[技术]Arizona眼睛模型 [复制链接]

简介 ,}xpYq_/  
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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。 ,6cbD  
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模型 ;XKo44%  
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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。 / y":/"h  
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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. v4Fnh`{  
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光源 s)`1Rf  
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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。 cLN[o8ZU  
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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。 Jnu}{^~  
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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。 n+RUPZ  
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视网膜的散射 709Uv5  
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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。 YWn6wzu%Vc  
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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。 [M8qU$&?]  
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脚本 4LB9w21  
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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： ixI5Xd<  
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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。 ;&t1FH#=  
余下的脚本计算与屈光度有关的所有参数。 ^
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分析 Oa_o"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。 }:c,SO!  
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脚本代码 }T1Xds8w)t  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b1['uJF  
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Dim entity As T_ENTITY L_zmU_zD  
Dim op As T_OPERATION (J;zkb
 
Dim mat As T_MODELMATERIAL *l'$pJ X  
Dim A As Double MIXrLh3  
Dim pupilDiam As Double dc@wf;o  
Dim eID As Long T~ q'y~9o  
Dim parID As Long glKs8^W  
Dim count As Integer as\K(c9  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tx&U"]  
Dim tlens As Double, nlens As Double /CQQ^/  
Dim curv As Double, conic As Double V.a]IkK'K  
Dim ok As Long n+F-,=0  
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Sub Main jv#" vQ9A]  
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    '用户输入对话框 )}9}"jrDlx  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7J!d3j2TR  
        TextBox 220,21,40,21,.TextBox1 'default: 0 K&P{2Hndr  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~9/nx|%D  
        OKButton 40,91,90,21 vJjj+:  
        CancelButton 190,91,90,21 *y\tnsU  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0&L0j$&h  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ^{sI'l~  
    End Dialog |u@>[*k'=  
    Dim dlg As UserDialog [j+0EVwB  
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    ok = Dialog (dlg) YrcC"  
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    If ok=0 Then    'cancel button was pressed T9;o.f S  
        Print "Execution cancelled." _itN.^  
        End T+{'W  
    End If XxU}|jTO#  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Ex&RR< 5  
    If dlg.TextBox1 = "" Then 0c;"bA0>Sx  
        A = 0           'Default accommodation n\)f.}YD8d  
    Else ~~E=E;9
  
        A = CDbl(dlg.TextBox1) ]8cX#N,M  
    End If zs^\zCb8  
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    If dlg.TextBox2 = "" Then NU\t3JaR  
        pupilDiam = 4   'Default pupil diameter $gtT5{"PN(  
    Else Z5^UF2`Q  
        pupilDiam = CDbl(dlg.TextBox2) GKDG5u;  
    End If xMGd'l
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    Print " " v__Go kj-  
    Print "Accommodation = " & A & " Diopters" R =c  
    Print "Pupil Diameter = " & pupilDiam & " mm" ]CJ>iS!V  
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    ' Calculate new parameters with accommodation iQR})=Q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 'eXw`kw(  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens x@\'@>_GM  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5GpK
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -Z&{$J  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  2x J5  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ,<WykeC  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 'WgwLE_  
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    'Adjust parameters to account for accommodation pKlT.<X7  
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    '************************************************************************* W n mRRq^  
    'Aqueous thickness (Position of Lens) @G{DOxE*  
    '************************************************************************* P@![P Ij  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7i8qB462  
    GetCustomElement eID, entity +~AI(h  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Hx0,kOh)  

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    ' Delete any shift(s) in z 5Rp2O4Z  
    count = 0 #iU/Yg!  
    While GetOperationCount(eID)>count ~"B[6^sW  
        GetOperation eID, count, op Nr+1N83S}  
        If op.Type="ShiftZ" Then >#|Q,hVU5  
            DeleteOperation eID,count #ms98pw%5  
            count=count-1 c?Qg:yU  
        End If 8TvPCZ$x  
        count=count+1 J#WPXE+Ds  
    Wend \F3t&:  
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    'Set new shift in '2#fkH[.  
    op.Type = "ShiftZ" 5ZxBmQ  
    op.val1 = taq jO.E#Ei}~  
    op.parent = parID r!uAofIi_  
    AddOperation eID, op S"z4jpqn3  
    Print "Set aqueous humor thickness = " & taq-0.55 @vh>GiR){  
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    '************************************************************************* s3^SjZb  
    'Radius and conic constant of anterior lens |Ay#0uQ5Y  
    '************************************************************************* 5xKR ]u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Pl6=
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    GetConic eID, entity, curv, conic v836nxLM  
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    SetConic eID, entity, 1/Rant, CCant VG^-aR_F  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _m-r}9au   
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    '************************************************************************* 95&HsgdxJ  
    'Radius and conic constant of posterior lens P.7B]&T6  
    '************************************************************************* c6|&?}F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) .&dcJh*O+  
    GetConic eID, entity, curv, conic S3fBZIPp  
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    SetConic eID, entity, 1/Rpost, CCpost WGn1pW  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Y8(yOVy9  
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    '************************************************************************* }OFk.6{{&v  
    'Lens thickness (Position of posterior lens surface) `^[ra%
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    '************************************************************************* X}Fv*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Y8T.RS0  
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    ' Delete any z-shift(s) @pz2}Hd|  
    count = 0 v\C+G[MV7  
    While GetOperationCount(eID)>count *<1m 2t>.  
        GetOperation eID, count, op z_)$g=9$  
        If op.Type="ShiftZ" Then qE[}Cf]X
 
            DeleteOperation eID,count NKws;/u  
            count=count-1 ?1sY S  
        End If 3t'K@W?AJh  
        count=count+1 M\3!elp2z  
    Wend XRkqMq%  
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    'Set new z-shift u9Ro=#xt  
    op.Type = "ShiftZ" 9q?gmAn.  
    op.val1 = tlens >qla,}x  
    op.parent = parID Q@R8qc=*  
    AddOperation eID, op  "(xu  
    Print "Set lens thickness = " & tlens 78wcMQNX9  
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    '************************************************************************* 04:Dbt~=?p  
    'Lens index of refraction y\x<!_&D  
    '*************************************************************************
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    eID = FindMaterial( "Lens" ) YeVhWPn@  
    GetModelMaterial eID, mat % |V:F.f  
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    mat.Nd = nlens ~n?U{ RmH  
    SetModelMaterial eID, mat u CXd% CzE  
    Print "Set lens index of refraction = " & nlens xS'So7:h  
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    '************************************************************************* (,>`\\  
    'Pupil diameter  `S|gfJ  
    '************************************************************************* #,sJd^uI  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4p]Y`];U  
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    'Adjust pupil diameter (trimming volume inner hole) +t f=  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ocvBKsfhE`  
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    ' Adjust pupil location to just in front of the lens x=k$^V~  
    parID = FindFullName( "Geometry.Arizona Eye" ) `?:'_Ki  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) BLRrHaX0  
    count = 0 %2.T1X%!  
    While GetOperationCount(eID)>count :}lE@Y,R   
        GetOperation eID, count, op 8cHZBM7'  
        If op.Type="ShiftZ" Then "F^EfpcJ{9  
            DeleteOperation eID,count Oe?nX>  
            count=count-1 =vWnqF:  
        End If F#hM S<  
        count=count+1 wBf bpoE7  
    Wend *+G K?Ga  
    op.Type = "ShiftZ" /cg!Ap5  
    op.val1 = taq-0.01 A/MOY@%G  
    op.parent = parID ,xiRP$hGhh  
    AddOperation eID, op ^0 t`EZ$  
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    Print "Set pupil diameter = " & pupilDiam nv={.H  
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    'Update AZ Eye subassembly Description Gf
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    eID = FindFullName( "Geometry.Arizona Eye" ) eu~;G H  
    GetEntity eID, entity *ULXJZ%  
    entity.Description = "Accommodation = " & A & "D" Sdn] f4  
    SetEntity eID, entity :=/DF  
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    Update `hbM2cM  
    Print "DONE!" U|>Js!$  
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End Sub *Hs5MXNu  
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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： x@/!H<y  
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Accommodation = 4 Diopters V/03m3!q  
Pupil Diameter = 4 mm dCinbAQ  
Set aqueous humor thickness = 2.81 _|F h^hq  
Set anterior lens radius = 10.4 and conic constant = -2.375869 zUOYH4+  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 b_B4  
Set lens thickness = 3.927 MT3UJ6~P  
Set lens index of refraction = 1.42672 ]UNmhF!W>u  
Set pupil diameter = 4 !l}es4~.a  
DONE! <|{=O9