[技术]Arizona眼睛模型 [复制链接]

简介 nU{Qi;0  
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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。 `-U?{U}H  
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模型 tH0
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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。 ]SAY\;,_  
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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. h`9 & :zr  
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光源 "
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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。 FsOJmWZ  
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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。 TT(R<hL  
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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。 3r[F1z2B  
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视网膜的散射 ~kV>nx2  
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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。 Kp7)my  
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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。 <f}:YDY'  
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脚本 *^{j!U37s  
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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： h5l_/vd  
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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。 '6\w4J(  
余下的脚本计算与屈光度有关的所有参数。 46 0/eW\  
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分析 v h)CB8  
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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。 6*$A/D  
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脚本代码 .i )K#82  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. @JdeOL;  
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Dim entity As T_ENTITY ,'YKL",  
Dim op As T_OPERATION 2\64~a^  
Dim mat As T_MODELMATERIAL vnbY^ASdw  
Dim A As Double u#u/uS"  
Dim pupilDiam As Double @HI@PZ>  
Dim eID As Long ~3Qa-s;g  
Dim parID As Long G]xN#O;  
Dim count As Integer uj%]+Llxv  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double =kq<J-:#R  
Dim tlens As Double, nlens As Double ]3]B$  
Dim curv As Double, conic As Double &l`_D?{<#  
Dim ok As Long V$
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Sub Main _a$5"  
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    '用户输入对话框 g=v'[JPd  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~k@{b&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 k&K'FaM!  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ESIeZhXVH  
        OKButton 40,91,90,21 =b)!l9TX  
        CancelButton 190,91,90,21 d{WOO)j  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y nTx)uW  
        TextBox 220,49,40,21,.TextBox2 'default: 4 -c0*  
    End Dialog *fyaAv  
    Dim dlg As UserDialog 6PWw^Cd  
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    ok = Dialog (dlg) ]-heG'y]{  
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    If ok=0 Then    'cancel button was pressed NN:zQ_RT  
        Print "Execution cancelled." kyYU 1gfh  
        End ]w-W  
    End If wB[ JFy"E  
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    'Assign accommodation and pupil diameter & use defaults if field left empty R5},E  
    If dlg.TextBox1 = "" Then Kp;<z<  
        A = 0           'Default accommodation m\=Cw&(  
    Else 7oL:C  
        A = CDbl(dlg.TextBox1) >)>~S_u  
    End If `X&d:!}F  
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    If dlg.TextBox2 = "" Then \`/ P*  
        pupilDiam = 4   'Default pupil diameter $`C$|9S  
    Else ]P^3uXi  
        pupilDiam = CDbl(dlg.TextBox2) "6%qi qt  
    End If t08[3Q&  
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    Print " " }U%E-:  
    Print "Accommodation = " & A & " Diopters" ?^8.Sa{  
    Print "Pupil Diameter = " & pupilDiam & " mm" $['`H)z  
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    ' Calculate new parameters with accommodation S@,x^/vT  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Z#;\Rb.x7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8-O:e  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens !D 'A  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "zIQ(|TL?d  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Y\(?&7Aax  
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    tlens = 3.767 + 0.04*A                  'Lens thickness UrS%t>6k  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction nu16L$]  
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    'Adjust parameters to account for accommodation sY}0PB  
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    '************************************************************************* MLDAr dvK  
    'Aqueous thickness (Position of Lens) |;C;d"JC2  
    '************************************************************************* c-?0~A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fL&e^Q  
    GetCustomElement eID, entity ciPq@kMV  
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    parID = FindFullName( "Geometry.Arizona Eye" ) $*9:a3>zny  
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    ' Delete any shift(s) in z 1eS@ihkP  
    count = 0 Q#4OgNt  
    While GetOperationCount(eID)>count ef:Zi_o   
        GetOperation eID, count, op HhTD/  
        If op.Type="ShiftZ" Then Y$ZDJNz  
            DeleteOperation eID,count QP6a,^];  
            count=count-1 j6rwlw
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        End If \AD|;tA\vE  
        count=count+1 R"71)ob4  
    Wend Op iVQr:  
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    'Set new shift in lIatM@gU  
    op.Type = "ShiftZ"  !h*F58  
    op.val1 = taq ?)/H
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    op.parent = parID q0_Pl*  
    AddOperation eID, op jpfFJon)w  
    Print "Set aqueous humor thickness = " & taq-0.55 zh
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    '************************************************************************* xC$CRzAe5p  
    'Radius and conic constant of anterior lens ZV:0:k.x  
    '************************************************************************* N..@}}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 1ZfhDtK(  
    GetConic eID, entity, curv, conic Zu^J X/um  
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    SetConic eID, entity, 1/Rant, CCant ]~m2#g%  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ^Pc&`1Ap  
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    '************************************************************************* ,09d"7`X  
    'Radius and conic constant of posterior lens x):h|/B  
    '************************************************************************* H|B4.z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K1fnHpK  
    GetConic eID, entity, curv, conic ;c>IM]  
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    SetConic eID, entity, 1/Rpost, CCpost nnnq6Z}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost q6N6QI8/  
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    '************************************************************************* _O>8jH!#  
    'Lens thickness (Position of posterior lens surface) kT{d pGU9  
    '************************************************************************* gA DF  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) q*K.e5"
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    ' Delete any z-shift(s) Ha20g/UN.  
    count = 0 ^y&sKO  
    While GetOperationCount(eID)>count M!b"c4|<  
        GetOperation eID, count, op 8u#2M8.5E  
        If op.Type="ShiftZ" Then By}>h6`[  
            DeleteOperation eID,count I>3]VRi  
            count=count-1 wO ?A/s  
        End If *`wgqin  
        count=count+1 VpmD1YSn  
    Wend +d,Z_ 6F  
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    'Set new z-shift ir3EA'_>N  
    op.Type = "ShiftZ" Q"sszz  
    op.val1 = tlens xsdi\ j;n>  
    op.parent = parID f^kH[C  
    AddOperation eID, op $n@B:kv5p  
    Print "Set lens thickness = " & tlens Lkl^ `  
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    '************************************************************************* WkR=(dss8  
    'Lens index of refraction xc6A&b>jI  
    '************************************************************************* [&a=vE  
    eID = FindMaterial( "Lens" ) ,[<+7  
    GetModelMaterial eID, mat B1Cu?k);.  
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    mat.Nd = nlens E(G&mfhb  
    SetModelMaterial eID, mat 'Q F@@48  
    Print "Set lens index of refraction = " & nlens H^C$2f  
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    '************************************************************************* /L?
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    'Pupil diameter &x<y4ORH|  
    '************************************************************************* K/ 5U;oC  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) /32x|Ow# 1  
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    'Adjust pupil diameter (trimming volume inner hole) N.@@ebuE  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" RYuR&0_{  
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    ' Adjust pupil location to just in front of the lens D>efr8Qd@  
    parID = FindFullName( "Geometry.Arizona Eye" ) X(*MHBd  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6#DDMP8;I  
    count = 0 0JM`*f%n  
    While GetOperationCount(eID)>count ;_Z[' %  
        GetOperation eID, count, op $|%BaEyk  
        If op.Type="ShiftZ" Then >
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            DeleteOperation eID,count T1_>qnSz  
            count=count-1 k~=_]sLn  
        End If %$CV?K$C  
        count=count+1 KoKd.%  
    Wend Iu|4QE  
    op.Type = "ShiftZ" w=feXA3-S  
    op.val1 = taq-0.01 &Y3r'"  
    op.parent = parID '|rhm  
    AddOperation eID, op ap|$8G  
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    Print "Set pupil diameter = " & pupilDiam Uon^z?0A  
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    'Update AZ Eye subassembly Description ,Vr-E  
    eID = FindFullName( "Geometry.Arizona Eye" ) C 5 xsh  
    GetEntity eID, entity Z(:q.{"r  
    entity.Description = "Accommodation = " & A & "D" r:-,qy  
    SetEntity eID, entity ^
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    Update m;@8z[ ^5  
    Print "DONE!" zSo(+D &[  
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End Sub P}8cSX9  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： (utk)  
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Accommodation = 4 Diopters 13K|=6si  
Pupil Diameter = 4 mm 3}kG ]#  
Set aqueous humor thickness = 2.81 1=z6m7@'-  
Set anterior lens radius = 10.4 and conic constant = -2.375869 u%sfHGrH  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 DrA\-G_7  
Set lens thickness = 3.927 BHNEP |=  
Set lens index of refraction = 1.42672 ^aR^M\38  
Set pupil diameter = 4 t5RV-$  
DONE! ,4--3 MU