[技术]Arizona眼睛模型 [复制链接]

简介 ID{Pzmt-  
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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。 H8=vQy  
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模型 hz>yv@1  
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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。 " N`V
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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. JXI+k.fi  
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光源 dKN3ZCw*gF  
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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。 XQ4^:3Yc  
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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。 m%[
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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。 *|.y
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视网膜的散射 Kw5+4R(5  
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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。 #\!hBL @b  
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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。 uBL~AC3>O  
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脚本 ~?8x0  
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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： jJ{ w -$  
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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。 GT`<jzAiQ  
余下的脚本计算与屈光度有关的所有参数。 7_d#XKz@  
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分析 1_E3DXe  
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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。 [8J}da}  
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脚本代码 $R#L@iL-  

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Option Explicit     'Remove this to enable non-dimensioned variables to be used. A,CPR0g%  
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Dim entity As T_ENTITY EA{*%9 A  
Dim op As T_OPERATION z(#hL-{c  
Dim mat As T_MODELMATERIAL D@vvy6
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Dim A As Double W;@ae,^  
Dim pupilDiam As Double vYm&AD  
Dim eID As Long |h~/Zz=  
Dim parID As Long Cot\i\]jv  
Dim count As Integer L"^366M!  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (9q{J(44  
Dim tlens As Double, nlens As Double YGO7lar  
Dim curv As Double, conic As Double Ak-7}i  
Dim ok As Long FoXQ]X7"  
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Sub Main Y,Zv0-"  
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    '用户输入对话框 ^E?V+3mV  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %IXW|mi  
        TextBox 220,21,40,21,.TextBox1 'default: 0 V4i%|vV  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {EHG |  
        OKButton 40,91,90,21 zMqEMx9  
        CancelButton 190,91,90,21 h}<
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 \osQwGPV  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ?{P6AF-xcf  
    End Dialog =]mx"0i[  
    Dim dlg As UserDialog Y_YIJ@  
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    ok = Dialog (dlg) w=>mG-  
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    If ok=0 Then    'cancel button was pressed (eE}W~Z  
        Print "Execution cancelled." cZT.vA#  
        End /<(ik&%N  
    End If 1e| M6*  
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    'Assign accommodation and pupil diameter & use defaults if field left empty xVX||rrh  
    If dlg.TextBox1 = "" Then Yf`.Cq_:  
        A = 0           'Default accommodation Afl'-  
    Else 9+Hb`  
        A = CDbl(dlg.TextBox1) _%%"Y}  
    End If Z_WTMs:x!  
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    If dlg.TextBox2 = "" Then Bzt`9lg  
        pupilDiam = 4   'Default pupil diameter (uc)^lfX  
    Else p+D6Z'B  
        pupilDiam = CDbl(dlg.TextBox2) _VJwC|  
    End If { 4{{;   
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    Print " " Z*3}L  
    Print "Accommodation = " & A & " Diopters" ?^5*[H  
    Print "Pupil Diameter = " & pupilDiam & " mm" ?Gw89r  
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    ' Calculate new parameters with accommodation n{WJ.Y*  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness / {~h?P}  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens f+~!s 2uw  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens bu9&sQ;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens L4Y3\4xXO
 
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens X6 :~Rjim*  
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    tlens = 3.767 + 0.04*A                  'Lens thickness kovzB]  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 5)<jP
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    'Adjust parameters to account for accommodation HNT8~s.2  
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    '************************************************************************* 7E)7sd  
    'Aqueous thickness (Position of Lens) +N_%|!F-c  
    '************************************************************************* H;&t"Ql.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) e1Hx"7ew_  
    GetCustomElement eID, entity U8z"{  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !WnI`  
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    ' Delete any shift(s) in z ]~ UkD*Ct  
    count = 0 B(dL`]@Xm  
    While GetOperationCount(eID)>count FR"^?z
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        GetOperation eID, count, op KVy5/A/8c  
        If op.Type="ShiftZ" Then 5C?1`-&65V  
            DeleteOperation eID,count ir#^5e@  
            count=count-1 "r+<=JU>OV  
        End If h_!"CF<n  
        count=count+1 S}O\<6&  
    Wend czRh.kz,  
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    'Set new shift in cf!R  
    op.Type = "ShiftZ" 4*W7{MPY  
    op.val1 = taq ztpb/9J9  
    op.parent = parID iKY&gnu"  
    AddOperation eID, op `I$A;OPK7  
    Print "Set aqueous humor thickness = " & taq-0.55 UC@"<$'C  
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    '************************************************************************* ~!kbB4`WK  
    'Radius and conic constant of anterior lens @eWx4bl  
    '************************************************************************* +Z*%,m=N(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) tEs$+b  
    GetConic eID, entity, curv, conic ~]W8NaQB(  
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    SetConic eID, entity, 1/Rant, CCant p<e~x/@m*  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant m Y0C7i  
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    '************************************************************************* A>puk2s  
    'Radius and conic constant of posterior lens .YRSd  
    '************************************************************************* C-Z,L#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i$bBN$<b<  
    GetConic eID, entity, curv, conic y[rLk
 
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    SetConic eID, entity, 1/Rpost, CCpost k~ue^^r}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %Z4=3?5B"9  
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    '************************************************************************* !Ao
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    'Lens thickness (Position of posterior lens surface) !TFVBK  
    '************************************************************************* kn\>ZgU  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) r "R\  
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    ' Delete any z-shift(s) sh1()vT  
    count = 0
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    While GetOperationCount(eID)>count :*1w;>o)n  
        GetOperation eID, count, op =F4}  
        If op.Type="ShiftZ" Then Cn<x  
            DeleteOperation eID,count Tx(R3B+u7  
            count=count-1 9D,&)6  
        End If hj4Rr(T  
        count=count+1 b}:Z(L,\  
    Wend |=POV]K  
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    'Set new z-shift YaU A}0cW  
    op.Type = "ShiftZ" XvdhPOMy  
    op.val1 = tlens zBbTj IFQ  
    op.parent = parID LHb{9x  
    AddOperation eID, op 6D],275`J  
    Print "Set lens thickness = " & tlens L;"<8\vWB  
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    '************************************************************************* ,o)MiR9-[A  
    'Lens index of refraction J*k4&l  
    '************************************************************************* Y"@kvd  
    eID = FindMaterial( "Lens" ) ect?9S[!y  
    GetModelMaterial eID, mat !Xm:$KH  
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    mat.Nd = nlens 5IMH G%W7  
    SetModelMaterial eID, mat d
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    Print "Set lens index of refraction = " & nlens P*SXfb"HC  
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    '************************************************************************* /2:r
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    'Pupil diameter X$* 'D)  
    '************************************************************************* IQDWH/c  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #lO;G k{  
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    'Adjust pupil diameter (trimming volume inner hole) $sJn: 8z  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ?,j:Y0l.L  
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    ' Adjust pupil location to just in front of the lens <da! #12L  
    parID = FindFullName( "Geometry.Arizona Eye" ) Cv|:.y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) (;"ICk&  
    count = 0 K +~  
    While GetOperationCount(eID)>count J: LSGj
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        GetOperation eID, count, op JG[+e*8  
        If op.Type="ShiftZ" Then Q%7EC>V  
            DeleteOperation eID,count TDoYp  
            count=count-1 R/#*~tPi8  
        End If (\}IOCNS  
        count=count+1 Z|W=.RdA;  
    Wend x\jHk}Buj  
    op.Type = "ShiftZ" zE[c$KPP  
    op.val1 = taq-0.01 B;m18LDu  
    op.parent = parID 9hv\%_>o  
    AddOperation eID, op L,WKL.  
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    Print "Set pupil diameter = " & pupilDiam !rWib`%  
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    'Update AZ Eye subassembly Description '/j`j>'!^  
    eID = FindFullName( "Geometry.Arizona Eye" ) :* 'i\  
    GetEntity eID, entity C?O{l%0  
    entity.Description = "Accommodation = " & A & "D" oI>;O#  
    SetEntity eID, entity !hq7R]TC+  
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    Update H.9J}k1S  
    Print "DONE!" Cpj_mMtu  
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End Sub "K8qmggTq  
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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： alG}Aw#gS  
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Accommodation = 4 Diopters |9y&;3  
Pupil Diameter = 4 mm ; etH)  
Set aqueous humor thickness = 2.81 6?_Uow}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 (~P&$$qfD  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 p])km%zB(  
Set lens thickness = 3.927 L$b9|j7  
Set lens index of refraction = 1.42672 t`LH\]6@  
Set pupil diameter = 4 HZ|6&9we  
DONE! !yxb<