[技术]Arizona眼睛模型 [复制链接]

简介 giw &&l=_  
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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。 R"t,xM  
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模型 A[{yCn`tM  
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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。 j-}O0~Jz  
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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. _|I#{jK  
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光源 }V`"s^  
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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。 ~P**O~  
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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。 AH7}/Rc  
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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。 5e^ChK0Q  
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视网膜的散射 iz PDd{[  
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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。 :tg)p+KB  
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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。 z46~@y%k  
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脚本 fr6fj  
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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： cR<fJ[*  
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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。 @lrztM
 
余下的脚本计算与屈光度有关的所有参数。 c<Tf 2]vZE  
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分析 +a{1)nCXe  
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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。 BUXpCxQ  
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脚本代码 j'"J%e]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. E{P|)`,V  
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Dim entity As T_ENTITY Z,Dl` w  
Dim op As T_OPERATION j{+.tIzpq[  
Dim mat As T_MODELMATERIAL `7V]y-  
Dim A As Double .Vvx
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Dim pupilDiam As Double #?- wm  
Dim eID As Long [?N~s:}  
Dim parID As Long ^o&. fQ*  
Dim count As Integer ;+
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M gi,$H  
Dim tlens As Double, nlens As Double BuXqd[;K%  
Dim curv As Double, conic As Double LBDjIpR6  
Dim ok As Long T!)(Dv8@F  
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Sub Main VQOezQs\  
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    '用户输入对话框 Ry6@VQ"NLb  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 T'Dv.h  
        TextBox 220,21,40,21,.TextBox1 'default: 0 v O_*yh1  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^WWQI+pk  
        OKButton 40,91,90,21 uiR8,H9*M  
        CancelButton 190,91,90,21 w@w(-F!%l  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'c$+sp ?  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Fd9[pU  
    End Dialog z1X`o  
    Dim dlg As UserDialog R%[ c;i  
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    ok = Dialog (dlg) {V CWn95Z  
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    If ok=0 Then    'cancel button was pressed -r]W  
        Print "Execution cancelled." 3eQ&F~S  
        End @_}P-h  
    End If G2: agqL/  
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    'Assign accommodation and pupil diameter & use defaults if field left empty p9{mS7R9T  
    If dlg.TextBox1 = "" Then C,|,-CY  
        A = 0           'Default accommodation =fFP5e ['  
    Else d
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        A = CDbl(dlg.TextBox1) FXkM#}RgNm  
    End If ,.FxIl]  
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    If dlg.TextBox2 = "" Then FJ)$f?=Qd  
        pupilDiam = 4   'Default pupil diameter smo~7;  
    Else Yr[\|$H5  
        pupilDiam = CDbl(dlg.TextBox2) 4~Q/"hMSkO  
    End If L) T (<  
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    Print " " ~oY^;/ j  
    Print "Accommodation = " & A & " Diopters" d>qY{Fdz  
    Print "Pupil Diameter = " & pupilDiam & " mm" *u;Iw{.{  
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    ' Calculate new parameters with accommodation 1=Z0w +v{  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ji0@P'^;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens nZYBE030  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens TAW/zpps$  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &gx%b*;`L0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {9q4)R}G  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @b2aNS<T  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 7J<5f)  
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    'Adjust parameters to account for accommodation XlR@pr6tw  
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    '************************************************************************* cSV aI  
    'Aqueous thickness (Position of Lens) Lw>N rY(Y  
    '************************************************************************* 7hPY_W y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3)ywX&4"L  
    GetCustomElement eID, entity $-sHWYZ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) =B@2#W#  
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    ' Delete any shift(s) in z #AQV(;r7@  
    count = 0 v` 1lxX'*  
    While GetOperationCount(eID)>count oNF6<A(@$  
        GetOperation eID, count, op Ig>(m49d  
        If op.Type="ShiftZ" Then brUF6rQ  
            DeleteOperation eID,count O:Tj"@h  
            count=count-1 TOQP'/   
        End If TuaBm1S{f  
        count=count+1 i=2N;sAl  
    Wend FU4L6n  
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    'Set new shift in b d!Y\OD
  
    op.Type = "ShiftZ" d/~9&wLSb  
    op.val1 = taq R (n2A$  
    op.parent = parID hp|YE'uYT  
    AddOperation eID, op `VguQl_,gA  
    Print "Set aqueous humor thickness = " & taq-0.55 '6%2.[o  
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    '************************************************************************* ' S/gmn  
    'Radius and conic constant of anterior lens :^h$AWR^f  
    '************************************************************************* \qJXF|z<K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G]&qx`TBK  
    GetConic eID, entity, curv, conic nAlQ7'  
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    SetConic eID, entity, 1/Rant, CCant -aCKRN8
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant FfT

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    '************************************************************************* Ml-6OvQ7g  
    'Radius and conic constant of posterior lens Uw<nxD/+  
    '************************************************************************* [ub e6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) sK?twg;D*|  
    GetConic eID, entity, curv, conic |M;7>'YNC*  
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    SetConic eID, entity, 1/Rpost, CCpost j^RmrOg,  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost <lJ345Q  
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    '************************************************************************* a/xn'"eli  
    'Lens thickness (Position of posterior lens surface) MkXmA`cP  
    '************************************************************************* E|shs=I  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z6MO^_m2  
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    ' Delete any z-shift(s) K_}K@'  
    count = 0 ]u/sphPe  
    While GetOperationCount(eID)>count )MT}+ai  
        GetOperation eID, count, op jq0O22 -R  
        If op.Type="ShiftZ" Then XC#oB~K'  
            DeleteOperation eID,count LCV(,lu  
            count=count-1 $U-0)4yf  
        End If s_p!43\J  
        count=count+1 S~G]~gt  
    Wend t\O16O7S  
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    'Set new z-shift QIFgQ0{  
    op.Type = "ShiftZ" -jmY)(\  
    op.val1 = tlens +R7
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    op.parent = parID i SQu#p@  
    AddOperation eID, op |-~Y#
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    Print "Set lens thickness = " & tlens * kh tJ]=  
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    '************************************************************************* @oGcuE  
    'Lens index of refraction goWuw}?  
    '************************************************************************* vtJJ#8a]  
    eID = FindMaterial( "Lens" ) "_?nN"A7  
    GetModelMaterial eID, mat AFt s(  
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    mat.Nd = nlens Zx>=t
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    SetModelMaterial eID, mat \a3+rNdj  
    Print "Set lens index of refraction = " & nlens Q\0'lQJdy  
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    '************************************************************************* V>3X\)qu  
    'Pupil diameter NvX[zqNP_R  
    '************************************************************************* 4s oJ.j8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) G=bCNn<  
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    'Adjust pupil diameter (trimming volume inner hole) u:  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %J-GKpo/S  
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    ' Adjust pupil location to just in front of the lens ~)M~EX&pK  
    parID = FindFullName( "Geometry.Arizona Eye" ) O^rDHFj,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) u)Whr@m  
    count = 0 WTiD[u  
    While GetOperationCount(eID)>count `kS
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        GetOperation eID, count, op 9;If&uM  
        If op.Type="ShiftZ" Then l;E(I_ i)  
            DeleteOperation eID,count M)(DZ}  
            count=count-1 Rf% a'b  
        End If 0b 54fD=  
        count=count+1 b\,+f n  
    Wend )QJUUn#  
    op.Type = "ShiftZ" &#i"=\d  
    op.val1 = taq-0.01 B`sAk %  
    op.parent = parID 'Z]w^<  
    AddOperation eID, op PQE=D0  
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    Print "Set pupil diameter = " & pupilDiam asqV~n
 
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    'Update AZ Eye subassembly Description yWf`rF{  
    eID = FindFullName( "Geometry.Arizona Eye" ) y>ktcuML  
    GetEntity eID, entity bW:!5"_{H  
    entity.Description = "Accommodation = " & A & "D" y<.5xq5_3  
    SetEntity eID, entity 1B\WA8  
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    Update lk=<A"^S  
    Print "DONE!" *yGGBqd  
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End Sub dgP3@`YS  
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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： :Iz8aQ  
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Accommodation = 4 Diopters A?0Nm{O;3v  
Pupil Diameter = 4 mm og>uj>H&  
Set aqueous humor thickness = 2.81 2+WaA,   
Set anterior lens radius = 10.4 and conic constant = -2.375869 2t1ZIyv3D  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 -7|H}!DFT  
Set lens thickness = 3.927 iJ|uvPCE  
Set lens index of refraction = 1.42672 fTX;.M/%   
Set pupil diameter = 4 8l">cVo]T  
DONE! .ccp