco  
        TextBox 220,21,40,21,.TextBox1 'default: 0 AFY;;_Xks  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MqNp*n2  
        OKButton 40,91,90,21 PmTA3aH  
        CancelButton 190,91,90,21 "? R$9i  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 R!-RSkB  
        TextBox 220,49,40,21,.TextBox2 'default: 4 E>7[ti_p5  
    End Dialog LUCpZ3F1  
    Dim dlg As UserDialog ^h' wZ7-\  
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    ok = Dialog (dlg) |w:\fK[  
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    If ok=0 Then    'cancel button was pressed {Ji[d.cY  
        Print "Execution cancelled." UZdpKi@  
        End [g%oo3`A  
    End If /*8"S mte  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ty
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    If dlg.TextBox1 = "" Then N7[i443a  
        A = 0           'Default accommodation Qg4qjX](?  
    Else ~s !+9\Fi  
        A = CDbl(dlg.TextBox1) > ^D10Nf*  
    End If A}W&=m8!  
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    If dlg.TextBox2 = "" Then 2!l)%F`  
        pupilDiam = 4   'Default pupil diameter PInU-"gG  
    Else SB]|y-su  
        pupilDiam = CDbl(dlg.TextBox2) t\'URpa+5%  
    End If Pxl7zz&pl=  
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    Print " " $Y>LUZ)b&8  
    Print "Accommodation = " & A & " Diopters" y%z$_V]  
    Print "Pupil Diameter = " & pupilDiam & " mm" |2^cPnv?G&  
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    ' Calculate new parameters with accommodation TTBl5X  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #Z8<H  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,I[  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v vOG]2z  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens poQY X
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens XlR.Y~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness <Ms,0YKx  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \_0nH`  
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    'Adjust parameters to account for accommodation >e'6RZRLA  
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    '************************************************************************* c]#F^(-A`  
    'Aqueous thickness (Position of Lens) 11O^)_|c  
    '************************************************************************* 3)p#}_u{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) a%V6RyT4qW  
    GetCustomElement eID, entity 3~%9;.I3!  
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    parID = FindFullName( "Geometry.Arizona Eye" ) eG=Hyc  
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    ' Delete any shift(s) in z 4ZSc'9e9  
    count = 0 k0Rd:
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    While GetOperationCount(eID)>count p^<*v8,~7  
        GetOperation eID, count, op "NMX>a,(  
        If op.Type="ShiftZ" Then M9M~[[   
            DeleteOperation eID,count #J#x,BLI  
            count=count-1 1T!(M"'Ij  
        End If v[A)r]"j"M  
        count=count+1 Hj2E-RwG  
    Wend JPRo<jt=  
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    'Set new shift in s\@RJ[(<  
    op.Type = "ShiftZ" g\ilK:r}  
    op.val1 = taq 7A<X!
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    op.parent = parID x2%xrlv<J/  
    AddOperation eID, op a9}7K/Y=d  
    Print "Set aqueous humor thickness = " & taq-0.55 I($0&Y\De  
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    '************************************************************************* /m"O.17N  
    'Radius and conic constant of anterior lens 6QO[!^lY  
    '************************************************************************* N`,ppj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) J2W#vFe\  
    GetConic eID, entity, curv, conic BE>^;`K  
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    SetConic eID, entity, 1/Rant, CCant bys5IOP{]o  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (_1(<Jw  
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    '************************************************************************* UNY O P{  
    'Radius and conic constant of posterior lens v,, .2UR4  
    '************************************************************************* 57@6O-t-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) N5_`  
    GetConic eID, entity, curv, conic >oh7f|  
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    SetConic eID, entity, 1/Rpost, CCpost @@uKOFA?  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost bAOL<0RS9`  
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    '************************************************************************* _?~EWT   
    'Lens thickness (Position of posterior lens surface) ^`iqa-1  
    '************************************************************************* &"lSq2  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )@(IhU)
  
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    ' Delete any z-shift(s) [Z]%jABR  
    count = 0 !1m7^3l7j  
    While GetOperationCount(eID)>count 10}<n_I  
        GetOperation eID, count, op Dm{9;Abs%  
        If op.Type="ShiftZ" Then 9u?[{h.`B  
            DeleteOperation eID,count ?COLjk  
            count=count-1 #|j8vmfn$e  
        End If NdxPC~Z+  
        count=count+1 .o#A(3&n  
    Wend Dbl3ef  
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    'Set new z-shift SL[EOz#  
    op.Type = "ShiftZ" 9z#z9|hj)3  
    op.val1 = tlens @oKW$\  
    op.parent = parID GHWt3K:*w  
    AddOperation eID, op W*;r}!ro  
    Print "Set lens thickness = " & tlens A'6-E{  
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    '************************************************************************* EQ [K  
    'Lens index of refraction ^#gJf*'UE  
    '************************************************************************* h~pQ  
    eID = FindMaterial( "Lens" ) 9y}/ G  
    GetModelMaterial eID, mat ;:  xE'-  
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    mat.Nd = nlens NG5k9pJ  
    SetModelMaterial eID, mat ~F"w  
    Print "Set lens index of refraction = " & nlens 1<G,0Lt  
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    '************************************************************************* 0e +Qn&$#4  
    'Pupil diameter qDS~|<Y5  
    '************************************************************************* A'aYH`j  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1lYQR`Uh  
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    'Adjust pupil diameter (trimming volume inner hole)  CH$K_\  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" )mH(Hx  
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    ' Adjust pupil location to just in front of the lens K BlJJH`z{  
    parID = FindFullName( "Geometry.Arizona Eye" ) :#OaE,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tISb
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    count = 0 4(? Z1S  
    While GetOperationCount(eID)>count /H*[~b  
        GetOperation eID, count, op G%fXHAs.+  
        If op.Type="ShiftZ" Then ]tNB^  
            DeleteOperation eID,count [(; .D  
            count=count-1 XMF#l]P  
        End If BPSie0  
        count=count+1 -amNz.`[PR  
    Wend zmg :Z p=  
    op.Type = "ShiftZ" oXQI"?^+  
    op.val1 = taq-0.01 Y,m=&U  
    op.parent = parID 8&:dzS  
    AddOperation eID, op !jR 1!i  

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    Print "Set pupil diameter = " & pupilDiam _xM}*_<VP  
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    'Update AZ Eye subassembly Description /~{fPS  
    eID = FindFullName( "Geometry.Arizona Eye" ) YRu/KUT$ 7  
    GetEntity eID, entity -n:;/ere7-  
    entity.Description = "Accommodation = " & A & "D" *-3*51 jW  
    SetEntity eID, entity Iv{uk$^7S  
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    Update IK,aA;d  
    Print "DONE!" })?KpYk  
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End Sub uyoV)  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： }-@h H(  
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Accommodation = 4 Diopters POQ4&ChA  
Pupil Diameter = 4 mm c^~R%Bx  
Set aqueous humor thickness = 2.81 ^@$T>SB1  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gb26Y!7%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;Ouu+#s  
Set lens thickness = 3.927 ]YUst]gu3  
Set lens index of refraction = 1.42672 d z\yP v~  
Set pupil diameter = 4 xgIb4Y%  
DONE! *X2dS {