[技术]Arizona眼睛模型 [复制链接]

简介 KM"BHaSkF  
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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。 vnWt8?)]^  
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模型 dVg'v7G&V(  
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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。 .k$Yleg  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 85
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光源 fr'DV/T  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 :k-@w5(  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ;l^'g}dQ^  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 z%BX^b$Hj  
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视网膜的散射 5g.w"0MkY  
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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。 BNe>Lko  
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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。 nch
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脚本 -?l`LbD  
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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： ej7L-~lxQ  
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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。 Al]*iw{  
余下的脚本计算与屈光度有关的所有参数。 .4l cES~  
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分析 7{l~\]6d  
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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。 GXk |p8  
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脚本代码 8Q"1I7U  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 11k}Ly  
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Dim entity As T_ENTITY 
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Dim op As T_OPERATION M`8c|*G   
Dim mat As T_MODELMATERIAL lon9oraF'  
Dim A As Double $e{[fmx  
Dim pupilDiam As Double fdHFSnQ g  
Dim eID As Long 2<@g *  
Dim parID As Long 2kk; z0f  
Dim count As Integer ;@:-T/=  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double rVRv*W  
Dim tlens As Double, nlens As Double rg=Ym.  
Dim curv As Double, conic As Double Ck>]+rl  
Dim ok As Long 6!USSipn  
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Sub Main :."6g)T  
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    '用户输入对话框 5iI(A'R[7  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Dd,i^,4Gj  
        TextBox 220,21,40,21,.TextBox1 'default: 0 t@a&&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^t*Ba>A  
        OKButton 40,91,90,21 X<pNc6  
        CancelButton 190,91,90,21 VS!v7-_N5  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9Zmq7a E  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ;g;1<? [  
    End Dialog OF)*kiJ  
    Dim dlg As UserDialog EcSu[b  
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    ok = Dialog (dlg) P2 qC[1hYH  
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    If ok=0 Then    'cancel button was pressed VR%*8=  
        Print "Execution cancelled." ;j[:tt\k  
        End )>^Ge9d]  
    End If F
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    'Assign accommodation and pupil diameter & use defaults if field left empty -N6ek`  
    If dlg.TextBox1 = "" Then \qlz<  
        A = 0           'Default accommodation )O$S3ojZ  
    Else PfB9 .f{  
        A = CDbl(dlg.TextBox1) 94]i|2qj*  
    End If 5*Qzw[[=  
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    If dlg.TextBox2 = "" Then %o0H#7'  
        pupilDiam = 4   'Default pupil diameter ${}9/(x/^  
    Else 1'iQlnMO@  
        pupilDiam = CDbl(dlg.TextBox2) 3+ 2&9mm  
    End If k,; (`L  
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    Print " " F1L[C4'  
    Print "Accommodation = " & A & " Diopters" <b\8<mTr  
    Print "Pupil Diameter = " & pupilDiam & " mm" .7:ecF
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    ' Calculate new parameters with accommodation 1mR@Bh  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -V[!qI  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Uz[#ye  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 'A\0^EvVv  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (:%t  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens x9 n(3Oa  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Lxv_{~I*  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 86dz Jh  
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    'Adjust parameters to account for accommodation "Vp:Sq9y  
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    '************************************************************************* ae
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    'Aqueous thickness (Position of Lens) '?fGI
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    '************************************************************************* |}/KueZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) b^(
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    GetCustomElement eID, entity Goy[P2m  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,OP\^  
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    ' Delete any shift(s) in z l
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    count = 0 1=!2|D:C)i  
    While GetOperationCount(eID)>count nPl,qcyY  
        GetOperation eID, count, op }#Iqq9[  
        If op.Type="ShiftZ" Then aD6!x3c/  
            DeleteOperation eID,count PGVp1TQ  
            count=count-1 p6)6Gcx  
        End If i=pfjC  
        count=count+1 MBU4Awj  
    Wend fD8GAav  
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    'Set new shift in U2~|AkL  
    op.Type = "ShiftZ" P=9UK`n  
    op.val1 = taq 0m\( @2E  
    op.parent = parID /+. m.TF  
    AddOperation eID, op ^EW6}oj[  
    Print "Set aqueous humor thickness = " & taq-0.55 :b_hF  
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    '************************************************************************* +bb-uoZf  
    'Radius and conic constant of anterior lens hgwS_L  
    '************************************************************************* 5Fq+^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Nd@/U c  
    GetConic eID, entity, curv, conic w_LkS/  
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    SetConic eID, entity, 1/Rant, CCant =KD[#au6a  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant iU=:YPE+.  
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    '************************************************************************* :6m"}8*q8  
    'Radius and conic constant of posterior lens /len8FRf  
    '************************************************************************* b.}J'?yLm  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) W3^^aD-  
    GetConic eID, entity, curv, conic <KStlfX  
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    SetConic eID, entity, 1/Rpost, CCpost U9Q[K
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5>=4$!`  
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    '************************************************************************* RmOkb~  
    'Lens thickness (Position of posterior lens surface) oJ#;XR  
    '************************************************************************* rg]z  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) J%!vhQ  
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    ' Delete any z-shift(s) \Il?$Kb/  
    count = 0 1$:O9{F  
    While GetOperationCount(eID)>count =vDDfPR  
        GetOperation eID, count, op 0wF)bQv1  
        If op.Type="ShiftZ" Then XXD4T9Wy  
            DeleteOperation eID,count ofgNL .u  
            count=count-1 r C
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        End If d4A:XNKB  
        count=count+1 b'ir$RL] c  
    Wend )2u_c=  
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    'Set new z-shift @B?'Mu*  
    op.Type = "ShiftZ" %.fwNS  
    op.val1 = tlens TIF =fQ  
    op.parent = parID e#WASHZN  
    AddOperation eID, op V,?])=Ax  
    Print "Set lens thickness = " & tlens /IHF  
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    '************************************************************************* @Yw42`>!s  
    'Lens index of refraction i@%a!].I  
    '************************************************************************* *
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    eID = FindMaterial( "Lens" ) Sg\+al7  
    GetModelMaterial eID, mat y~VLa  
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    mat.Nd = nlens TpHzf3.I  
    SetModelMaterial eID, mat @Q!Tvw/  
    Print "Set lens index of refraction = " & nlens SF"r</c[  
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    '************************************************************************* fEGnI
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    'Pupil diameter #;;A~d:V  
    '************************************************************************* "wxyY^"  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _!?a9  
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    'Adjust pupil diameter (trimming volume inner hole) xF 3Z>  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q*e\I8R}  
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    ' Adjust pupil location to just in front of the lens }5Km \OI  
    parID = FindFullName( "Geometry.Arizona Eye" ) :1v.Jk  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Qr-,
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    count = 0 Yq{R*HO  
    While GetOperationCount(eID)>count }z2[w@M  
        GetOperation eID, count, op Q4g69
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        If op.Type="ShiftZ" Then FB3}M)G>M  
            DeleteOperation eID,count MaF4lFmS  
            count=count-1 E[FE-{B#  
        End If 1`~.!yd8(  
        count=count+1 7IrH(~Fo  
    Wend :edy(vC<  
    op.Type = "ShiftZ" m+x$LkP  
    op.val1 = taq-0.01 m.lzkS]P  
    op.parent = parID NuX
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    AddOperation eID, op 0Ld"df*  
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    Print "Set pupil diameter = " & pupilDiam ROO@EQ#`Z  
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    'Update AZ Eye subassembly Description T5dnj&N ]  
    eID = FindFullName( "Geometry.Arizona Eye" ) [7,q@>:CS  
    GetEntity eID, entity NFqGbA|  
    entity.Description = "Accommodation = " & A & "D" L08lkq,  
    SetEntity eID, entity 7s Gf_`Z  
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    Update F4IU2_CnPD  
    Print "DONE!" <driD'=F  
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End Sub vz&88jt  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： Y<_;8%S  
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Accommodation = 4 Diopters \Qf2:[-V0  
Pupil Diameter = 4 mm xrv0%  
Set aqueous humor thickness = 2.81 |w5,%#AeO$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 X3?RwN:P  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 /0XmU@B  
Set lens thickness = 3.927 *n6L3"cO  
Set lens index of refraction = 1.42672 /-+hMYe  
Set pupil diameter = 4 2AEVBkF;M  
DONE! FB %-$