[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 }U^9(  
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。 `Z@wWs  
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模型 >_F&oA#  
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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。 P@5^`b|  
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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. } KMdfA  
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光源 uq 6T|Zm  
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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。 4h~Oj y16&  
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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。 6&u,.
 
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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。 r?[mn^Bo5  
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视网膜的散射 NA3yd^sr  
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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。 gai?LXM l}  
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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。 6Nl$&jL  
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脚本 .i. |wY  
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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：
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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。 T.|0;Eb  
余下的脚本计算与屈光度有关的所有参数。 H?~u%b@   
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分析 ~/#?OLj(T  
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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。 JA)gM  

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脚本代码 *K98z ?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. FQ87[| S  
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Dim entity As T_ENTITY ~XxD[T5  
Dim op As T_OPERATION 6d.m@T6~  
Dim mat As T_MODELMATERIAL /Z
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Dim A As Double :E^B~ OuL  
Dim pupilDiam As Double .ClCP?HG  
Dim eID As Long (Q4_3<G+  
Dim parID As Long p/5!a~1'xN  
Dim count As Integer B>]5/!_4  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double QbNv+Eu5  
Dim tlens As Double, nlens As Double e7?W VV,  
Dim curv As Double, conic As Double jK=*~I  
Dim ok As Long =ddx/zN  
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Sub Main %1<p1u'r?#  
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    '用户输入对话框 87Uv+((H  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .;F+ QP0  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \I'Zc]  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X@Bpjg  
        OKButton 40,91,90,21 7E5Dz7  
        CancelButton 190,91,90,21 ~pA;j7*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %<"11;0tp  
        TextBox 220,49,40,21,.TextBox2 'default: 4 6^aYW#O<Ua  
    End Dialog {x4[Bx1  
    Dim dlg As UserDialog ^VIUXa  
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    ok = Dialog (dlg) P3yiJ|vP  
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    If ok=0 Then    'cancel button was pressed ygW@[^g  
        Print "Execution cancelled." PHK#b.B>a8  
        End .apX72's,  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty KVcZ@0[S  
    If dlg.TextBox1 = "" Then 0V#t ;`Q3  
        A = 0           'Default accommodation h]MVFn{  
    Else
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        A = CDbl(dlg.TextBox1) ?|7+cz$g  
    End If :I'Ezxv|  
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    If dlg.TextBox2 = "" Then XH *tChf<  
        pupilDiam = 4   'Default pupil diameter Yq?I>  
    Else by U\I5  
        pupilDiam = CDbl(dlg.TextBox2) UjDF  
    End If 5An0DV5  
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    Print " " ; BZM~'  
    Print "Accommodation = " & A & " Diopters" L
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    Print "Pupil Diameter = " & pupilDiam & " mm" Tb={g;0@  
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    ' Calculate new parameters with accommodation %7evPiNB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h*KHEg"+  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens JZ%F  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |3,V%>z  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U+"=  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4LEE /  
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    tlens = 3.767 + 0.04*A                  'Lens thickness YU=ZZEVi  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction M#cr*%  
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    'Adjust parameters to account for accommodation <gdgcvd  
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    '************************************************************************* n6-Ic',;  
    'Aqueous thickness (Position of Lens) ' f$L  
    '************************************************************************* "x;k'{S  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) L{LU
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    GetCustomElement eID, entity ~J-|,ZMd  
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    parID = FindFullName( "Geometry.Arizona Eye" ) }#G"!/ZA0:  
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    ' Delete any shift(s) in z uT}TSwgp  
    count = 0 T#n1@FgC  
    While GetOperationCount(eID)>count vif8{S  
        GetOperation eID, count, op kr(<Y|  
        If op.Type="ShiftZ" Then OJsd[l3xR  
            DeleteOperation eID,count PGPbpl&\t  
            count=count-1 `f+8WPJPZ  
        End If n<:d%&^n  
        count=count+1 Px#QZZ  
    Wend Yb
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    'Set new shift in EotwUT|  
    op.Type = "ShiftZ" @ 9 {%Kn  
    op.val1 = taq {?/8jCVd  
    op.parent = parID ~$4.Mf,u  
    AddOperation eID, op akhL\-d)al  
    Print "Set aqueous humor thickness = " & taq-0.55 zZ9<4"CIk  
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    '************************************************************************* So=nB} b[?  
    'Radius and conic constant of anterior lens lW$&fuDHF  
    '************************************************************************* d{yIy'+0/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) FGwnESCC  
    GetConic eID, entity, curv, conic #<wpSs  
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    SetConic eID, entity, 1/Rant, CCant N<06sRg#  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant '}Wu3X  
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    '************************************************************************* *NW QmC~  
    'Radius and conic constant of posterior lens ^.#X<8hr  
    '************************************************************************* @?Gw|bP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) OwA~(  
    GetConic eID, entity, curv, conic vK6ibl0  
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    SetConic eID, entity, 1/Rpost, CCpost bEBBwv  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *IWFeu
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    '************************************************************************* [v0ri<sm  
    'Lens thickness (Position of posterior lens surface) 1BMB?I  
    '************************************************************************* PZuq'^p  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) G
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    ' Delete any z-shift(s) F#1 Kk#t  
    count = 0 dK}WM46$  
    While GetOperationCount(eID)>count Pr5g6I'G   
        GetOperation eID, count, op Q1`<fD  
        If op.Type="ShiftZ" Then .?rbny  
            DeleteOperation eID,count 2.LJp}>  
            count=count-1 ]<kupaRQ  
        End If  [eNkU">}  
        count=count+1 nn
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    Wend b96t0w!cs  
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    'Set new z-shift +M'aWlPg,  
    op.Type = "ShiftZ" 5: daa  
    op.val1 = tlens R:'Ou:Mh  
    op.parent = parID +@emX$cFV  
    AddOperation eID, op 'tb(J3ZP  
    Print "Set lens thickness = " & tlens 6<x~Mk'u)  
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    '************************************************************************* *Y85DEA  
    'Lens index of refraction >4n+PXRXX  
    '************************************************************************* iq"ob8.  
    eID = FindMaterial( "Lens" ) #l*a~^dhqC  
    GetModelMaterial eID, mat .
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    mat.Nd = nlens 4q>7OB:e  
    SetModelMaterial eID, mat {=UFk-$=  
    Print "Set lens index of refraction = " & nlens fdlvn*H  
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    '************************************************************************* +|y*
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    'Pupil diameter #D+7TWDwNt  
    '************************************************************************* 0A;"V'i  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) AV40:y\RW  
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    'Adjust pupil diameter (trimming volume inner hole) 'X =p7 d|'  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {5^K Xj$B  
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    ' Adjust pupil location to just in front of the lens !FTNmyM~F  
    parID = FindFullName( "Geometry.Arizona Eye" ) *GQDfs`m  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .VT;H1#  
    count = 0 +R-h ,$\=7  
    While GetOperationCount(eID)>count u!Xb?:3uj  
        GetOperation eID, count, op ~C&*.ZR  
        If op.Type="ShiftZ" Then aaDP9FW9e  
            DeleteOperation eID,count '|A|vCRCG  
            count=count-1 Hd9XfU  
        End If ^ eQFg>  
        count=count+1 f-;$0mTQ  
    Wend I>PZYh'.T  
    op.Type = "ShiftZ" TZ[Zm  
    op.val1 = taq-0.01 1y J5l,q  
    op.parent = parID LL&ud_Y  
    AddOperation eID, op Cyq?5\a  
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    Print "Set pupil diameter = " & pupilDiam y$X(S\W
 
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    'Update AZ Eye subassembly Description .evbE O5  
    eID = FindFullName( "Geometry.Arizona Eye" ) ,P{mk%=9  
    GetEntity eID, entity :.kZR;  
    entity.Description = "Accommodation = " & A & "D" j^flwk  
    SetEntity eID, entity E<>*(x/\e  
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    Update 62)d22  
    Print "DONE!" E@-ta):  
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End Sub Z(j{F<\jS  
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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： +TK3{5`!Ae  
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Accommodation = 4 Diopters a5@z:i  
Pupil Diameter = 4 mm F]UQuOR)  
Set aqueous humor thickness = 2.81 3iRA$C-p  
Set anterior lens radius = 10.4 and conic constant = -2.375869 As~(7?]r  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +Y}V3(w9X  
Set lens thickness = 3.927 ;}qhc l+  
Set lens index of refraction = 1.42672 +k.%PO0np  
Set pupil diameter = 4 :4:N f  
DONE! ?+~cA^-3T  
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