[技术]Arizona眼睛模型 [复制链接]

简介 @jMo/kO/A  
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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。 ts@$*  
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模型  ?f'`b<o  
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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。 L[*cbjt[  
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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. 2~g-k3  
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光源 is^R8a  
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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。 PZZPx<?N  
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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。 $t"QLsk0  
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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。 wG)[Ik6:  
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视网膜的散射 pG)dF@  
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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。 eS ?9}TG|  
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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。 *,O3@,+>H  
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脚本 OT|0_d?bD  
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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： $/#[,1  
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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。 a+k3wzJ  
余下的脚本计算与屈光度有关的所有参数。 Y|hd!C-x
  
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分析
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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。 ~/aCzx~  
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脚本代码 =c&.I}^1L  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. XA.1Y)  
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Dim entity As T_ENTITY 'BgR01w J  
Dim op As T_OPERATION ""N~##)8  
Dim mat As T_MODELMATERIAL /#eS3`48  
Dim A As Double E|_8#xvb  
Dim pupilDiam As Double gy|o#&e]%  
Dim eID As Long /6y{?0S  
Dim parID As Long !a!4^zqp  
Dim count As Integer 3N2d@R  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xy&*s\=:  
Dim tlens As Double, nlens As Double $X\2h+ Os  
Dim curv As Double, conic As Double Z
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Dim ok As Long L|-|DOgw  
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Sub Main aAn p7\7  
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    '用户输入对话框 x6Gl|e[jv  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 368 g>/#'  
        TextBox 220,21,40,21,.TextBox1 'default: 0 hV) `e"r\s  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 tBl(E  
        OKButton 40,91,90,21 z?|bs?HKS  
        CancelButton 190,91,90,21 )g3c-W=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 P (Y\l  
        TextBox 220,49,40,21,.TextBox2 'default: 4 s+&0Z3+  
    End Dialog /"~UGn]R  
    Dim dlg As UserDialog t pxk8Ys  
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    ok = Dialog (dlg) S-7C'dc  
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    If ok=0 Then    'cancel button was pressed Clap3E|a  
        Print "Execution cancelled." 2
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        End Qr6PkHU  
    End If V joVC$ZX  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7xG~4N<)]  
    If dlg.TextBox1 = "" Then 7<B-2g  
        A = 0           'Default accommodation hK{<&T  
    Else mZM7 4!4X  
        A = CDbl(dlg.TextBox1) f3>DmH#  
    End If H5UF r,t  
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    If dlg.TextBox2 = "" Then @+y,E-YTdV  
        pupilDiam = 4   'Default pupil diameter vO/3bu}  
    Else YZtd IG  
        pupilDiam = CDbl(dlg.TextBox2) |*-<G3@  
    End If WoNY8 8hT  
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    Print " " *{Z=)k%  
    Print "Accommodation = " & A & " Diopters" ,LmP >Q.  
    Print "Pupil Diameter = " & pupilDiam & " mm" Wa&!1' @  
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    ' Calculate new parameters with accommodation %@TC- xx  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness aS\$@41"  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens |pq9i)e&  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens WA:r4V  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens SQx&4R.  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens n;>=QG -v  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `QW=<Le?  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L2~'Z'q  
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    'Adjust parameters to account for accommodation O.xtY@'"  
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    '************************************************************************* iy]?j$B$  
    'Aqueous thickness (Position of Lens) @_#\qGY  
    '************************************************************************* rcY &n^:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <l5m\A  
    GetCustomElement eID, entity #V#!@@c;?  
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    parID = FindFullName( "Geometry.Arizona Eye" ) AS;qJ)JfzQ  
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    ' Delete any shift(s) in z C4|OsC7J  
    count = 0 wp> z04  
    While GetOperationCount(eID)>count rK:cUW0]X  
        GetOperation eID, count, op 'U0W  
        If op.Type="ShiftZ" Then RU~ku{8?  
            DeleteOperation eID,count uhp.Yv@c  
            count=count-1 ;/JXn  
        End If L
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        count=count+1 \^RKb-6n  
    Wend _5x]BH6f  
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    'Set new shift in BHZhdm@),  
    op.Type = "ShiftZ" <1<xSr  
    op.val1 = taq WjM7s]ZRv  
    op.parent = parID .q[}e);)  
    AddOperation eID, op ylQj2B,CB  
    Print "Set aqueous humor thickness = " & taq-0.55 `<M>"~W  
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    '************************************************************************* P+OS  
    'Radius and conic constant of anterior lens :Q@/
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    '************************************************************************* {P_7AM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yTZo4c"  
    GetConic eID, entity, curv, conic )c'E9ZuZ>d  
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    SetConic eID, entity, 1/Rant, CCant < *;GJ{  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #(i pF  
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    '************************************************************************* (K84J*;  
    'Radius and conic constant of posterior lens `.3@Ki~$#  
    '************************************************************************* ?2dI8bG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 4K? \5(b  
    GetConic eID, entity, curv, conic CS(2bj^6D  
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    SetConic eID, entity, 1/Rpost, CCpost jC{KI!kPt  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &);P|v`8  
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    '************************************************************************* u'>94Gm}  
    'Lens thickness (Position of posterior lens surface) 5r~jo7  
    '************************************************************************* !jSgpIp  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @DY"~ccH  
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    ' Delete any z-shift(s) UXJblo#  
    count = 0 cBZEyy&  
    While GetOperationCount(eID)>count y1Z>{SDiq  
        GetOperation eID, count, op DZnqCu"J  
        If op.Type="ShiftZ" Then xy"'8uRi  
            DeleteOperation eID,count X:;x5'|
 
            count=count-1 HK~SD:d  
        End If bE'{zU}o  
        count=count+1 ::$W .!Uv  
    Wend [3nWxFz$R  
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    'Set new z-shift dpylJ2  
    op.Type = "ShiftZ" vO~Tx  
    op.val1 = tlens O#=%t  
    op.parent = parID *qk7e[IP  
    AddOperation eID, op ThI}~$Y  
    Print "Set lens thickness = " & tlens "#E<Leh'  
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    '************************************************************************* f pq|mY  
    'Lens index of refraction ftR& 5!Wm  
    '************************************************************************* G:tY1'5  
    eID = FindMaterial( "Lens" ) 'hs4k|B  
    GetModelMaterial eID, mat 4Yik
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    mat.Nd = nlens -9,~b9$  
    SetModelMaterial eID, mat s_VcC_A  
    Print "Set lens index of refraction = " & nlens jga\Ry=nw  
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    '************************************************************************* mY4pvpZw8  
    'Pupil diameter L-D4>+  
    '************************************************************************* _avf
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xn503,5G*7  
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    'Adjust pupil diameter (trimming volume inner hole) ~h;   
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" "IT7.!=@9  
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    ' Adjust pupil location to just in front of the lens ka\{?:r,8  
    parID = FindFullName( "Geometry.Arizona Eye" ) N\g=9o|Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rD SYR\cg  
    count = 0 *S:~U  
    While GetOperationCount(eID)>count <a @7's  
        GetOperation eID, count, op Z6i~Dy3  
        If op.Type="ShiftZ" Then Z}uY%]  
            DeleteOperation eID,count 4hwb] Yz  
            count=count-1 5 k3m"*  
        End If ge GhM>G  
        count=count+1 :#^qn|{e  
    Wend
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    op.Type = "ShiftZ" ZxwrlaA  
    op.val1 = taq-0.01 s~A-qG>  
    op.parent = parID 208^Yu  
    AddOperation eID, op 8e*skL  
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    Print "Set pupil diameter = " & pupilDiam 4F#H$`:[  
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    'Update AZ Eye subassembly Description S7f.^8  
    eID = FindFullName( "Geometry.Arizona Eye" ) VbvP!<8  
    GetEntity eID, entity _90D4kGU  
    entity.Description = "Accommodation = " & A & "D" w>^(w<~Y  
    SetEntity eID, entity \j`0f=z_  
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    Update HdqB B
  
    Print "DONE!" {k_\1t(/  
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End Sub [:cD  
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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： : "|/  
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Accommodation = 4 Diopters <.n,:ir  
Pupil Diameter = 4 mm 9,INyEyAL  
Set aqueous humor thickness = 2.81 rz%~=Ca2j  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )-)rL@s.  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 x:MwM?  
Set lens thickness = 3.927 Jq&Hz$L|  
Set lens index of refraction = 1.42672 yogavCD9b/  
Set pupil diameter = 4 $
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DONE! ?pW1}:z