[技术]Arizona眼睛模型 [复制链接]

简介 po'b((q  
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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。 KQb&7k.  
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模型 J)yg<*/3  
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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。 RM,aG}6M)M  
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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. rr2!H%:
 
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光源 [<{r~YFjWW  
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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。 9G2rVk  
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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。 DnJ `]r  
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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。
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视网膜的散射 9XtO#!+48  
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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。 $:oC\K6  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 4H,c;g=!  
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脚本 z9OpMA  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： z8'zH>  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 w0Nm.=I-   
余下的脚本计算与屈光度有关的所有参数。 B0gD4MX/  
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分析 >itabG-&  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 %Rf9KQ  
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脚本代码
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 'Ca;gi !U  
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Dim entity As T_ENTITY ;A@DE@^5w  
Dim op As T_OPERATION
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Dim mat As T_MODELMATERIAL -N^Ah_9ek  
Dim A As Double *A8*FX>\F  
Dim pupilDiam As Double Spx%`O<  
Dim eID As Long {_*G"A 9  
Dim parID As Long MG.c`t/w  
Dim count As Integer c CDT27@  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !',%kvJI  
Dim tlens As Double, nlens As Double "u4x#7n|  
Dim curv As Double, conic As Double #[x*0K-h  
Dim ok As Long /
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Sub Main DMsqTB`  
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    '用户输入对话框 5vR])T/S0  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 cMT:Ij];  
        TextBox 220,21,40,21,.TextBox1 'default: 0 T}msF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X\H P{$fY_  
        OKButton 40,91,90,21 8]vut{  
        CancelButton 190,91,90,21 [kN_b<Pc,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 F."ZCEb  
        TextBox 220,49,40,21,.TextBox2 'default: 4 65O 8?
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    End Dialog z\UXnRL  
    Dim dlg As UserDialog _6c/,a8;*J  
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    ok = Dialog (dlg) tKe-Dk9  
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    If ok=0 Then    'cancel button was pressed x"C7NW[$  
        Print "Execution cancelled." /{[<J<(8  
        End "62g!e}!c  
    End If hg0{x/Dgny  
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    'Assign accommodation and pupil diameter & use defaults if field left empty :/5GHfyj  
    If dlg.TextBox1 = "" Then ]R}(CaT1  
        A = 0           'Default accommodation }AB_i'C0  
    Else DBaZcO(U  
        A = CDbl(dlg.TextBox1) l
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    End If `kvIw,c.  
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    If dlg.TextBox2 = "" Then cH5  
        pupilDiam = 4   'Default pupil diameter PIo@B|W-SX  
    Else <>f;g"qS  
        pupilDiam = CDbl(dlg.TextBox2) Xr8fmJtg'  
    End If dr&G>  
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    Print " " D
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    Print "Accommodation = " & A & " Diopters" &v;fK$=2C  
    Print "Pupil Diameter = " & pupilDiam & " mm" : KFK2yD  
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    ' Calculate new parameters with accommodation T!9AEG  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness R6Md_t\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens OS<GA
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -u"|{5? '  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~&ns?z>x  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0`WFuFi^o  
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    tlens = 3.767 + 0.04*A                  'Lens thickness wnQy  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction "PN4{"`V  
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    'Adjust parameters to account for accommodation gSwHPm%zn  
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    '************************************************************************* FMF mn|  
    'Aqueous thickness (Position of Lens) 1c]{rO=taN  
    '************************************************************************* i!UT =  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) W"
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    GetCustomElement eID, entity 0iR?r+|  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,38M6yD  
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    ' Delete any shift(s) in z 7\yh(+kN  
    count = 0 mDv<d=p!  
    While GetOperationCount(eID)>count _s0
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        GetOperation eID, count, op 9-_Lc<  
        If op.Type="ShiftZ" Then gq*W 0S  
            DeleteOperation eID,count V6c8o2G;+  
            count=count-1 ^["D>@yIR  
        End If Dmy=_j?ej  
        count=count+1 kiyKL:6D|  
    Wend K+M\E[1W  
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    'Set new shift in  gsi2  
    op.Type = "ShiftZ" *5s*-^'#!  
    op.val1 = taq ]:2Ro:4Yv  
    op.parent = parID baTd;`Pn  
    AddOperation eID, op "x;FE<I  
    Print "Set aqueous humor thickness = " & taq-0.55 @mg5vt!$`  
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    '************************************************************************* jz;{,F  
    'Radius and conic constant of anterior lens >f^kp8`3{Y  
    '************************************************************************* EFI!b60mc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) nwfu@h0G  
    GetConic eID, entity, curv, conic @m%B>X28F  
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    SetConic eID, entity, 1/Rant, CCant >b0Bvx-  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +.^pAz U}R  
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    '************************************************************************* RZq_}-P,.c  
    'Radius and conic constant of posterior lens Oi~Dio_?  
    '************************************************************************* M e:l)8+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) QALr   
    GetConic eID, entity, curv, conic T 8]*bw  
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    SetConic eID, entity, 1/Rpost, CCpost &Y9%Y/Y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost p(4B"[!S  
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    '************************************************************************* qSD`S1'2;  
    'Lens thickness (Position of posterior lens surface) "mU2^4q  
    '************************************************************************* +G!# /u1  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ER&
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    ' Delete any z-shift(s) NaQ~iY?  
    count = 0 Wq1OYZ,  
    While GetOperationCount(eID)>count V^n=@CZT9C  
        GetOperation eID, count, op +5R8mbD!  
        If op.Type="ShiftZ" Then @J^ Oy 3z  
            DeleteOperation eID,count qyy.&+  
            count=count-1 mxJe\[I  
        End If \YF;/KwX$  
        count=count+1 wNFx1u^/)  
    Wend 5__B M5|  
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    'Set new z-shift `)w=@9B)"  
    op.Type = "ShiftZ" '< >Q20  
    op.val1 = tlens @'hkU$N)  
    op.parent = parID 9-1'jNV  
    AddOperation eID, op vt(
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    Print "Set lens thickness = " & tlens qn{9vr  
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    '************************************************************************* x|^p9m"=%  
    'Lens index of refraction &FZ~n?;hQ  
    '************************************************************************* \>j@!W  
    eID = FindMaterial( "Lens" ) uz3 ?c6b  
    GetModelMaterial eID, mat B'vIL'  
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    mat.Nd = nlens _|MK0'+f  
    SetModelMaterial eID, mat w9gfva$&  
    Print "Set lens index of refraction = " & nlens !T~uxeZ/;  
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    '************************************************************************* jzi^OI7  
    'Pupil diameter M#8_Qbvfk  
    '************************************************************************* o:as}7/^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $Grk{]nT  
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    'Adjust pupil diameter (trimming volume inner hole) lPA}06
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Z%I 'sWOd  
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    ' Adjust pupil location to just in front of the lens rJ6N'vw>  
    parID = FindFullName( "Geometry.Arizona Eye" ) &wkbr2P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,^v_gc  
    count = 0 <{Rz1CMc  
    While GetOperationCount(eID)>count n{m[ j+UG  
        GetOperation eID, count, op =gd~rk9  
        If op.Type="ShiftZ" Then /;}o0 DYeW  
            DeleteOperation eID,count }C=+Tn  
            count=count-1 1^WkW\9kO  
        End If !L)|N<  
        count=count+1 K\lu;   
    Wend 2j{T8F\]  
    op.Type = "ShiftZ" 00Ye ]j_  
    op.val1 = taq-0.01 d:z7 U  
    op.parent = parID CX5>/  
    AddOperation eID, op tjne[p  
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    Print "Set pupil diameter = " & pupilDiam @zt"Y~9i  
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    'Update AZ Eye subassembly Description W<~u0AyO 3  
    eID = FindFullName( "Geometry.Arizona Eye" ) .=Uu{F  
    GetEntity eID, entity bK!uR&i^l  
    entity.Description = "Accommodation = " & A & "D" /}d)g4\j  
    SetEntity eID, entity fLkC

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    Update #Qu|9Q[QH  
    Print "DONE!" 9wC='  
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End Sub es$<Vkbp  
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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： r|953e  
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Accommodation = 4 Diopters .SWn/Kk  
Pupil Diameter = 4 mm Vg"vC  
Set aqueous humor thickness = 2.81 iVM% ]\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2>^jMln  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]4\6_J&  
Set lens thickness = 3.927 "Z-YZ>2  
Set lens index of refraction = 1.42672 @< 0c  
Set pupil diameter = 4 v/Xz.?a\jF  
DONE! P@Pe5H"o