[技术]Arizona眼睛模型 [复制链接]

简介 +a$|Sc  
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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。 Fr5 Xp  
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模型 ^8K/xo-  
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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。 GGnp Pp  
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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. Acu@[I^  
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光源 JNo8>aFOb  
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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。 S_Z`so}  
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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。 R^8{bP  
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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。 Q"VMNvKYB  
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视网膜的散射 ^oeJKjJ  
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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。 3f&|h^\nD  
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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。 "s_Z&  
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脚本 NQLiWz-q  
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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： Jqfm@Y  
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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。 >i~
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余下的脚本计算与屈光度有关的所有参数。 fL6e?\Pw  
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分析 0I%: BT  
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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。 2`Gv5}LfyR  
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脚本代码 fx?$9(r,  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. LmLGki$w  
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Dim entity As T_ENTITY "H+,E_&(  
Dim op As T_OPERATION e7k%6'@  
Dim mat As T_MODELMATERIAL g9>~HF$U  
Dim A As Double ZGz|m0b (  
Dim pupilDiam As Double :.nRN`e  
Dim eID As Long W{Z^n(f4  
Dim parID As Long E
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Dim count As Integer nk@atK,38^  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double JYmAn?o-  
Dim tlens As Double, nlens As Double o"q+,"QL  
Dim curv As Double, conic As Double K
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Dim ok As Long Q5n`F5   
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Sub Main 8<dOMp;}r  
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    '用户输入对话框 };katqzEg  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ;=~Xr"(/z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 A lwtmDa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~]fJ
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        OKButton 40,91,90,21 @*O?6>  
        CancelButton 190,91,90,21 pn%#w*'  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r>n" 51*  
        TextBox 220,49,40,21,.TextBox2 'default: 4 wk$,k  
    End Dialog Q{y{rC2P  
    Dim dlg As UserDialog X6@wkrf-  
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    ok = Dialog (dlg) PHra+NY#A  
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    If ok=0 Then    'cancel button was pressed b2)\ MNH  
        Print "Execution cancelled." HlB]38  
        End :qj<p3w~}  
    End If 4s.]M>Yb  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7"2b H  
    If dlg.TextBox1 = "" Then Zi ESlf$  
        A = 0           'Default accommodation =/9^, 6Q(  
    Else _8fA?q=  
        A = CDbl(dlg.TextBox1) N4{nG,Mo]  
    End If )D@~|j:  
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    If dlg.TextBox2 = "" Then ^k/i-%k0  
        pupilDiam = 4   'Default pupil diameter {aOkV::  
    Else d8x%SQ!V  
        pupilDiam = CDbl(dlg.TextBox2) M\2"gT-LV  
    End If 5ukp^OxE  
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    Print " " FxW&8 9G  
    Print "Accommodation = " & A & " Diopters" *3+-W  
    Print "Pupil Diameter = " & pupilDiam & " mm" ZxHJ<2oD  
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    ' Calculate new parameters with accommodation H[WQ=){  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness -n))*.V  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?=On%bh  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens a)s;dp}T%  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens >lzA]aM$c  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens EU+cca|qS9  
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    tlens = 3.767 + 0.04*A                  'Lens thickness u=NG6
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1y5Ex:JVZT  
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    'Adjust parameters to account for accommodation %w}gzxN^  
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    '************************************************************************* )N!>=  
    'Aqueous thickness (Position of Lens) [c&B|h=>  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `:|@Zln  
    GetCustomElement eID, entity jgu*Y{ocm  
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    parID = FindFullName( "Geometry.Arizona Eye" ) w4};q%OBj  
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    ' Delete any shift(s) in z 5>_5]t {  
    count = 0 x4kWLy7Sz  
    While GetOperationCount(eID)>count 4[2_,9}  
        GetOperation eID, count, op X
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        If op.Type="ShiftZ" Then ?UZ?NY
  
            DeleteOperation eID,count 3=.Y,ENM;  
            count=count-1 }SfbCa)UO  
        End If bud&R4+  
        count=count+1 ERMa# L  
    Wend l]LxL  
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    'Set new shift in 0D&>Gyc*0  
    op.Type = "ShiftZ" X`r*ob  
    op.val1 = taq E1V^}dn  
    op.parent = parID Mt>oI SN&d  
    AddOperation eID, op UE0$ o?  
    Print "Set aqueous humor thickness = " & taq-0.55 uGH?N  
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    '************************************************************************* @cvP0A  
    'Radius and conic constant of anterior lens RYR-K^;R  
    '************************************************************************* a:rX9-**  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m@G i6  
    GetConic eID, entity, curv, conic RrV>r<Z"Q  
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    SetConic eID, entity, 1/Rant, CCant oF:v JDSS  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant K?.e|  
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    '************************************************************************* $W8Cf[a  
    'Radius and conic constant of posterior lens |L3X_Me  
    '************************************************************************* 3z =^(Y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) FiAY\4  
    GetConic eID, entity, curv, conic Ve3 ;  
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    SetConic eID, entity, 1/Rpost, CCpost 9.OA, 6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost HTjkR*E  
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    '************************************************************************* c/3
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    'Lens thickness (Position of posterior lens surface) "j
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    '************************************************************************* `FF8ie8L  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1+kE!2b;b  
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    ' Delete any z-shift(s) B|=|.qp$)  
    count = 0 [3/VCYje  
    While GetOperationCount(eID)>count },-*  
        GetOperation eID, count, op v1G"3fy
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        If op.Type="ShiftZ" Then W#F Q,+0)  
            DeleteOperation eID,count r`'y?Bra;  
            count=count-1 "9y( }   
        End If C}}/)BYi  
        count=count+1 ??qq:`s  
    Wend jQs>`P-CM  
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    'Set new z-shift @\P4/+"9  
    op.Type = "ShiftZ" F3U`ueP  
    op.val1 = tlens Fzq41jiS  
    op.parent = parID T/r#H__`  
    AddOperation eID, op ^-)txC5{T  
    Print "Set lens thickness = " & tlens %8.J=B  
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    '************************************************************************* T3%C%BcX  
    'Lens index of refraction ;^){|9@  
    '************************************************************************* 0$.m_0H  
    eID = FindMaterial( "Lens" ) <X7\z  
    GetModelMaterial eID, mat Of}|ib^t  
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    mat.Nd = nlens _Q(g(p&
  
    SetModelMaterial eID, mat %D}H|*IPu  
    Print "Set lens index of refraction = " & nlens =duks\)O  
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    '************************************************************************* {r85l\u)Q\  
    'Pupil diameter xG2+(f#C1  
    '************************************************************************* m#e3%150{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) X"MU3]  
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    'Adjust pupil diameter (trimming volume inner hole) v;1F[?@3Y  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" XL}"1lE  
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    ' Adjust pupil location to just in front of the lens dP2irC%f8  
    parID = FindFullName( "Geometry.Arizona Eye" ) e 8\;t"D  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2;3f=$3  
    count = 0 GbP!9I  
    While GetOperationCount(eID)>count bru/AZ#de  
        GetOperation eID, count, op arK_oh0B  
        If op.Type="ShiftZ" Then $(pF;_W  
            DeleteOperation eID,count m} ?r
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            count=count-1 Ey[On^$  
        End If eJCjJ)  
        count=count+1 ~X(UcZ2  
    Wend B@YyQ'  
    op.Type = "ShiftZ" YGvUwj'2a  
    op.val1 = taq-0.01 13'vH]S$M  
    op.parent = parID ^eYqll/U  
    AddOperation eID, op 5~sx:0;  
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    Print "Set pupil diameter = " & pupilDiam I`(l*U  
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    'Update AZ Eye subassembly Description '\#EIG  
    eID = FindFullName( "Geometry.Arizona Eye" ) m#/_x  
    GetEntity eID, entity +k<w!B*  
    entity.Description = "Accommodation = " & A & "D" ~ (On|h  
    SetEntity eID, entity ?(6mVyIe  
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    Update q"qo.TPh|$  
    Print "DONE!" Ty(@+M~-  
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End Sub r,P1^uHx  
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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： ?|{XZQ~  
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Accommodation = 4 Diopters P>Euq'ajX  
Pupil Diameter = 4 mm tirIgZ  
Set aqueous humor thickness = 2.81 kUx&
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Set anterior lens radius = 10.4 and conic constant = -2.375869 3Ug  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 r`S< A;  
Set lens thickness = 3.927 xda; K~w  
Set lens index of refraction = 1.42672 i`(^[h ?;  
Set pupil diameter = 4 ^E`(*J/o  
DONE! ?YM4b5!3T