[技术]Arizona眼睛模型 [复制链接]

简介 9F4Dm*_<  
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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。 hJn%mdx~w|  
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模型 d{XO/YQw  
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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。 X*&[u7No  
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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. WOQP$D9  
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光源 Fz1_w$^  
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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。 vW
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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。 j:k[90  
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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。 ?**+e%$$  
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视网膜的散射 K@#(*."  
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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。 9:,V5n=  
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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。 30XR 82P/  
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脚本 XLAN Np%E  
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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： !OA]s%u  
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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。 "kMguK}c  
余下的脚本计算与屈光度有关的所有参数。 DTaN"{  
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分析 3 |hHR  
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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。 3=Cc.a/3  
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脚本代码 G`\f  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }z\_;\7  
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Dim entity As T_ENTITY 6`v7c!7  
Dim op As T_OPERATION 1_\;- !t  
Dim mat As T_MODELMATERIAL 4g :>[q  
Dim A As Double MxY/`9>E|+  
Dim pupilDiam As Double Md0sK  
Dim eID As Long 7VMvF/ap]u  
Dim parID As Long <5NF;  
Dim count As Integer \8<BLmf4U  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double gF$V$cU  
Dim tlens As Double, nlens As Double f}1&HI8r  
Dim curv As Double, conic As Double .Fnwm}  
Dim ok As Long Z00+!Tnd  
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Sub Main R}lsnX<  
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    '用户输入对话框 )('%R|$ /  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 VUhbD  
        TextBox 220,21,40,21,.TextBox1 'default: 0 wi4=OU1L)a  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 GDD '[;  
        OKButton 40,91,90,21 \ gLHi~  
        CancelButton 190,91,90,21 4\6N~P86  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2Z3('?\z~  
        TextBox 220,49,40,21,.TextBox2 'default: 4 tI7:5Cm  
    End Dialog emdoA:w+   
    Dim dlg As UserDialog P#fM:z@[  
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    ok = Dialog (dlg) -u?S=h}  
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    If ok=0 Then    'cancel button was pressed d)pV;6%[$q  
        Print "Execution cancelled." P&b19K'  
        End ]p;FZ4-T  
    End If xo&]RYG[<  
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    'Assign accommodation and pupil diameter & use defaults if field left empty q*2N{  
    If dlg.TextBox1 = "" Then 1qf!DMcdZ  
        A = 0           'Default accommodation RLSc+kDH_  
    Else #/I[Jqf  
        A = CDbl(dlg.TextBox1) <<i3r|
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    End If PSPmO'C+  
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    If dlg.TextBox2 = "" Then +reor@h  
        pupilDiam = 4   'Default pupil diameter TpHfS]W-P  
    Else v76D3'8  
        pupilDiam = CDbl(dlg.TextBox2) D<V~f B  
    End If -.T&(&>^  
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    Print " " 4E+hRKuo,  
    Print "Accommodation = " & A & " Diopters" }J7zTj~{  
    Print "Pupil Diameter = " & pupilDiam & " mm" m+#iR}*1L  
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    ' Calculate new parameters with accommodation xCYE B}o9r  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness k%E2n:|*  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens $*kxTiG!
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \#rI
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _z54Ycr4H  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens J]q%gcM  
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    tlens = 3.767 + 0.04*A                  'Lens thickness #vzEu
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0 s70r  
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    'Adjust parameters to account for accommodation &m[Qn!>i6  
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    '************************************************************************* Dc+'<"  
    'Aqueous thickness (Position of Lens) Zr-U&9.`  
    '************************************************************************* 4[BG#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $DZHQH  
    GetCustomElement eID, entity !H2QjW  
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    parID = FindFullName( "Geometry.Arizona Eye" )  y2+p1  
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    ' Delete any shift(s) in z NuYkz"O]  
    count = 0 V~ TWKuR  
    While GetOperationCount(eID)>count efD)S92  
        GetOperation eID, count, op YFTjPBV  
        If op.Type="ShiftZ" Then iR\Hv'|  
            DeleteOperation eID,count sg8/#_S1i  
            count=count-1 ]IL;`>Gp  
        End If meCC?YAB  
        count=count+1 Z(ZiFPx2Z  
    Wend 7#~+@'Oe  
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    'Set new shift in @?[1_g_'P  
    op.Type = "ShiftZ" 7Su#Je]  
    op.val1 = taq I(S)n+E  
    op.parent = parID W;1|+6x  
    AddOperation eID, op FVKW9"AyW  
    Print "Set aqueous humor thickness = " & taq-0.55 ncSFj.}w]  
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    '************************************************************************* 8v7
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    'Radius and conic constant of anterior lens 1&/FG(*/  
    '************************************************************************* |TE}`?y[g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 4:7V./" 9  
    GetConic eID, entity, curv, conic jA(>sz  
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    SetConic eID, entity, 1/Rant, CCant ZbT/$\0(6  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant VqE~c  
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    '************************************************************************* oxj3[</'k  
    'Radius and conic constant of posterior lens zvvP81$W  
    '************************************************************************* >I<r)w]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) tV9LD>3  
    GetConic eID, entity, curv, conic [|~2X>  
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    SetConic eID, entity, 1/Rpost, CCpost QaGlR`Y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost $HG}[XD?  
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    '************************************************************************* zd_HxYrN  
    'Lens thickness (Position of posterior lens surface) KIeT!kmDl  
    '************************************************************************* DOz\n|8S  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {}o>{&X  
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    ' Delete any z-shift(s) ~O 3D[PNW~  
    count = 0 j,d*?'X  
    While GetOperationCount(eID)>count CAT.4GM  
        GetOperation eID, count, op >|Q:g,I  
        If op.Type="ShiftZ" Then f1PN|  
            DeleteOperation eID,count "C?5f]T  
            count=count-1 \7z^!m  
        End If .d?%;2*{q  
        count=count+1 _al|'obomy  
    Wend ICB~_O5  
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    'Set new z-shift $DB
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    op.Type = "ShiftZ" +uWYK9  
    op.val1 = tlens ?4CNkk=v  
    op.parent = parID _28<m JfG  
    AddOperation eID, op 7B3w\
 
    Print "Set lens thickness = " & tlens NA$zd(  
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    '************************************************************************* @>x pYV  
    'Lens index of refraction NDO\B,7  
    '************************************************************************* I =Wc&1g  
    eID = FindMaterial( "Lens" ) ^O^:$nXhYy  
    GetModelMaterial eID, mat '<
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    mat.Nd = nlens Y`6rEA0  
    SetModelMaterial eID, mat i77GE  
    Print "Set lens index of refraction = " & nlens S>q>K"j^!  
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    '************************************************************************* nsb4S{  
    'Pupil diameter |DF9cd^  
    '************************************************************************* -V %gVI[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) z5Qs@dG  
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    'Adjust pupil diameter (trimming volume inner hole)  \4ghYQ:  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" B6}FIg)  
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    ' Adjust pupil location to just in front of the lens D~K;~nI  
    parID = FindFullName( "Geometry.Arizona Eye" ) hbOnlj4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iF+RnWX\  
    count = 0 ?v}Bd!'+P  
    While GetOperationCount(eID)>count n uQM^2  
        GetOperation eID, count, op S06Hs~>Y  
        If op.Type="ShiftZ" Then 1U\$iy8}  
            DeleteOperation eID,count _L.n,  
            count=count-1 t>UkE9=3\  
        End If 9=dkx^q  
        count=count+1 *
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    Wend (y4#.vZh:  
    op.Type = "ShiftZ" RBGlz
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    op.val1 = taq-0.01 Ix
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    op.parent = parID %1M
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    AddOperation eID, op TB aVW  
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    Print "Set pupil diameter = " & pupilDiam s]B"qFA  
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    'Update AZ Eye subassembly Description ZC^C  
    eID = FindFullName( "Geometry.Arizona Eye" ) \[wCp*;1}  
    GetEntity eID, entity HO|-@yOF^  
    entity.Description = "Accommodation = " & A & "D" )E7 FA|  
    SetEntity eID, entity cJ}QXuuUv  

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    Update ~KIDv;HSb[  
    Print "DONE!" SjcL#S($&Y  
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End Sub Xwu.AVsr  
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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： >N`6;gn*l  
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Accommodation = 4 Diopters MXAEX2xmme  
Pupil Diameter = 4 mm Il~01|3+m  
Set aqueous humor thickness = 2.81 U_z2J(e~  
Set anterior lens radius = 10.4 and conic constant = -2.375869 EH9Hpo  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 )xl6,bq3  
Set lens thickness = 3.927 p_terD:  
Set lens index of refraction = 1.42672 1-;?0en&0
 
Set pupil diameter = 4 zDBD.5R;  
DONE! a,Kky^B