[技术]Arizona眼睛模型 [复制链接]

简介 3leg,qd  
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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。 SiojOH  
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模型 M;zRf3S  
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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。 3D\.Sj%  
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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. lGG
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光源 "+nURdicO  
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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。 4)2*|w  
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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。 &%u,b~cL?  
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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。 +6<MK;  
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视网膜的散射 +*0THol-  
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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。 @T/C<-/:  
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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。 xDADJ>u2K  
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脚本 [&3"kb  
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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： sef!hS06  
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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。 _IlL'c5  
余下的脚本计算与屈光度有关的所有参数。 LiV]!*9$KG  
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分析 `SW`d<+L  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 =?*V3e3{  
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脚本代码 :cynZab  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. r1?LKoJOn  
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Dim entity As T_ENTITY 7H>dv'  
Dim op As T_OPERATION pu>LC6m3a  
Dim mat As T_MODELMATERIAL 0e7v ?UT  
Dim A As Double sJM}p5V  
Dim pupilDiam As Double T@vVff  
Dim eID As Long JK_$A;Q  
Dim parID As Long g:,4Kd|  
Dim count As Integer ]iNSa{G  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double R>0ta
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Dim tlens As Double, nlens As Double +M.|D,wg2  
Dim curv As Double, conic As Double dO8Z {
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Dim ok As Long X*Q7Yu  
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Sub Main u8,T>VNVw  
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    '用户输入对话框 }oU&J81  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 n&V(c&C  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \@F{Q-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 rvfl~<G*  
        OKButton 40,91,90,21 fsmH];"GD  
        CancelButton 190,91,90,21 jyT(LDsS  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 1)Ag
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        TextBox 220,49,40,21,.TextBox2 'default: 4 LnyA5T  
    End Dialog ,`Mlo  
    Dim dlg As UserDialog )eG&"3kFe!  
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    ok = Dialog (dlg) ypifXO;m7  
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    If ok=0 Then    'cancel button was pressed D@ lJ^+  
        Print "Execution cancelled." G?V3lQI1n  
        End .ev]tu2N  
    End If d)AkA\neWo  
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    'Assign accommodation and pupil diameter & use defaults if field left empty "bO]  
    If dlg.TextBox1 = "" Then 50Jr(OeU<  
        A = 0           'Default accommodation o._^  
    Else g!QumRF  
        A = CDbl(dlg.TextBox1) He@= bLLa  
    End If a3)#tt=rA  
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    If dlg.TextBox2 = "" Then l00D|W_9  
        pupilDiam = 4   'Default pupil diameter L7b{H22  
    Else xSUR<  
        pupilDiam = CDbl(dlg.TextBox2) />oU}m"k  
    End If Af%?WZlOq  
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    Print " " [/kO>  
    Print "Accommodation = " & A & " Diopters" V:+bq`  
    Print "Pupil Diameter = " & pupilDiam & " mm" S`^W#,rj  
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    ' Calculate new parameters with accommodation f_\-y&)+*  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness )}aF=%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens :tgTYIF  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens s [!SG`&  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 93dotuF  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -jy"?]ve.  
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    tlens = 3.767 + 0.04*A                  'Lens thickness M}<=~/k`j
 
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction -a[{cu{  
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    'Adjust parameters to account for accommodation *l^'v9  
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    '************************************************************************* 3{z|301<m  
    'Aqueous thickness (Position of Lens) ?uN(" I  
    '************************************************************************* ..:V3]-D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) i<?4iwX%i*  
    GetCustomElement eID, entity 9|`@czw  
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    parID = FindFullName( "Geometry.Arizona Eye" ) gK(4<PO'  
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    ' Delete any shift(s) in z iQF}x&a<  
    count = 0 8iNAs#s  
    While GetOperationCount(eID)>count bM-Rj1#Lo  
        GetOperation eID, count, op /z5lxS@#  
        If op.Type="ShiftZ" Then abnd U,s  
            DeleteOperation eID,count !;gke,fB  
            count=count-1 *PEuaRDN  
        End If Q(6(Scp{  
        count=count+1 t["Df;"O  
    Wend j1<1D@UO  
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    'Set new shift in \sd"iMEi  
    op.Type = "ShiftZ" q@9i3*q;  
    op.val1 = taq `[CJtd2\  
    op.parent = parID p#d UL9  
    AddOperation eID, op <T
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    Print "Set aqueous humor thickness = " & taq-0.55 JWL J<z  
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    '************************************************************************* @45H8|:k  
    'Radius and conic constant of anterior lens ea0tx3'  
    '************************************************************************* njMy&$6a##  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H\mVK!](D  
    GetConic eID, entity, curv, conic D8Rmxq!  
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    SetConic eID, entity, 1/Rant, CCant E+zn\v  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant :$aW@?zAY  
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    '************************************************************************* |sa7Y_  
    'Radius and conic constant of posterior lens HW726K*
 
    '************************************************************************* PEEY;x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) AFTed?(  
    GetConic eID, entity, curv, conic >` QX xTn  
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    SetConic eID, entity, 1/Rpost, CCpost PAV2w_X~  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost r5!M;hU1j  
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    '************************************************************************* B5HdC%8/}  
    'Lens thickness (Position of posterior lens surface) !h>$bm  
    '************************************************************************* 8$UZL  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tcEf ~|3  
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    ' Delete any z-shift(s) ddDJXk)!0  
    count = 0 Az9J{
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    While GetOperationCount(eID)>count ;}~Bv
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        GetOperation eID, count, op OIty ]c  
        If op.Type="ShiftZ" Then 8'"/gC{  
            DeleteOperation eID,count sFCs_u1tNN  
            count=count-1 xKST-:c+  
        End If Uv`v|S:+2  
        count=count+1 {mnSTL`  
    Wend ysJhP .  
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    'Set new z-shift }|"*"kxi!  
    op.Type = "ShiftZ" rqe_zyc&  
    op.val1 = tlens G>S1Ld'MV  
    op.parent = parID |uwteG5?$s  
    AddOperation eID, op n3g WMC  
    Print "Set lens thickness = " & tlens NvHy'
 
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    '************************************************************************* {C0^D*U:  
    'Lens index of refraction u|>U`[Zpj  
    '************************************************************************* ; 9&.QR(  
    eID = FindMaterial( "Lens" ) -sH.yAvC6  
    GetModelMaterial eID, mat 0*
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    mat.Nd = nlens ?Wz(f{Hm  
    SetModelMaterial eID, mat H&=4y) /.  
    Print "Set lens index of refraction = " & nlens `pAp[]SfQd  
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    '************************************************************************* us,,W(q  
    'Pupil diameter %%,hR'+|  
    '************************************************************************* pF*~)e  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \v P2B  
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    'Adjust pupil diameter (trimming volume inner hole)  !QW 0  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }%ZG>LG5J  
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    ' Adjust pupil location to just in front of the lens <_{4-Q>S3#  
    parID = FindFullName( "Geometry.Arizona Eye" ) JvWs/AG1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *ez~~ Y  
    count = 0 M3;v3 }z<-  
    While GetOperationCount(eID)>count l)rvh#D  
        GetOperation eID, count, op q,,>:]f#  
        If op.Type="ShiftZ" Then - Zoo)  
            DeleteOperation eID,count Hs`#{W{.  
            count=count-1 ))69a  
        End If nh&J3b}B!  
        count=count+1 K-Dk2(x  
    Wend CbH T #  
    op.Type = "ShiftZ" %=mwOoMk0L  
    op.val1 = taq-0.01 MV;Y?%>  
    op.parent = parID -G<2R"Q#N  
    AddOperation eID, op sHPwW5j/o'  
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    Print "Set pupil diameter = " & pupilDiam voej ~z+  
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    'Update AZ Eye subassembly Description ;GgQ@s@  
    eID = FindFullName( "Geometry.Arizona Eye" ) Yx}"> ;\  
    GetEntity eID, entity #nf%ojh  
    entity.Description = "Accommodation = " & A & "D" mA] 84zO  
    SetEntity eID, entity >gZk 581/  
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    Update o +QzQ+ Z  
    Print "DONE!" 3VRZM@i  
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End Sub Ibv_D$cT  
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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： C`th^dqBV  
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Accommodation = 4 Diopters b6WC@j`*T  
Pupil Diameter = 4 mm 2c>H(t h=  
Set aqueous humor thickness = 2.81 "U5Ln2X{J
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 0q>NE
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 .t^UK#@#4  
Set lens thickness = 3.927 v1X&p\[d  
Set lens index of refraction = 1.42672 Xx y Bg!R  
Set pupil diameter = 4 fdq^!MWTi  
DONE! hDD~,/yVxs