[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 [B#R94  
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。 -.u]Ge
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模型 s%nUaWp~  
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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。 F4}]b(L  
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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. -Ta9 pxZk  
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光源 5\5/   

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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。 ;c-(ObSm  
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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。 ~?4PBq  
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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。 /YP{,#p  
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视网膜的散射 W>Y@^U&x`  
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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。 Pk{_(ybaY  
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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。 8Wrh]egu1  
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脚本 sT3^hY7  
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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： 4ni<E*  
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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。 /\ y?Y  
余下的脚本计算与屈光度有关的所有参数。 B8.P
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分析 *xx'@e|<;  
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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。 8{wwd:6  
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脚本代码 -[*,^Ti`  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 4x{0iav  
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Dim entity As T_ENTITY yh Yb'GK  
Dim op As T_OPERATION 3QV*%  
Dim mat As T_MODELMATERIAL Jj>?GAir  
Dim A As Double iZ#!O*>  
Dim pupilDiam As Double q!{y&.&\  
Dim eID As Long oibsh(J3  
Dim parID As Long sv: 9clJ  
Dim count As Integer *;l]8.  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (|[2J3ZET  
Dim tlens As Double, nlens As Double 9v;Vv0k_  
Dim curv As Double, conic As Double  ,V,`Jf  
Dim ok As Long 4^p5&5F  
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Sub Main L6t+zIUc-~  
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    '用户输入对话框 nGpXI\K  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {'XggI%  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lW+\j3?Z$  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Pj#<K%Bz  
        OKButton 40,91,90,21 ]mo-rhDsM  
        CancelButton 190,91,90,21 8|):`u  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k52/w)Ro,$  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Qiua  
    End Dialog .R)D3NZp  
    Dim dlg As UserDialog S'|,
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    ok = Dialog (dlg) T m_bz&Q  
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    If ok=0 Then    'cancel button was pressed Q}1 R5@7  
        Print "Execution cancelled." -(~.6WnhS  
        End Vr)<\h  
    End If FK:;e lZ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty O-ew%@_  
    If dlg.TextBox1 = "" Then WB?jRYp  
        A = 0           'Default accommodation NE"@Bk cm  
    Else 98j>1"8  
        A = CDbl(dlg.TextBox1) x^HGVWw_  
    End If 19&<|qTz  
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    If dlg.TextBox2 = "" Then J,V9k[88  
        pupilDiam = 4   'Default pupil diameter A'j;\ `1  
    Else $LKIT0  
        pupilDiam = CDbl(dlg.TextBox2) ~?D4[D|sB  
    End If Te.Y#lCT$  
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    Print " " t`WB;o!  
    Print "Accommodation = " & A & " Diopters" ~c8?>oN(  
    Print "Pupil Diameter = " & pupilDiam & " mm" ;Yx)tWQI  
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    ' Calculate new parameters with accommodation fdxLAC  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &)8:h+&Z  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens u}>#Eb  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o4`hY/<t  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens k>F'ypm  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens E4gYemuN  
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    tlens = 3.767 + 0.04*A                  'Lens thickness VGfMN|h  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction c;%_EN%  
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    'Adjust parameters to account for accommodation kd=GCO  
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    '************************************************************************* x9$` W  
    'Aqueous thickness (Position of Lens) &K[_J  
    '************************************************************************* _9faBrzd  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) R?v>Q` Qi  
    GetCustomElement eID, entity ]Oh@,V8  
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    parID = FindFullName( "Geometry.Arizona Eye" ) {_b%/eR1  
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    ' Delete any shift(s) in z T:t]"d}}  
    count = 0 A3rPt&<a  
    While GetOperationCount(eID)>count g+DzscIT  
        GetOperation eID, count, op F|F]970  
        If op.Type="ShiftZ" Then ~1cnE:x;V  
            DeleteOperation eID,count l=]cy-H  
            count=count-1 WzAb|&?  
        End If `kOD[*  
        count=count+1 lwHzj&/ ~  
    Wend P#pn*L*"T  
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    'Set new shift in |s)Rxq){"V  
    op.Type = "ShiftZ" &/mA7Vf>eR  
    op.val1 = taq vK 7^*qr;j  
    op.parent = parID 1lq(PGX)  
    AddOperation eID, op 4 d;|sI@  
    Print "Set aqueous humor thickness = " & taq-0.55 pM x
 
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    '************************************************************************* &Q+Ln,(&L  
    'Radius and conic constant of anterior lens Ae mDJ8Y  
    '************************************************************************* =3|O%\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M>DaQ`b  
    GetConic eID, entity, curv, conic Z= jr-)kK  
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    SetConic eID, entity, 1/Rant, CCant zEs>b(5u  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant I*LknU@  
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    '************************************************************************* ([ jF4/  
    'Radius and conic constant of posterior lens eL^.,H0  
    '************************************************************************* F_Z- 8>P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) `^bgUmJ~  
    GetConic eID, entity, curv, conic K
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    SetConic eID, entity, 1/Rpost, CCpost 5:O-tgig.  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost RMX:9aQ3F  
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    '************************************************************************* ;epV<{e$q4  
    'Lens thickness (Position of posterior lens surface) 1=#q5dZ]  
    '************************************************************************* cU0s p  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) lCAIK  
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    ' Delete any z-shift(s) *_R]*o!W'  
    count = 0 `jzTm
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    While GetOperationCount(eID)>count I([!]z  
        GetOperation eID, count, op ul
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        If op.Type="ShiftZ" Then ~GTz:nC*  
            DeleteOperation eID,count <.p
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            count=count-1 Wm_4avXtO  
        End If ,z3{u162  
        count=count+1 0|2%vh>J  
    Wend _$= _du  
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    'Set new z-shift 7nHF@Y|*"  
    op.Type = "ShiftZ" *F ?8c  
    op.val1 = tlens M>&%(4K  
    op.parent = parID Atflf2K  
    AddOperation eID, op r)Ap8?
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    Print "Set lens thickness = " & tlens an4GSL  
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    '************************************************************************* t=_J9|  
    'Lens index of refraction 7h6,c/<  
    '************************************************************************* BDVHol*g  
    eID = FindMaterial( "Lens" ) D<8HZ%o  
    GetModelMaterial eID, mat `VKf3&|<A  
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    mat.Nd = nlens ZZcE
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    SetModelMaterial eID, mat &07]LF$]  
    Print "Set lens index of refraction = " & nlens 0GB:GBhZ  
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    '************************************************************************* *GxTX3i}vc  
    'Pupil diameter g0>,%b  
    '************************************************************************* 43={Xy   
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) F;=4vS]\  
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    'Adjust pupil diameter (trimming volume inner hole) 'rMN=1:iu"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" )t$,e2FY  
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    ' Adjust pupil location to just in front of the lens [[>wB[w  
    parID = FindFullName( "Geometry.Arizona Eye" ) *H?!;u=8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) PUo/J~v  
    count = 0 u}!@ ,/)  
    While GetOperationCount(eID)>count xEf'Bmebk  
        GetOperation eID, count, op ##@$|6  
        If op.Type="ShiftZ" Then COTp  
            DeleteOperation eID,count 356>QW'm  
            count=count-1 {Zh>mHW3  
        End If K$M^gh0  
        count=count+1 N@O8\oQG  
    Wend L:_bg8eD#  
    op.Type = "ShiftZ" Bn61AFy`  
    op.val1 = taq-0.01 9uRFnzJVx  
    op.parent = parID PQK(0iCo4  
    AddOperation eID, op .so[I
 
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    Print "Set pupil diameter = " & pupilDiam QmLF[\Oo_  
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    'Update AZ Eye subassembly Description GP&vLt51  
    eID = FindFullName( "Geometry.Arizona Eye" ) r*$Ner  
    GetEntity eID, entity Z^]|o<.<I  
    entity.Description = "Accommodation = " & A & "D" $aN-Y?U%  
    SetEntity eID, entity *uo'VJI7_,  
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    Update g.'yZvaP  
    Print "DONE!" n|b5? 3  
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End Sub 5B&;uY   
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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： Pu"R,a  
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Accommodation = 4 Diopters |1ST=O7.LH  
Pupil Diameter = 4 mm AC;V m: @{  
Set aqueous humor thickness = 2.81 hQ(q
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Set anterior lens radius = 10.4 and conic constant = -2.375869 N\HQN0d9  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 L0&RvI#  
Set lens thickness = 3.927
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Set lens index of refraction = 1.42672 Qb)C[5a}  
Set pupil diameter = 4 FBpH21|/y  
DONE! dn}`i  
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