[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 l!}7GWj  
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。 :~,V+2e  
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模型 krXU*64  
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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。 " _TAo  
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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. S&'-wAEd  
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光源 IXR%IggJA  
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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。 asYUb&Hz88  
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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。 b.xG'  
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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。 k,r}X:<6jz  
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视网膜的散射 +?0r%R%\  
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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。 u9ue>I/  
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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。 4?aNJyV%&  
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脚本 .wcKG9u  
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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： ,)t/1oQ}>^  
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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。 bHmn0fZ9  
余下的脚本计算与屈光度有关的所有参数。 OJ)XJL  
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分析 /#e-x|L  
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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。 OH vV_  
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脚本代码 ":01M},RA  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. DbH'Qs?z  
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Dim entity As T_ENTITY I<$m%  
Dim op As T_OPERATION Ny 7vId  
Dim mat As T_MODELMATERIAL ||rZ
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Dim A As Double G8OnNI  
Dim pupilDiam As Double p~Mw^SN'  
Dim eID As Long cu"ge]},  
Dim parID As Long 6Vy4]jdT5  
Dim count As Integer Ly`FU)  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^ V8?6E  
Dim tlens As Double, nlens As Double 5`1p ?  
Dim curv As Double, conic As Double a |0f B4G  
Dim ok As Long EdS7m,d  
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Sub Main Rj/y.g  
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    '用户输入对话框 Cg%}=  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2M?L++i  
        TextBox 220,21,40,21,.TextBox1 'default: 0 _SQ0`=+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 LKu ,H  
        OKButton 40,91,90,21 fBct%M 3  
        CancelButton 190,91,90,21 p|'Rm]&jb  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9I*`~il>{  
        TextBox 220,49,40,21,.TextBox2 'default: 4 D? FWSv  
    End Dialog "o$)z'q
 
    Dim dlg As UserDialog '8UhYwyr  
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    ok = Dialog (dlg) ~DUOL~E  
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    If ok=0 Then    'cancel button was pressed l=^^l`  
        Print "Execution cancelled." <~35tOpv  
        End %jj\w>  
    End If jI,?*n<  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7N[Cs$_]  
    If dlg.TextBox1 = "" Then @d6N[?3;  
        A = 0           'Default accommodation ;F\sMf{  
    Else TDHS/"MbA7  
        A = CDbl(dlg.TextBox1) !9.`zW"40  
    End If [35>T3Ku  
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    If dlg.TextBox2 = "" Then #%SF2P
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        pupilDiam = 4   'Default pupil diameter x.aqy'/`  
    Else 5tm:|.`SQ  
        pupilDiam = CDbl(dlg.TextBox2) -owap-Va  
    End If dZ'H'm;,!  
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    Print " " Rln@9muXA  
    Print "Accommodation = " & A & " Diopters" :V:siIDn  
    Print "Pupil Diameter = " & pupilDiam & " mm" @!2vS@f  
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    ' Calculate new parameters with accommodation &cB+la\_  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ihg1%.^V\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens l08JL  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~MLBO  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Tlz~o[`&  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens pJ H@v &a  
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    tlens = 3.767 + 0.04*A                  'Lens thickness tz`T#9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }tUr V  
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    'Adjust parameters to account for accommodation k2ZMDU  
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    '************************************************************************* @w@ `-1  
    'Aqueous thickness (Position of Lens) s!\Gi5b  
    '************************************************************************* Cw]bhaG g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) u13v@<HGc  
    GetCustomElement eID, entity T,fDH!a  
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    parID = FindFullName( "Geometry.Arizona Eye" ) $' >|r]  
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    ' Delete any shift(s) in z [p&2k&.XYe  
    count = 0 k{w  
    While GetOperationCount(eID)>count ]:F?k
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        GetOperation eID, count, op :ej`]yK |  
        If op.Type="ShiftZ" Then *4RL  
            DeleteOperation eID,count ^fxS=Qs+  
            count=count-1 <+)B8I^  
        End If B5H=#  
        count=count+1 H"J>wIuGX  
    Wend 'v'=t<wgl  
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    'Set new shift in !DNk!]|  
    op.Type = "ShiftZ" LCkaSv/[RB  
    op.val1 = taq 7F 1nBd  
    op.parent = parID P~7p~ke  
    AddOperation eID, op QsH?qI&2jp  
    Print "Set aqueous humor thickness = " & taq-0.55 5R/k8UZ  
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    '************************************************************************* NJ$c0CNy  
    'Radius and conic constant of anterior lens 2kVQ#JyuRI  
    '************************************************************************* bx=9XZ9g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) v.Zr,Z=eV  
    GetConic eID, entity, curv, conic TC^fyxq  
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    SetConic eID, entity, 1/Rant, CCant j<C p&}X  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !S5_+.U#  
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    '************************************************************************* 7)37AKw  
    'Radius and conic constant of posterior lens ZRLS3*`  
    '************************************************************************* O t1:z:Pl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) x|q|> dPB  
    GetConic eID, entity, curv, conic wl:[Ad
 
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    SetConic eID, entity, 1/Rpost, CCpost  Jyo(Etp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost G>w+J'7  
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    '************************************************************************* tA]Y=U+Q  
    'Lens thickness (Position of posterior lens surface) `CF.-Vl3J#  
    '************************************************************************* ?N(opggiD  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?_+8K`B  
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    ' Delete any z-shift(s) C!s !j  
    count = 0 N4[^!}4  
    While GetOperationCount(eID)>count eL{6;.C  
        GetOperation eID, count, op y?.l9  
        If op.Type="ShiftZ" Then T@x_}a:g  
            DeleteOperation eID,count Rg6/6/ IN  
            count=count-1 )G=hgqy  
        End If ~Op~~ m  
        count=count+1 (YKkJ  
    Wend r0/o{Y|l6  
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    'Set new z-shift c},wW@SF2W  
    op.Type = "ShiftZ" yy#4DYht  
    op.val1 = tlens +je{%,*  
    op.parent = parID JPGEE1!B{b  
    AddOperation eID, op *#g[ jl4  
    Print "Set lens thickness = " & tlens _8'z"wF  
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    '************************************************************************* &JHqUVs^  
    'Lens index of refraction 5;_&C=[  
    '************************************************************************* HlC[Nu^6U  
    eID = FindMaterial( "Lens" ) (4oO8aBB  
    GetModelMaterial eID, mat VSW"/{Lp  
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    mat.Nd = nlens q"|#KT^)  
    SetModelMaterial eID, mat .}x:yKyi@  
    Print "Set lens index of refraction = " & nlens YMD&U   
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    '************************************************************************* kb2M3%6V  
    'Pupil diameter =%ZR0cWPoI  
    '************************************************************************* [[gfR'79{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) SvN2}]Kh  
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    'Adjust pupil diameter (trimming volume inner hole) !j-JMa?  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" g&`[r6B  
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    ' Adjust pupil location to just in front of the lens yOr5kWqX  
    parID = FindFullName( "Geometry.Arizona Eye" ) 0FG|s#Ig  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) mH)th7  
    count = 0 KmE<+/x~?  
    While GetOperationCount(eID)>count =VOl *  
        GetOperation eID, count, op sad[(|  
        If op.Type="ShiftZ" Then 4oywP^
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            DeleteOperation eID,count ZKco  
            count=count-1 VH2/  
        End If CyEEE2cV  
        count=count+1 )!jX$bK  
    Wend !:|[?M.`  
    op.Type = "ShiftZ" $G@^!(  
    op.val1 = taq-0.01 7R5!(g  
    op.parent = parID #23m_w^L  
    AddOperation eID, op f+W8Gszi  
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    Print "Set pupil diameter = " & pupilDiam QLum=YB  
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    'Update AZ Eye subassembly Description ]/y69ou  
    eID = FindFullName( "Geometry.Arizona Eye" ) \r7gubD  
    GetEntity eID, entity JBxizJBP  
    entity.Description = "Accommodation = " & A & "D" ug.'OR  
    SetEntity eID, entity 4,P!D3SH  
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    Update 7<p?E7  
    Print "DONE!" 2<GN+Wv[#  
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End Sub &nX,)"  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： T_1p1Sg  
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Accommodation = 4 Diopters
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Pupil Diameter = 4 mm ?~#{3b  
Set aqueous humor thickness = 2.81 Zk#?.z}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 h&$,mbEoI  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `p{,C`g,R  
Set lens thickness = 3.927 >h<bYk"9Q  
Set lens index of refraction = 1.42672 ps=+wg?]  
Set pupil diameter = 4 cA]Ch>]A%  
DONE! _mSQ>BBRl  
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