[技术]Arizona眼睛模型 [复制链接]

简介 D[~}uZ4\  
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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。 =|0/Ynfe  
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模型 lzfDH=&  
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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。 %fpsc_  
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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. &@; RI~  
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光源 AbZ:(+@cP  
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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。 :bv|Ah  
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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。 O+FBQiv  
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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。 1S*P"8N}0h  
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视网膜的散射 .e$%[)D  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 @dV9Dpu  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 !a[
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脚本 GZ"/k<~0  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 8^T2^gs  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 4d-q!lRpa  
余下的脚本计算与屈光度有关的所有参数。 fz8h]PZ  
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分析 `Sx.|`x8  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 zn^v!:[  
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脚本代码 N(BiOLZL6  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. #%WCL'6B  
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Dim entity As T_ENTITY +,wWhhvlzv  
Dim op As T_OPERATION U/5$%0)  
Dim mat As T_MODELMATERIAL f?5A"-NS  
Dim A As Double e&ts\0  
Dim pupilDiam As Double 7vq DZg  
Dim eID As Long (GNEYf|  
Dim parID As Long _<2
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Dim count As Integer vG3M5G  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  feN!_-  
Dim tlens As Double, nlens As Double Iy.mVtcsZ  
Dim curv As Double, conic As Double Y2D>tpqNw  
Dim ok As Long !U[:5@s06  
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Sub Main !"%S#nrL$  
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    '用户输入对话框 ?cJA^W  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 kw#X]`c3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 [x|)}P7%s  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ]f5c\\)  
        OKButton 40,91,90,21 U\?+s2I)v  
        CancelButton 190,91,90,21 UI_v3c3b  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 4`6< {  
        TextBox 220,49,40,21,.TextBox2 'default: 4 :i}@Br+R7L  
    End Dialog `xGT_0&ck  
    Dim dlg As UserDialog py.!%vIOQ  
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    ok = Dialog (dlg) hWm0$v1p  
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    If ok=0 Then    'cancel button was pressed /wlFD,+8  
        Print "Execution cancelled." d96fjj~  
        End ]h0Y8kpd  
    End If D>S8$]^Dm  
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    'Assign accommodation and pupil diameter & use defaults if field left empty A`g.[7  
    If dlg.TextBox1 = "" Then _V&x`ks  
        A = 0           'Default accommodation r\B"?oqC  
    Else /0-\ek ye  
        A = CDbl(dlg.TextBox1) 8,H~4Ce3  
    End If zNwc((  
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    If dlg.TextBox2 = "" Then sN=KRqe  
        pupilDiam = 4   'Default pupil diameter EFeAr@nj  
    Else N?zV*ngBS  
        pupilDiam = CDbl(dlg.TextBox2) &D^e<j}RQ  
    End If /RMer Xj  
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    Print " " j+ I*Xw  
    Print "Accommodation = " & A & " Diopters" y=wdR|b  
    Print "Pupil Diameter = " & pupilDiam & " mm" ss*5.(y  
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    ' Calculate new parameters with accommodation vWuyft*  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness JLml#Pu4  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens pRb<wt7v
 
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8cB=}XgYS  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens L-j/R1fTvl  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *Q0lC1GQ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ,Io0ZE>`V  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !eV^Ah>PZ  
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    'Adjust parameters to account for accommodation $vz_
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    '************************************************************************* FXcc1X/  
    'Aqueous thickness (Position of Lens) dWMccn;-m  
    '************************************************************************* *u58l(&`8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =Z^un&'  
    GetCustomElement eID, entity y)0gJP L^  
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    parID = FindFullName( "Geometry.Arizona Eye" ) .iN-4"_j1  
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    ' Delete any shift(s) in z dP?nP(l  
    count = 0 L(W%~UGN V  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op \MF3CK@/  
        If op.Type="ShiftZ" Then !'+\]eA  
            DeleteOperation eID,count D\@e{.$MZ|  
            count=count-1 w 7Cne%J8  
        End If dvC0 <*V  
        count=count+1 H^ESAs6  
    Wend 7?+5%7-  
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    'Set new shift in  b$PT_!d  
    op.Type = "ShiftZ" /5&3WG&<u  
    op.val1 = taq O 0Vn";Q 4  
    op.parent = parID 7ZL,p:f  
    AddOperation eID, op 4 `j,&=  
    Print "Set aqueous humor thickness = " & taq-0.55 fLLnf].O  
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    '************************************************************************* F">Nrj-b
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    'Radius and conic constant of anterior lens tq2-.]Y@U  
    '************************************************************************* B?$S~5  }  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &19lk   
    GetConic eID, entity, curv, conic JHnk%h0  
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    SetConic eID, entity, 1/Rant, CCant Z|V"8jE  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4x=V|"  
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    '************************************************************************* xgZV0!%  
    'Radius and conic constant of posterior lens er&uC4Y]a  
    '************************************************************************* Y{+zg9L*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) =>gyc;{2K<  
    GetConic eID, entity, curv, conic !%SdTaC{T  
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    SetConic eID, entity, 1/Rpost, CCpost  Oz"@yL}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost W@R$'r,@O  
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    '************************************************************************* x.jYip  
    'Lens thickness (Position of posterior lens surface) ls8olLM>  
    '************************************************************************* _C7abw-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) IKNFYe[9e  
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    ' Delete any z-shift(s) o=mq$Z:}  
    count = 0 fvAh?<Ul  
    While GetOperationCount(eID)>count G%V=idU*"  
        GetOperation eID, count, op DDqC}l_  
        If op.Type="ShiftZ" Then eO|^Lu]+  
            DeleteOperation eID,count '6Pu[^x  
            count=count-1 :F!dTD$  
        End If @m !9"QhC  
        count=count+1 'sT}DX(7M  
    Wend >S?C {_g  
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    'Set new z-shift #+2:d?t  
    op.Type = "ShiftZ" rf1wS*uU+  
    op.val1 = tlens CSd9\V  
    op.parent = parID C,sD?PcSi+  
    AddOperation eID, op qv ;1$  
    Print "Set lens thickness = " & tlens lx A<iQi
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    '************************************************************************* ?~]1Gd  
    'Lens index of refraction a<a&63  
    '************************************************************************* r{Qs9  
    eID = FindMaterial( "Lens" ) =F^->e0N  
    GetModelMaterial eID, mat ~PU1vbv9T  
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    mat.Nd = nlens YW4bm  
    SetModelMaterial eID, mat Q G=-LXv:@  
    Print "Set lens index of refraction = " & nlens e4>L@7  
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    '************************************************************************* Se;?j-  
    'Pupil diameter WwCK  K  
    '************************************************************************* 110>p  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ulz\x2[Pf  
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    'Adjust pupil diameter (trimming volume inner hole) V1CSXY\2  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" T}b( M*E  
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    ' Adjust pupil location to just in front of the lens }v'PY/d.  
    parID = FindFullName( "Geometry.Arizona Eye" ) Eezlx9b  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]P}K3tN%]  
    count = 0 , $D&WH  
    While GetOperationCount(eID)>count :#Ex3H7  
        GetOperation eID, count, op Yt O@n@1  
        If op.Type="ShiftZ" Then +s*l#'Q  
            DeleteOperation eID,count _($-dJ{  
            count=count-1
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        End If E |GK3/  
        count=count+1 b*6c.o  
    Wend Q'Q72Fg  
    op.Type = "ShiftZ" 3wa<,^kqy  
    op.val1 = taq-0.01 C9z~)aL}7  
    op.parent = parID *k@0:a(>  
    AddOperation eID, op -UD~>s  
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    Print "Set pupil diameter = " & pupilDiam ]` &[Se d  
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    'Update AZ Eye subassembly Description s:m<(8WRw  
    eID = FindFullName( "Geometry.Arizona Eye" ) {Y@-*pL]  
    GetEntity eID, entity :)+@qxTy  
    entity.Description = "Accommodation = " & A & "D" :UJUh/U  
    SetEntity eID, entity dPyBY]`  
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    Update D?*sdm9r`  
    Print "DONE!" [WO%rO^p  
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End Sub u{{xnyl?  
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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： @L>NN>?SGQ  
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Accommodation = 4 Diopters (fk, 80  
Pupil Diameter = 4 mm yZ(Nv $[5  
Set aqueous humor thickness = 2.81 )R a/  
Set anterior lens radius = 10.4 and conic constant = -2.375869 !EmR(x  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +{Vwz  
Set lens thickness = 3.927 ixJ20A7  
Set lens index of refraction = 1.42672 }r<@o3t  
Set pupil diameter = 4 Er)_[^) HG  
DONE! sWZtbW;)