[技术]Arizona眼睛模型 [复制链接]

简介
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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。 Vu1swq)l  
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模型 r'E|6_0  
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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。 _p^&]eQ+k#  
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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. og)
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光源 $s,A
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 r t\eze_5A  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Q35jJQ$<`  
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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。 ]7:*A7/!.  
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视网膜的散射 xI(t!aYp  
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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。
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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。 XZH\HK)K-]  
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脚本 &{zRuF  
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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： ("txj[v-/  
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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。 +V;@)-   
余下的脚本计算与屈光度有关的所有参数。 Su*f`~G];  
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分析 .g8db d  
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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。 8/BWe ;4  
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脚本代码 zya2 O?s  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >})W5Y+  
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Dim entity As T_ENTITY Xcw6mpLt  
Dim op As T_OPERATION mT&?DZ9<  
Dim mat As T_MODELMATERIAL y$`@QRW  
Dim A As Double t*(buAx  
Dim pupilDiam As Double $ )orXe|  
Dim eID As Long M=#'+CF}W  
Dim parID As Long Y"UB\_=  
Dim count As Integer [/GCy0jk  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Y@2v/O,\  
Dim tlens As Double, nlens As Double }[b3$WZ  
Dim curv As Double, conic As Double TaNcnAY>9  
Dim ok As Long m ^'!  
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Sub Main }2.0e5[  
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    '用户输入对话框 zY2o;-d|4  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $q 9dkt  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9`T2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |DkK7gw  
        OKButton 40,91,90,21 u )kQ*&  
        CancelButton 190,91,90,21 HJ0Rcw%  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 K_o[m!:jU  
        TextBox 220,49,40,21,.TextBox2 'default: 4 7QM1E(cMg  
    End Dialog 1g>>{ y  
    Dim dlg As UserDialog S:{`eDk\A_  
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    ok = Dialog (dlg) YES-,;ZQ'  
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    If ok=0 Then    'cancel button was pressed rq![a};~  
        Print "Execution cancelled." 3e ?J#;  
        End }II)<g'  
    End If BXa.XZ<n(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Tu&W7aoX5  
    If dlg.TextBox1 = "" Then 0P^&{ek+)  
        A = 0           'Default accommodation DT[WO_=  
    Else d]+2rt}]hL  
        A = CDbl(dlg.TextBox1) \fSo9$  
    End If i<-a-Z+^  
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    If dlg.TextBox2 = "" Then -fT}Nj\  
        pupilDiam = 4   'Default pupil diameter X3R:^ff\  
    Else }dpE>  
        pupilDiam = CDbl(dlg.TextBox2) eZMfn$McJv  
    End If q$7/X;A  
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    Print " " 9"cyZO  
    Print "Accommodation = " & A & " Diopters" Ws;X;7tS  
    Print "Pupil Diameter = " & pupilDiam & " mm" }.N~jx0R  
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    ' Calculate new parameters with accommodation 0;tu}]jnN  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Q9{f'B  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens tOxTiaa=  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens r;@"s g  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 4azqH;i  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens #+(@i|!ifo  
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    tlens = 3.767 + 0.04*A                  'Lens thickness F!zGk(Pu  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction `*y%[J,I#  
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    'Adjust parameters to account for accommodation z C7b  
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    '************************************************************************* o,[Em<  
    'Aqueous thickness (Position of Lens) ', P_a,\  
    '************************************************************************* KskPFXxP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ccwz:7r  
    GetCustomElement eID, entity qflOi8  
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    parID = FindFullName( "Geometry.Arizona Eye" ) iM M s3  
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    ' Delete any shift(s) in z GC7W7B  
    count = 0
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    While GetOperationCount(eID)>count =}'7}0M_=  
        GetOperation eID, count, op T$1(6<:+.  
        If op.Type="ShiftZ" Then )0zg1z  
            DeleteOperation eID,count cp2a @  
            count=count-1 j<A<\K  
        End If ta0;:o?/d  
        count=count+1 d#|%h] 6  
    Wend JfRqOEP4Y  
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    'Set new shift in RmJ|g<  
    op.Type = "ShiftZ" Uj^Y\w-@Z  
    op.val1 = taq 7ea%mg\  
    op.parent = parID #6mr'e1  
    AddOperation eID, op i4lB]k  
    Print "Set aqueous humor thickness = " & taq-0.55 Au"BDP  
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    '************************************************************************* W4"1H0s`l  
    'Radius and conic constant of anterior lens $ZlzS`XF7  
    '************************************************************************* s:oj
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) jJAr #|  
    GetConic eID, entity, curv, conic |y&vMx~t  
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    SetConic eID, entity, 1/Rant, CCant Sobp;OZ5  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant UaBN
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    '************************************************************************* #rQT)n  
    'Radius and conic constant of posterior lens ~h$ H@&5  
    '************************************************************************* K0\`0E
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *iV#_  
    GetConic eID, entity, curv, conic 9Us'Q{CD   
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    SetConic eID, entity, 1/Rpost, CCpost zS'{F>w  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost s8SCEpz  
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    '************************************************************************* ihD|e&  
    'Lens thickness (Position of posterior lens surface) Ct]? /  
    '************************************************************************* \O)u' Bu  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q}uh`?t  
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    ' Delete any z-shift(s) 
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    count = 0 n<Ki.;-ZE  
    While GetOperationCount(eID)>count eBqF@'DQ  
        GetOperation eID, count, op e?WI=Og  
        If op.Type="ShiftZ" Then y1#QP3'Z1  
            DeleteOperation eID,count R)Dh;XA  
            count=count-1 F6"QsFG  
        End If JqtOoR  
        count=count+1 zLg_0r*h1  
    Wend mxICQ>s b  
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    'Set new z-shift hA+;eXy/  
    op.Type = "ShiftZ" AjINO}b  
    op.val1 = tlens d.k'\1o  
    op.parent = parID aZ}z/.b]  
    AddOperation eID, op 1~vv<`-  
    Print "Set lens thickness = " & tlens =cxG4R1x  
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    '************************************************************************* Ox6^=D"  
    'Lens index of refraction Z|j\_VKhl  
    '************************************************************************* |UN#utw{^Y  
    eID = FindMaterial( "Lens" ) }3R
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    GetModelMaterial eID, mat h8P_/.+g|V  
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    mat.Nd = nlens i|fkwV,5  
    SetModelMaterial eID, mat LP) IL~  
    Print "Set lens index of refraction = " & nlens e*o:ltP./  
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    '************************************************************************* \oO&c  
    'Pupil diameter mWuhXY^Q  
    '************************************************************************* <n0j'P>1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) f0g&=k{OD  
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    'Adjust pupil diameter (trimming volume inner hole) ]CgZt'h{  

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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ~AR0,lak  
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    ' Adjust pupil location to just in front of the lens [}y"rs`!  
    parID = FindFullName( "Geometry.Arizona Eye" ) "~T06!F45  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fw0Z- 9*  
    count = 0 EiWd =jDm  
    While GetOperationCount(eID)>count s_76)7  
        GetOperation eID, count, op uQkQ#'e|  
        If op.Type="ShiftZ" Then E /V`NqC  
            DeleteOperation eID,count Y4*?QBYA  
            count=count-1 AmcBu"  
        End If @fd
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        count=count+1 QM'>
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    Wend 0vM,2:kf*  
    op.Type = "ShiftZ" bc\?y2 3  
    op.val1 = taq-0.01 ^7C,GaDsn  
    op.parent = parID 2^&5D,}
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    AddOperation eID, op Yq:TWeZD  
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    Print "Set pupil diameter = " & pupilDiam #K/#-S  
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    'Update AZ Eye subassembly Description *JVJKqed  
    eID = FindFullName( "Geometry.Arizona Eye" ) 6dYUMqQ  
    GetEntity eID, entity <(Ktf0'__  
    entity.Description = "Accommodation = " & A & "D" sUsIu,1Q  
    SetEntity eID, entity 8C2!Wwz`J8  
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    Update G)\6W#de
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    Print "DONE!" m`/!7wQs  
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End Sub mC84fss  
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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： 9_pOV%Qs  
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Accommodation = 4 Diopters .gd'<l  
Pupil Diameter = 4 mm +IfU 5&5<  
Set aqueous humor thickness = 2.81
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Set anterior lens radius = 10.4 and conic constant = -2.375869 Zh.[f+l]  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 3/2G~$C  
Set lens thickness = 3.927 pw1&WP&?3  
Set lens index of refraction = 1.42672 sTO9>~sj  
Set pupil diameter = 4 gnU##Km|  
DONE! j es[a