[技术]Arizona眼睛模型 [复制链接]

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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。 VIg\]%qse  
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模型 Zs73 a
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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。 +XQPjg  
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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. mu>] 9ZW  
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光源 zq=&4afOE  
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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。 6sy,A~e  
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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。 !ew6 n I  
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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。 D
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视网膜的散射 s9 &)Fv-#V  
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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。 b~9`]+  
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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。 {83C,C-  
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脚本 +K&?)?/=  
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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： wA1Ey:q  
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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。

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余下的脚本计算与屈光度有关的所有参数。 Fr2kbQTg;  
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分析 HM 90Sb  
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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。 jQ)L pjS1  
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脚本代码 F:S"gRKz  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. G LoiH#R  
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Dim entity As T_ENTITY }\DAg'e)  
Dim op As T_OPERATION m[W/j/$A+x  
Dim mat As T_MODELMATERIAL <5M_EJp  
Dim A As Double B_!wutV@  
Dim pupilDiam As Double gU+ss  
Dim eID As Long ~z&0qQ  
Dim parID As Long x ~wNO/  
Dim count As Integer u |'8a1  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double */4tJG1U  
Dim tlens As Double, nlens As Double '
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Dim curv As Double, conic As Double 2G ZF/9}  
Dim ok As Long $,.3&zsy  
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Sub Main D/e&7^iK  
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    '用户输入对话框 s:3aRQ%  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Qg[heND  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }M^_Z#|,  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1E8$% 6VV  
        OKButton 40,91,90,21 *B%y`cj|  
        CancelButton 190,91,90,21 QjI#Cs}w  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 7,f:Qi@g  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Wux0RF&  
    End Dialog `(P "u  
    Dim dlg As UserDialog )ni"qv~J  
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    ok = Dialog (dlg) ?n2C  
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    If ok=0 Then    'cancel button was pressed XMomFW_@  
        Print "Execution cancelled." 93 [rL+l.Y  
        End vz- 9<w;>a  
    End If *U:VM'a  
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    'Assign accommodation and pupil diameter & use defaults if field left empty aXQ&@BZ{j  
    If dlg.TextBox1 = "" Then ?Y%}(3y  
        A = 0           'Default accommodation J0&zb'1  
    Else 3(MoXA*  
        A = CDbl(dlg.TextBox1) @8QFP3\1  
    End If d:A\<F  
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    If dlg.TextBox2 = "" Then pi|\0lH6W  
        pupilDiam = 4   'Default pupil diameter 52da]BW<  
    Else bh{E&1sLh  
        pupilDiam = CDbl(dlg.TextBox2) f+{c1fb>s  
    End If 0Wjd-rzc,  
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    Print " "
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    Print "Accommodation = " & A & " Diopters" T@B"BoKU  
    Print "Pupil Diameter = " & pupilDiam & " mm" ,NjX&A@  
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    ' Calculate new parameters with accommodation dz{#"No0  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Dq{:R  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens nUiS<D2  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;+TMx(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -FQC9~rR;g  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Q1aHIc  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ,.~ W  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ue,#,
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    'Adjust parameters to account for accommodation E~'q?LJOB  
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    '************************************************************************* oxUE79  
    'Aqueous thickness (Position of Lens) >`<Ued  
    '************************************************************************* X(4s;i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) v]B0!k&4.  
    GetCustomElement eID, entity ^RYn8I  
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    parID = FindFullName( "Geometry.Arizona Eye" ) t.3Ct@wK  
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    ' Delete any shift(s) in z l\q*%'Pe  
    count = 0 OAmES;Ck$(  
    While GetOperationCount(eID)>count r~8D\_=s  
        GetOperation eID, count, op ^>3tYg&7  
        If op.Type="ShiftZ" Then 5x:Ift *  
            DeleteOperation eID,count *jYHd#UZx4  
            count=count-1 Dm7Y#)%8  
        End If ST[2]   
        count=count+1 >+yqjXRzm  
    Wend CnxK+1n
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    'Set new shift in 1~["{u  
    op.Type = "ShiftZ" #JK;&Dg!  
    op.val1 = taq F?*Dr  
    op.parent = parID E"Ya-8d=  
    AddOperation eID, op nAQyxP%  
    Print "Set aqueous humor thickness = " & taq-0.55 vp"%IW  
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    '************************************************************************* \[Sm2/9v  
    'Radius and conic constant of anterior lens FQ;4'B^k]  
    '************************************************************************* P5'iYahCq_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #G'S ve?  
    GetConic eID, entity, curv, conic 7P3<o!YA  
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    SetConic eID, entity, 1/Rant, CCant tQNk=}VR7r  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant [W^6u7~  
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    '************************************************************************* 'Qm` A=  
    'Radius and conic constant of posterior lens u=p ;A1oy  
    '************************************************************************* /e-ka{WS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8>C; >v  
    GetConic eID, entity, curv, conic />dB%*  
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    SetConic eID, entity, 1/Rpost, CCpost .Q=2WCv0  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3::3r}g  
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    '************************************************************************* &{-oA_@  
    'Lens thickness (Position of posterior lens surface) )GiFkG  
    '************************************************************************* eT7!a']x  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %8}WX@SB  
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    ' Delete any z-shift(s) X_lUD?y  
    count = 0 @A~B ,  
    While GetOperationCount(eID)>count uE,i-g0$Id  
        GetOperation eID, count, op WUE)SVf  
        If op.Type="ShiftZ" Then c,#~L7  
            DeleteOperation eID,count "E@NZ*"u  
            count=count-1 QLn5#x~xb  
        End If )bB"12Z|8  
        count=count+1 O:oU`vE  
    Wend Ze$^UR  
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    'Set new z-shift !SLP8|Cd  
    op.Type = "ShiftZ" fP^W"y  
    op.val1 = tlens ..P=D <'f  
    op.parent = parID E%wV  
    AddOperation eID, op 8]cv&d1f  
    Print "Set lens thickness = " & tlens <3SFP3^:  
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    '************************************************************************* "4Vi=*2V  
    'Lens index of refraction WrE-Zti  
    '************************************************************************* ]t.WJC %  
    eID = FindMaterial( "Lens" ) w%i+>\tO  
    GetModelMaterial eID, mat u%+6Mp[E  
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    mat.Nd = nlens Xm"w,J&  
    SetModelMaterial eID, mat 'Yaf\Hp  
    Print "Set lens index of refraction = " & nlens Dg9--wI}I9  
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    '************************************************************************* Z`-)1!  
    'Pupil diameter ?J^IAFy  
    '************************************************************************* O+(. 29  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) x[GFX8h(k6  
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    'Adjust pupil diameter (trimming volume inner hole) dK0}% ]i3#  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |kBg8)
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    ' Adjust pupil location to just in front of the lens .-C+0L1j  
    parID = FindFullName( "Geometry.Arizona Eye" ) _H^^2#wc/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) >j(I[_g  
    count = 0 haEZp6Z  
    While GetOperationCount(eID)>count ohQz%?r  
        GetOperation eID, count, op 0,vj,ic*WX  
        If op.Type="ShiftZ" Then M\Uc;:) H  
            DeleteOperation eID,count BRo R"#'  
            count=count-1 DU*g~{8T$  
        End If MYDf`0{$_a  
        count=count+1 dN$D6*  
    Wend M/8#&RycQ  
    op.Type = "ShiftZ" J-eA,9J  
    op.val1 = taq-0.01 @}zS/LO  
    op.parent = parID D*d 3w  
    AddOperation eID, op V\k5h  
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    Print "Set pupil diameter = " & pupilDiam T9<H%iF  
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    'Update AZ Eye subassembly Description uusY,Dt/9  
    eID = FindFullName( "Geometry.Arizona Eye" ) HonAK  
    GetEntity eID, entity 6S! lD=  
    entity.Description = "Accommodation = " & A & "D" a!^-~pH:  
    SetEntity eID, entity :r vO8.\  
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    Update '$kS
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    Print "DONE!" 0f=N3)  
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End Sub [kp7LA"`  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 8CnvvMf  
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Accommodation = 4 Diopters ;8%@
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Pupil Diameter = 4 mm ys.!S.k+  
Set aqueous humor thickness = 2.81 ^;bGP.!p  
Set anterior lens radius = 10.4 and conic constant = -2.375869 =AnZ>6  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 \fM!^  
Set lens thickness = 3.927 V%
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Set lens index of refraction = 1.42672 5EV8zf  
Set pupil diameter = 4 e$/Zb`k  
DONE! _,K>u6N&