[技术]Arizona眼睛模型 [复制链接]

简介 3z -="_p  
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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。 bZu2.?{  
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模型 -=)+)9~G  
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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。 A\|:hzu+  
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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. %!]CP1S  
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光源 lKV7IoJ&;  
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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。 B !Z~jT  
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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。 ]s`cn}d  
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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。 Nzl`mx16  
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视网膜的散射 C5=m~  
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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。 S y^et  
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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。 Ie4Xk  
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脚本 ~>rnq7j  
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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： N
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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。 -"}nm!j /5  
余下的脚本计算与屈光度有关的所有参数。 %[BOe4[  
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分析 M)CQ|P  
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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。 pI}6AAs}Z  
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脚本代码 lD,;xuQ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. z W*Z  
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Dim entity As T_ENTITY \6vr)1~N>  
Dim op As T_OPERATION 8!qzG4F/  
Dim mat As T_MODELMATERIAL 'v_k#%  
Dim A As Double BP8jReX^  
Dim pupilDiam As Double dQ
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Dim eID As Long 5
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Dim parID As Long j "e]Ui  
Dim count As Integer q!<n\X3]u  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6dKJt  
Dim tlens As Double, nlens As Double -x+K#T0Z  
Dim curv As Double, conic As Double yXCJ?  
Dim ok As Long 0t -=*7w%  
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Sub Main BZk0B?  
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    '用户输入对话框 :F pt>g  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $q0i=l&$&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 E6clVa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 2I0Zr;\f  
        OKButton 40,91,90,21 uw{K&Hxw  
        CancelButton 190,91,90,21 r^;1Sm  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Pk)H(,  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (gF{S*`  
    End Dialog {3K`yDF  
    Dim dlg As UserDialog sEcg;LFp  
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    ok = Dialog (dlg) zj7?2  
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    If ok=0 Then    'cancel button was pressed !Er)|YP  
        Print "Execution cancelled." #>O+!IH
 
        End C ,#D4  
    End If EsjZ;D,c(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 2t:CK  
    If dlg.TextBox1 = "" Then z{A~d  
        A = 0           'Default accommodation ""x>-j4  
    Else IAb-O  
        A = CDbl(dlg.TextBox1) _PGS"O?j  
    End If 9bu1Ax1M  
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    If dlg.TextBox2 = "" Then .Tc?PmN  
        pupilDiam = 4   'Default pupil diameter !]=S A &  
    Else }/M`G]wT#  
        pupilDiam = CDbl(dlg.TextBox2) BH2JH>'X  
    End If [Ee <SB{  
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    Print " " 5@`dKFB5  
    Print "Accommodation = " & A & " Diopters" *m:'~\[u  
    Print "Pupil Diameter = " & pupilDiam & " mm" h:{^&d a  
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    ' Calculate new parameters with accommodation E\*M4n\!  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness A9ZK :i7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens .pPtBqp  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens iKAqM{(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $im6v  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 3'6by!N,d  
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    tlens = 3.767 + 0.04*A                  'Lens thickness |!uC [=  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction R|R3Ob.e  
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    'Adjust parameters to account for accommodation `l+9g"q  
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    '*************************************************************************  @zSj&4  
    'Aqueous thickness (Position of Lens) \_AoG8B  
    '************************************************************************* KBwY _  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) o5<w2(  
    GetCustomElement eID, entity *DPKV$  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Q6=>*}Cm6m  
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    ' Delete any shift(s) in z smat6p[  
    count = 0 2 D!$x+|  
    While GetOperationCount(eID)>count jP"yG#  
        GetOperation eID, count, op /[>zFYaQ  
        If op.Type="ShiftZ" Then 0l~z0pvT  
            DeleteOperation eID,count PAs.T4Av^  
            count=count-1 XA
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        End If (V#*}eGy  
        count=count+1 %oiA'hz;*  
    Wend Lr<?eWdCwJ  
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    'Set new shift in c}D>.x|]  
    op.Type = "ShiftZ" [_zoJ  
    op.val1 = taq )/uCdSDIc  
    op.parent = parID yr34&M(a  
    AddOperation eID, op `lN Z|U  
    Print "Set aqueous humor thickness = " & taq-0.55 <*5`TE0J  
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    '************************************************************************* i2n66d  
    'Radius and conic constant of anterior lens yrV]I(Xe  
    '************************************************************************* 1eMaKT_=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zmh5x{US1  
    GetConic eID, entity, curv, conic A&=`?4>  
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    SetConic eID, entity, 1/Rant, CCant KAm$^N5  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant H263<^   
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    '************************************************************************* lv\^@9r  
    'Radius and conic constant of posterior lens Oy~X@A  
    '************************************************************************* lBfG#\rdW~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b"&1l2\ A  
    GetConic eID, entity, curv, conic u
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    SetConic eID, entity, 1/Rpost, CCpost {iq)[)n  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost z|sR `
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    '************************************************************************* gclw>((5  
    'Lens thickness (Position of posterior lens surface) =\)qUs\z  
    '************************************************************************* WkK.ON^  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) F+::UWKA  
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    ' Delete any z-shift(s) :qO)^~x  
    count = 0 1}b1RKKj<  
    While GetOperationCount(eID)>count J7s\  
        GetOperation eID, count, op .DZ8kKY  
        If op.Type="ShiftZ" Then iM{UB=C  
            DeleteOperation eID,count K 6HH_T  
            count=count-1
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        End If +B-;.]L T  
        count=count+1 7;H P_oAu  
    Wend il>XV>  
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    'Set new z-shift 1[H1l;  
    op.Type = "ShiftZ" Y<9Lqc.i  
    op.val1 = tlens b5d;_-~d  
    op.parent = parID pPtw(5bH  
    AddOperation eID, op }[8Nr+y  
    Print "Set lens thickness = " & tlens 3(R]QO`%'  
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    '************************************************************************* %eLf6|1x  
    'Lens index of refraction h?`'%m?_b  
    '************************************************************************* g)#.|d+  
    eID = FindMaterial( "Lens" ) 8i'EO6  
    GetModelMaterial eID, mat YztW1GvI  
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    mat.Nd = nlens ;mLbgiqQ J  
    SetModelMaterial eID, mat ZsepTtY  
    Print "Set lens index of refraction = " & nlens +q@g  
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    '************************************************************************* ?^W`7HF%0  
    'Pupil diameter \' ;zD-MX  
    '************************************************************************* \)mV2r!%  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xyc`p[n&  
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    'Adjust pupil diameter (trimming volume inner hole) '*,P33h9<!  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" r-k,4Yz  
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    ' Adjust pupil location to just in front of the lens VA0p1AD  
    parID = FindFullName( "Geometry.Arizona Eye" ) @I,:(<6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) (L7@ez  
    count = 0 Af{K#R8!  
    While GetOperationCount(eID)>count mzh7E[S_,i  
        GetOperation eID, count, op J|GEt@o3  
        If op.Type="ShiftZ" Then 8ECBi(  
            DeleteOperation eID,count +_E96`P  
            count=count-1 64h$sC0z/e  
        End If v$i[dZSN[  
        count=count+1 5fVm392+  
    Wend "=ogO/_Q"  
    op.Type = "ShiftZ" q&N1| f7  
    op.val1 = taq-0.01 h|S6LgB  
    op.parent = parID FR9*WI   
    AddOperation eID, op H`028^CH$
 
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    Print "Set pupil diameter = " & pupilDiam Zn9ecN  
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    'Update AZ Eye subassembly Description 4x%R4tk  
    eID = FindFullName( "Geometry.Arizona Eye" ) dl&402  
    GetEntity eID, entity js<}>wD7<  
    entity.Description = "Accommodation = " & A & "D" TB  
    SetEntity eID, entity YoEL|r|  
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    Update #3m7`}c  
    Print "DONE!" `lA[-x~  
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End Sub w`;>+_ E7  
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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： `tb@x ^  
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Accommodation = 4 Diopters Cvf^3~q  
Pupil Diameter = 4 mm G)'(%rl  
Set aqueous humor thickness = 2.81 \C
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Set anterior lens radius = 10.4 and conic constant = -2.375869 #(KE9h%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 :P1/kYg  
Set lens thickness = 3.927 Zc Y* TGx  
Set lens index of refraction = 1.42672 Hg}@2n)/  
Set pupil diameter = 4 ?
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DONE! 7,![oY[