[技术]Arizona眼睛模型 [复制链接]

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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。 E0sbU<11  
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模型  )x$!K[=  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 r:fwrC  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 06PhrPVa!\  
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光源 qJ\X~5{  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 I?f"<5[0  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 k TFz_*6.  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 i{<8 hLO  
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视网膜的散射 8&?^XcJ*x  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 2;&mkcK'  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 -Bl/4p  
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脚本 Xfj)gPt}  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： g+:$X- r  
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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。 OMl8 a B9  
余下的脚本计算与屈光度有关的所有参数。 bAUHUPe  
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分析 #1MKEfv(~  
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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。 {PL,VY)Z  
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脚本代码 C=8H)Ef,l  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. MY&<)|v\  
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Dim entity As T_ENTITY <|otZJ'2r  
Dim op As T_OPERATION #U\$@4D  
Dim mat As T_MODELMATERIAL 6tX.(/+L  
Dim A As Double GX7VlI[  
Dim pupilDiam As Double x 96}#0'  
Dim eID As Long 5Lw{0uLr  
Dim parID As Long  KvGbDG  
Dim count As Integer %@>YNPD`E  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double DQcWq'yY^  
Dim tlens As Double, nlens As Double ?%93b ,7  
Dim curv As Double, conic As Double JW-|<CJ  
Dim ok As Long #&k8TY  
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Sub Main  j|ozGO  
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    '用户输入对话框 U8E0~[y'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !`Le`c  
        TextBox 220,21,40,21,.TextBox1 'default: 0 r;9z5'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f7.m=lbe  
        OKButton 40,91,90,21 ZH% we  
        CancelButton 190,91,90,21 Sq<3
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |%-YuD  
        TextBox 220,49,40,21,.TextBox2 'default: 4 cFw3Iw"JJ  
    End Dialog ,b$z!dvhl  
    Dim dlg As UserDialog t~q?lT  
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    ok = Dialog (dlg) R \ia6  
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    If ok=0 Then    'cancel button was pressed rj}(muM,R  
        Print "Execution cancelled." FbmsN)mv!%  
        End m!;G/s*  
    End If !W(`<d]68:  
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    'Assign accommodation and pupil diameter & use defaults if field left empty S3QaYq"v  
    If dlg.TextBox1 = "" Then G<|:605  
        A = 0           'Default accommodation sLNNcj(Cy>  
    Else lz- iCZ  
        A = CDbl(dlg.TextBox1) 'g2vX&=$A  
    End If \PzN XQ$  
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    If dlg.TextBox2 = "" Then (N7O+3+G  
        pupilDiam = 4   'Default pupil diameter 5 1"8Py  
    Else _Cj(fFL  
        pupilDiam = CDbl(dlg.TextBox2) Q]^Yi1PbS  
    End If PFm\[2  
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    Print " " .ByU  
    Print "Accommodation = " & A & " Diopters" Ohi D  
    Print "Pupil Diameter = " & pupilDiam & " mm" ^zHRSO  
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    ' Calculate new parameters with accommodation BK*z 4m  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness wz h.$?~  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens p+vh[+yp  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens U[bgu#P;  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens j!7Qw 8  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2Sjt=LOc="  
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    tlens = 3.767 + 0.04*A                  'Lens thickness tGC2 ^a#~  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction g9`[Y~  
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    'Adjust parameters to account for accommodation B2Qp}  
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    '************************************************************************* dGU8+)2cn  
    'Aqueous thickness (Position of Lens) HZ{n&iJ  
    '************************************************************************* H@Q`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) UDMyyVd  
    GetCustomElement eID, entity SYeE) mI  
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    parID = FindFullName( "Geometry.Arizona Eye" ) \
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    ' Delete any shift(s) in z RT/qcS^Oz  
    count = 0 b9DR%hO:  
    While GetOperationCount(eID)>count nGns}\!7'  
        GetOperation eID, count, op /h7.oD8CU  
        If op.Type="ShiftZ" Then ODek%0=  
            DeleteOperation eID,count ~GA8_B  
            count=count-1 5N1}Ns  
        End If p&\K9hfi  
        count=count+1 e62y  
    Wend BKX9SL]  
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    'Set new shift in \q,s?`+B  
    op.Type = "ShiftZ" i%MA"I\9  
    op.val1 = taq dqxd3,Z  
    op.parent = parID L_k9g12  
    AddOperation eID, op %Ci^*zb  
    Print "Set aqueous humor thickness = " & taq-0.55 O)1E$#~  
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    '************************************************************************* F3Dt7q  
    'Radius and conic constant of anterior lens bNXAU\M^  
    '************************************************************************* nPOO3!<{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3p&jLFphL  
    GetConic eID, entity, curv, conic /p 5=i  
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    SetConic eID, entity, 1/Rant, CCant .&PzkqWZ  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant V~[:*WOX  
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    '************************************************************************* gApz:K[l  
    'Radius and conic constant of posterior lens f1J%]g!  
    '************************************************************************* 6g~+( ({lQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @mNJ=mEV  
    GetConic eID, entity, curv, conic JjQ
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    SetConic eID, entity, 1/Rpost, CCpost [%?y( q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }PZ=`w*O  
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    '************************************************************************* !UcOl0"6  
    'Lens thickness (Position of posterior lens surface) 4w;~4#ZPp  
    '************************************************************************* T .
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) nP;;MX:B  
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    ' Delete any z-shift(s) LipxAE?O  
    count = 0 k}U JVH21k  
    While GetOperationCount(eID)>count )88nMH-  
        GetOperation eID, count, op Um\0i;7 ~4  
        If op.Type="ShiftZ" Then ;s}3e#$L  
            DeleteOperation eID,count $rB6<  
            count=count-1 i.M2E$b|  
        End If lQL:3U0DjU  
        count=count+1 R8 jovr  
    Wend ($SLb
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    'Set new z-shift GS4_j
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    op.Type = "ShiftZ" Pr/]0<s  
    op.val1 = tlens 6c&Y  
    op.parent = parID :Eo8v$W\RB  
    AddOperation eID, op V7@ {D  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* Onw24&  
    'Lens index of refraction ]Uh1l.O  
    '************************************************************************* 6v>z h  
    eID = FindMaterial( "Lens" ) oCuV9dA
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    GetModelMaterial eID, mat 8^vArS;  
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    mat.Nd = nlens 7kd
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    SetModelMaterial eID, mat CL1;Inzl  
    Print "Set lens index of refraction = " & nlens xqv[? ?  
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    '************************************************************************* tN2 W8d  
    'Pupil diameter (3W&AM  
    '************************************************************************* |[LE9Lq/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?bI?GvSh  
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    'Adjust pupil diameter (trimming volume inner hole) FUqt)YHi  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 75AslL?t  
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    ' Adjust pupil location to just in front of the lens eXG57<t ON  
    parID = FindFullName( "Geometry.Arizona Eye" ) U|?,N0%Z1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Rsn^eR6^  
    count = 0 "@)lH  
    While GetOperationCount(eID)>count zo44^=~%  
        GetOperation eID, count, op 6#|qg*OS  
        If op.Type="ShiftZ" Then mPG7Zy$z  
            DeleteOperation eID,count vi|Zit  
            count=count-1 Ay%:@j(E  
        End If j)";:v  
        count=count+1 n1 v,#GE  
    Wend afUTAP@  
    op.Type = "ShiftZ" Rcf=J){D6  
    op.val1 = taq-0.01 &I)\*Ue2t  
    op.parent = parID Nb1J ~v  
    AddOperation eID, op HfZtL  
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    Print "Set pupil diameter = " & pupilDiam j+Zt.KXjT  
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    'Update AZ Eye subassembly Description tW
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    eID = FindFullName( "Geometry.Arizona Eye" ) +?V0:Kz]  
    GetEntity eID, entity )Mi'(C;  
    entity.Description = "Accommodation = " & A & "D" r<|nwFJ  
    SetEntity eID, entity -[$&s FD  
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    Update N&x:K+Zm.  
    Print "DONE!" ]QS](BbD:  
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End Sub BSDk9Oc  
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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： [Xh\mDU.  
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Accommodation = 4 Diopters V{GXc:=  
Pupil Diameter = 4 mm [-58Ezyr  
Set aqueous humor thickness = 2.81 HlRAD|]\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ; 8E;  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Ut_mrb+W  
Set lens thickness = 3.927 6(.H3bu
 
Set lens index of refraction = 1.42672 <I1y  
Set pupil diameter = 4 w+Vk3c5uI)  
DONE! !qw4mN