[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。 KDq="=q  
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模型 !T][c~l  
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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。 +h4W<YnW  
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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. o+A1-&qhN  
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光源 Mh
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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。 w3(|A> s3  
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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。 QDg5B6>$  
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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。 #5@(^N5p`  
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视网膜的散射 112WryS  
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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。 PN l/}'  
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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。 6(bN*.  
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脚本 _-_iw&F  
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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： c`!e#w  
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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。 )[Tm[o?Y.  
余下的脚本计算与屈光度有关的所有参数。 u?Ffqt9'  
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分析 'v6@5t19j  
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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。 t{]Ew4Y4%O  
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脚本代码 .uJ J<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ccag8LC  
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Dim entity As T_ENTITY >a?Bk4w  
Dim op As T_OPERATION
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Dim mat As T_MODELMATERIAL 0~qc,-)3  
Dim A As Double |H?t+Dyn)q  
Dim pupilDiam As Double 7S a9  
Dim eID As Long zEI+)|4?r  
Dim parID As Long .Fo#Dmq3  
Dim count As Integer kW/G=_6  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 'Lrn<  
Dim tlens As Double, nlens As Double l)%PvLbL  
Dim curv As Double, conic As Double tAAMSb9[d  
Dim ok As Long EK';\}  
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Sub Main zZ=SAjT QP  
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    '用户输入对话框 FCEy1^u  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m)Plv+R}  
        TextBox 220,21,40,21,.TextBox1 'default: 0 JsJP
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qbv\uYow3k  
        OKButton 40,91,90,21 kUd]8Ff!  
        CancelButton 190,91,90,21 FiUQ2w4  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?\V#^q-  
        TextBox 220,49,40,21,.TextBox2 'default: 4 X4V>qHV72  
    End Dialog @_+aX.,  
    Dim dlg As UserDialog iOk;o=  
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    ok = Dialog (dlg) PQ&*(G  
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    If ok=0 Then    'cancel button was pressed VQ9A/DH/  
        Print "Execution cancelled." 6'#5Dqw"r  
        End +{:uPY#1  
    End If 53i]Q;k[  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Z1HH0{q-A  
    If dlg.TextBox1 = "" Then "-Q+!byh  
        A = 0           'Default accommodation AF'<  
    Else {MgRi7  
        A = CDbl(dlg.TextBox1) )2[)11J9t  
    End If T8^9*]:@c!  
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    If dlg.TextBox2 = "" Then 981-[ga`Y  
        pupilDiam = 4   'Default pupil diameter X)b$CG  
    Else hF2e--  
        pupilDiam = CDbl(dlg.TextBox2) S{=5nR9j  
    End If 1/}H 0\9'  
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    Print " " ,X@o@W+L  
    Print "Accommodation = " & A & " Diopters" k\f _\pj6  
    Print "Pupil Diameter = " & pupilDiam & " mm" pfN(Ae Pt  
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    ' Calculate new parameters with accommodation "hk#pQ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness F1Z'tj
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens *9'3 `^l  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens @]Cg5QW>T  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :q9!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ;(i6 X)  
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    tlens = 3.767 + 0.04*A                  'Lens thickness f[o~d`
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction As,`($=  
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    'Adjust parameters to account for accommodation y'2|E+*V  
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    '************************************************************************* \g}]u(zg%  
    'Aqueous thickness (Position of Lens) y7HFmGM  
    '************************************************************************* f?5>V   
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (?4%Xtul1  
    GetCustomElement eID, entity 6GxLaI  
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    parID = FindFullName( "Geometry.Arizona Eye" ) noWF0+%  
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    ' Delete any shift(s) in z Wiis<^)  
    count = 0 J M`w6}  
    While GetOperationCount(eID)>count f}-'67*Y  
        GetOperation eID, count, op aXe&c^AR  
        If op.Type="ShiftZ" Then Dz}i-tw+  
            DeleteOperation eID,count 2`=jKt  
            count=count-1 (|QJ[@?q  
        End If si0}b~t  
        count=count+1 t
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    Wend u&zY>'}zm  
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    'Set new shift in @O#!W]6NT6  
    op.Type = "ShiftZ" u zZ|0  
    op.val1 = taq Ks.b).fH  
    op.parent = parID j)J |'b|  
    AddOperation eID, op _o~ pVBl/  
    Print "Set aqueous humor thickness = " & taq-0.55 Mq> 4!  
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    '************************************************************************* 7By7F:[b  
    'Radius and conic constant of anterior lens r^ r+
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    '************************************************************************* +<bj}"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !gXxM,R  
    GetConic eID, entity, curv, conic 7@c!4hmr
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    SetConic eID, entity, 1/Rant, CCant RC_Pj)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant i%i~qTN  
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    '************************************************************************* | Y:`>2ev  
    'Radius and conic constant of posterior lens kz=ho~ @  
    '************************************************************************* pBqf+}g4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) //@6w;P  
    GetConic eID, entity, curv, conic o0r&w;!  
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    SetConic eID, entity, 1/Rpost, CCpost 'w:ugb9]  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O=Su E/q  
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    '************************************************************************* =3(v4E':5  
    'Lens thickness (Position of posterior lens surface) /?81Ypt  
    '************************************************************************* k0Vri$x  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) fN2Sio:  

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    ' Delete any z-shift(s) hDXTC_^s  
    count = 0 kff N0(MR  
    While GetOperationCount(eID)>count 7C|AiSH  
        GetOperation eID, count, op 6J;!p/C8E  
        If op.Type="ShiftZ" Then Xqf\}p n  
            DeleteOperation eID,count Yn?beu'  
            count=count-1 n@pwOHQn<|  
        End If _9BL7W $;  
        count=count+1 y[McdlH m  
    Wend SK}jhm"y  
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    'Set new z-shift aImzK/  
    op.Type = "ShiftZ" X;LYGJ{Xk  
    op.val1 = tlens "ku[b\W  
    op.parent = parID $:u*)&"t|  
    AddOperation eID, op ykQb;ZP8jh  
    Print "Set lens thickness = " & tlens bd/A0i?C  
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    '************************************************************************* }8#olZ/(q  
    'Lens index of refraction x(c+~4:_M  
    '*************************************************************************
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    eID = FindMaterial( "Lens" )  ~&~4{  
    GetModelMaterial eID, mat D5"5`w=C  
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    mat.Nd = nlens &A s>Y,y  
    SetModelMaterial eID, mat (^yaAy#4  
    Print "Set lens index of refraction = " & nlens Y%i<~"k  
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    '************************************************************************* vU%o5y:  
    'Pupil diameter M8H hjoo  
    '************************************************************************* sm18u-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2*snMA  
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    'Adjust pupil diameter (trimming volume inner hole) kw59`z Es  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {^oohW -  
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    ' Adjust pupil location to just in front of the lens |0ZJ[[2  
    parID = FindFullName( "Geometry.Arizona Eye" ) ];5J  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -O &>HA  
    count = 0 >|S@twy  
    While GetOperationCount(eID)>count =*fq5v  
        GetOperation eID, count, op La6 9or   
        If op.Type="ShiftZ" Then xR-;,=J  
            DeleteOperation eID,count +VVn@=&?  
            count=count-1 jA"}\^%3  
        End If A^}#  
        count=count+1 k*_Gg  
    Wend `N[@lV\xp!  
    op.Type = "ShiftZ" Op0*tj2i),  
    op.val1 = taq-0.01 o;c"-^>  
    op.parent = parID <Ve0PhK  
    AddOperation eID, op DWtITO>  
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    Print "Set pupil diameter = " & pupilDiam @Yt394gA%\  
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    'Update AZ Eye subassembly Description qBF|' .$^  
    eID = FindFullName( "Geometry.Arizona Eye" ) 6!i`\>I]  
    GetEntity eID, entity ((Av3{05H&  
    entity.Description = "Accommodation = " & A & "D" e oE)Mq  
    SetEntity eID, entity ,~7~ S"  
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    Update bB0/FiY7o  
    Print "DONE!" 8$c)]Bv  
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End Sub sm"Rp~[i  
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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： %KF I~Qk  
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Accommodation = 4 Diopters .hckZx /  
Pupil Diameter = 4 mm NEIF1(:  
Set aqueous humor thickness = 2.81 nt"\FZ*;3  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )z&C&Gqz  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 e 6wevK\  
Set lens thickness = 3.927 O-.G("  
Set lens index of refraction = 1.42672 sI6*.nR  
Set pupil diameter = 4 ?o)?N8U  
DONE! Q|[^dju