[技术]Arizona眼睛模型 [复制链接]

简介 FT<H]Nf  
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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。 DL %S(l  
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模型 DgC3> yL  
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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。 KlY,NSlQ  
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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. :jBZK=3F>  
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光源 5r^1CFO  
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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。 t'dHCp}  
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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。 KbXbT  
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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。 Sjw2 j#Q  
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视网膜的散射 N-XVRuv  
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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。 ub[""M?  
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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。 aUKh})B  
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脚本 p.@0=)  
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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： x1.3W j  
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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。 f@wsSm  
余下的脚本计算与屈光度有关的所有参数。 j5PaSk&o=  
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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。 cYZwWMzp  
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脚本代码 "}S9`-Wd|  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. )$ ofl%+  
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Dim entity As T_ENTITY =nJOaXR0  
Dim op As T_OPERATION B0-4ZT  
Dim mat As T_MODELMATERIAL o,*folL  
Dim A As Double 1bV2  
Dim pupilDiam As Double _ff=B  
Dim eID As Long hg%@W  
Dim parID As Long 6Y;Y}E  
Dim count As Integer 4a(g<5wfI  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Z
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Dim tlens As Double, nlens As Double /Oq1q._9F  
Dim curv As Double, conic As Double *]{9K  
Dim ok As Long &,W_#l{  
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Sub Main F,'^se4&  
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    '用户输入对话框 LVPt*S=/  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,H.(\p_N  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]I{qp~^#n  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1VhoJGH;C  
        OKButton 40,91,90,21 Ck ~V5  
        CancelButton 190,91,90,21 uB5h9&57  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .\z|Fr  
        TextBox 220,49,40,21,.TextBox2 'default: 4 8gVxiFjo  
    End Dialog ~[d
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    Dim dlg As UserDialog pr0@sri@  
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    ok = Dialog (dlg) !A'
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    If ok=0 Then    'cancel button was pressed p/\$P=  
        Print "Execution cancelled." 6. +[ z  
        End dD/29b(  
    End If c8k6(#\  
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    'Assign accommodation and pupil diameter & use defaults if field left empty m[g< K  
    If dlg.TextBox1 = "" Then Hj5WJ{p.  
        A = 0           'Default accommodation gFWEodx,9  
    Else 9B!im\]O  
        A = CDbl(dlg.TextBox1) >wg9YZ~8  
    End If ^DW#  
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    If dlg.TextBox2 = "" Then &;
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        pupilDiam = 4   'Default pupil diameter r85Xa'hh  
    Else jV,(P$ 5;  
        pupilDiam = CDbl(dlg.TextBox2) [a>JG8[,t  
    End If <B]i80.  
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    Print " " }#\;np  
    Print "Accommodation = " & A & " Diopters" Q.pEUDq/  
    Print "Pupil Diameter = " & pupilDiam & " mm" P`Hd*xh".j  
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    ' Calculate new parameters with accommodation V7B=
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [#hl}q(P#  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens c-s`>m  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Kc JP^
 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c:h.J4mv  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens E&iWtwkz  
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    tlens = 3.767 + 0.04*A                  'Lens thickness RS||KA])J  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \pewbu5^  
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    'Adjust parameters to account for accommodation !\&7oAs=I  
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    '************************************************************************* [5RFQ!  
    'Aqueous thickness (Position of Lens) &{%S0\K Y  
    '************************************************************************* u'$yYzBE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) TzevC$m;z  
    GetCustomElement eID, entity 6PzN>+t^y  
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    parID = FindFullName( "Geometry.Arizona Eye" ) yNLa3mW  
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    ' Delete any shift(s) in z MUCJ/GF*  
    count = 0 Z5*(W;;  
    While GetOperationCount(eID)>count (Qx-KRH  
        GetOperation eID, count, op 5|6z1{g8  
        If op.Type="ShiftZ" Then 86^ZY
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            DeleteOperation eID,count L6rs9su=7  
            count=count-1 Lilk8|?#W  
        End If ^O$[Y9~*  
        count=count+1 ~P]HG;$?n  
    Wend w}U5dM`
 
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    'Set new shift in ohc/.5Kl  
    op.Type = "ShiftZ" wCq)w=,  
    op.val1 = taq TN |{
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    op.parent = parID YA;8uMqh;  
    AddOperation eID, op ?(,5eg  
    Print "Set aqueous humor thickness = " & taq-0.55 $@u^Jt, ?  
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    '************************************************************************* +}(B856+  
    'Radius and conic constant of anterior lens 2W"cTm  
    '************************************************************************* q*RaX 4V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,syA()  
    GetConic eID, entity, curv, conic ;8;~C"  
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    SetConic eID, entity, 1/Rant, CCant cP#]n)<  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant pZ_FVID  
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    '************************************************************************* #o r7T^  
    'Radius and conic constant of posterior lens 7u`}t83a  
    '************************************************************************* '#4mDz~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ,a]~hNR*X  
    GetConic eID, entity, curv, conic G%p!os\>  
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    SetConic eID, entity, 1/Rpost, CCpost u'~b<@wHB  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @8<uAu%  
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    '************************************************************************* 4na4Jsq{  
    'Lens thickness (Position of posterior lens surface) /qkIoF2  
    '************************************************************************* zy/tQGTr@  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) !{]v='   
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    ' Delete any z-shift(s) XM@-Y&c$A  
    count = 0 h-_0 A]  
    While GetOperationCount(eID)>count aD/,c1  
        GetOperation eID, count, op MY<!\4/  
        If op.Type="ShiftZ" Then }'.Sn{OWf  
            DeleteOperation eID,count -{:LxE  
            count=count-1 cdtzf:#q  
        End If h&k^l,  
        count=count+1 4|Gs(^nU  
    Wend 8{4D|o#O  
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    'Set new z-shift c7nk~K[6  
    op.Type = "ShiftZ" fkv{
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    op.val1 = tlens Lq $4.l[j  
    op.parent = parID Znl>*e/|  
    AddOperation eID, op u&d v[  
    Print "Set lens thickness = " & tlens DHumBnQ  
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    '************************************************************************* Pl5NHVr  
    'Lens index of refraction KGE-RK  
    '************************************************************************* L^al1T  
    eID = FindMaterial( "Lens" ) v!RB(T3  
    GetModelMaterial eID, mat QWW7I.9r  
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    mat.Nd = nlens 69I.*[  
    SetModelMaterial eID, mat ??%T  
    Print "Set lens index of refraction = " & nlens <#x%A0  
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    '************************************************************************* >*i8RqU  
    'Pupil diameter f_P+qm  
    '************************************************************************* cA*X$j6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %:;[M|.  
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    'Adjust pupil diameter (trimming volume inner hole) i!}nGJGg  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ZNC?Ntw  
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    ' Adjust pupil location to just in front of the lens gZ>orZL'  
    parID = FindFullName( "Geometry.Arizona Eye" ) M>H^<N}'A  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) L"du"-  
    count = 0 aj'8;E+  
    While GetOperationCount(eID)>count &Cpxo9-  
        GetOperation eID, count, op Q.E^9giC  
        If op.Type="ShiftZ" Then j!_^5d#d  
            DeleteOperation eID,count Rb}&c)4  
            count=count-1 :8|3V~%m  
        End If nTy,Jml  
        count=count+1 K84cE  
    Wend 6M vRR  
    op.Type = "ShiftZ" ;s B:s9M  
    op.val1 = taq-0.01 .L{+O6*c  
    op.parent = parID E?h2e~ ,]  
    AddOperation eID, op ,,#rv-*  
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    Print "Set pupil diameter = " & pupilDiam GKx,6E#JM  
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    'Update AZ Eye subassembly Description {*Wwu f.  
    eID = FindFullName( "Geometry.Arizona Eye" ) D&6Qk&>  
    GetEntity eID, entity I;.E}k   
    entity.Description = "Accommodation = " & A & "D" 6V6g{6W,/  
    SetEntity eID, entity ,~?A. 5  
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    Update qkG;YGio  
    Print "DONE!" #`)-$vUv^f  
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End Sub 7{6.  
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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： KPe.AK,8  
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Accommodation = 4 Diopters QT l._j@  
Pupil Diameter = 4 mm Rpd/9x.)&  
Set aqueous humor thickness = 2.81 gw"l&r  
Set anterior lens radius = 10.4 and conic constant = -2.375869 U\ E{-7  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 (tLQX~Ur  
Set lens thickness = 3.927 '{k Nbx51  
Set lens index of refraction = 1.42672 XaS_3d  
Set pupil diameter = 4 7^TXlWn^G  
DONE! 2bxMIr