[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 6E^m*la%  
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。 RI'}C`%v  
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模型 c<q33dZ!*  
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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。 $5ea[nc  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. OP(om$xm  
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光源 ;O>zA]Z8r  
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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。 9^sz,auB  
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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。 S{XO3  
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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。 USgO`l\}4  
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视网膜的散射 {P?p*2J'  
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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。 X+\=dhn69  
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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。 HD$r<bl  
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脚本 $Vs5d=
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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： ~2Mcw`<  
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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。 SrWmV@"y  
余下的脚本计算与屈光度有关的所有参数。 1X&scVw  
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分析 {oo(HD;5  
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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。 KAy uv  
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脚本代码 @, z4{B  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. L_zB/(h  
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Dim entity As T_ENTITY gHvkr?Cg  
Dim op As T_OPERATION {4R;C~E8  
Dim mat As T_MODELMATERIAL 2F,?}jJ.K  
Dim A As Double Es:oXA  
Dim pupilDiam As Double y.Yni*xt/  
Dim eID As Long RDqQ6(e"  
Dim parID As Long 90Z4saSUw  
Dim count As Integer $4CsiZ6  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5.Nc6$ N  
Dim tlens As Double, nlens As Double 2Nx#:Rz  
Dim curv As Double, conic As Double F B&l|#e  
Dim ok As Long "? 5@j/ e`  
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Sub Main {`% q0Nr  
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    '用户输入对话框 0o?2Sf`L\*  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >$A,B  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9aKCO4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 "SwM%j  
        OKButton 40,91,90,21 TGG-rA6@Lx  
        CancelButton 190,91,90,21 Ymcc|u6$"  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m&6I@S2  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +oa>k 0  
    End Dialog }~NWOJ3;  
    Dim dlg As UserDialog kkV*
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    ok = Dialog (dlg) J#k.!]r,Y  
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    If ok=0 Then    'cancel button was pressed G]>P!]  
        Print "Execution cancelled." ]K>x:vMKH  
        End j2!^iGS}  
    End If PKNpR  
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    'Assign accommodation and pupil diameter & use defaults if field left empty sCRmLUD  
    If dlg.TextBox1 = "" Then 9Or  
        A = 0           'Default accommodation :P\RiaZAT  
    Else P
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        A = CDbl(dlg.TextBox1) C@FX[:l@-  
    End If rt!Uix&  
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    If dlg.TextBox2 = "" Then v>p~y u+G  
        pupilDiam = 4   'Default pupil diameter O(44Dy@2  
    Else pS<j>y  
        pupilDiam = CDbl(dlg.TextBox2) ]`n6H[6O  
    End If 'uV;)~  
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    Print " " 0%hOB:  
    Print "Accommodation = " & A & " Diopters" bp(X\:zAy  
    Print "Pupil Diameter = " & pupilDiam & " mm" [=KA
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    ' Calculate new parameters with accommodation ;1woTAuD  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness VZ$FTM^b8  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ]^@!ID$c  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens oSqkAAGz\  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |R$/oq  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens o;Ma)/P  
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    tlens = 3.767 + 0.04*A                  'Lens thickness q6 Rr?  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Snf1vH  
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    'Adjust parameters to account for accommodation +zLh<q0  
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    '************************************************************************* OQm-BL  
    'Aqueous thickness (Position of Lens) (
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    '************************************************************************* ZQPv@6+oY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" )  } h0 )  
    GetCustomElement eID, entity ")ZsY9-P  
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    parID = FindFullName( "Geometry.Arizona Eye" ) jZvQMW  
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    ' Delete any shift(s) in z %?[H=v(b  
    count = 0 x_TtS|  
    While GetOperationCount(eID)>count L[FNr&  
        GetOperation eID, count, op kdHP v=/U  
        If op.Type="ShiftZ" Then (VzabO  
            DeleteOperation eID,count g<r'f"^  
            count=count-1 92HxZ*t7km  
        End If _~b$6Nf!83  
        count=count+1 ;/phZ$l  
    Wend `CXAE0Fx  
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    'Set new shift in :. ja~Q  
    op.Type = "ShiftZ" ]B"YW_.x2  
    op.val1 = taq
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    op.parent = parID 4uG:*0{Yx  
    AddOperation eID, op J3B
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    Print "Set aqueous humor thickness = " & taq-0.55 !(EJ.|LH  
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    '************************************************************************* (X"WEp^Q{I  
    'Radius and conic constant of anterior lens L3g}Z1<!$  
    '************************************************************************* L:g!f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _jW}p-j  
    GetConic eID, entity, curv, conic ch%-Cg~%  
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    SetConic eID, entity, 1/Rant, CCant s
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 1$g]&'  
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    '************************************************************************* ['S
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    'Radius and conic constant of posterior lens phA^ kdW  
    '************************************************************************* 'y?(s+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) u~9gR@e2{  
    GetConic eID, entity, curv, conic /J"U`/ {4  
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    SetConic eID, entity, 1/Rpost, CCpost /Af:{|'$%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost )"IBw0]  

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    '************************************************************************* :/kz*X=<  
    'Lens thickness (Position of posterior lens surface) IwHYuOED]  
    '************************************************************************* 3UBg"1IC  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tC=`J%Ik  
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    ' Delete any z-shift(s) }!-K)j.  
    count = 0 :Sx!jx>W  
    While GetOperationCount(eID)>count 5mD]uB9  
        GetOperation eID, count, op OI9V'W$  
        If op.Type="ShiftZ" Then D4x~Vk%H  
            DeleteOperation eID,count xsq+RBJi  
            count=count-1 os]P6TFFX?  
        End If 0!c
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        count=count+1 6Y|jK<n?H  
    Wend y/ #{pyJ  
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    'Set new z-shift RQZ|:SvV  
    op.Type = "ShiftZ" mE"?{~XVL  
    op.val1 = tlens ?=%Q$|]-  
    op.parent = parID Q-X<zn  
    AddOperation eID, op \B'rWk33,  
    Print "Set lens thickness = " & tlens ]Y'oxh  
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    '************************************************************************* ptS1
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    'Lens index of refraction  6[<*C?  
    '************************************************************************* BTwLx-p9t  
    eID = FindMaterial( "Lens" )
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    GetModelMaterial eID, mat Ri@`sc{n  
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    mat.Nd = nlens '[ZRWwhr  
    SetModelMaterial eID, mat yB&+2  
    Print "Set lens index of refraction = " & nlens ic}M)S FD;  
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    '************************************************************************* @iZ"I i&+  
    'Pupil diameter GT[,[l  
    '************************************************************************* %=:*yf>}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8:%=@p>$  
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    'Adjust pupil diameter (trimming volume inner hole) +X4O.6Mn  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >9o(84AxIH  
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    ' Adjust pupil location to just in front of the lens "#4p#dM0e  
    parID = FindFullName( "Geometry.Arizona Eye" ) un4q,Ac~0  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e>-a\g  
    count = 0 D@V1}/$UoN  
    While GetOperationCount(eID)>count etX&o5A  
        GetOperation eID, count, op =(f+geA"hm  
        If op.Type="ShiftZ" Then [TAW68f'  
            DeleteOperation eID,count 8*nl Wl9qo  
            count=count-1 =v4;t'_^  
        End If Z&hzsJK{m$  
        count=count+1 lF]cUp#<  
    Wend y9?~^pTx  
    op.Type = "ShiftZ" 3Zm'09A-.  
    op.val1 = taq-0.01 x&6SjlDb$K  
    op.parent = parID lMu}|d  
    AddOperation eID, op gO*:<B g  
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    Print "Set pupil diameter = " & pupilDiam |sN>/89=/  
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    'Update AZ Eye subassembly Description 1]HEwTT/1_  
    eID = FindFullName( "Geometry.Arizona Eye" ) 2\flTO2Ny  
    GetEntity eID, entity  >:whNp  
    entity.Description = "Accommodation = " & A & "D" Yx21~:9}  
    SetEntity eID, entity ""[(e0oA  
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    Update ;-=Q6Ms8  
    Print "DONE!" O2|[g8(_F  
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End Sub {*VCR  
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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： sd;J(<Ofh  
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Accommodation = 4 Diopters >uS?Nz5/  
Pupil Diameter = 4 mm L&wJ-}'l  
Set aqueous humor thickness = 2.81
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Set anterior lens radius = 10.4 and conic constant = -2.375869 I#0WN  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 hlPZTr=a  
Set lens thickness = 3.927 ].f28bY  
Set lens index of refraction = 1.42672 usb.cE3z  
Set pupil diameter = 4 ;[*jLi,uc  
DONE! jd9GueV*(  
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