[技术]Arizona眼睛模型 [复制链接]

简介 6_4B!  
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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。 cd1G.10  
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模型 5\MC5us3  
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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。 k1q/L|')  
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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. 5K ;E*s,  
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光源 4_kN';a4Q  
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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。 A vq+s.h  
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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。 )Q'E^[Ua  
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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。 Fs(PVN  
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视网膜的散射 GYfOwV!zB  
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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。 &bW,N  
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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。 &2y4k"B&)  
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脚本 ,2nu*+6Y/  
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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： }_]AQN$'G  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 y("WnVI  
余下的脚本计算与屈光度有关的所有参数。 Q?k
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分析 q@ -B+  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 'q-q4QCB  
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脚本代码 eWcqf/4?"  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. < '5~p$  
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Dim entity As T_ENTITY #{8IFA  
Dim op As T_OPERATION mVZh_R=a  
Dim mat As T_MODELMATERIAL e^Zm09J  
Dim A As Double }csA|cC  
Dim pupilDiam As Double }=^ ,c  
Dim eID As Long R |c=I}@F  
Dim parID As Long 7AV{ h[J  
Dim count As Integer KNx/1lf  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double zuvPV{ X  
Dim tlens As Double, nlens As Double ;5j|B|v  
Dim curv As Double, conic As Double $Z@*!B^  
Dim ok As Long hC<ROD  
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Sub Main >|QH I d8  
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    '用户输入对话框 )7>GXZG>=  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 aOzIo-  
        TextBox 220,21,40,21,.TextBox1 'default: 0 QH/py  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 S<
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        OKButton 40,91,90,21 Rd#R}yA  
        CancelButton 190,91,90,21  =_dM@j  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "I.
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        TextBox 220,49,40,21,.TextBox2 'default: 4 F0:]@0>r  
    End Dialog QtW9!p7(  
    Dim dlg As UserDialog D\Ak-$kJ^  
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    ok = Dialog (dlg) 68tyWd}  
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    If ok=0 Then    'cancel button was pressed y]j.PT`Cw  
        Print "Execution cancelled." {"ST hTZ  
        End I=0c\ U}  
    End If *2/Jg'de  
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    'Assign accommodation and pupil diameter & use defaults if field left empty op6]"ZV-C  
    If dlg.TextBox1 = "" Then TA[%eMvA  
        A = 0           'Default accommodation -zg*p&F  
    Else aCG rS{  
        A = CDbl(dlg.TextBox1) ]Z!Y*v  
    End If $Rm~ VwY#  
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    If dlg.TextBox2 = "" Then Q0xO;20  
        pupilDiam = 4   'Default pupil diameter 7>yd  
    Else gu k,GF9p]  
        pupilDiam = CDbl(dlg.TextBox2) fs!dI  
    End If 8M5)fDu*?  
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    Print " " %N8I'*u  
    Print "Accommodation = " & A & " Diopters" P#O"{+`  
    Print "Pupil Diameter = " & pupilDiam & " mm" <o(;~  
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    ' Calculate new parameters with accommodation FZ-Wgh 0z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness qez
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7'\.QJ!<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens t!?`2Z5  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens C[
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens B"43o7C  
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    tlens = 3.767 + 0.04*A                  'Lens thickness J}V4.R5d  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction zIc6L3w$  
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    'Adjust parameters to account for accommodation ?{J1&;j*  
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    '************************************************************************* i/X
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    'Aqueous thickness (Position of Lens) 7U [C=NL  
    '************************************************************************* (qAF2&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~>:JwTy  
    GetCustomElement eID, entity 0LQRQuh1  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ;j0.#P:a  
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    ' Delete any shift(s) in z +Y?Tri  
    count = 0  4!!|P  
    While GetOperationCount(eID)>count fG2)r  
        GetOperation eID, count, op 0AnL]`"t.3  
        If op.Type="ShiftZ" Then k=)U  
            DeleteOperation eID,count #]Vw$X_S  
            count=count-1 !&U75FpN}:  
        End If |.
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        count=count+1 K'&,]r#  
    Wend +k=*AQt^8  
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    'Set new shift in ?wtKi#k'v#  
    op.Type = "ShiftZ" (u?s@/e:`/  
    op.val1 = taq m-{DhJV  
    op.parent = parID \KV.lG!  
    AddOperation eID, op kHK<~srB  
    Print "Set aqueous humor thickness = " & taq-0.55 7] y3<t  
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    '************************************************************************* }-[l)<F:  
    'Radius and conic constant of anterior lens i3 js'?7E  
    '************************************************************************* lr&2,p<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ei2?H;H;  
    GetConic eID, entity, curv, conic jnV#Q ;  
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    SetConic eID, entity, 1/Rant, CCant r,eH7&P9{  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant }%KQrlbHJl  
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    '************************************************************************* +9HU&gQ3  
    'Radius and conic constant of posterior lens #o&T$D5  
    '************************************************************************* <@7j37,R7V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Wi$?k{C  
    GetConic eID, entity, curv, conic $I5|rB/4?  
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    SetConic eID, entity, 1/Rpost, CCpost WGV]O|  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -t
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    '************************************************************************* 55v=Ij?M  
    'Lens thickness (Position of posterior lens surface)  WDNj7  
    '************************************************************************* !UzE&CirV  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6~ET@"0uK  
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    ' Delete any z-shift(s) A7QT4h&6  
    count = 0 u9_?c G-  
    While GetOperationCount(eID)>count 7gtaI3   
        GetOperation eID, count, op K81FKV.  
        If op.Type="ShiftZ" Then NiG&Lw*8  
            DeleteOperation eID,count s\.r3U&6  
            count=count-1 ;4+z~7Je]^  
        End If T c-fO /0  
        count=count+1 tT`S" 9T  
    Wend P'$2%P$8:~  
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    'Set new z-shift "P5,p"k:)  
    op.Type = "ShiftZ" O-AC$C[d  
    op.val1 = tlens .9DhD=8aIO  
    op.parent = parID CS%ut-K<5M  
    AddOperation eID, op L `2{H%J`  
    Print "Set lens thickness = " & tlens d3oRan}z  
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    '************************************************************************* r 8N<<^  
    'Lens index of refraction g9GPyU  
    '************************************************************************* NrcV%-+u%  
    eID = FindMaterial( "Lens" ) = CXX.%N  
    GetModelMaterial eID, mat :t;\`gQoS  
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    mat.Nd = nlens =)#XZ[#F  
    SetModelMaterial eID, mat kH06Cb  
    Print "Set lens index of refraction = " & nlens Kj"n Id)  
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    '************************************************************************* $hM9{  
    'Pupil diameter \hJLa  
    '************************************************************************* -6q7ze{@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) vSQB~Vw8t  
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    'Adjust pupil diameter (trimming volume inner hole) ^b&hy&ag  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [CnoMN  
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    ' Adjust pupil location to just in front of the lens 7CT446
 
    parID = FindFullName( "Geometry.Arizona Eye" ) NR^Z#BU  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) yrzyus  
    count = 0 nCldH|>5w  
    While GetOperationCount(eID)>count ?r0>HvUf!l  
        GetOperation eID, count, op `=TJw,q  
        If op.Type="ShiftZ" Then dDe$<g5L4  
            DeleteOperation eID,count OoOwEV2p_  
            count=count-1 B)DtJf  
        End If Or1ikI"  
        count=count+1 FOa2VP%  
    Wend NS4W!o;"  
    op.Type = "ShiftZ" xG%O^  
    op.val1 = taq-0.01 `C:J{`  
    op.parent = parID f+Bv8 g  
    AddOperation eID, op o<S(ODOfi  
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    Print "Set pupil diameter = " & pupilDiam LZPLz@=&]  
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    'Update AZ Eye subassembly Description xqVIw!J?/}  
    eID = FindFullName( "Geometry.Arizona Eye" ) 4m9]d)  
    GetEntity eID, entity r-}C !aF]  
    entity.Description = "Accommodation = " & A & "D" Yv;iduc('  
    SetEntity eID, entity uQkFFWS  
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    Update +_fxV|}P  
    Print "DONE!" dqL)q3  
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End Sub 2)`4(38  
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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： _`]YWvh  
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Accommodation = 4 Diopters {Pi]i?  
Pupil Diameter = 4 mm ADZU?7)  
Set aqueous humor thickness = 2.81 \g;-q9g;O  
Set anterior lens radius = 10.4 and conic constant = -2.375869 \H?r[]*c%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 SQBe}FlktK  
Set lens thickness = 3.927 XCZNvLG  
Set lens index of refraction = 1.42672 x_KJCU  
Set pupil diameter = 4 , rc %#eF  
DONE! Pu|3_3^