[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 8a9RML}G<  
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。 W<NmsG})_g  
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模型 n>P!u71  
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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。 ^Gq5ig1rxy  
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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. W/r^ugDV  
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光源 b{RqwV5P  
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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。 'S?;J ,/  
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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。 Kd3QqVJBz1  
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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。 ~Fw<eY  
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视网膜的散射 aI(>]sWJ  
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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。 |;u}sX1t9  
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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。 o2=A0ogz?  
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脚本 [$a<b/4  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ['[KR BJL  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 *Oo &}oAj  
余下的脚本计算与屈光度有关的所有参数。 S#8>ZwQ  
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分析 E'c
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ;/LD)$_  
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脚本代码 :\yc*OtX  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. %f&< wC  
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Dim entity As T_ENTITY $h28(K%  
Dim op As T_OPERATION PlCc8Zy  
Dim mat As T_MODELMATERIAL _:J*Cm[q  
Dim A As Double vR>o}%`  
Dim pupilDiam As Double v6uxxsI>Hm  
Dim eID As Long .L;@=Yg)  
Dim parID As Long ;sPzOS9  
Dim count As Integer x&=9P e(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4MW ]EQ-  
Dim tlens As Double, nlens As Double Zk? =  
Dim curv As Double, conic As Double XnU
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Dim ok As Long wW`}VKu  
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Sub Main Hl7:*]l7b  
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    '用户输入对话框 \u{8Bak0  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 YaY8 `M{  
        TextBox 220,21,40,21,.TextBox1 'default: 0 .mxTfP=9  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 @"|i"Hk^  
        OKButton 40,91,90,21 cHD%{xlb  
        CancelButton 190,91,90,21 X-JV'KE}^z  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 K7`YJp`i  
        TextBox 220,49,40,21,.TextBox2 'default: 4 .36^[Jsz":  
    End Dialog 9=+-QdX+0]  
    Dim dlg As UserDialog rwqv V^  
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    ok = Dialog (dlg) 7#2j>G{?]v  
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    If ok=0 Then    'cancel button was pressed Fu _@!K  
        Print "Execution cancelled." B0)]s<<  
        End g]$ 4~"|.  
    End If Hs?zq  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 'BqZOZw  
    If dlg.TextBox1 = "" Then Y=B3q8l5  
        A = 0           'Default accommodation yA7)Y})>  
    Else <GIwRVCU  
        A = CDbl(dlg.TextBox1) s& yk  
    End If GJQc!cqk  
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    If dlg.TextBox2 = "" Then ,M6ZZ* ,e  
        pupilDiam = 4   'Default pupil diameter ($!KzxF3  
    Else ]/dVRkZeAE  
        pupilDiam = CDbl(dlg.TextBox2) Ruaur]  
    End If sbsu(Sz+  
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    Print " " pSAR/':eg  
    Print "Accommodation = " & A & " Diopters" 8X7{vN_3K  
    Print "Pupil Diameter = " & pupilDiam & " mm" pGWA\}'  
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    ' Calculate new parameters with accommodation r
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness pP/@  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `T WN^0!]  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens t#b0H)  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens UuJjO^t  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens RA1yr+)  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -l*g~7|j  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ;Ss$2V'a  
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    'Adjust parameters to account for accommodation 'Cg{_z.~c  
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    '************************************************************************* _PXdzeI.  
    'Aqueous thickness (Position of Lens) dbF M,"^  
    '************************************************************************* l},NcPL`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {]/8skov5]  
    GetCustomElement eID, entity ;5S}~+j  
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    parID = FindFullName( "Geometry.Arizona Eye" ) d>i13dAI  
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    ' Delete any shift(s) in z Jh@_9/?  
    count = 0 q~Jq/E"f  
    While GetOperationCount(eID)>count Dz&+PES_k  
        GetOperation eID, count, op Fwfo2  
        If op.Type="ShiftZ" Then 9O98Q6-s  
            DeleteOperation eID,count M7dU@Ag  
            count=count-1 3#GqmhqKDk  
        End If isK;mU?<  
        count=count+1 P%>?[9!Nt  
    Wend XW~bu2%{7"  
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    'Set new shift in (4+1lOd  
    op.Type = "ShiftZ" }C#3O{5  
    op.val1 = taq i$Z
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    op.parent = parID ygViPz<J  
    AddOperation eID, op VXKT\9g3A  
    Print "Set aqueous humor thickness = " & taq-0.55 b:MG@Hxc  
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    '************************************************************************* &O1v,$}'  
    'Radius and conic constant of anterior lens Y E1Hpeb  
    '************************************************************************* 284zmZZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +=fKT,-*G!  
    GetConic eID, entity, curv, conic ?d-70pm  
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    SetConic eID, entity, 1/Rant, CCant WH$HI/%*m  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .iv3q?8.b  
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    '************************************************************************* U[8{_h<#  
    'Radius and conic constant of posterior lens ZF{~ih*^u  
    '************************************************************************* lOerrP6f(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) v'ay.oVzw  
    GetConic eID, entity, curv, conic wK*PD&nN  
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    SetConic eID, entity, 1/Rpost, CCpost b|?;h21rG  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #Z9L_gDp  
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    '************************************************************************* Spj9H?m  
    'Lens thickness (Position of posterior lens surface) la, h  
    '************************************************************************* U{#xW  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }~I|t!GL  
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    ' Delete any z-shift(s) BQ
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    count = 0 ~j&?/{7I  
    While GetOperationCount(eID)>count DeQDH5X"  
        GetOperation eID, count, op %$9bce-fcG  
        If op.Type="ShiftZ" Then w|Q
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            DeleteOperation eID,count _z"o1`{w  
            count=count-1 -!dQ)UEP  
        End If &]NZvqdj.]  
        count=count+1 uxDLDA$;  
    Wend HeS'~Z$  
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    'Set new z-shift \E hr@g  
    op.Type = "ShiftZ" =AkX4k  
    op.val1 = tlens kk_zVrQ<  
    op.parent = parID 5gK~('9'?1  
    AddOperation eID, op 2d&^Sp&11  
    Print "Set lens thickness = " & tlens ?r3e*qJGn  
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    '************************************************************************* ^H=o3#P~L  
    'Lens index of refraction UR:n5V4  
    '************************************************************************* s]x2DH+_  
    eID = FindMaterial( "Lens" ) +by|  
    GetModelMaterial eID, mat ;=p;v .l  
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    mat.Nd = nlens i+ic23$4M  
    SetModelMaterial eID, mat 78w4IICk  
    Print "Set lens index of refraction = " & nlens ~@fanR =  
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    '************************************************************************* 7}07Pit  
    'Pupil diameter 7'UWRRsxUF  
    '************************************************************************* ?h&l tD  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Wa/geQE1<  
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    'Adjust pupil diameter (trimming volume inner hole) !Bncx`pl  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Esa6hU#  
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    ' Adjust pupil location to just in front of the lens f>4+,@G  
    parID = FindFullName( "Geometry.Arizona Eye" ) 't ;/,+:V  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) WiwwCKjSa  
    count = 0 NIL^UN}  
    While GetOperationCount(eID)>count pfNThMf  
        GetOperation eID, count, op #nDL  
        If op.Type="ShiftZ" Then 98ayA$  
            DeleteOperation eID,count KZ @l/s  
            count=count-1 -%N}A3m!5  
        End If '[xut1{  
        count=count+1 9Mut p4#  
    Wend 9XY|V<}  
    op.Type = "ShiftZ" [L)V(o)v  
    op.val1 = taq-0.01 0=gF6U  
    op.parent = parID -MsuBf  
    AddOperation eID, op 81cv:|"  
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    Print "Set pupil diameter = " & pupilDiam R+x%r&L5F  
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    'Update AZ Eye subassembly Description 0sY#MHPT&  
    eID = FindFullName( "Geometry.Arizona Eye" ) Mof)2Hbd:  
    GetEntity eID, entity t2m
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    entity.Description = "Accommodation = " & A & "D" wsna5D6i  
    SetEntity eID, entity 5auL<Pq  

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    Update =+k&&vOAn  
    Print "DONE!" E^'C"6  
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End Sub 18J.vcP  
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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_|M&lR>  
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Accommodation = 4 Diopters av7q>NEZ!1  
Pupil Diameter = 4 mm l6yB_M
  
Set aqueous humor thickness = 2.81 ?%_]rr9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gE-lM/w  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 $Cut  
Set lens thickness = 3.927 xu0;a  
Set lens index of refraction = 1.42672 s}z(|IrH  
Set pupil diameter = 4 (0O`A~M3  
DONE! #wq
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