[技术]Arizona眼睛模型 [复制链接]

简介 ri:fo'4TO  
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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。 T>c;q%A/  
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模型 ?eu=0|d  
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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。 \z_@.Jw{  
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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. [)*fN|Hy  
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光源 ]8mBFr5E9  
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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。 :>,d$f^tqE  
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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。  oCduY2  

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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。 MVdE7P  
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视网膜的散射 v9<p@GY"\  
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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。 Ad"::&&Wk  
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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。 9oaq%Sf  
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脚本 F`-? 3]\3  
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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： i P/I% D  
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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。 xUG|@xIwc  
余下的脚本计算与屈光度有关的所有参数。 X=DJOepH'  
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分析 EqOB 0\  
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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。 ~:JKXa?  
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脚本代码 x.d9mjLN8m  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.  fBQZ=zh  
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Dim entity As T_ENTITY |C5i3?  
Dim op As T_OPERATION
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Dim mat As T_MODELMATERIAL -8EdTc@  
Dim A As Double %``FIv15w  
Dim pupilDiam As Double C~l5D4D#  
Dim eID As Long //WgK{Mt  
Dim parID As Long KYlWV<sR  
Dim count As Integer 7}nOF{RH]  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double KKOu":b  
Dim tlens As Double, nlens As Double ~M <4HC  
Dim curv As Double, conic As Double MT0}MMr  
Dim ok As Long .fZv H  
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Sub Main *yt/ Dj  
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    '用户输入对话框 Muarryh}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ; I=z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ^P]: etld9  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 )`g[k"yB3  
        OKButton 40,91,90,21 ka]n+"~==\  
        CancelButton 190,91,90,21 ,PY<AI^59  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y\j &84  
        TextBox 220,49,40,21,.TextBox2 'default: 4 A]R"C:o  
    End Dialog PY`V]|J  
    Dim dlg As UserDialog IPJs$PtKok  
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    ok = Dialog (dlg) u0i @.  
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    If ok=0 Then    'cancel button was pressed
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        Print "Execution cancelled." NeNKOW#X  
        End F.O2;M|x  
    End If TN l$P~X>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 1-q\C<Q)  
    If dlg.TextBox1 = "" Then bG\1<:6B  
        A = 0           'Default accommodation J :,  
    Else [J:vSt  
        A = CDbl(dlg.TextBox1) 1P6~IZVN  
    End If \f._I+gJ  
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    If dlg.TextBox2 = "" Then FmnA+fA  
        pupilDiam = 4   'Default pupil diameter OxqP:kM  
    Else 654PW9{(  
        pupilDiam = CDbl(dlg.TextBox2) <01MXT-  
    End If 6C)OO"Bc  
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    Print " " /wIZ '  
    Print "Accommodation = " & A & " Diopters" 4
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    Print "Pupil Diameter = " & pupilDiam & " mm" ]Q^oc  
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    ' Calculate new parameters with accommodation QAX+oy  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X2o5Hc)l<  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #
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    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 Ot v{#bB$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens =#1/<q)L  
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    tlens = 3.767 + 0.04*A                  'Lens thickness aIkxN&  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^QXUiXzl  
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    'Adjust parameters to account for accommodation vn|X,1o  
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    '************************************************************************* igz&7U8gg  
    'Aqueous thickness (Position of Lens) :%s9<g;-h_  
    '************************************************************************* viKN:n! Ev  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <$ '#@jW  
    GetCustomElement eID, entity bp5hS/A^1w  
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    parID = FindFullName( "Geometry.Arizona Eye" ) t$s)S>  
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    ' Delete any shift(s) in z J&h 3,  
    count = 0 8B\,*JGY2  
    While GetOperationCount(eID)>count $k}+,tHtJO  
        GetOperation eID, count, op R(x%<I  
        If op.Type="ShiftZ" Then r\L:JTZ$  
            DeleteOperation eID,count f61
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            count=count-1 6I 2`m(5  
        End If 48w3gye  
        count=count+1 ,![C8il,  
    Wend a!wPBJJ  
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    'Set new shift in ,P5HR+h  
    op.Type = "ShiftZ" Cvi-4   
    op.val1 = taq R:OoQ^c  
    op.parent = parID 8CMI\yk  
    AddOperation eID, op wwE9|'Ok  
    Print "Set aqueous humor thickness = " & taq-0.55 ;Q-sie(#  
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    '************************************************************************* w=O:|Xu#*  
    'Radius and conic constant of anterior lens v]vrD2L  
    '************************************************************************* 4|x5-m+T  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .bew,92  
    GetConic eID, entity, curv, conic w[loV  
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    SetConic eID, entity, 1/Rant, CCant ./.E=,j  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant  M3u[E  
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    '************************************************************************* 0wxQ,PI1'  
    'Radius and conic constant of posterior lens ~H?RHYP~  
    '************************************************************************* `5h$@  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0]NjsOU=  
    GetConic eID, entity, curv, conic l--xq^,`o]  
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    SetConic eID, entity, 1/Rpost, CCpost sp'q=^t  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost FVL0K(V(  
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    '************************************************************************* !/Hln;{  
    'Lens thickness (Position of posterior lens surface) wG19NX(  
    '************************************************************************* ])0&el3-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Hk$|.TjzI  
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    ' Delete any z-shift(s) YjLPW@  
    count = 0 qo4AQ}0 <  
    While GetOperationCount(eID)>count pHKj*Y  
        GetOperation eID, count, op ;LthdY()n(  
        If op.Type="ShiftZ" Then 9OP d'f  
            DeleteOperation eID,count vk.Y2 :  
            count=count-1 B.|2w  
        End If Hya*7l']B  
        count=count+1 (w@|:0t^y[  
    Wend R3%T}^;f  
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    'Set new z-shift m[]pIXc(  
    op.Type = "ShiftZ" A#LK2II^  
    op.val1 = tlens Hq6VwQu?  
    op.parent = parID Mx0c #d.  
    AddOperation eID, op B8;_h#^q  
    Print "Set lens thickness = " & tlens C[<&%=  
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    '************************************************************************* O:pQf/Xn  
    'Lens index of refraction Je+L8TB  
    '************************************************************************* Qa(u+  
    eID = FindMaterial( "Lens" ) &UQKZ.  
    GetModelMaterial eID, mat \ssuO  

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    mat.Nd = nlens G8f7N;D  
    SetModelMaterial eID, mat ?Q:se  
    Print "Set lens index of refraction = " & nlens dID]{  
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    '*************************************************************************
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    'Pupil diameter jAN(r>zVL  
    '************************************************************************* xLq+njH E  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) dax|4R  
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    'Adjust pupil diameter (trimming volume inner hole) (|h<{ -L  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" F_\\n#bv  
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    ' Adjust pupil location to just in front of the lens t[)z/[m  
    parID = FindFullName( "Geometry.Arizona Eye" ) ]^ZC^z;H  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) z[IG+2  
    count = 0 /O/u5P{J  
    While GetOperationCount(eID)>count iTqv=  
        GetOperation eID, count, op LP#CA^*S  
        If op.Type="ShiftZ" Then rx|/]NE;  
            DeleteOperation eID,count s
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            count=count-1 Z*jhSy  
        End If !Z<Z"R/  
        count=count+1 (:M6*RV  
    Wend PY)C=={p  
    op.Type = "ShiftZ" 69O?sIk  
    op.val1 = taq-0.01 rQN+x|dKMb  
    op.parent = parID FSc730rM  
    AddOperation eID, op &hjrJ/'^  
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    Print "Set pupil diameter = " & pupilDiam  2Np9*[C  
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    'Update AZ Eye subassembly Description 3)__b:7J  
    eID = FindFullName( "Geometry.Arizona Eye" ) q35%t61Lc  
    GetEntity eID, entity [@Uc4LX  
    entity.Description = "Accommodation = " & A & "D" u&2uQ-T0  
    SetEntity eID, entity wz>j>e6k`  
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    Update c\]h YKA  
    Print "DONE!" h, +2Mc<  
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End Sub g7_a8_  
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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： \AkeC6[D  
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Accommodation = 4 Diopters /HI#8  
Pupil Diameter = 4 mm 2R:['QT  
Set aqueous humor thickness = 2.81 O#cXvv]Z*  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [Gt|Qp[  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 AkT_ZU>  
Set lens thickness = 3.927 vA(3H/)-  
Set lens index of refraction = 1.42672 A-c3B+  
Set pupil diameter = 4 DV{Qbe#In  
DONE! 7Q
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