[技术]Arizona眼睛模型 [复制链接]

简介 css64WX^0c  
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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。 I&n  
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模型 /~*_x=p:  
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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。 sGh(#A0Pt  
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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. su*Pk|6%  
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光源 niB`2J  
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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。 A_Frk'{qhB  
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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。 g&/T*L  
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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。 __mF?m  
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视网膜的散射 %p%%~ewmx  
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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。 (o3 Iy  
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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。 %^RN#_ro(3  
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脚本 $DG?M6  
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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： J2:y6kGj>  
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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。 #%DE;  
余下的脚本计算与屈光度有关的所有参数。 s[UHe{^T  
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分析 ;*MLRXq  
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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。 #U14-
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脚本代码 .V,@k7U,V  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =>-Rnc@  
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Dim entity As T_ENTITY #\=FO>  
Dim op As T_OPERATION ^0Mt*e{q  
Dim mat As T_MODELMATERIAL `nu''B H  
Dim A As Double u?C#4  
Dim pupilDiam As Double E>K!Vrh-L  
Dim eID As Long ov, hI>0!D  
Dim parID As Long q<M2,YrbAI  
Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double v?geCe=ng  
Dim tlens As Double, nlens As Double &v
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Dim curv As Double, conic As Double vam;4vyu  
Dim ok As Long \kZ?
 
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Sub Main vX.VfY  
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    '用户输入对话框 Abc)i7!.,.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,y#Kv|R  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;0Tx-8l  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 HAa;hb  
        OKButton 40,91,90,21 A6thXs2  
        CancelButton 190,91,90,21 c24dSNJg,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 $&n=$C&x  
        TextBox 220,49,40,21,.TextBox2 'default: 4 r8RoE`/T  
    End Dialog DW[N|-
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    Dim dlg As UserDialog cz8T  
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    ok = Dialog (dlg) .:F%_dS D  
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    If ok=0 Then    'cancel button was pressed t7aefV&_,  
        Print "Execution cancelled." koug[5T5  
        End glDu2a,Q  
    End If {ttysQ-  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ds<2I,t  
    If dlg.TextBox1 = "" Then |IzPgC  
        A = 0           'Default accommodation |Y,b?*UF  
    Else .(cw>7e3D  
        A = CDbl(dlg.TextBox1) Fww :$^_ k  
    End If b0Ps5G\ u  
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    If dlg.TextBox2 = "" Then k5'Vy8q  
        pupilDiam = 4   'Default pupil diameter sYI-5D]  
    Else V2wb%;q  
        pupilDiam = CDbl(dlg.TextBox2) 3[Qxd{8r  
    End If zBzZxK>$  
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    Print " " )"7iJb<E  
    Print "Accommodation = " & A & " Diopters" ~qTx|",  
    Print "Pupil Diameter = " & pupilDiam & " mm" *XIF)Q=<>  
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    ' Calculate new parameters with accommodation W{ q U  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;,%fE2c  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Q+{xZ'o"Z  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &w_j/nW^'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens pmyXLT  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G[uK-U  
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    tlens = 3.767 + 0.04*A                  'Lens thickness #lL^?|M  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3YOq2pW72G  
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    'Adjust parameters to account for accommodation 2} /aFR  
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    '************************************************************************* NJWA3zz   
    'Aqueous thickness (Position of Lens) - M4JJV(  
    '************************************************************************* {EB;h\C  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ot_]3:`J~  
    GetCustomElement eID, entity hj*pTuym  
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    parID = FindFullName( "Geometry.Arizona Eye" ) /NI;P]s.  
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    ' Delete any shift(s) in z /~%&vpF-L  
    count = 0
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    While GetOperationCount(eID)>count
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        GetOperation eID, count, op 2lH&  
        If op.Type="ShiftZ" Then k<CJ{u0<  
            DeleteOperation eID,count gwuI-d^  
            count=count-1 >* f-Wde  
        End If 5H<m$K4z  
        count=count+1 /K@XzwM  
    Wend
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    'Set new shift in UNu#(nP  
    op.Type = "ShiftZ" [Kg+^N%+  
    op.val1 = taq NRs13M<ftf  
    op.parent = parID g[' ^L+hd  
    AddOperation eID, op 5}l[>lF  
    Print "Set aqueous humor thickness = " & taq-0.55 24 'J  
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    '************************************************************************* r= `Jn6@  
    'Radius and conic constant of anterior lens _Eo[7V{NY  
    '************************************************************************* ^eY!U%.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ]nn
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    GetConic eID, entity, curv, conic &AeX   
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    SetConic eID, entity, 1/Rant, CCant @alK;\  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant C_}]`[  
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    '************************************************************************* oq
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    'Radius and conic constant of posterior lens Cw3a0u  
    '************************************************************************* G5BfNU  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) m]6mGp  
    GetConic eID, entity, curv, conic yLvDMPj  
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    SetConic eID, entity, 1/Rpost, CCpost I3L<[-ZE  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2`K=Hby  
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    '************************************************************************* BA:VPTZq  
    'Lens thickness (Position of posterior lens surface) y%cP1y)  
    '************************************************************************* vH@ds k  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q~ w|#  
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    ' Delete any z-shift(s) Jq-]7N%k/  
    count = 0 Naf0)3q>!  
    While GetOperationCount(eID)>count q"lSZ; 'E  
        GetOperation eID, count, op 1v27;Q<+Q  
        If op.Type="ShiftZ" Then Ty?cC**  
            DeleteOperation eID,count )D7m,Wi+  
            count=count-1 L,/%f<wd  
        End If %$Tji  
        count=count+1 h7Kzq{$  
    Wend tXs\R(?T  
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    'Set new z-shift IFL*kB   
    op.Type = "ShiftZ" ydA8wL  
    op.val1 = tlens lTgjq:mn  
    op.parent = parID ~qKY) "gG  
    AddOperation eID, op U?Zq6_M&  
    Print "Set lens thickness = " & tlens $7ZX]%<s  
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    '************************************************************************* *w\W/Y  
    'Lens index of refraction <iC(`J$D  
    '************************************************************************* g]H<}4lgq"  
    eID = FindMaterial( "Lens" ) N=}A Z{$  
    GetModelMaterial eID, mat %5n_ p^xp  
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    mat.Nd = nlens e
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    SetModelMaterial eID, mat *]) `z8Ox  
    Print "Set lens index of refraction = " & nlens K+3=tk]W9u  
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    '************************************************************************* uw_Y\F-$  
    'Pupil diameter ^jZbo{  
    '************************************************************************* :4/3q|cn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .Yn_*L+4*  
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    'Adjust pupil diameter (trimming volume inner hole) f.$af4 u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" l'_r:b  
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    ' Adjust pupil location to just in front of the lens }Zn}  
    parID = FindFullName( "Geometry.Arizona Eye" ) ]{@-HTt  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) $<EM+oJ|ER  
    count = 0 Z@!+v19^  
    While GetOperationCount(eID)>count Wh*uaad7  
        GetOperation eID, count, op H<,gU`&R  
        If op.Type="ShiftZ" Then BW4J>{  
            DeleteOperation eID,count 5U$0F$BBp  
            count=count-1 U'bEL^Jf  
        End If ;HO=  
        count=count+1 W^l-Y%a/o  
    Wend Qp3_f8  
    op.Type = "ShiftZ" >|UOz&  
    op.val1 = taq-0.01 /*
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    op.parent = parID `X&gE,Ii  
    AddOperation eID, op XW]tnrs  
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    Print "Set pupil diameter = " & pupilDiam #@Jq~$N|  
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    'Update AZ Eye subassembly Description r;N|)  
    eID = FindFullName( "Geometry.Arizona Eye" ) Rima;9.Y0  
    GetEntity eID, entity [{,1=AB  
    entity.Description = "Accommodation = " & A & "D" ~Mxvq9vaD  
    SetEntity eID, entity wbl&  
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    Update *$g-:ILRuZ  
    Print "DONE!" Y$@?.)tY  
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End Sub wFZP,fQ9l  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： Qvhl4-XjZa  
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Accommodation = 4 Diopters i9x+A/o[  
Pupil Diameter = 4 mm .$vK&k  
Set aqueous humor thickness = 2.81 c\j/k[\<  
Set anterior lens radius = 10.4 and conic constant = -2.375869 sXFZWj}\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 4o[{>gW  
Set lens thickness = 3.927 o66}yJzmD  
Set lens index of refraction = 1.42672 F:S}w  
Set pupil diameter = 4 Z7Hbj!d/Sz  
DONE! UkFC~17P