[技术]Arizona眼睛模型 [复制链接]

简介 {x|kg;  
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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。 ?cO8'4 bq  
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模型 nQ642i%RQ  
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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。 TmYP_5g:  
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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. ^S#\O>GHP  
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光源 *^D@l%av;  
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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。 7<3U?]0  
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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。 U=kx`j>  
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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。 ^XBzZ!h|  
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视网膜的散射 *K(k Kph
 
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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。 tlV &eN  
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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。 BT
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脚本 qKdS7SoS  
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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： 0n:?sFY>  
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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。 "l@A[@R  
余下的脚本计算与屈光度有关的所有参数。 #:J:YMv  
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分析  7%}a
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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。 I^~=,D  
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脚本代码 ^r
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0"EoC  
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Dim entity As T_ENTITY <B6[i*&  
Dim op As T_OPERATION AR%hf  
Dim mat As T_MODELMATERIAL X8/Tl\c  
Dim A As Double OAv>g pw  
Dim pupilDiam As Double _!n}P5  
Dim eID As Long $<B +K  
Dim parID As Long 'p%=<0vrr  
Dim count As Integer d%0+i/p  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Dv&>*0B  
Dim tlens As Double, nlens As Double lT.zNhz:d9  
Dim curv As Double, conic As Double &lAQ &  
Dim ok As Long c=6ahX}d  
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Sub Main )QmGsU}?  
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    '用户输入对话框 \PpXL*.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ! ja[4.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 _%Bz,C8  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?O??cjiA@  
        OKButton 40,91,90,21 N{8"s&  
        CancelButton 190,91,90,21 Ia2(Km  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 jM~Bu.7 i6  
        TextBox 220,49,40,21,.TextBox2 'default: 4 AUfS-  
    End Dialog aD9rp V  
    Dim dlg As UserDialog
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    ok = Dialog (dlg) IdP
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    If ok=0 Then    'cancel button was pressed J$Fnm\  
        Print "Execution cancelled." kbxg_UI;  
        End n@!wp/J,  
    End If Z%}4bJ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty c'Z:9?#5  
    If dlg.TextBox1 = "" Then igDG}q3jG  
        A = 0           'Default accommodation q$
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    Else ["y6b*;x  
        A = CDbl(dlg.TextBox1) 5 L/x-i  
    End If 6;o3sf@Tf  
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    If dlg.TextBox2 = "" Then Qzqc .T  
        pupilDiam = 4   'Default pupil diameter >"v9iT  
    Else #)s!}X^  
        pupilDiam = CDbl(dlg.TextBox2) }aF  
    End If TBCp L]QT  
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    Print " " tx"LeZZ  
    Print "Accommodation = " & A & " Diopters" zI^]esX!2_  
    Print "Pupil Diameter = " & pupilDiam & " mm" ?cKZ_c  
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    ' Calculate new parameters with accommodation gl{B=NN  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Xc*U+M>U  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens yb2}_k.JG  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :^i^0dC  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Y9Z]i$qS&k  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +5!&E7bcd  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _V2xA88
 
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction OcmRZ  
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    'Adjust parameters to account for accommodation o(!@7Lqq  
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    '************************************************************************* 0|c}p([~  
    'Aqueous thickness (Position of Lens) }^xE|~p  
    '************************************************************************* *$,:m  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) SmhGZ  
    GetCustomElement eID, entity d$t40+v  
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    parID = FindFullName( "Geometry.Arizona Eye" ) NI aFI(  
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    ' Delete any shift(s) in z SJ?cI!=x  
    count = 0 o]ePP,  
    While GetOperationCount(eID)>count GbI-SbE  
        GetOperation eID, count, op c9wfsapJ  
        If op.Type="ShiftZ" Then j$Ab>}g]  
            DeleteOperation eID,count zmI]cD@G  
            count=count-1 kV;fD$iW;  
        End If e}hmS1>H  
        count=count+1 c!#:E`  
    Wend +s++7<C  
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    'Set new shift in [P~hjm
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    op.Type = "ShiftZ" P 43P]M2  
    op.val1 = taq |'d>JT:  
    op.parent = parID ]bZ(HC?KZr  
    AddOperation eID, op au7.4ln>Y  
    Print "Set aqueous humor thickness = " & taq-0.55 =K\r-'V  
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    '************************************************************************* 3
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    'Radius and conic constant of anterior lens as
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    '************************************************************************* TX=yPq  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n/~A`%E@  
    GetConic eID, entity, curv, conic (wRgus  
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    SetConic eID, entity, 1/Rant, CCant MUnEuhXTr  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant En{`@JsM  
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    '************************************************************************* vS\Nd1~?  
    'Radius and conic constant of posterior lens i|`dWOVb  
    '************************************************************************* z2_6??tS/c  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ~6YMD  
    GetConic eID, entity, curv, conic br-]fE.be  
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    SetConic eID, entity, 1/Rpost, CCpost _g%TSumvq<  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost El\%E"Tk%  
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    '************************************************************************* I$q]. B  
    'Lens thickness (Position of posterior lens surface) s\!>"J bAQ  
    '************************************************************************* Hso|e?Z  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Guz"wY  
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    ' Delete any z-shift(s) *(C(tPhC  
    count = 0 }>)[<;M>%  
    While GetOperationCount(eID)>count p sL?Y  
        GetOperation eID, count, op )nL`H^  
        If op.Type="ShiftZ" Then 8
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            DeleteOperation eID,count .7K7h^*F  
            count=count-1 kuyjnSo9i  
        End If WSuw
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        count=count+1 )W/;=K  
    Wend i&{DOI%w  
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    'Set new z-shift zR2B- &]H  
    op.Type = "ShiftZ" aDO!  
    op.val1 = tlens T5a*z}L5  
    op.parent = parID '>r7V  
    AddOperation eID, op i3rH'B-I.  
    Print "Set lens thickness = " & tlens xJ#d1[kzo  
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    '************************************************************************* :q#Xq;Wp  
    'Lens index of refraction DI+fwXe
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    '************************************************************************* g+J-Zg6  
    eID = FindMaterial( "Lens" ) _/i4MtM  
    GetModelMaterial eID, mat 'Lu__NfN  
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    mat.Nd = nlens d_IAs  
    SetModelMaterial eID, mat |JQQU!x  
    Print "Set lens index of refraction = " & nlens YW7b)uYf  
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    '************************************************************************* 8-2cRs  
    'Pupil diameter l1f\=G?tmU  
    '************************************************************************* ?Y@N`S  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |`.([2  
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    'Adjust pupil diameter (trimming volume inner hole) hEp(A8g)bQ  

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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" x QIq^/F0  
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    ' Adjust pupil location to just in front of the lens gP;&e:/3  
    parID = FindFullName( "Geometry.Arizona Eye" ) 
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) V,cBk  
    count = 0 8uWa=C)  
    While GetOperationCount(eID)>count [PDNwh0g5  
        GetOperation eID, count, op )c)vTZy  
        If op.Type="ShiftZ" Then RS8Hf~0G  
            DeleteOperation eID,count {GQ^fu;q  
            count=count-1 Le\?+h42>  
        End If h2XfC.f  
        count=count+1 "thdPZ  
    Wend ~vyf4TF<#  
    op.Type = "ShiftZ" oM>Z;QVRC:  
    op.val1 = taq-0.01 5yP\I+Fm  
    op.parent = parID B!?%O  
    AddOperation eID, op ;IZwTXu!S  
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    Print "Set pupil diameter = " & pupilDiam `~By)?cT_>  
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    'Update AZ Eye subassembly Description 5:KQg  
    eID = FindFullName( "Geometry.Arizona Eye" ) ^G}47(  
    GetEntity eID, entity :gWu9Y|{  
    entity.Description = "Accommodation = " & A & "D" w|K'M?N14  
    SetEntity eID, entity E
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    Update v@ lM3_rbO  
    Print "DONE!" 1=d6NX)B  
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End Sub [J?aD`{#O  
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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： :%,:"  
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Accommodation = 4 Diopters b?tB(if!I  
Pupil Diameter = 4 mm klT@cO-9  
Set aqueous humor thickness = 2.81 H[U!%Z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 fof
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 $Avjnm  
Set lens thickness = 3.927 ?kbiMs1;u  
Set lens index of refraction = 1.42672 l~w2B>i)  
Set pupil diameter = 4 Pg
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DONE! LnH?dy