[技术]Arizona眼睛模型 [复制链接]

简介 kUx&
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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。 )2q~u%9n  
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模型 ?rX]x8iP  
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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。 RPnRVJ&"Z  
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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. {%v-(  
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光源 f ).1]~  
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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。 e(F42;$$  
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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。 O#EV5FeF.  
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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。 Fk;oE'"D  
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视网膜的散射 Hy"x  
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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。 kU-t7'?4  
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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。 /y7M lU9  
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脚本 e^YHJ>@  
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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： Uawpfgc}  
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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。 LLWB
  
余下的脚本计算与屈光度有关的所有参数。 H xV#WoYKj  
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分析 X7UuwIIP  

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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。 Fhz*&JC#  
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脚本代码 6<,dRn  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. -"Y{$/B  
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Dim entity As T_ENTITY I]Tsz'T!9  
Dim op As T_OPERATION ?.c;
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Dim mat As T_MODELMATERIAL WD;Y~|  
Dim A As Double @''GPL@  
Dim pupilDiam As Double t&5%?QyM  
Dim eID As Long Sx:Ur>?hd5  
Dim parID As Long Nfe>3uQK  
Dim count As Integer SYeadsvF  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2>-S-;i  
Dim tlens As Double, nlens As Double D47R  
Dim curv As Double, conic As Double "x941}  
Dim ok As Long N$Y" c*  
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Sub Main 2Nxm@B` {  
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    '用户输入对话框 1iL'V-y  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [U#72+K  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,y9iKkg  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -16K7yk  
        OKButton 40,91,90,21 P^MOx4  
        CancelButton 190,91,90,21 H* ,,^  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 OI} &m^IOo  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Tj~IaU  
    End Dialog ;v17K  
    Dim dlg As UserDialog Obw?_@X  
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    ok = Dialog (dlg) bW#@OrsS  

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    If ok=0 Then    'cancel button was pressed ?Y:x[pOe  
        Print "Execution cancelled." 5#3W5z  
        End zPEg  
    End If PqNFyQkl  
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    'Assign accommodation and pupil diameter & use defaults if field left empty m`4R]L]  
    If dlg.TextBox1 = "" Then x#~ x;)  
        A = 0           'Default accommodation 3:"]Rn([P  
    Else 3$vRW.c\q  
        A = CDbl(dlg.TextBox1) \JG8KE=j  
    End If P+
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    If dlg.TextBox2 = "" Then %2'A pp  
        pupilDiam = 4   'Default pupil diameter >$gG/WD?KR  
    Else 6#}93Dgv4  
        pupilDiam = CDbl(dlg.TextBox2) c8)/:xxl  
    End If >Sa*`q3J  
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    Print " " `<^VR[Mx  
    Print "Accommodation = " & A & " Diopters" $&|y<Y=  
    Print "Pupil Diameter = " & pupilDiam & " mm" oRN-xng  
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    ' Calculate new parameters with accommodation C\_zdADUb%  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness a m-b!l!q^  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens H@X oqgI  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens U(&oj e  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens EG'[`<*h  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~5ZvOX6L2  
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    tlens = 3.767 + 0.04*A                  'Lens thickness W$dn_9W  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4vK8kkW1  
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    'Adjust parameters to account for accommodation E< 4l#Z<  
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    '************************************************************************* >idBS  
    'Aqueous thickness (Position of Lens) ;vhyhP.oM  
    '************************************************************************* wI
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) RO\gax  
    GetCustomElement eID, entity L+B?~_*  
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    parID = FindFullName( "Geometry.Arizona Eye" ) d "BW/%m|g  
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    ' Delete any shift(s) in z 0)YbI!  
    count = 0 v8>v.}y  
    While GetOperationCount(eID)>count fQWIw  
        GetOperation eID, count, op ]u-SL md  
        If op.Type="ShiftZ" Then F0~k1TDw  
            DeleteOperation eID,count vv6$>SU  
            count=count-1 RhF>T&Q  
        End If K*K1(_x=  
        count=count+1 39e;  
    Wend \^+ILYO:$  
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    'Set new shift in >1L=,M  
    op.Type = "ShiftZ" '2J0>Bla  
    op.val1 = taq XA0(f*  
    op.parent = parID JL}\*  
    AddOperation eID, op rgIrr5  
    Print "Set aqueous humor thickness = " & taq-0.55 2J;`m_oP  
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    '************************************************************************* { PlK@#UN  
    'Radius and conic constant of anterior lens (A k\Lm  
    '************************************************************************* [~5p>'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) KYJ1}5n  
    GetConic eID, entity, curv, conic b yg0.+e0  
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    SetConic eID, entity, 1/Rant, CCant k>4qkigjc  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <Pqv;WI|R  
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    '*************************************************************************
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    'Radius and conic constant of posterior lens iY[+Ywh  
    '************************************************************************* :2V^K&2L  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) I"L;L?\S  
    GetConic eID, entity, curv, conic B,$l4m4  
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    SetConic eID, entity, 1/Rpost, CCpost Z{-Lc68  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost )\/ =M*  
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    '************************************************************************* z,;;=V6j  
    'Lens thickness (Position of posterior lens surface) 3{raKM6F  
    '************************************************************************* 3
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ! U0z"  
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    ' Delete any z-shift(s) 3EFD%9n  
    count = 0 )9"oL!2h  
    While GetOperationCount(eID)>count 8``;0}'PC  
        GetOperation eID, count, op S[M4ukYK  
        If op.Type="ShiftZ" Then u.|~   
            DeleteOperation eID,count UP1?5Q=H]Q  
            count=count-1 d<p2/aA  
        End If
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        count=count+1 rp! LP#*  
    Wend s}x>J8hK  
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    'Set new z-shift IxSV?k   
    op.Type = "ShiftZ" hAR? t5c  
    op.val1 = tlens ZwI 1* f  
    op.parent = parID GrEs1M1]*  
    AddOperation eID, op To"dG&h  
    Print "Set lens thickness = " & tlens g9tu%cIkR  
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    '************************************************************************* wJ"ev.A)  
    'Lens index of refraction *DeTqO65  
    '************************************************************************* oVkq2  
    eID = FindMaterial( "Lens" ) uF(k[[qaiN  
    GetModelMaterial eID, mat ,4F,:w  
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    mat.Nd = nlens Z_z#QX>=D  
    SetModelMaterial eID, mat 0A$SYF$O+[  
    Print "Set lens index of refraction = " & nlens B+VuUt{S  
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    '************************************************************************* 60B-ay0e$b  
    'Pupil diameter mMw;0/n  
    '************************************************************************* 97~K!'/^+y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) +H'\3^C-  
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    'Adjust pupil diameter (trimming volume inner hole) Q}vbm4)[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens QX
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    parID = FindFullName( "Geometry.Arizona Eye" ) |O (G nsZ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Vewzo1G2  
    count = 0 =MSu3<y,  
    While GetOperationCount(eID)>count R2^iSl%pj  
        GetOperation eID, count, op 7kz-V.  
        If op.Type="ShiftZ" Then LHi6:G"Y(  
            DeleteOperation eID,count P^IY: -s  
            count=count-1 981!2*  
        End If )SiY(8y  
        count=count+1 {+=i?  
    Wend $L{7%]7QC  
    op.Type = "ShiftZ" 7:o+iP46  
    op.val1 = taq-0.01 f=ib9WbR#  
    op.parent = parID Dd/}Ya(Gi  
    AddOperation eID, op 7%CIt?Z%  
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    Print "Set pupil diameter = " & pupilDiam oh&Y<d0  
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    'Update AZ Eye subassembly Description D@hmO]5c  
    eID = FindFullName( "Geometry.Arizona Eye" ) Ju
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    GetEntity eID, entity V\zsDP  
    entity.Description = "Accommodation = " & A & "D" U42\.V0  
    SetEntity eID, entity .BL:h&h|y  
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    Update E^syrEz  
    Print "DONE!" C4_t_N  
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End Sub s^PmnFR  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： (46U|P(v  
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Accommodation = 4 Diopters +{ab1))/  
Pupil Diameter = 4 mm ^ wQcB  
Set aqueous humor thickness = 2.81 r}@< K  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [+DNM 2A  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 G
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Set lens thickness = 3.927 0*{p Oe/u  
Set lens index of refraction = 1.42672 >@Khm"/T  
Set pupil diameter = 4 bX{PSjD  
DONE! a}D&$yz2