[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 maUHjI 5A-  
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。 f@Rpb}zg+C  
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模型 hf+/kc!>i  
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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。 |8qK%n f}  
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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. X]pWvQ Q]  
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光源 A6UdWK  
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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。 7hN6IP*so  
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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。 $dZ>bXUw:  
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视网膜的散射 eN|HJ=  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 9!xD~(Kr  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 +\k9w.[:/  
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脚本 RQo$iISwy  
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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： l~fh_IV1  
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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。 $#G6m`V  
余下的脚本计算与屈光度有关的所有参数。 Q3BLL`W~  
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分析 ?z5ne??  
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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。 $^vp'^uW>  
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脚本代码 L,b|Iq  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. nszpG1U:  
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Dim entity As T_ENTITY ~']&.  
Dim op As T_OPERATION Y)Znb;`?a  
Dim mat As T_MODELMATERIAL f.b8ZBNj>  
Dim A As Double hF7V !*5  
Dim pupilDiam As Double #$rf-E5g-K  
Dim eID As Long %;pD8WgJA  
Dim parID As Long j<l#qho{h  
Dim count As Integer ->&BcPLn  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Xzx[C_G  
Dim tlens As Double, nlens As Double Yl)eh(\&J  
Dim curv As Double, conic As Double TnN^2:cU  
Dim ok As Long (j8GiJ]{L,  
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Sub Main ~a'nHy1  
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    '用户输入对话框 %`bs<ZWT  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dzIBdth  
        TextBox 220,21,40,21,.TextBox1 'default: 0 bSIY|/d+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 %1{S{FB  
        OKButton 40,91,90,21 lz`\Q6rZ  
        CancelButton 190,91,90,21 Aa9l-:R  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 E/H9
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        TextBox 220,49,40,21,.TextBox2 'default: 4 ()|e xWW  
    End Dialog pss')YP.  
    Dim dlg As UserDialog Xn"#Zy_  
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    ok = Dialog (dlg) S_sHwObFu|  
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    If ok=0 Then    'cancel button was pressed
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        Print "Execution cancelled." J)g +I  
        End #`@)lU+/  
    End If _Q #[IH9  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @w33u^  
    If dlg.TextBox1 = "" Then t,Tq3zB  
        A = 0           'Default accommodation /\fR6|tJ  
    Else M7qg\1L  
        A = CDbl(dlg.TextBox1) d1yLDj?  
    End If -.)f~#8  
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    If dlg.TextBox2 = "" Then "X<V>q$0~c  
        pupilDiam = 4   'Default pupil diameter T pCXe\W  
    Else g1XpERsSEV  
        pupilDiam = CDbl(dlg.TextBox2) FpB3SJ6 B  
    End If qW3XA$g|j'  
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    Print " " 9|jMN j]vo  
    Print "Accommodation = " & A & " Diopters" 6oWFjeZ0  
    Print "Pupil Diameter = " & pupilDiam & " mm" A/zAB3  
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    ' Calculate new parameters with accommodation *k\;G?  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {dh@|BzsbH  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ybf,pDY#f  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [g==#[  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens D!,'}G#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens :S`12*_g"  
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    tlens = 3.767 + 0.04*A                  'Lens thickness >xRUw5jN  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction r{*Qsaw  
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    'Adjust parameters to account for accommodation {#t7lV'4  
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    '************************************************************************* 3W[||V[r]<  
    'Aqueous thickness (Position of Lens) s_Z5M2o  
    '************************************************************************* n1x3q/~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;<MHl[jJD  
    GetCustomElement eID, entity OZKZv,  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ra ,.vJuT  
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    ' Delete any shift(s) in z [IyC}lSW^-  
    count = 0 %U[H`E  
    While GetOperationCount(eID)>count k/Urz*O  
        GetOperation eID, count, op OgK' ~j  
        If op.Type="ShiftZ" Then TCgW^iu  
            DeleteOperation eID,count XB[EJGaX  
            count=count-1 #T>pu/EQX_  
        End If `OZiN;*|  
        count=count+1 -Zg.o$  
    Wend J6 A3Hrg  
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    'Set new shift in /+<G@+(  
    op.Type = "ShiftZ" #|V)>")  
    op.val1 = taq B90fUK2g  
    op.parent = parID x=W5e ^0?  
    AddOperation eID, op -LFk7a  
    Print "Set aqueous humor thickness = " & taq-0.55 |*~SR.[`  
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    '************************************************************************* *mw *z|-^V  
    'Radius and conic constant of anterior lens Lq#!}QcW=  
    '************************************************************************* LCSJIt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M>*xbBl  
    GetConic eID, entity, curv, conic fndH]Yp  
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    SetConic eID, entity, 1/Rant, CCant *]Eyf")  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7 $dibTER  
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    '************************************************************************* .|:R#VW  
    'Radius and conic constant of posterior lens 8y4t9V  
    '************************************************************************* "`KT7  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $GD Q1&Z  
    GetConic eID, entity, curv, conic ]~pM;6Pu0  
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    SetConic eID, entity, 1/Rpost, CCpost iML?`%/vN  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 94lz?-j  
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    '************************************************************************* K:$GmV9o  
    'Lens thickness (Position of posterior lens surface) AgOti]`aR  
    '************************************************************************* FW4#/H  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1,n\Osd  
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    ' Delete any z-shift(s) ;IT'6m`@W  
    count = 0 z|<?=c2P  
    While GetOperationCount(eID)>count !#4b#l(e6  
        GetOperation eID, count, op Tog'3k9Uw  
        If op.Type="ShiftZ" Then 2FM}"g<8  
            DeleteOperation eID,count m>DJ w7<  
            count=count-1 k7nke^,|  
        End If g T0@pxl  
        count=count+1 ^HWa owy=  
    Wend LP>GM=S#"  

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    'Set new z-shift ;(Z9.  
    op.Type = "ShiftZ" :TP\pH7E  
    op.val1 = tlens QOv@rP
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    op.parent = parID G4EuW *~
 
    AddOperation eID, op #a 4X*X.8c  
    Print "Set lens thickness = " & tlens ^5R2~  
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    '************************************************************************* MVDy|i4  
    'Lens index of refraction .bNG:y
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    '************************************************************************* N1JM[<PP  
    eID = FindMaterial( "Lens" ) qKI)*o062  
    GetModelMaterial eID, mat gAK"ShOhG=  
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    mat.Nd = nlens (J.U{N v  
    SetModelMaterial eID, mat *$Z?Owl7  
    Print "Set lens index of refraction = " & nlens L1MG("R  
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    '************************************************************************* 6&"GTK  
    'Pupil diameter 55zy]|F"  
    '************************************************************************* N@I=X-7nh|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) V17!~  
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    'Adjust pupil diameter (trimming volume inner hole) Eo0/cln|  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [`!%u3  
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    ' Adjust pupil location to just in front of the lens 8Q73h/3  
    parID = FindFullName( "Geometry.Arizona Eye" ) Fzy5k?R  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4i+H(d n  
    count = 0 rw[Ioyr-  
    While GetOperationCount(eID)>count 9D7i>e%,;-  
        GetOperation eID, count, op C~04#z_$  
        If op.Type="ShiftZ" Then sY&Z/Y  
            DeleteOperation eID,count G|z%T`!U1;  
            count=count-1 a2eE!I  
        End If nPUD6<bF  
        count=count+1 *eMMfxFl  
    Wend @el  
    op.Type = "ShiftZ" ]&X}C{v)G  
    op.val1 = taq-0.01 y N,grU(  
    op.parent = parID #GzowI'  
    AddOperation eID, op \%&eDE0  
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    Print "Set pupil diameter = " & pupilDiam !1/F71l DX  
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    'Update AZ Eye subassembly Description wJh/tb=$o  
    eID = FindFullName( "Geometry.Arizona Eye" ) k +Cwnp  
    GetEntity eID, entity _Sl3)  
    entity.Description = "Accommodation = " & A & "D" TrBW0Bn>p  
    SetEntity eID, entity sGc.;":  
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    Update "NTiQ}i  
    Print "DONE!" (
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End Sub 9T0g%&  
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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： h=B= J  
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Accommodation = 4 Diopters ]`M2Kwp  
Pupil Diameter = 4 mm Q"H/RMo-  
Set aqueous humor thickness = 2.81 <6X*k{  
Set anterior lens radius = 10.4 and conic constant = -2.375869 z7TyS.z  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 I moxg+u  
Set lens thickness = 3.927 `4g}(-  
Set lens index of refraction = 1.42672 PlCj<b1D:  
Set pupil diameter = 4 ilAhw4A  
DONE! _tE55X&  
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