[技术]Arizona眼睛模型 [复制链接]

简介 9Bw.Ih[Z  
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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。 j_Qkw ?  
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模型 z-;2)RkV2  
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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。 v5`Q7ZZ  
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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. p`}'-A|@  
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光源 
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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。 VdetY\  
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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。 +8~C&K:  
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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。 -`<KjS  
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视网膜的散射 Vp~c$y+  
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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。 =vc8u&L2
 
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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。 TE!+G\@  
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脚本 ;R x Rap  
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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： F#^<t$5t  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 !0k'fYCa  
余下的脚本计算与屈光度有关的所有参数。 W$b
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分析 ZI>')T<@j"  
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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。 &3t[p=  
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脚本代码 dW`!/OaQD  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |1[3RnGS  
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Dim entity As T_ENTITY eKw!%97>  
Dim op As T_OPERATION ]:X# w0UR  
Dim mat As T_MODELMATERIAL N(W;\>P  
Dim A As Double Gi=s|vt  
Dim pupilDiam As Double zA g.,dA  
Dim eID As Long 2@~hELkk/E  
Dim parID As Long d%wy@h  
Dim count As Integer ooW;s<6  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double bB->7.GXu  
Dim tlens As Double, nlens As Double *`g'*R  
Dim curv As Double, conic As Double k(bDj[0q^  
Dim ok As Long _hz}I>G@B  
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Sub Main 2b i:Q9  
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    '用户输入对话框 :fx^{N!T  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 tzn+ M0'  
        TextBox 220,21,40,21,.TextBox1 'default: 0 [)wLj
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =}1)/gcM  
        OKButton 40,91,90,21 ^ b`wf"A  
        CancelButton 190,91,90,21 NQpC]#n  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 kQt#^pO)  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Q%*987i  
    End Dialog ^_rBEyz@  
    Dim dlg As UserDialog `k]2*$%  
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    ok = Dialog (dlg) YQ7\99tj  
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    If ok=0 Then    'cancel button was pressed Dm+[cA"I  
        Print "Execution cancelled." !CGpE=V  
        End FOS5?%J  
    End If ;rqW?':(i  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 4A{6)<e  
    If dlg.TextBox1 = "" Then y`Nprwb  
        A = 0           'Default accommodation N}\%r&KR=  
    Else W_bp~Wu  
        A = CDbl(dlg.TextBox1) FD[o94`%  
    End If ,%X"Caz  
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    If dlg.TextBox2 = "" Then ]p-xds#d  
        pupilDiam = 4   'Default pupil diameter "PePiW(i+  
    Else E gD$A!6N8  
        pupilDiam = CDbl(dlg.TextBox2) Mc@_[q!xY?  
    End If j' }4ZwEh  
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    Print " " 3o^~6A  
    Print "Accommodation = " & A & " Diopters" B"Hz)-MW  
    Print "Pupil Diameter = " & pupilDiam & " mm" #Y%(CI  
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    ' Calculate new parameters with accommodation |QHIB?C?`  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness UY}EW`$#m  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens m8Y>4:Nw  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens TR&7AiqB  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8I]rC<O6:  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -2qI2Z  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction dthtWnB@  
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    'Adjust parameters to account for accommodation fJK;[*&Y  
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    '************************************************************************* !IC@^kkh{  
    'Aqueous thickness (Position of Lens) ql I1<Jx  
    '************************************************************************* 9WT{~PGj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) iit 5IV  
    GetCustomElement eID, entity
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    parID = FindFullName( "Geometry.Arizona Eye" ) 9|l6.$Me/  
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    ' Delete any shift(s) in z 08_<G`r  
    count = 0 Mt*eC)~Yx  
    While GetOperationCount(eID)>count q-r5zGI  
        GetOperation eID, count, op 0 } |21YED  
        If op.Type="ShiftZ" Then ? ]H'egG6  
            DeleteOperation eID,count !N74y%=M  
            count=count-1 z0 J:"M  
        End If Z5`U+ (  
        count=count+1 bo &QKK  
    Wend T!1Np'12zF  
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    'Set new shift in ekCt1^5Y  
    op.Type = "ShiftZ" G7k.YtW  
    op.val1 = taq :v%iF!+.P  
    op.parent = parID I|tn7|*-A[  
    AddOperation eID, op {4B7a6
 
    Print "Set aqueous humor thickness = " & taq-0.55 9Idgib&  
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    '************************************************************************* F$HL\y  
    'Radius and conic constant of anterior lens *fp4u_:`  
    '************************************************************************* SD.c9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~EO=;a_  
    GetConic eID, entity, curv, conic 2>vn'sXdj  
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    SetConic eID, entity, 1/Rant, CCant ?MD\\gN  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant fl71{jJ_  
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    '************************************************************************* ;5:3 =F>ao  
    'Radius and conic constant of posterior lens y<^hM6S?Z  
    '************************************************************************* jTN!\RH9NF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) U(\ ^!S1  
    GetConic eID, entity, curv, conic DIWcX<s  
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    SetConic eID, entity, 1/Rpost, CCpost fvM|Jb  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost G\Q0{4w8  
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    '************************************************************************* eXCH*vZY  
    'Lens thickness (Position of posterior lens surface) p}lFV,V  
    '************************************************************************* 18JAca8Zs  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (@cZmU,  
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    ' Delete any z-shift(s) K~ VUD(  
    count = 0 'cf8VD  
    While GetOperationCount(eID)>count q&V=A[<rz  
        GetOperation eID, count, op 4Dv42fO  
        If op.Type="ShiftZ" Then 4fau 9bW  
            DeleteOperation eID,count R|K#nh  
            count=count-1 A{ Ejk|  
        End If Am)XbN')1  
        count=count+1 +$D~?sk  
    Wend #6za  
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    'Set new z-shift d1/uI^8>  
    op.Type = "ShiftZ" N}7tjk  
    op.val1 = tlens Jc,{n*  
    op.parent = parID :\,3=suWq  
    AddOperation eID, op BCw0kq@  
    Print "Set lens thickness = " & tlens z=a{;1A  
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    '************************************************************************* ^?gs<-)B  
    'Lens index of refraction n##d!d|g  
    '************************************************************************* Oxr?y8C~  
    eID = FindMaterial( "Lens" ) I~NQt^sg  
    GetModelMaterial eID, mat `"<tk1Kq"  
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    mat.Nd = nlens pax;#*QcQ  
    SetModelMaterial eID, mat a*nx2d  
    Print "Set lens index of refraction = " & nlens *m`KY)b=l  
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    '************************************************************************* Zn"1qLPF  
    'Pupil diameter ($Y6hn+  
    '************************************************************************* Wo~#R   
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) L\y>WR%s  
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    'Adjust pupil diameter (trimming volume inner hole) 9UeK}Rl^n  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" d=8q/]_p  
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    ' Adjust pupil location to just in front of the lens ~$Pz`amT|  
    parID = FindFullName( "Geometry.Arizona Eye" ) {h *Pkn1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ET}Dh3A  
    count = 0 Hm55
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    While GetOperationCount(eID)>count PK|"+I0  
        GetOperation eID, count, op ( mKuFz7  
        If op.Type="ShiftZ" Then s7}46\/U  
            DeleteOperation eID,count fS(IN~
 
            count=count-1 l-RwCw4f  
        End If L/n?1'he  
        count=count+1 x"Q
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    Wend 7iBN!"G0  
    op.Type = "ShiftZ" C"!k`i=Lj  
    op.val1 = taq-0.01 uGMmS9v$ J  
    op.parent = parID Q`7.-di  
    AddOperation eID, op cN\Fg
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    Print "Set pupil diameter = " & pupilDiam l gzA) (  
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    'Update AZ Eye subassembly Description /htM/pR  
    eID = FindFullName( "Geometry.Arizona Eye" ) wA;C
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    GetEntity eID, entity zVU{jmS  
    entity.Description = "Accommodation = " & A & "D" jjrhl  
    SetEntity eID, entity ?#0|A?U  
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    Update I@<\DltPi  
    Print "DONE!" o0'!u  
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End Sub \tx4bV#  
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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： 4]18=?r>  
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Accommodation = 4 Diopters  N\9Wxz$  
Pupil Diameter = 4 mm @XL5$k[Y  
Set aqueous humor thickness = 2.81 -@EAL:kY  
Set anterior lens radius = 10.4 and conic constant = -2.375869 =~f\m:Y  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 BQfq]ti  
Set lens thickness = 3.927 P 4|p[V8  
Set lens index of refraction = 1.42672 
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Set pupil diameter = 4 swh8-_[c/  
DONE! yhpeP