[技术]Arizona眼睛模型 [复制链接]

简介 97!5Q~I  
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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。 9L)L|4A.l  
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模型 Y<LNQ]8\G  
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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。 .3wY\W8Dr-  
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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. ]\;xN~l  
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光源 Y}.Ystem  
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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。 I/s.xk_i  
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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。 lrys3  
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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。 D ,M@8h,  
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视网膜的散射 }kPVtSQ  
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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。 ~A >oO-0K  
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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。 H;I~N*ltJ(  
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脚本 /77z\[CeYH  
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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： J}@GKNm  
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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。 {L9yhY
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余下的脚本计算与屈光度有关的所有参数。 (=JueF@J  
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分析 `P.CNYR<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。 `C'}e  
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脚本代码 E5{n?e  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3*WS"bt  
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Dim entity As T_ENTITY %dmfBf Ev  
Dim op As T_OPERATION Yu3_=: <C  
Dim mat As T_MODELMATERIAL `d*b]2  
Dim A As Double e2Jp'93o'  
Dim pupilDiam As Double 0QoLS|voA/  
Dim eID As Long h7?.2Q&S  
Dim parID As Long QymD-A"P  
Dim count As Integer WQt5#m; W  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :qnokrGzB  
Dim tlens As Double, nlens As Double \!wh[qEQ\  
Dim curv As Double, conic As Double Yy@g9mi  
Dim ok As Long AgsR-"uh  
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Sub Main t w!.%_1^  
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    '用户输入对话框 ,}<RrUfD  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /*P7<5n0  
        TextBox 220,21,40,21,.TextBox1 'default: 0 qLRE}$P  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b *9-}g:  
        OKButton 40,91,90,21 O+FBQiv  
        CancelButton 190,91,90,21 a: IwA9!L  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 b42QBTeg  
        TextBox 220,49,40,21,.TextBox2 'default: 4 RbAt3k;y  
    End Dialog /q*KO\L  
    Dim dlg As UserDialog ][t6VA  
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    ok = Dialog (dlg) .e$%[)D  
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    If ok=0 Then    'cancel button was pressed @dV9Dpu  
        Print "Execution cancelled." V6+Zh>'S  
        End A^g>fv  
    End If " $=qGHA~  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 6Ahr_{  
    If dlg.TextBox1 = "" Then ,s? dAy5  
        A = 0           'Default accommodation +2y&B,L_Wh  
    Else GZ"/k<~0  
        A = CDbl(dlg.TextBox1) @g\;` #l  
    End If p1^
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    If dlg.TextBox2 = "" Then raHVkE{<  
        pupilDiam = 4   'Default pupil diameter B^m!t7/,  
    Else r=0j7^B#  
        pupilDiam = CDbl(dlg.TextBox2) $rTu6(i1  
    End If 4k$0CbHx0  
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    Print " " >{F!ntEj  
    Print "Accommodation = " & A & " Diopters" l $w/Fz  
    Print "Pupil Diameter = " & pupilDiam & " mm" .qinR6=  
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    ' Calculate new parameters with accommodation xp=Zd\5W$  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >KHp-|0pv  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #%WCL'6B  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens g? I!OG  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U/5$%0)  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens f?5A"-NS  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 7vq DZg  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _<2
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    'Adjust parameters to account for accommodation p2^)2v  
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    '************************************************************************* `fMpV8vv  
    'Aqueous thickness (Position of Lens) 94YA2_f;  
    '************************************************************************* nqeVV&b!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) HSC6;~U  
    GetCustomElement eID, entity -U:2H7  
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    parID = FindFullName( "Geometry.Arizona Eye" ) lfgtcR{l5  
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    ' Delete any shift(s) in z  RY9.n  
    count = 0 ( mt*y]p?  
    While GetOperationCount(eID)>count EO"6Dq(  
        GetOperation eID, count, op cTy'JT7  
        If op.Type="ShiftZ" Then F#KF6)P  
            DeleteOperation eID,count GqMB^Ad  
            count=count-1 s"N\82z)  
        End If yH+c#w  
        count=count+1 I<KCt2:X  
    Wend ,A?{~?u.  
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    'Set new shift in V4Qz*z%  
    op.Type = "ShiftZ" [lZ=s[n.  
    op.val1 = taq CMFC"eSe  
    op.parent = parID SNN#$8\  
    AddOperation eID, op _C5n
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    Print "Set aqueous humor thickness = " & taq-0.55 A`g.[7  
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    '************************************************************************* r\B"?oqC  
    'Radius and conic constant of anterior lens /0-\ek ye  
    '************************************************************************* 8,H~4Ce3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zNwc((  
    GetConic eID, entity, curv, conic "5y<G:$+~  
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    SetConic eID, entity, 1/Rant, CCant EFeAr@nj  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N?zV*ngBS  
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    '************************************************************************* /RMer Xj  
    'Radius and conic constant of posterior lens \Me"'.F?  
    '************************************************************************* j+ I*Xw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) y=wdR|b  
    GetConic eID, entity, curv, conic ss*5.(y  
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    SetConic eID, entity, 1/Rpost, CCpost vWuyft*  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost JLml#Pu4  
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    '************************************************************************* pRb<wt7v
 
    'Lens thickness (Position of posterior lens surface) ?S8$5gA  
    '************************************************************************* oH=4m~'V  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) G%Y*q(VrEu  
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    ' Delete any z-shift(s) p?}&)Un  
    count = 0 )Gmb?!/^  
    While GetOperationCount(eID)>count X"wFQa  
        GetOperation eID, count, op a!&bc8J7  
        If op.Type="ShiftZ" Then 80dSQ"y  
            DeleteOperation eID,count { qjUI  
            count=count-1 xiEcEz'lk  
        End If W%=Zdm rv  
        count=count+1 \G]K,TG  
    Wend 58 kv#;j  
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    'Set new z-shift EkDws`@  
    op.Type = "ShiftZ" ,#=eu85'  
    op.val1 = tlens $tEdBnf^ca  
    op.parent = parID kja4!_d  
    AddOperation eID, op u4@, *tT  
    Print "Set lens thickness = " & tlens u
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    '************************************************************************* -?[O"D"c  
    'Lens index of refraction /@6E3lhS  
    '************************************************************************* <1TlW ~q<  
    eID = FindMaterial( "Lens" ) ux%&lff  
    GetModelMaterial eID, mat e
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    mat.Nd = nlens 'W}~)+zK  
    SetModelMaterial eID, mat pHigxeV2  
    Print "Set lens index of refraction = " & nlens w{RNv%hJ$=  
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    '************************************************************************* Pv^(Q]  
    'Pupil diameter v`@5enr  
    '************************************************************************* ;OQ#@|D  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <WO&$&  
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    'Adjust pupil diameter (trimming volume inner hole) CX
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" tq2-.]Y@U  
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    ' Adjust pupil location to just in front of the lens b5lk0jA  
    parID = FindFullName( "Geometry.Arizona Eye" ) SJso'6 g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) [Od>NO,n+]  
    count = 0 BERn _5gb  
    While GetOperationCount(eID)>count "bv,I-\  
        GetOperation eID, count, op p7%0hLW  
        If op.Type="ShiftZ" Then Xw&QrTDS`  
            DeleteOperation eID,count SD)5?{6<  
            count=count-1 Bu*W1w\  
        End If !#}v:~[A  
        count=count+1 rhlW  
    Wend nXx6L!HJ#  
    op.Type = "ShiftZ" >xhd[  
    op.val1 = taq-0.01 67Af} >Q  
    op.parent = parID W;xW: -  
    AddOperation eID, op O|A~dj`  
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    Print "Set pupil diameter = " & pupilDiam Zkwy.Hq^  
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    'Update AZ Eye subassembly Description *+_fP|cv  
    eID = FindFullName( "Geometry.Arizona Eye" ) =;~%L  
    GetEntity eID, entity u5[1Z|O  
    entity.Description = "Accommodation = " & A & "D" S3%.-)ib  
    SetEntity eID, entity pko!{,c  
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    Update {hW +^  
    Print "DONE!" xiOv$.@q  
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End Sub DTX/3EN  
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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： >Hd~Ca>  
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Accommodation = 4 Diopters g]EQ2g_N1  
Pupil Diameter = 4 mm N}.Q%&6:  
Set aqueous humor thickness = 2.81 .ruz l(6  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Thht_3_C,f  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ,H#qgnp  
Set lens thickness = 3.927 $
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Set lens index of refraction = 1.42672 G#9o?  
Set pupil diameter = 4 N\CEocU  
DONE! #z-iL!?