[技术]Arizona眼睛模型 [复制链接]

简介 )N*Jc @Y@  
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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。 oKCv$>Y  
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模型 ITg<u?z_  
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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。 X`1R&K;z^  
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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. \EsT1aT  
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光源 ^,#
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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。 x|O^#X(,  
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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。 EY:IwDA.}  

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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。 U`lK'..  
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视网膜的散射 Z %Ozzp/  
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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。 &w#!
 
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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。 ?3p7MjvZ  
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脚本 |K"Q>V2y  
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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： ]"lB!O~  
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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。 xC,x_:R`  
余下的脚本计算与屈光度有关的所有参数。 @phVfP"M  

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分析 e=WjFnK[x7  
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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。  }:Gs ,  
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脚本代码 v6s,lC5qR  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. BtZ]~
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Dim entity As T_ENTITY *y!O\-\S#>  
Dim op As T_OPERATION )63 $,y-;$  
Dim mat As T_MODELMATERIAL +yp:douERi  
Dim A As Double <;6{R#Tuh  
Dim pupilDiam As Double pA6KiY&  
Dim eID As Long jYFJk&c  
Dim parID As Long /{\ /e"5  
Dim count As Integer ]7O<|8n!d  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double UowvkVa  
Dim tlens As Double, nlens As Double motK}G
 
Dim curv As Double, conic As Double =/!lK&  
Dim ok As Long z*EV>Y[  
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Sub Main G aV&y  
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    '用户输入对话框 e@Lxduq  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 IT1YF.i  
        TextBox 220,21,40,21,.TextBox1 'default: 0 G}fBd  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 <w{?b'/q  
        OKButton 40,91,90,21 ?vFy3  
        CancelButton 190,91,90,21 6OAs%QZ  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 d
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        TextBox 220,49,40,21,.TextBox2 'default: 4 ^$K&Met  
    End Dialog UqOBr2UmG  
    Dim dlg As UserDialog %.Ma_4o Z  
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    ok = Dialog (dlg) DB5J3r81  
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    If ok=0 Then    'cancel button was pressed dU$VRgP/  
        Print "Execution cancelled."  :\\NK/"  
        End 0O9b 7F  
    End If ;=Ma+d#  
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    'Assign accommodation and pupil diameter & use defaults if field left empty H<(F$7Q!\  
    If dlg.TextBox1 = "" Then /MGapmqV9  
        A = 0           'Default accommodation {^WK#$]  
    Else cZYy+  
        A = CDbl(dlg.TextBox1) &-3e3)  
    End If y9r4]4

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    If dlg.TextBox2 = "" Then `tkoS  
        pupilDiam = 4   'Default pupil diameter c*;oR$VW  
    Else #\
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        pupilDiam = CDbl(dlg.TextBox2) 3~~X,ZL  
    End If S,c{LTL  

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    Print " " Q$E.G63Wl  
    Print "Accommodation = " & A & " Diopters" !l (Vk  
    Print "Pupil Diameter = " & pupilDiam & " mm" ,/\`Rc^n  
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    ' Calculate new parameters with accommodation n<.7tr0f\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness A2|Bbqd  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 0D(8-H  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens x?Abk  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \@gV$+{9  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens D+]mKPB  
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    tlens = 3.767 + 0.04*A                  'Lens thickness .U!EA0B  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Jt_=aMY:7  
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    'Adjust parameters to account for accommodation kR<sSLEb  
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    '************************************************************************* Bh
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    'Aqueous thickness (Position of Lens) TO6F  
    '************************************************************************* Y&6jFT_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) QVT0.GzR  
    GetCustomElement eID, entity '12m4quO  
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    parID = FindFullName( "Geometry.Arizona Eye" ) >z<L60S  
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    ' Delete any shift(s) in z ;jzJ6~<  
    count = 0 mdc?~??8  
    While GetOperationCount(eID)>count F5*-HR  
        GetOperation eID, count, op n!4}Hwz!  
        If op.Type="ShiftZ" Then o?a2wY^
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            DeleteOperation eID,count 3r~8:F"g  
            count=count-1 8-;.Ejz!\A  
        End If 6s@!Yn|?
 
        count=count+1 D?KLV_Op  
    Wend Otq3nBZ  
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    'Set new shift in RuHDAJ"&a  
    op.Type = "ShiftZ" G#7*O`  
    op.val1 = taq awzlLI<2p  
    op.parent = parID ,a5q62)q  
    AddOperation eID, op >!fTWdD^  
    Print "Set aqueous humor thickness = " & taq-0.55 ;~F*2)  
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    '************************************************************************* Te+#  
    'Radius and conic constant of anterior lens Id?-Og2iV  
    '************************************************************************* )u(,.O[cw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) c]*y
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    GetConic eID, entity, curv, conic EZj rX>"#  
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    SetConic eID, entity, 1/Rant, CCant {L$$"r,  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #
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    '************************************************************************* 2m$C;j!D  
    'Radius and conic constant of posterior lens $?ss5: S  
    '************************************************************************* %s}{5Qcl/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) T>'w]wi  
    GetConic eID, entity, curv, conic 61_PSScSY  
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    SetConic eID, entity, 1/Rpost, CCpost ]+G .S-a  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 
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    '************************************************************************* _#~D{91 j:  
    'Lens thickness (Position of posterior lens surface) |K.I%B  
    '************************************************************************* ~vYF
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Lum=5zDo  
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    ' Delete any z-shift(s) @Ov}X]ELi  
    count = 0 c6b51)sQ"  
    While GetOperationCount(eID)>count I!!cA?W  
        GetOperation eID, count, op j~bNH~3  
        If op.Type="ShiftZ" Then n%WjU)<  
            DeleteOperation eID,count 5Y;&L!T  
            count=count-1 W /v &V#  
        End If ea{zL  
        count=count+1 PC5$TJnj3  
    Wend =F
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    'Set new z-shift hcW>R  
    op.Type = "ShiftZ" e>_a (  
    op.val1 = tlens _ow7E\70  
    op.parent = parID zn/>t-Bc  
    AddOperation eID, op /QB;0PrE  
    Print "Set lens thickness = " & tlens Ho#nM_ q  
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    '************************************************************************* 8yIBx%"4MH  
    'Lens index of refraction P*[wB_^&UP  
    '************************************************************************* E 6#/@C,  
    eID = FindMaterial( "Lens" ) O\!'Ds+gX  
    GetModelMaterial eID, mat LT)I ?ud  
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    mat.Nd = nlens  "O# V/(  
    SetModelMaterial eID, mat Ca5LLG  
    Print "Set lens index of refraction = " & nlens B3yTN6-  
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    '************************************************************************* k^d^Todq.  
    'Pupil diameter }x#e.}hf&  
    '************************************************************************* Fsl="RB7f  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  O,7S1  
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    'Adjust pupil diameter (trimming volume inner hole) 'Jek< 5  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" IPn!iv)  
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    ' Adjust pupil location to just in front of the lens X!{K`~DRX  
    parID = FindFullName( "Geometry.Arizona Eye" ) "1\GU1x  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) W9} ,f  
    count = 0 $[Ut])4 ~  
    While GetOperationCount(eID)>count 'pUJR
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        GetOperation eID, count, op /:!l&1l:p  
        If op.Type="ShiftZ" Then 2xUgM}e
 
            DeleteOperation eID,count Txl|F\nK`  
            count=count-1 d=D#cs;\  
        End If cBbumf9C  
        count=count+1 "Uf1;;b  
    Wend \-Xtbm  
    op.Type = "ShiftZ" t>a D;|Y  
    op.val1 = taq-0.01 ]H{*Z3S  
    op.parent = parID BK)<~I  
    AddOperation eID, op @0 x   
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    Print "Set pupil diameter = " & pupilDiam d"E3ypPK  
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    'Update AZ Eye subassembly Description a>-qHX-l  
    eID = FindFullName( "Geometry.Arizona Eye" ) B[h^]k  
    GetEntity eID, entity @@-TW`G7  
    entity.Description = "Accommodation = " & A & "D" @*|UyK.   
    SetEntity eID, entity .nNZdta&=  
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    Update hi(e%da  
    Print "DONE!" eB_r.R{  
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End Sub 0;)Q  
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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： :.=j)ljTx  
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Accommodation = 4 Diopters m<k6oev$  
Pupil Diameter = 4 mm $;$vcV9*  
Set aqueous humor thickness = 2.81 G; exH$y  
Set anterior lens radius = 10.4 and conic constant = -2.375869 T*8S7l  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 liy/
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Set lens thickness = 3.927 zN;P_@U  
Set lens index of refraction = 1.42672 br TP}A  
Set pupil diameter = 4 N5`z S79W  
DONE! 'Q7^bF^