[技术]Arizona眼睛模型 [复制链接]

简介 DVlJ*A  
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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。 DIaYo4  
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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。 "0CjP+1k  
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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. hIYTe  
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光源 t P"\J(x  
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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。 Wh( |+rJ?Z  
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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。 2-'Opu  
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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。 9zBMlc$X  
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视网膜的散射 k|YWOy@D~  
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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。 VZy4_v=  
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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。 EH*o"N`!r  
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脚本 Q`%R
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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： IA

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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。 d[D&J  
余下的脚本计算与屈光度有关的所有参数。 N8r*dadDd  
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分析 SOZPZUUEJ  
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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。 S=`+Ryc  
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脚本代码 `d]IX^;  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. @f+8%I3D  
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Dim entity As T_ENTITY wC_l@7t  
Dim op As T_OPERATION nl aM  
Dim mat As T_MODELMATERIAL H9)m^*  
Dim A As Double M:KbD|  
Dim pupilDiam As Double b2,mCfLsv  
Dim eID As Long $2^
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Dim parID As Long (>4aibA'P  
Dim count As Integer 2&PPz}Sw  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 51C2u)HE  
Dim tlens As Double, nlens As Double <h).fX  
Dim curv As Double, conic As Double 3.d"
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Dim ok As Long \c v?^AI  
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Sub Main D4Al3fe  
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    '用户输入对话框 }v9\F-0>Q  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w%AcG~`j!B  
        TextBox 220,21,40,21,.TextBox1 'default: 0 T<3BT  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 $ ,SF@BhO  
        OKButton 40,91,90,21 |Xi%  
        CancelButton 190,91,90,21 FWue;pw3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %J:SO_6  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,;?S\V  
    End Dialog Ji1Pz)fq  
    Dim dlg As UserDialog -oeL{9;  
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    ok = Dialog (dlg) T{qTj6I  
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    If ok=0 Then    'cancel button was pressed {t"+ 3zy'  
        Print "Execution cancelled." A[IL H_w  
        End R[z`:1lo  
    End If <!-sZ_qq  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?Xdak|?i  
    If dlg.TextBox1 = "" Then BqDKT  
        A = 0           'Default accommodation 9a\nszwa  
    Else Xs&TJ8a  
        A = CDbl(dlg.TextBox1) MV_Srz  
    End If :j|IP)-f  
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    If dlg.TextBox2 = "" Then NK|?
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        pupilDiam = 4   'Default pupil diameter nJ4@I7Sk;  
    Else ? J}r  
        pupilDiam = CDbl(dlg.TextBox2) CQel3Jtt.  
    End If 8[r9HC  
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    Print " " ,B4VT 96*  
    Print "Accommodation = " & A & " Diopters" }X GEX:1K  
    Print "Pupil Diameter = " & pupilDiam & " mm" oH
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    ' Calculate new parameters with accommodation JN^&S  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j!
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,+`61J3W  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .@ xF6UZ  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1/p*tZP8i  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens gtUUsQ%y.  
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    tlens = 3.767 + 0.04*A                  'Lens thickness  Rqwzh@}  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^[%%r3"$C  
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    'Adjust parameters to account for accommodation 6wco&7   
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    '************************************************************************* 7t,t`  
    'Aqueous thickness (Position of Lens) 1c JF/"v  
    '************************************************************************* I^o!n5VM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ikE<=:pe  
    GetCustomElement eID, entity Fnk_\d6Ma  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ax!+P\\2~  
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    ' Delete any shift(s) in z 4f(Kt,0  
    count = 0 Vh}SCUof'  
    While GetOperationCount(eID)>count eZ"
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        GetOperation eID, count, op FU=w(< R;  
        If op.Type="ShiftZ" Then >0p$(>N]  
            DeleteOperation eID,count qfcYE=  
            count=count-1 GUslPnG  
        End If }|%eCVB  
        count=count+1 4v[~r1!V  
    Wend [ sd;`xk  
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    'Set new shift in }I`a`0/  
    op.Type = "ShiftZ" [r/k% <  
    op.val1 = taq 5NJ4  
    op.parent = parID oD}uOC}FS{  
    AddOperation eID, op vkLC-Mzm<  
    Print "Set aqueous humor thickness = " & taq-0.55 gm9mg*aM  
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    '************************************************************************* xkOpa,=FI  
    'Radius and conic constant of anterior lens OFj
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    '************************************************************************* =@F&o4)r  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) e.c3nKXZ q  
    GetConic eID, entity, curv, conic Zo>]rKeV  
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    SetConic eID, entity, 1/Rant, CCant p&VU0[LIC0  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Gycm,Cy  
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    '************************************************************************* 9'hv%A:\3  
    'Radius and conic constant of posterior lens |lv|!]qAma  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) !%dN
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    GetConic eID, entity, curv, conic yoAfc  
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    SetConic eID, entity, 1/Rpost, CCpost RmZ]" `  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ah~YeJp  
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    '************************************************************************* \c^45<G2qA  
    'Lens thickness (Position of posterior lens surface) V`@>MOw^d  
    '*************************************************************************  gk`zA  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %/updw#{B  
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    ' Delete any z-shift(s) pKi&[  
    count = 0 y!]CJigpZ  
    While GetOperationCount(eID)>count ,]b~t0|B  
        GetOperation eID, count, op 3P;>XGCxZ  
        If op.Type="ShiftZ" Then sUPz/Z.h  
            DeleteOperation eID,count F
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            count=count-1 :T9<der,  
        End If vOg#Dqn-  
        count=count+1 _ 84ut  
    Wend a'\o7_  
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    'Set new z-shift KF4PJi;*  
    op.Type = "ShiftZ" |r bWYl.b  
    op.val1 = tlens |^@dFOz  
    op.parent = parID 0?>dCu\  
    AddOperation eID, op `O'`eY1f  
    Print "Set lens thickness = " & tlens P (S>=,Y&  
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    '************************************************************************* %w7]@VZ  
    'Lens index of refraction @gG<le6  
    '************************************************************************* "*})3['n  
    eID = FindMaterial( "Lens" ) I"KN"v^  
    GetModelMaterial eID, mat \}]!)}G  
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    mat.Nd = nlens )aX,%yK  
    SetModelMaterial eID, mat j!3 Gz  
    Print "Set lens index of refraction = " & nlens 1IVuSp`{FU  
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    '************************************************************************* 2YDM9`5xs\  
    'Pupil diameter a5w:u5  
    '************************************************************************* uw2hMt (N  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;D$)P7k6  
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    'Adjust pupil diameter (trimming volume inner hole) <vwkjCA`  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" QD%L0;j  
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    ' Adjust pupil location to just in front of the lens uIZWO.OdU  
    parID = FindFullName( "Geometry.Arizona Eye" ) q/n,,!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) \_B[{e7z  
    count = 0 K#"O a h  
    While GetOperationCount(eID)>count 5<w g8y  
        GetOperation eID, count, op L5,NP5RC  
        If op.Type="ShiftZ" Then nR`ov1RH  
            DeleteOperation eID,count '}$Dgp6e  
            count=count-1 QV\eMuNy  
        End If aE2.L;Tk?  
        count=count+1 NQ6sGL  
    Wend NC38fiH_N  
    op.Type = "ShiftZ" >;[*!<pfK5  
    op.val1 = taq-0.01 {D=@n4JO  
    op.parent = parID I(XOE$3  
    AddOperation eID, op A
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    Print "Set pupil diameter = " & pupilDiam ^#sU*trr  
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    'Update AZ Eye subassembly Description
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    eID = FindFullName( "Geometry.Arizona Eye" ) s;A@*Y;v  
    GetEntity eID, entity KRA/MQ^7~U  
    entity.Description = "Accommodation = " & A & "D" k5T,990  
    SetEntity eID, entity MNV% =G  
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    Update hodgDrmO/  
    Print "DONE!" X*\J_  
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End Sub )vSRHE  
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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： L+i(TM=  
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Accommodation = 4 Diopters pfI"36]F  
Pupil Diameter = 4 mm aca=yDs2  
Set aqueous humor thickness = 2.81 3p'I5,}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 GI1  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 1
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Set lens thickness = 3.927 {yExQbN  
Set lens index of refraction = 1.42672 hzvd t  
Set pupil diameter = 4 <Sr  
DONE! f=9|b