[技术]Arizona眼睛模型 [复制链接]

简介 i!S
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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。 pAJ=f}",]E  
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模型 gro7*<  
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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。 2!{_/@I\Y  
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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. F* 3G_V  
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光源 A+0T"2  
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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。 c&Gz> L  
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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。 Wk/fB0  
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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。 PU^[HC*K  
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视网膜的散射 Q?* nuE  
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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。 *TJBPM,  
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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。 'is,^q:@  
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脚本 96vj)ql  
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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：  AGh~8[  
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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。 2#'rk'X,K  
余下的脚本计算与屈光度有关的所有参数。 a;56k  
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分析 &\&'L|0F  
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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。 ?$<SCN=  
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脚本代码 L5R `w&Up  

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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3|q2rA  
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Dim entity As T_ENTITY vkd *ER^  
Dim op As T_OPERATION Er`TryN|}  
Dim mat As T_MODELMATERIAL W7%p^;ZQ$  
Dim A As Double
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Dim pupilDiam As Double fG<Dhz@  
Dim eID As Long xy2\'kS`G  
Dim parID As Long Dz,uS nnm  
Dim count As Integer  W|lH  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double SrSG{/{  
Dim tlens As Double, nlens As Double +:}kZDl@ X  
Dim curv As Double, conic As Double *:?QB8YJ  
Dim ok As Long E yd$fcRK  
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Sub Main >g=^,G}y  
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    '用户输入对话框 OO-_?8I}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8098y,mQe  
        TextBox 220,21,40,21,.TextBox1 'default: 0 jz|
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 hl`u"?rg  
        OKButton 40,91,90,21 g&Z"_7L~  
        CancelButton 190,91,90,21 vxb@9eb!H  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 x,w8r+~5  
        TextBox 220,49,40,21,.TextBox2 'default: 4 |4=ihB9+  
    End Dialog u',b1 3g(  
    Dim dlg As UserDialog ?'Cb-C_  
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    ok = Dialog (dlg) Umij!=GPG^  
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    If ok=0 Then    'cancel button was pressed kPWBDpzN  
        Print "Execution cancelled." $Tfm/=e  
        End Qy/uB$q{A  
    End If L,#^&9bHa#  
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    'Assign accommodation and pupil diameter & use defaults if field left empty NJk)z&M  
    If dlg.TextBox1 = "" Then ;r3}g"D@  
        A = 0           'Default accommodation )u<eO FI+  
    Else KVg[#~3  
        A = CDbl(dlg.TextBox1) : g5(HH  
    End If ~)_K"h.DY  
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    If dlg.TextBox2 = "" Then oI*d/*  
        pupilDiam = 4   'Default pupil diameter 5PDSA*  
    Else 7q!?1 -?8R  
        pupilDiam = CDbl(dlg.TextBox2) 2R\+}  
    End If [O(m/  
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    Print " " uj)yk*  
    Print "Accommodation = " & A & " Diopters" "$r1$mBi  
    Print "Pupil Diameter = " & pupilDiam & " mm" alVdQfu  
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    ' Calculate new parameters with accommodation "sD1T3!\)Q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness P:qz2Hw  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens cu)U7  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens a#$N%=j  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0t+])>  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens f\ 'T_  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _H8*ReFG  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "-P/jk  
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    'Adjust parameters to account for accommodation _W}(!TKO  
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    '************************************************************************* +mLD/gK`  
    'Aqueous thickness (Position of Lens) zSKKr?{  
    '************************************************************************* JYQ.EAsr!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @`S.@^%7fO  
    GetCustomElement eID, entity hXc}r6<B  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |g!`\@O  
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    ' Delete any shift(s) in z ioWo ]  
    count = 0 ^&NN]?  
    While GetOperationCount(eID)>count F\-Si!~oOz  
        GetOperation eID, count, op ^&MK42,\  
        If op.Type="ShiftZ" Then *7Xzht&f  
            DeleteOperation eID,count xG1?F_]  
            count=count-1 TM-Fu([LMV  
        End If \E77SO,$  
        count=count+1 Fm5Q&'`l  
    Wend !3V{2-y$-  
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    'Set new shift in 5{X*a  
    op.Type = "ShiftZ" nA+F  
    op.val1 = taq $''UlWK  
    op.parent = parID 6OtVaT=}<O  
    AddOperation eID, op GyK(Vb"h6  
    Print "Set aqueous humor thickness = " & taq-0.55 CdL.?^  
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    '************************************************************************* K{2h9 ]VF  
    'Radius and conic constant of anterior lens #x)8f3I  
    '************************************************************************* = ^s$ <  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #w|5jN?  
    GetConic eID, entity, curv, conic =k_UjwgN^  
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    SetConic eID, entity, 1/Rant, CCant |IN[uQ  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant P0 b4Hq3  
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    '************************************************************************* |'$ l7  
    'Radius and conic constant of posterior lens P,ydt  
    '************************************************************************* V%51k{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y{+3}drJE  
    GetConic eID, entity, curv, conic vxVOcO9<  
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    SetConic eID, entity, 1/Rpost, CCpost Y[um|M315  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3[V
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    '************************************************************************* d}+W"j;  
    'Lens thickness (Position of posterior lens surface) M4:s;@qZ.  
    '************************************************************************* l9J*um-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (f>M &..  
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    ' Delete any z-shift(s) s[X B#)H4  
    count = 0 r6 }_H?j  
    While GetOperationCount(eID)>count 6|#g+&[  
        GetOperation eID, count, op g "*;nHI D  
        If op.Type="ShiftZ" Then cmDT +$s  
            DeleteOperation eID,count QNg\4%  
            count=count-1 hB>^'6h+  
        End If 1tGgDbJU  
        count=count+1 !y[3]8Xxv  
    Wend gDC2 >nV  
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    'Set new z-shift vyU!+mlc  
    op.Type = "ShiftZ" Yt{&rPv,  
    op.val1 = tlens QBihpA1;  
    op.parent = parID n&d/?aJ7a\  
    AddOperation eID, op /b%Q[ Ck_  
    Print "Set lens thickness = " & tlens $[z<oN_Q  
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    '************************************************************************* :1_mfX  
    'Lens index of refraction i}lRIXjdV  
    '************************************************************************* -;Uj|^  
    eID = FindMaterial( "Lens" ) >rf5)Y~f  
    GetModelMaterial eID, mat niWx^gKb$  
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    mat.Nd = nlens |^Kjz{  
    SetModelMaterial eID, mat C}Qt "-%  
    Print "Set lens index of refraction = " & nlens 9g]M4*?C9P  
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    '************************************************************************* mi^
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    'Pupil diameter mH\@QdF  
    '************************************************************************* 1;&T^Gdj  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) PGX+p+wB  
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    'Adjust pupil diameter (trimming volume inner hole) ti9}*8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" vr4S9`,  
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    ' Adjust pupil location to just in front of the lens '9q6aM/&  
    parID = FindFullName( "Geometry.Arizona Eye" ) m UgRm]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )  SFpQ#  
    count = 0 'n4u-pM(nB  
    While GetOperationCount(eID)>count q-IWRb0j%a  
        GetOperation eID, count, op VMHC/jlX@r  
        If op.Type="ShiftZ" Then =bL{i&&  
            DeleteOperation eID,count 2C1+_IL   
            count=count-1 UvBnf+,  
        End If ea~i-7  
        count=count+1 o;QZe&  
    Wend Sk=N [hwU  
    op.Type = "ShiftZ" KY+]RxX  
    op.val1 = taq-0.01 j)L1H* S%  
    op.parent = parID &yLc1#H  
    AddOperation eID, op LdEE+"Jw  
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    Print "Set pupil diameter = " & pupilDiam 6K 4+0xXv  
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    'Update AZ Eye subassembly Description eqhAus?)  
    eID = FindFullName( "Geometry.Arizona Eye" ) D]u=PqHk2  
    GetEntity eID, entity 4bI*jEc\[  
    entity.Description = "Accommodation = " & A & "D" JIV
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    SetEntity eID, entity ;BVDt  
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    Update K)5;2lN,  
    Print "DONE!" g+|Bf&_  
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End Sub (}~ucI<~  
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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： [z+x"9l0!  
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Accommodation = 4 Diopters |Fp'/~|w2d  
Pupil Diameter = 4 mm a))*F!}c  
Set aqueous humor thickness = 2.81 5i9Ub|!P  
Set anterior lens radius = 10.4 and conic constant = -2.375869 4z0L ke  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 s0!kwrBsp  
Set lens thickness = 3.927 C #aFc01B  
Set lens index of refraction = 1.42672 e1^l.>2d6  
Set pupil diameter = 4 os**hFPk;1  
DONE! o#}mkE87