[技术]Arizona眼睛模型 [复制链接]

简介 &Nj:XX;X  
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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。 =X%R*~!#Of  
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模型 q_%w l5\F  
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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。 vh:UXE lm  
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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. ePu2t3E  
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光源 ID{Pzmt-  
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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^-H_|/M  
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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。 0N} wD-  
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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。 M7cI$=G  
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视网膜的散射 6{FS/+  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 )oz-<zW  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ZCOuv6V+  
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脚本 Af! W K=  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： w1!\L_::Y  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 W
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余下的脚本计算与屈光度有关的所有参数。 xr7<(:d  
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分析 ;]`NR  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 AQBx k[  
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脚本代码 YaE['a  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. + 1%^c(3  
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Dim entity As T_ENTITY 6;=wuoJi  
Dim op As T_OPERATION ^{]sD}Q"  
Dim mat As T_MODELMATERIAL KX`nHu;  
Dim A As Double ~Sem_U`G  
Dim pupilDiam As Double {CyPcD'$s  
Dim eID As Long kpMM%"=V  
Dim parID As Long V/[,1W[B  
Dim count As Integer `LHfAXKN  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0{Ll4  
Dim tlens As Double, nlens As Double =rtA{g$)+  
Dim curv As Double, conic As Double h,jAtL!  
Dim ok As Long X72X:"  
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Sub Main Chi<)P$^  
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    '用户输入对话框 !iz vY  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 n[w,x;  
        TextBox 220,21,40,21,.TextBox1 'default: 0 CzsY=DBH=  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1R~
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        OKButton 40,91,90,21 3*23+}^G  
        CancelButton 190,91,90,21 r`"#c7)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 M{k
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        TextBox 220,49,40,21,.TextBox2 'default: 4 q>oH(A  
    End Dialog `j"G=%e3.  
    Dim dlg As UserDialog 7;-i_&vws  
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    ok = Dialog (dlg) U=#ylQ   
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    If ok=0 Then    'cancel button was pressed %L|bF"K5;  
        Print "Execution cancelled." >\x 39B  
        End =X'7V}Q}  
    End If DczF0Ow  
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    'Assign accommodation and pupil diameter & use defaults if field left empty :T
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    If dlg.TextBox1 = "" Then KcF+!;:  
        A = 0           'Default accommodation bvRGTOxO  
    Else <%JO3E  
        A = CDbl(dlg.TextBox1) o-Fle, qf  
    End If +rO<'H:umJ  
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    If dlg.TextBox2 = "" Then ' 1]bjW*!  
        pupilDiam = 4   'Default pupil diameter 9F1stT0G%  
    Else oi4Wxcj  
        pupilDiam = CDbl(dlg.TextBox2) g*imswj7
 
    End If wupD  
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    Print " " 1>{-wL4rc  
    Print "Accommodation = " & A & " Diopters" 17 iq  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~*]`XL.-  
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    ' Calculate new parameters with accommodation .TS=[WGMS  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness !#s7 F  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens t? Ja q  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens oT{yttSNo  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens GlD'?Mk1  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens wo9f99  
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    tlens = 3.767 + 0.04*A                  'Lens thickness <]qd9mj5  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3m7V6##+  
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    'Adjust parameters to account for accommodation xmx;tq  
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    '************************************************************************* fG5}'8  
    'Aqueous thickness (Position of Lens) oF^hq-xcP  
    '************************************************************************* )B4c;O4t  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) rL"k-5>fd  
    GetCustomElement eID, entity 8{t&8Ql n  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 3mz>Y*^?0  
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    ' Delete any shift(s) in z W/Q%%)J  
    count = 0 gi >{`.]  
    While GetOperationCount(eID)>count Isb^~c_P  
        GetOperation eID, count, op f`rz)C03  
        If op.Type="ShiftZ" Then qEz'l'%(  
            DeleteOperation eID,count TvwIro  
            count=count-1 HE'8  
        End If ibw;BU  
        count=count+1 +[
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    Wend /MtacR  
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    'Set new shift in 6s2g+[  
    op.Type = "ShiftZ" Xy&#}S}9  
    op.val1 = taq 6<nO2GW  
    op.parent = parID :h~!#;w_  
    AddOperation eID, op 4gENV{L  
    Print "Set aqueous humor thickness = " & taq-0.55 1X.1t^HH:  
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    '************************************************************************* u)pBFs<dn  
    'Radius and conic constant of anterior lens RVnYe='  
    '************************************************************************* h]P$L>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zt0 zKXw  
    GetConic eID, entity, curv, conic sAlgp2-  
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    SetConic eID, entity, 1/Rant, CCant TD7ONa-,  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant &r%3)Z8Et  
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    '************************************************************************* T7'$A!c  
    'Radius and conic constant of posterior lens ^+<uHd>  
    '************************************************************************* q(W@=-uDK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -Ma"V  
    GetConic eID, entity, curv, conic DUr1s]+P  
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    SetConic eID, entity, 1/Rpost, CCpost xd@DN;e  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost k#n=mm'N9  
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    '************************************************************************* dz 2d`=`3  
    'Lens thickness (Position of posterior lens surface) eGil`:JY"  
    '************************************************************************* h@d m:=ul  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) cj *4XYu  
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    ' Delete any z-shift(s) k_B^2=  
    count = 0 %54![-@  
    While GetOperationCount(eID)>count GZo4uwG@a  
        GetOperation eID, count, op %*nZ,r  
        If op.Type="ShiftZ" Then .bGeZwvf:G  
            DeleteOperation eID,count }d(6N&;"zN  
            count=count-1 VUb*,/h
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        End If %ZK}y{u\  
        count=count+1 *gn*S3Is[j  
    Wend .$iIr:Tc>  
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    'Set new z-shift tDo0Q/`  
    op.Type = "ShiftZ" f/ZE_MN2  
    op.val1 = tlens KX`,7-  
    op.parent = parID w6_}] &F  
    AddOperation eID, op Up&q#vqIj  
    Print "Set lens thickness = " & tlens ks}o9[D3  
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    '************************************************************************* x3Uv&  
    'Lens index of refraction ?x@khzk  
    '************************************************************************* )[1m$>  
    eID = FindMaterial( "Lens" ) OBZj-`fqJ  
    GetModelMaterial eID, mat (EX  
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    mat.Nd = nlens &%lhov  
    SetModelMaterial eID, mat BlUY9`VWh@  
    Print "Set lens index of refraction = " & nlens $$@Tgkg?o  
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    '************************************************************************* >@"j9  
    'Pupil diameter ect?9S[!y  
    '************************************************************************* !Xm:$KH  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ARE~jzakg  
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    'Adjust pupil diameter (trimming volume inner hole) d
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :.cX3dP@  
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    ' Adjust pupil location to just in front of the lens o;.-I[9h]  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;%1^k/b6t  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e([&Nr8h  
    count = 0 ZLkJYZk  
    While GetOperationCount(eID)>count D1f=f88/}  
        GetOperation eID, count, op 0`W~
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        If op.Type="ShiftZ" Then v>XE]c_  
            DeleteOperation eID,count
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            count=count-1 ^tv*I~>J!  
        End If gJ])A7O  
        count=count+1 j!s&yHE1  
    Wend ? _W*7<  
    op.Type = "ShiftZ" S;])Nt'X'  
    op.val1 = taq-0.01 0e7!_/9  
    op.parent = parID N]duv~JS  
    AddOperation eID, op '|Oi#S  
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    Print "Set pupil diameter = " & pupilDiam '.=Z2O3p  
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    'Update AZ Eye subassembly Description W{0:8_EI  
    eID = FindFullName( "Geometry.Arizona Eye" ) *%O1d.,  
    GetEntity eID, entity
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    entity.Description = "Accommodation = " & A & "D" :.dQY=6I  
    SetEntity eID, entity
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    Update HiC\U%We  
    Print "DONE!" ymKdRF  
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End Sub /$n${M5!  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： P ,i)A  
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Accommodation = 4 Diopters |"mb
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Pupil Diameter = 4 mm 8{ep`$(K@  
Set aqueous humor thickness = 2.81 F JzjS;  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @.})nU  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 dw&Xg_$  
Set lens thickness = 3.927 TX>;2S3q  
Set lens index of refraction = 1.42672 982$d<0%  
Set pupil diameter = 4 68y
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DONE! HV sIbQS