[分享]Arizona眼睛模型 [复制链接]

简介 I0=_=aZO(  
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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。 OI R5QH  
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模型 ijI/z5  
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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。 bP,<^zA|X  
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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. `h}eP[jA  
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光源 e_BG%+;G,  
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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。 ^}3^|
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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。 HN47/]"*  
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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。 4.6$m  

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视网膜的散射 T.q2tC[bR  
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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。 KaIKb=4L|  
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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。 &K[*vyD  
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脚本 |9@,ri\'Rg  
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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： _ %s#Cb  

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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。  %zavSm"  
余下的脚本计算与屈光度有关的所有参数。 $+gQnI3w  
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分析 `At.$3B  
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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。 x"r0<RK  
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脚本代码 <y 4(!z"  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. u09Tlqh0 3  
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Dim entity As T_ENTITY zcpL[@B  
Dim op As T_OPERATION , 3R=8  
Dim mat As T_MODELMATERIAL ; :e7Z^\/k  
Dim A As Double wG3L+[,  
Dim pupilDiam As Double E4#{&sRT  
Dim eID As Long aRd~T6I  
Dim parID As Long = XZU9df  
Dim count As Integer gl
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [i.@q}c~E  
Dim tlens As Double, nlens As Double #%,X),%-  
Dim curv As Double, conic As Double 1N5 E  
Dim ok As Long gt4GN`-k  
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Sub Main O[X*F2LC4  
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    '用户输入对话框 ZbRRDXk!  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Za.}bR6?Y  
        TextBox 220,21,40,21,.TextBox1 'default: 0 cIug~ x>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5-dt0I@<  
        OKButton 40,91,90,21 =dm9+ff  
        CancelButton 190,91,90,21 WC_.j^sW  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 pj'gTQ),0  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ]#~J[uk  
    End Dialog /Qgb t  
    Dim dlg As UserDialog 8 Ku9;VEk  
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    ok = Dialog (dlg) cGot0' mB  
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    If ok=0 Then    'cancel button was pressed +U fw  
        Print "Execution cancelled." >=k7#av  
        End Q`CuZkP(  
    End If Vjs2Yenx  
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    'Assign accommodation and pupil diameter & use defaults if field left empty u5CSx'h]  
    If dlg.TextBox1 = "" Then F6{g{ B  
        A = 0           'Default accommodation ;NP-tA)  
    Else <I,4Kc!  
        A = CDbl(dlg.TextBox1) f,YORJ  
    End If LP3#f{U  

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    If dlg.TextBox2 = "" Then 288mP]a(v_  
        pupilDiam = 4   'Default pupil diameter &Vj@){  
    Else CKw-HgXG  
        pupilDiam = CDbl(dlg.TextBox2) 97c0bgI!+  
    End If qw+7.h#V  
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    Print " " W83d$
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    Print "Accommodation = " & A & " Diopters" DLwlA!z  
    Print "Pupil Diameter = " & pupilDiam & " mm" t!D
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    ' Calculate new parameters with accommodation tbQY&TO1  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness GEPWb[Oa  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens F'~r?D  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens kn#?+Q  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens d /jx8(0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?M90K)&g{  
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    tlens = 3.767 + 0.04*A                  'Lens thickness >A
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction zkt~[-jm}  
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    'Adjust parameters to account for accommodation 51:5rN(_  
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    '************************************************************************* $#^3>u  
    'Aqueous thickness (Position of Lens) G-CL \G\n  
    '************************************************************************* .J.}}"+U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) gd[muR ~  
    GetCustomElement eID, entity >$kFYb>~q  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ->#wDL!6  

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    ' Delete any shift(s) in z 'q}Ud10
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    count = 0 yCz"~c  
    While GetOperationCount(eID)>count mI2Gs)SO  
        GetOperation eID, count, op ZW M:Wj192  
        If op.Type="ShiftZ" Then h5{//0 y  
            DeleteOperation eID,count P]"@3Z&w  
            count=count-1 D[W` q#W  
        End If *b;)7lj0h  
        count=count+1 *Y1s4FXu2  
    Wend 2k!uk
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    'Set new shift in C,;?`3bH@  
    op.Type = "ShiftZ" D~inR3(}  
    op.val1 = taq Gb2|e.z  
    op.parent = parID aT/2rMKPF  
    AddOperation eID, op zt2#
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    Print "Set aqueous humor thickness = " & taq-0.55 DN9x<
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    '************************************************************************* @3eMvbI  
    'Radius and conic constant of anterior lens W}F~vx.  
    '************************************************************************* [6@bsXiw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eDo4>k"5  
    GetConic eID, entity, curv, conic *K>2B99TXu  
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    SetConic eID, entity, 1/Rant, CCant bSM|"  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant
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    '************************************************************************* ;8VZsh  
    'Radius and conic constant of posterior lens 7<kr|-  
    '************************************************************************* !}A`6z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) gy1kb,MO  
    GetConic eID, entity, curv, conic 0"-H34M<D  
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    SetConic eID, entity, 1/Rpost, CCpost y;0Zk~R$  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 'bv(T2d~~  
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    '************************************************************************* 'Q'-7z-6  
    'Lens thickness (Position of posterior lens surface) W9Us I  
    '************************************************************************* vU/sQt8  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2AqcabI9  
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    ' Delete any z-shift(s) mGz'%?zj  
    count = 0 WbFCj0  
    While GetOperationCount(eID)>count v&sp;%I6=  
        GetOperation eID, count, op 4&]NC2I  
        If op.Type="ShiftZ" Then YC{7;=Pf  
            DeleteOperation eID,count C _W]3  
            count=count-1 j%vxCs>  
        End If 48gpXc
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        count=count+1 U;4;
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    Wend "{{@N4^  
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    'Set new z-shift _#<l -R`  
    op.Type = "ShiftZ" p<VW;1bt5  
    op.val1 = tlens <!u(_Bxw/  
    op.parent = parID B^1jd!m  
    AddOperation eID, op 8Z@O%\1x6  
    Print "Set lens thickness = " & tlens Rlr[uU_  
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    '************************************************************************* +SRM?av  
    'Lens index of refraction 4
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    '************************************************************************* sx9[#6~{Y  
    eID = FindMaterial( "Lens" ) j

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    GetModelMaterial eID, mat jaTCRn3|<  
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    mat.Nd = nlens OUHd@up@n  
    SetModelMaterial eID, mat  GwD"j]  
    Print "Set lens index of refraction = " & nlens ^w RD|  
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    '************************************************************************* {.,y v>%  
    'Pupil diameter =66,$~g{  
    '************************************************************************* )o_$AbPt  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) piUfvw  
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    'Adjust pupil diameter (trimming volume inner hole) "%t !+E>nr  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Lj3q?>D*^6  
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    ' Adjust pupil location to just in front of the lens :n?}G0y  
    parID = FindFullName( "Geometry.Arizona Eye" ) '$OLU[(
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Y0OVzp9 b  
    count = 0 )ULxB'Dm  
    While GetOperationCount(eID)>count PDh1*bf{u  
        GetOperation eID, count, op PJcz] <  
        If op.Type="ShiftZ" Then rNHV  
            DeleteOperation eID,count 20uR?/|@  
            count=count-1 =>h~<88#5  
        End If @l2AL9z$m>  
        count=count+1 jr5x!@rb  
    Wend =HvLuVc  
    op.Type = "ShiftZ" _bq2h%G=8  
    op.val1 = taq-0.01 @*LESN>T@t  
    op.parent = parID xZ"kJ'C4}  
    AddOperation eID, op Q ?W6  

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    Print "Set pupil diameter = " & pupilDiam ">RDa<H]  
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    'Update AZ Eye subassembly Description D#9W [6  
    eID = FindFullName( "Geometry.Arizona Eye" ) 0g(hY:  
    GetEntity eID, entity 4a~9?}V:  
    entity.Description = "Accommodation = " & A & "D" QPa&kl  
    SetEntity eID, entity 7" cgj#  
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    Update <tTn$<b  
    Print "DONE!" mE]W#?   
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End Sub :
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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： WaWx5Fx+  
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Accommodation = 4 Diopters !$5U\"M  
Pupil Diameter = 4 mm #/1,Cv yj  
Set aqueous humor thickness = 2.81 hpym!G  
Set anterior lens radius = 10.4 and conic constant = -2.375869 SIRZ_lt$r  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 CLD*\)QD\  
Set lens thickness = 3.927 C31SXQ  
Set lens index of refraction = 1.42672 A]vQ1*pnk  
Set pupil diameter = 4 oZ~M`
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DONE! jKu"Vi|j>  
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