[技术]Arizona眼睛模型 [复制链接]

简介 9l2,:EQ
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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。 )xiiTkJd5  
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模型 <A&mc,kj  
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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。 4g]Er<-P  
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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. Ed9ynJ~)X  
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光源 }fnp}L  
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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。 \o9-[V#Gm  
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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。 fk4s19;?  
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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。 p+U}oC  
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视网膜的散射 7PO3{I  
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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。 |cStN[97%  
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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。 9tsI1]1[m  
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脚本 b'Qia'a%  
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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%d\DuJ5'~  
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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。 m\`dLrPX4j  
余下的脚本计算与屈光度有关的所有参数。 <uUQ-]QOIh  
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分析 k@U8K(:x  
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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。 <l]P <N8^  
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脚本代码 e*p7(b-  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. tAFKq>\  
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Dim entity As T_ENTITY '_,/N!-V  
Dim op As T_OPERATION T%~w~stW  
Dim mat As T_MODELMATERIAL 3ny>5A!;2  
Dim A As Double >c%OnA,3  
Dim pupilDiam As Double exw~SvT3  
Dim eID As Long [G2@[CtY1  
Dim parID As Long 6nh!g  
Dim count As Integer 1>P[3Y@}  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4Gs#_|!  
Dim tlens As Double, nlens As Double b/'{6zn  
Dim curv As Double, conic As Double hc OT+L>  
Dim ok As Long AE`X4q  
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Sub Main d4KTwn5g  
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    '用户输入对话框 P'.MwS  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 XWN ra  
        TextBox 220,21,40,21,.TextBox1 'default: 0 f =@'F
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Fb=(FQ2Y?  
        OKButton 40,91,90,21 stuj,8  
        CancelButton 190,91,90,21 koOkm:(,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 OE
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        TextBox 220,49,40,21,.TextBox2 'default: 4 jGpSECs  
    End Dialog c} )U:?6  
    Dim dlg As UserDialog hw! l{yv  
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    ok = Dialog (dlg) ~_opU(;f  
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    If ok=0 Then    'cancel button was pressed q1ybJii  
        Print "Execution cancelled." ,5oe8\uz  
        End Yt&Isi +  
    End If zQ3
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    'Assign accommodation and pupil diameter & use defaults if field left empty s}Phw2`1U  
    If dlg.TextBox1 = "" Then Y~\71QE>  
        A = 0           'Default accommodation n^aSio6  
    Else z~&uLu  
        A = CDbl(dlg.TextBox1) uQh dg4  
    End If wZ6
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    If dlg.TextBox2 = "" Then 6. N?=R  
        pupilDiam = 4   'Default pupil diameter xCN6?  
    Else '%Og9Bgd+  
        pupilDiam = CDbl(dlg.TextBox2) e RY2.!  
    End If _8t5rF  
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    Print " " rR`'l=,t  
    Print "Accommodation = " & A & " Diopters" *D`]7I~}  
    Print "Pupil Diameter = " & pupilDiam & " mm" a&:1W83  
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    ' Calculate new parameters with accommodation J{>9ctN  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =k.:XblEe[  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?bFP'.  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens cUW>`F(S  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens vJZ0G:1  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?88k`T'EI  
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    tlens = 3.767 + 0.04*A                  'Lens thickness :QKxpHi  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction GX2aV6}  
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    'Adjust parameters to account for accommodation V{!fag  
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    '*************************************************************************  1B}q?8n  
    'Aqueous thickness (Position of Lens) _N8Tu~lqV  
    '************************************************************************* F`!B!uY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (al.7VA;9
 
    GetCustomElement eID, entity Vb{5-v ;a  
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    parID = FindFullName( "Geometry.Arizona Eye" ) yx5F]Z<M2  
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    ' Delete any shift(s) in z =^liong0  
    count = 0 :`u?pc27Sm  
    While GetOperationCount(eID)>count V
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        GetOperation eID, count, op tW<i;2 l  
        If op.Type="ShiftZ" Then GMk\ l  
            DeleteOperation eID,count 5x$/.U  
            count=count-1 9Z?P/ o  
        End If )m8ve)l  
        count=count+1 RLnsy,  
    Wend { 'A`ram  
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    'Set new shift in /zt9;^e  
    op.Type = "ShiftZ" C]@v60I  
    op.val1 = taq j^4KczJl  
    op.parent = parID lKVy{X3]*  
    AddOperation eID, op IZ
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    Print "Set aqueous humor thickness = " & taq-0.55 a[e&O&Z  

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    '************************************************************************* yf|,/{S  
    'Radius and conic constant of anterior lens G.j R  
    '************************************************************************* P9d%80(b4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m/{HZKh  
    GetConic eID, entity, curv, conic 6d4e~F  
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    SetConic eID, entity, 1/Rant, CCant 1zo0/<dk  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Lj]I7ICNh  
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    '************************************************************************* rw CFt6;v  
    'Radius and conic constant of posterior lens Y!3Mm*  
    '************************************************************************* a#i85su  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0QzUcr)3+  
    GetConic eID, entity, curv, conic z@70{*  
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    SetConic eID, entity, 1/Rpost, CCpost hMcSB8?  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O &/9wi>!q  
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    '************************************************************************* =1!,A  
    'Lens thickness (Position of posterior lens surface) Vgh;w-a  
    '************************************************************************* OO7sj@  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 25bbuhss  

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    ' Delete any z-shift(s) 8S8^sP  
    count = 0 ?nVwT[  
    While GetOperationCount(eID)>count =O~ J  
        GetOperation eID, count, op t=-t xnlr<  
        If op.Type="ShiftZ" Then $ 12mS  
            DeleteOperation eID,count |3Fo4K%+  
            count=count-1 N}$$<i2o  
        End If P4\{be>e  
        count=count+1 8LI aN}  
    Wend 7g* "AEk  
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    'Set new z-shift @Feusprs  
    op.Type = "ShiftZ" 8vk*",  
    op.val1 = tlens 9+z5$  
    op.parent = parID >DFpL$oP  
    AddOperation eID, op DGs=.U-=e  
    Print "Set lens thickness = " & tlens rNi]|)-ET  
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    '************************************************************************* /J0Y
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    'Lens index of refraction (31ia"i%  
    '************************************************************************* z;c~(o@4  
    eID = FindMaterial( "Lens" ) ^)JUl!5j]C  
    GetModelMaterial eID, mat gY\g+df-  
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    mat.Nd = nlens .Mn_T*F  
    SetModelMaterial eID, mat 8fG$><@
 
    Print "Set lens index of refraction = " & nlens BLepCF38  
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    '************************************************************************* 5s
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    'Pupil diameter g6s&nH`Z2  
    '************************************************************************* Q|gw\.]$&[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _f"HUKGN  
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    'Adjust pupil diameter (trimming volume inner hole) +t9$*i9`L  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens bNH72gX2Yh  
    parID = FindFullName( "Geometry.Arizona Eye" ) +vDEDOS1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 46yq F  
    count = 0 `Kt]i5[ "  
    While GetOperationCount(eID)>count slQxz;t  
        GetOperation eID, count, op ""Ub^:ucD  
        If op.Type="ShiftZ" Then t PJW|wo  
            DeleteOperation eID,count n?UFFi+a  
            count=count-1 D2,2Yy5y  
        End If JU6PBY~C'  
        count=count+1 )=k8W9i8b  
    Wend n#US4&uT4A  
    op.Type = "ShiftZ" b0PQ;?R#V  
    op.val1 = taq-0.01 l[,RA?i {  
    op.parent = parID j O-H1@;  
    AddOperation eID, op a?d)lnk  
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    Print "Set pupil diameter = " & pupilDiam C;m,{MD  
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    'Update AZ Eye subassembly Description !1X^lFf;~  
    eID = FindFullName( "Geometry.Arizona Eye" ) x;F^7c1  
    GetEntity eID, entity j;BMuLTm1  
    entity.Description = "Accommodation = " & A & "D" q2$-U&  
    SetEntity eID, entity V[Z^Z  
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    Update k2-:!IE  
    Print "DONE!" rnkq.  
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End Sub ,G
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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： z#j)uD  
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Accommodation = 4 Diopters +,g"8&>  
Pupil Diameter = 4 mm FX yyY-(O  
Set aqueous humor thickness = 2.81 hx5oTJR  
Set anterior lens radius = 10.4 and conic constant = -2.375869 I,nW~;OV0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 nt5x[xa  
Set lens thickness = 3.927 %k"qpu  
Set lens index of refraction = 1.42672 pA%Sybw+  
Set pupil diameter = 4 1DTA Dh0  
DONE! 5PRS|R7