[分享]Arizona眼睛模型 [复制链接]

简介 d=xU f`^  
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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。 eDX{}Dq(  
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模型 1q}iUnR  
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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。 !RFl
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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. -+Kx^V#'R  
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光源 =>)l6**UE  
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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。 xs.>+(@|;  
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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。 $*H_0wQc  
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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。 h-<('w:A  
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视网膜的散射 PUuxKW}  
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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。 =n cu#T]  
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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。 -iR}kP|  
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脚本 mHM38T9C%
 
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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： Z[)t34EY"  
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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。 %nSm 32/t3  
余下的脚本计算与屈光度有关的所有参数。 S*Qip,u  
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分析 9s>q4_D  
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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。 0BMKwZg  
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脚本代码 "T=Z/@Vy  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. TD'RvTpl  
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Dim entity As T_ENTITY ]>tYU   
Dim op As T_OPERATION uUB,OmLN  
Dim mat As T_MODELMATERIAL 3k.{gAZKh  
Dim A As Double 4/;hA z  
Dim pupilDiam As Double :.e`w#$7  
Dim eID As Long q_bE?j{  
Dim parID As Long 'W(+rTFf!  
Dim count As Integer z#ab V1 Xi  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^I4'7]n-  
Dim tlens As Double, nlens As Double E
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Dim curv As Double, conic As Double 48hu=,)81*  
Dim ok As Long pM],-7UM  
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Sub Main ]-QY, k  
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    '用户输入对话框 b`){f\#t  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #
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        TextBox 220,21,40,21,.TextBox1 'default: 0 S96H`kedZo  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 R4"*<%1  
        OKButton 40,91,90,21 Ydm0  
        CancelButton 190,91,90,21 $&&mGD;?K  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 t2skg
  
        TextBox 220,49,40,21,.TextBox2 'default: 4 i8iv{e2  
    End Dialog )hs"P%Zg  
    Dim dlg As UserDialog K&Ner(/X`6  
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    ok = Dialog (dlg) @ol=gBU  
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    If ok=0 Then    'cancel button was pressed PP)iw@9j  
        Print "Execution cancelled." w^OV;gp  
        End 1N6.r:wg)%  
    End If %IrR+f+H  
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    'Assign accommodation and pupil diameter & use defaults if field left empty wNo2$>*  
    If dlg.TextBox1 = "" Then <Hd8Jd4f  
        A = 0           'Default accommodation c%y(Z5  
    Else H'KCIqo  
        A = CDbl(dlg.TextBox1) j5Kw0Wy7  
    End If `EKmp|B_p_  
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    If dlg.TextBox2 = "" Then KYE)#<V}@  
        pupilDiam = 4   'Default pupil diameter MDV<[${   
    Else EQe!&;   
        pupilDiam = CDbl(dlg.TextBox2) @Wgd(Ezd  
    End If .5L|(B=
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    Print " " ?QA![  
    Print "Accommodation = " & A & " Diopters" .#^ta9^t7  
    Print "Pupil Diameter = " & pupilDiam & " mm" Pq\ `0/4_  
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    ' Calculate new parameters with accommodation NSe Huk  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ot\  FZ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens T_t5Tg~i[N  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens (V&5EO8)  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens =MR.*m{  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens o\/&05rp]  
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    tlens = 3.767 + 0.04*A                  'Lens thickness h/
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _{j'` #  
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    'Adjust parameters to account for accommodation w8=&rzr8  
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    '************************************************************************* x
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    'Aqueous thickness (Position of Lens) 5(wmy-x\  
    '************************************************************************* x[?N[>uw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0gRj3al(  
    GetCustomElement eID, entity l7h6R$7; 0  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 87!D@X
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    ' Delete any shift(s) in z 6=cfr; BH2  
    count = 0 LTZ8Eu  
    While GetOperationCount(eID)>count zH"a>+st=  
        GetOperation eID, count, op su$IXI#R-&  
        If op.Type="ShiftZ" Then u+/Uc:XK)  
            DeleteOperation eID,count 5)5$h]Nz>  
            count=count-1 WCNycH+1  
        End If rn$G.SMgz  
        count=count+1 ]ilQq~X  
    Wend 3Pu8IXW  
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    'Set new shift in C/$bgK[ev  
    op.Type = "ShiftZ" 18^#:
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    op.val1 = taq --fRhN>  
    op.parent = parID SND@#?hiO  
    AddOperation eID, op D`|8Og  
    Print "Set aqueous humor thickness = " & taq-0.55 ^ps6\>=0cW  
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    '************************************************************************* reQr=OAez  
    'Radius and conic constant of anterior lens %p48=|+  
    '************************************************************************* >jU25"XI[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Y/x>wNW  
    GetConic eID, entity, curv, conic @T"-%L8PL  
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    SetConic eID, entity, 1/Rant, CCant `uKsFXM  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant [vGkr" =  
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    '************************************************************************* XF&_**0n  
    'Radius and conic constant of posterior lens eo@kn yA<&  
    '************************************************************************* 4wMZNa<S
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic tk)JE^'  
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    SetConic eID, entity, 1/Rpost, CCpost ,i jB3J  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &SG5f[  
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    '************************************************************************* C'y4 ~7  
    'Lens thickness (Position of posterior lens surface) s=e`}4  
    '************************************************************************* {Gr"lOi*@  

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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +CVB[r#hu  
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    ' Delete any z-shift(s) "{S6iH)]8  
    count = 0 lak,lDt]  
    While GetOperationCount(eID)>count mm9uhlV8  
        GetOperation eID, count, op s{Og3qUy  
        If op.Type="ShiftZ" Then csd9[=HW/Q  
            DeleteOperation eID,count iT;Ld $!{f  
            count=count-1 pO/vD~C>  
        End If 5DpvMhc_  
        count=count+1 }4g$aTc  
    Wend soRYM  
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    'Set new z-shift
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    op.Type = "ShiftZ" Z2L7US-  
    op.val1 = tlens i[?VF\Y(  
    op.parent = parID sf0\#Q  
    AddOperation eID, op ]K3bDU~  
    Print "Set lens thickness = " & tlens 04WxV(fo'  
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    '************************************************************************* (rc7Cp3  
    'Lens index of refraction l^XOW- ;u  
    '************************************************************************* cyLl,OA  
    eID = FindMaterial( "Lens" ) S0Ur{!9\#^  
    GetModelMaterial eID, mat 3-=AmRxW't  
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    mat.Nd = nlens ymp ik.'  
    SetModelMaterial eID, mat [dR#!"6t  
    Print "Set lens index of refraction = " & nlens Y_}_)n
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    '************************************************************************* UT5xUv5'  
    'Pupil diameter 6g\hQ\+Z}  
    '************************************************************************* a)4%sX
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) cV"Ov@_.k  
op@=0d
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    'Adjust pupil diameter (trimming volume inner hole) qw*) R#=  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _R(
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    ' Adjust pupil location to just in front of the lens `rXb:P7m{j  
    parID = FindFullName( "Geometry.Arizona Eye" ) Zb&pH~ 7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ?(Ua+*b  
    count = 0 ie11syhV"  
    While GetOperationCount(eID)>count >S-JAPuO  
        GetOperation eID, count, op }VRl L>HAC  
        If op.Type="ShiftZ" Then n=PfV3B  
            DeleteOperation eID,count +0 }_
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            count=count-1 [mv!r-=  
        End If LXWI'nxV  
        count=count+1 '=O1n H<  
    Wend d``wx}#Uk  
    op.Type = "ShiftZ" xFekSH7[F  
    op.val1 = taq-0.01 @)x*62r+
 
    op.parent = parID qe'ssX;  
    AddOperation eID, op ?E_;[(Mcr  
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    Print "Set pupil diameter = " & pupilDiam m[(_
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    'Update AZ Eye subassembly Description z@J>A![m  
    eID = FindFullName( "Geometry.Arizona Eye" ) K@JaN/OM  
    GetEntity eID, entity [KFCc_:  
    entity.Description = "Accommodation = " & A & "D" ByuBZ!m  
    SetEntity eID, entity RJUIB  
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    Update  VM:|I~gJ  
    Print "DONE!" kMK0|+  
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End Sub !yVY[  
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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： Xt
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Accommodation = 4 Diopters Qclq^|O0  
Pupil Diameter = 4 mm %$kd`Rl}  
Set aqueous humor thickness = 2.81 k0O5c[j  
Set anterior lens radius = 10.4 and conic constant = -2.375869 a??8)=0|}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 UlXxG|  
Set lens thickness = 3.927 a$h^<D ^  
Set lens index of refraction = 1.42672 wPm  
Set pupil diameter = 4 SE43C %hv  
DONE! %k32:qe  
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