[技术]Arizona眼睛模型 [复制链接]

简介 CdQ!GS<'y  
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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。 D,feF9  
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模型 5j(k:a+!H  
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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。 i/4>2y9/F4  
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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. i_%_x*  
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光源 rILYI;'o  
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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。 02^rV*re  
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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。 XL^GZ  
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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。 $UwCMPs X  
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视网膜的散射 gbA_DZ  
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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。 $&c*'3  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 SXh-A1t  
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脚本 i%?*@uj  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： "AqB$^S9t  
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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。 A#,ZUOPGH  
余下的脚本计算与屈光度有关的所有参数。 c+ie8Q!  
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分析 %BODkc Zh  
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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。 sLk-x\P]|  
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脚本代码 |.dRily+  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. l[J8!u2Xp  
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Dim entity As T_ENTITY /-s6<e!  
Dim op As T_OPERATION cMIE
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Dim mat As T_MODELMATERIAL Z_NCD`i;  
Dim A As Double xIn:ZKJ'  
Dim pupilDiam As Double K=&>t6s<  
Dim eID As Long \U_@S.  
Dim parID As Long y();tsWqc  
Dim count As Integer Hn:Crl y#  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]M3yLYK/P  
Dim tlens As Double, nlens As Double %so]L+r2!  
Dim curv As Double, conic As Double %iB,IEw  
Dim ok As Long l^}c!  
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Sub Main EQ_aa@M7  
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    '用户输入对话框 7>RY/O;Z,  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 F'Z,]b'st3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 v:#tWEbo-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 AXB7oV,xt  
        OKButton 40,91,90,21 uAk.@nfiEv  
        CancelButton 190,91,90,21 7EJ+c${e.-  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 X>^fEQq"  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =~gvZV-<  
    End Dialog 6\t@)=C,Q  
    Dim dlg As UserDialog Y:`&=wjP~  
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    ok = Dialog (dlg) '"Nr,vQo  
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    If ok=0 Then    'cancel button was pressed jiGTA:v
 
        Print "Execution cancelled." y7<|_:00  
        End Wn6Sn{8W{  
    End If Gm`8q}<I  
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    'Assign accommodation and pupil diameter & use defaults if field left empty HZOMlOZ  
    If dlg.TextBox1 = "" Then +T+#q@  
        A = 0           'Default accommodation Rb;'O89Hj@  
    Else @VI@fN  
        A = CDbl(dlg.TextBox1) EX"yxZ~  
    End If 4Tc~b3\!Y  
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    If dlg.TextBox2 = "" Then >mkFV@`  
        pupilDiam = 4   'Default pupil diameter )5H?Vh>36  
    Else {{1G`;|v9  
        pupilDiam = CDbl(dlg.TextBox2) ?A0)L27UE&  
    End If 8XaQAy%d]  
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    Print " " $Kd>:f=A  
    Print "Accommodation = " & A & " Diopters" u@^LW<eD  
    Print "Pupil Diameter = " & pupilDiam & " mm" 4e  
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    ' Calculate new parameters with accommodation bK7J}8hH  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bd`P0f?  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens V~
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens _dU\JD  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0}9h]X'  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens sRf
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    tlens = 3.767 + 0.04*A                  'Lens thickness U!]dEW|G  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1*7@BP5  
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    'Adjust parameters to account for accommodation 1x^GWtRp  
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    '************************************************************************* 8k79&|  
    'Aqueous thickness (Position of Lens) 4K74=r),i  
    '************************************************************************* fy$1YI>!Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !9x}  
    GetCustomElement eID, entity ?ubro0F:  
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    parID = FindFullName( "Geometry.Arizona Eye" ) =c7;r]Ol  
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    ' Delete any shift(s) in z t<qiGDJ<d  
    count = 0 7z-[f'EIUI  
    While GetOperationCount(eID)>count ,?3G;-  
        GetOperation eID, count, op 5dg(e3T  
        If op.Type="ShiftZ" Then adw2x pj  
            DeleteOperation eID,count 4P0}+  
            count=count-1 0YHFvy)  
        End If Pc9H0\+Xk  
        count=count+1 _f{{( 7  
    Wend e(yh[7p=  
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    'Set new shift in F[0]/  
    op.Type = "ShiftZ" OJxl<Q=z  
    op.val1 = taq 9FX-1,Jx  
    op.parent = parID ~XIb\m9H  
    AddOperation eID, op $8FUfJ1@  
    Print "Set aqueous humor thickness = " & taq-0.55 /O9EQPm(  
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    '************************************************************************* cnLro  
    'Radius and conic constant of anterior lens Wjc'*QCPl  
    '************************************************************************* tVjsRnb{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) d'2A,B~_*  
    GetConic eID, entity, curv, conic (w{j6).3Dj  
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    SetConic eID, entity, 1/Rant, CCant qWw=8Bq  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant YzWz|  
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    '************************************************************************* (#
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    'Radius and conic constant of posterior lens 3sk9`=[{$  
    '************************************************************************* *`U~?q}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) rs.)CMk53  
    GetConic eID, entity, curv, conic 'VbiVLWD  
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    SetConic eID, entity, 1/Rpost, CCpost w(rE`IgW  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost fZ. ONq  
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    '************************************************************************* _g.{MT
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    'Lens thickness (Position of posterior lens surface) $u.z*b_yy  
    '************************************************************************* 1"g<0 W  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) AR=]=8  
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    ' Delete any z-shift(s) yjAL\U7`T  
    count = 0 8_8l.!~  
    While GetOperationCount(eID)>count Vc2`b3"Br  
        GetOperation eID, count, op A's{j7  
        If op.Type="ShiftZ" Then Ned
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            DeleteOperation eID,count =}*0-\QG  
            count=count-1 Uv.)?YeGh  
        End If pUTr!fR  
        count=count+1 "fI6Cpc  
    Wend d5.4l&\u  
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    'Set new z-shift w@b)g  
    op.Type = "ShiftZ" yw!{MO  
    op.val1 = tlens Fp:'MX  
    op.parent = parID E3i4=!Y  
    AddOperation eID, op w &(ag$p'  
    Print "Set lens thickness = " & tlens _^;Z~/.  
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    '************************************************************************* T|p"0b A  
    'Lens index of refraction ""H?gsL[  
    '************************************************************************* q@&6#B  
    eID = FindMaterial( "Lens" ) H.c7Nle  
    GetModelMaterial eID, mat sRW<me;  
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    mat.Nd = nlens OPi

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    SetModelMaterial eID, mat =WLY6)]A  
    Print "Set lens index of refraction = " & nlens
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    '************************************************************************* R=dC4;  
    'Pupil diameter JLYi]nZ  
    '************************************************************************* U(Zq= M  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6mE\OS-I  
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    'Adjust pupil diameter (trimming volume inner hole) TV:9bn?r)  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >7FHo-H/T  
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    ' Adjust pupil location to just in front of the lens OVJ0}5P*  
    parID = FindFullName( "Geometry.Arizona Eye" ) 2/f}S?@   
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) : +u]S2u{  
    count = 0 z{6Z 11|  
    While GetOperationCount(eID)>count T+$[eWk"a  
        GetOperation eID, count, op @7u0v  
        If op.Type="ShiftZ" Then 7P T{lT  
            DeleteOperation eID,count E@\e$?*X  
            count=count-1 >sF)BoLc  
        End If b'y%n  
        count=count+1 i1085ztN  
    Wend 5N]
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    op.Type = "ShiftZ" HsWk*L `y  
    op.val1 = taq-0.01 /efUjkP  
    op.parent = parID i@q&5;%%  
    AddOperation eID, op #z(]xI)"  
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    Print "Set pupil diameter = " & pupilDiam }qUX=s GG  
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    'Update AZ Eye subassembly Description }b}m3i1  
    eID = FindFullName( "Geometry.Arizona Eye" ) LP-o8c  
    GetEntity eID, entity uNyVf7u  
    entity.Description = "Accommodation = " & A & "D" _GPe<H  
    SetEntity eID, entity Ni>[D"|  
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    Update 5(2;|I,T  
    Print "DONE!" "7 yD0T)2  
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End Sub JC"z&ka  
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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： k+/6$pI  
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Accommodation = 4 Diopters ;"I^ZFYX  
Pupil Diameter = 4 mm 6Zo}(^Ovz  
Set aqueous humor thickness = 2.81 _aphkeqd  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ~Ei<Z`3}7"  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 5G#n"}T  
Set lens thickness = 3.927 4| f*eO  
Set lens index of refraction = 1.42672 ;a/E42eN;  
Set pupil diameter = 4 `V1]k_h  
DONE! s.rm7r@#