[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 =gB{(   
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。 lo>:S1  
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模型 AkqGk5e ^  
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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。 qSVg.<+   
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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. 6Qm .k$[  
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光源 5g4c1K  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 VzFzVeJ  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 inx0W3d"T  
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视网膜的散射 {S5D~A*a+  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 P,Rqv)}X  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 y/A<eHLy  
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脚本 _:;j)J0  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ?"qS%EH  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Hz<)a(r!J  
余下的脚本计算与屈光度有关的所有参数。 nnO@$
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分析 I*)eP||  
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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。 4&LoE~  
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脚本代码 ud.Bzg:/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. #3u471bp  
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Dim entity As T_ENTITY U_,K_6vj  
Dim op As T_OPERATION MtO p][i  
Dim mat As T_MODELMATERIAL '}wYSG-  
Dim A As Double ?|9$o/Q}  
Dim pupilDiam As Double D+
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Dim eID As Long {VE$i2nC8  
Dim parID As Long KBFAV&  
Dim count As Integer %z0@4Gq  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5Gsj;  
Dim tlens As Double, nlens As Double {*CLWs4  
Dim curv As Double, conic As Double 9qQFIw~S  
Dim ok As Long s2ys>2k  
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Sub Main HCifO  
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    '用户输入对话框 D r$N{d  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 pf`li]j'V  
        TextBox 220,21,40,21,.TextBox1 'default: 0 |KC
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G1'w50Yu  
        OKButton 40,91,90,21 r4qFEFV3%  
        CancelButton 190,91,90,21 5+O#5"v_  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 <!|2Ru  
        TextBox 220,49,40,21,.TextBox2 'default: 4 v+=_  
    End Dialog O_PC/=m1@  
    Dim dlg As UserDialog n1W}h@>8  
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    ok = Dialog (dlg) ~+$l9~`{  
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    If ok=0 Then    'cancel button was pressed n%<.,(.(S  
        Print "Execution cancelled." 7_/.a9$G  
        End (Qq$ql27  
    End If #UJ@P Dwil  
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    'Assign accommodation and pupil diameter & use defaults if field left empty BWX&5""  
    If dlg.TextBox1 = "" Then 4p~:(U[q  
        A = 0           'Default accommodation %GS)9{T&  
    Else MU&5&)m  
        A = CDbl(dlg.TextBox1) Ck.GN<#-^P  
    End If Ec6{?\  
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    If dlg.TextBox2 = "" Then Gf'V68,l$  
        pupilDiam = 4   'Default pupil diameter I|O~F e.  
    Else tY:-13
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        pupilDiam = CDbl(dlg.TextBox2) O!]wJ
  
    End If +V8yv-/{  
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    Print " " 3G8uXB_`}  
    Print "Accommodation = " & A & " Diopters" l>&)_:\  
    Print "Pupil Diameter = " & pupilDiam & " mm" oa1a5+A  
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    ' Calculate new parameters with accommodation (lPNMS|V  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness y9)l,@D  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~0 FqY&4  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens $C)@GGY  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0 q3<RX>M%  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {@, L  
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    tlens = 3.767 + 0.04*A                  'Lens thickness kxUGd)S  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction IW BVfN->}  
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    'Adjust parameters to account for accommodation _Wb-&6{  
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    '************************************************************************* Iwn@%?7  
    'Aqueous thickness (Position of Lens) 0`ib_&yI  
    '************************************************************************* aQ~x$T|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) b]g.
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    GetCustomElement eID, entity {G{@bUG]p  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Io"=X!k  
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    ' Delete any shift(s) in z 'FUPv61()  
    count = 0 >I
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    While GetOperationCount(eID)>count ~IWi@m{  
        GetOperation eID, count, op d,)F #;^5  
        If op.Type="ShiftZ" Then g*tLqV  
            DeleteOperation eID,count <zDe;&  
            count=count-1 ca-n:1  
        End If  7:p]~eM)  
        count=count+1 TwhK>HN  
    Wend z vYDE]  
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    'Set new shift in */+s^{W7  
    op.Type = "ShiftZ" e-K8K+7  
    op.val1 = taq {oJa8~P  
    op.parent = parID :<v$vER,&  
    AddOperation eID, op \rN_CBM  
    Print "Set aqueous humor thickness = " & taq-0.55 ) k2NF="o  
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    '************************************************************************* &4%J35~  
    'Radius and conic constant of anterior lens 7lj-Z~1  
    '************************************************************************* GB+d0 S4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6b8Klrar!  
    GetConic eID, entity, curv, conic ^+wz
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    SetConic eID, entity, 1/Rant, CCant ]`kvq0Gyb  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant
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    '************************************************************************* <Ztda !  
    'Radius and conic constant of posterior lens lKD@2  
    '************************************************************************* (hV"z;rI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) v}Nx
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    GetConic eID, entity, curv, conic jlP7'xt1%  
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    SetConic eID, entity, 1/Rpost, CCpost 3"hR:'ts  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost A-u5  
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    '************************************************************************* )/AvWDKvO  
    'Lens thickness (Position of posterior lens surface) BT1'@qF  
    '************************************************************************* Y_B 4s-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,+BgY4OY  
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    ' Delete any z-shift(s) T??aVe]c  
    count = 0 7EO&:b]  
    While GetOperationCount(eID)>count MdjLAD)f+C  
        GetOperation eID, count, op ;X6y.1N~  
        If op.Type="ShiftZ" Then kC5,yj  
            DeleteOperation eID,count .%<&W1  
            count=count-1 9"RfL7{  
        End If )l}wjKfgO  
        count=count+1 u_"h/)C'H  
    Wend I}v#r8'!  
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    'Set new z-shift Kzu9Qm-+z^  
    op.Type = "ShiftZ" B3t>M) 9  
    op.val1 = tlens ?t42=nvf  
    op.parent = parID c):*R ]=  
    AddOperation eID, op @/(7kh+  
    Print "Set lens thickness = " & tlens j1C.#-P[  
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    '************************************************************************* kAliCD)  
    'Lens index of refraction &FVlTo1  
    '************************************************************************* Hu7zmh5
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    eID = FindMaterial( "Lens" ) 4Z<l>!  
    GetModelMaterial eID, mat @<=#i  
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    mat.Nd = nlens {:X];A$  
    SetModelMaterial eID, mat 9y*!W  
    Print "Set lens index of refraction = " & nlens ]r1{%:8  
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    '************************************************************************* O mIBk  
    'Pupil diameter j/pQSlV  
    '************************************************************************* f{c[_OR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Kn$1W=B1.  
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    'Adjust pupil diameter (trimming volume inner hole) aQ:f"0fL  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Hk*cO;c  
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    ' Adjust pupil location to just in front of the lens %,cFX[D/)  
    parID = FindFullName( "Geometry.Arizona Eye" ) Pq>[q?>?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +%\j$Pv  
    count = 0 VFSn!o:C  
    While GetOperationCount(eID)>count 2\\3<  
        GetOperation eID, count, op e=UVsYNx  
        If op.Type="ShiftZ" Then *b{lL5  
            DeleteOperation eID,count ]U1,Nh
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            count=count-1 Q]5^Eiq8  
        End If QU!'W&F6  
        count=count+1 T$8~9qx  
    Wend Z"|P(]A  
    op.Type = "ShiftZ" AE4~M`6D  
    op.val1 = taq-0.01 GR[>mkW!M  
    op.parent = parID
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    AddOperation eID, op N$&ePU J  
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    Print "Set pupil diameter = " & pupilDiam U.7y8#qf3R  
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    'Update AZ Eye subassembly Description ?b7g9 G4  
    eID = FindFullName( "Geometry.Arizona Eye" ) 
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    GetEntity eID, entity UdW(\%  
    entity.Description = "Accommodation = " & A & "D" *m&: Yje  
    SetEntity eID, entity Cm;qDvj+u  
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    Update _<*GU@  
    Print "DONE!" RL Zf{Q>  
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End Sub 1 j^c  
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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： m?VRX.>  
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Accommodation = 4 Diopters a950M7  
Pupil Diameter = 4 mm )Ct*G= N  
Set aqueous humor thickness = 2.81 -?B9>6h"  
Set anterior lens radius = 10.4 and conic constant = -2.375869 42>m,fb2[  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 soq".
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Set lens thickness = 3.927 99Yo1Q0  
Set lens index of refraction = 1.42672 %FyygTb;S  
Set pupil diameter = 4 G(0y|Eq  
DONE! 2vkB<[
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