[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 U66}nN9  
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。 hcJny  
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模型 R)u ${  
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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。
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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. uJ_"g
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光源 M hJ;)(  
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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。 Yv7`5b{N.  
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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。 [R9!Tz  
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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。 .
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视网膜的散射 u*C"d1v=  
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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。 o7#Mr`6H  

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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。 GP._C=]?c  
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脚本 AG==A&d>$  
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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： ;th]/ G  
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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。 <1EmQ)B  
余下的脚本计算与屈光度有关的所有参数。 O&c~7tM%  
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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。 eS{ xma  
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脚本代码 [va7+=[1=  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. .
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Dim entity As T_ENTITY $EuWQq7OI2  
Dim op As T_OPERATION ->S6S_H/+&  
Dim mat As T_MODELMATERIAL ]CIZF,  
Dim A As Double (KDv>@5  
Dim pupilDiam As Double b[I;6HW  
Dim eID As Long -S(_ZbeN  
Dim parID As Long h c9?z}  
Dim count As Integer ,UD,)ZPf[  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i%R2#F7I  
Dim tlens As Double, nlens As Double BkTGH.4G%  
Dim curv As Double, conic As Double "[LSDE"(  
Dim ok As Long  8/|~E  
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Sub Main sa71Vh{  
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    '用户输入对话框 I@f">&^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 u/h!i@_w[  
        TextBox 220,21,40,21,.TextBox1 'default: 0 |F'k5Lh  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 e!5nz_J1}  
        OKButton 40,91,90,21 y&.[Nt '+  
        CancelButton 190,91,90,21 :K)=Hf2y  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `[+nz rLkO  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =lf&mD _/  
    End Dialog |Gw[vY  
    Dim dlg As UserDialog X%1fMC  
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    ok = Dialog (dlg) n+EK}=DK  
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    If ok=0 Then    'cancel button was pressed 3psCV=/z  
        Print "Execution cancelled." <Dr*^GX>?  
        End ;NrkX?Y  
    End If xwH+Q7O&l  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @ P=eu3  
    If dlg.TextBox1 = "" Then T1y,L<7?  
        A = 0           'Default accommodation 'xdM>y#S  
    Else eqSCNYN  
        A = CDbl(dlg.TextBox1) lxRzyx  
    End If GLe(?\Ug=  
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    If dlg.TextBox2 = "" Then qO<'_7TN[  
        pupilDiam = 4   'Default pupil diameter H]. 4~ 8  
    Else !P, 9Sg&5)  
        pupilDiam = CDbl(dlg.TextBox2) UC^Bn1  
    End If -o+_PL $\  
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    Print " " c 25wm\\  
    Print "Accommodation = " & A & " Diopters" yT42u|xZA  
    Print "Pupil Diameter = " & pupilDiam & " mm" $ ;/Ny)"  
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    ' Calculate new parameters with accommodation #;RP ?s  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @NXGVmY1}  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens  ->-  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens hGH{Xp[mW  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens #ZIV>(Q\H  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 1;ulqO  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction P,!k^J3:l  
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    'Adjust parameters to account for accommodation *g5df[  
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    '************************************************************************* V|{ )P@Q  
    'Aqueous thickness (Position of Lens) IPcAE!h6zN  
    '************************************************************************* \PzC:H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `X]-blHo  
    GetCustomElement eID, entity sp[nKo^  
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    parID = FindFullName( "Geometry.Arizona Eye" ) sm}v0V.Js  
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    ' Delete any shift(s) in z MUNeGqv  
    count = 0 )%C482GO-  
    While GetOperationCount(eID)>count DRi!WWivn  
        GetOperation eID, count, op ##

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        If op.Type="ShiftZ" Then tqrvcnQr^  
            DeleteOperation eID,count BoP%f'0N  
            count=count-1 G#Z%jO-XN  
        End If 1
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        count=count+1 6(oGU4  
    Wend f9D7T|J?10  
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    'Set new shift in i,ku91T  
    op.Type = "ShiftZ" 3O
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    op.val1 = taq p7!q#o  
    op.parent = parID QA.B.U7!  
    AddOperation eID, op (H+'sf^h  
    Print "Set aqueous humor thickness = " & taq-0.55 &}w,bG$  
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    '************************************************************************* gSu+]N  
    'Radius and conic constant of anterior lens
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    '************************************************************************* *NDLGdQqz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xVKx#X9yk  
    GetConic eID, entity, curv, conic "S[VtuxPCU  
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    SetConic eID, entity, 1/Rant, CCant %dL|i2+*8  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant a|5GC pp  
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    '************************************************************************* c.&vWmLSGE  
    'Radius and conic constant of posterior lens 8c__ U<  
    '************************************************************************* u|
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3 %dbfT j  
    GetConic eID, entity, curv, conic ClVMZ  
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    SetConic eID, entity, 1/Rpost, CCpost |fTQ\q]W  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &.<{c `-  
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    '************************************************************************* G~4^`[elB  
    'Lens thickness (Position of posterior lens surface) zK:/ 1  
    '************************************************************************* v1 oSf  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) f*5=,$0  
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    ' Delete any z-shift(s) [ Q=)
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    count = 0 <`|}bt  
    While GetOperationCount(eID)>count h{<^?=  
        GetOperation eID, count, op giaO7Qh~  
        If op.Type="ShiftZ" Then W .Hv2r3  
            DeleteOperation eID,count fb`VYD9[^  
            count=count-1 kHz3_B9[  
        End If 2E2J=Do  
        count=count+1 {Fb)Z"8]  
    Wend (: ZOoL  
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    'Set new z-shift (eO0Ic[c  
    op.Type = "ShiftZ" sur2Mw(M"  
    op.val1 = tlens -+Q,xxu  
    op.parent = parID %iD>^Dp  
    AddOperation eID, op &% M^:WT  
    Print "Set lens thickness = " & tlens mL6/NSSz  
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    '************************************************************************* O%c6vp7  
    'Lens index of refraction )\VUAD%~e7  
    '************************************************************************* ]vT  
    eID = FindMaterial( "Lens" ) c}v:X Slh7  
    GetModelMaterial eID, mat uVscF
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    mat.Nd = nlens V!},a@>p  
    SetModelMaterial eID, mat |UR.7rOV  
    Print "Set lens index of refraction = " & nlens Uut,cQ". d  
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    '************************************************************************* YuPgsJ[m  
    'Pupil diameter X% _~9'#%  
    '************************************************************************* tanuP@O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) C7+TnJ  
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    'Adjust pupil diameter (trimming volume inner hole) -BoN}xE4  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" `+zr PpX  
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    ' Adjust pupil location to just in front of the lens B0R[f  
    parID = FindFullName( "Geometry.Arizona Eye" ) &G<ZK9Ot}0  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 9wWjl}%  
    count = 0 k+i}U9c"  
    While GetOperationCount(eID)>count 5@Py`  
        GetOperation eID, count, op {5%<@<?)  
        If op.Type="ShiftZ" Then 8d$~wh  
            DeleteOperation eID,count !%@n067  
            count=count-1 O]2h=M@q.  
        End If ^?J:eB!  
        count=count+1 j6v +S  
    Wend R [uo:.  
    op.Type = "ShiftZ" 1^Caz-  
    op.val1 = taq-0.01 P_ZguNH  
    op.parent = parID Vq<|DM3z<  
    AddOperation eID, op 'Ob5l:  
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    Print "Set pupil diameter = " & pupilDiam qx!IlO  
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    'Update AZ Eye subassembly Description 'GW@P  
    eID = FindFullName( "Geometry.Arizona Eye" ) Hpsg[d)!  
    GetEntity eID, entity TR%?U/_4;r  
    entity.Description = "Accommodation = " & A & "D" #bdJ]v.n  
    SetEntity eID, entity 2G'G45Q  
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    Update \h0e09& I  
    Print "DONE!" ^ul`b  
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End Sub 0cS.|\ZTA  
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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： :YV!;dKJ  
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Accommodation = 4 Diopters d+^4;Hv4  
Pupil Diameter = 4 mm Jp,ohVRNq  
Set aqueous humor thickness = 2.81 igo7F@_,  
Set anterior lens radius = 10.4 and conic constant = -2.375869 I}8F3_b,#  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 !.w S+  
Set lens thickness = 3.927 (ZI&'"H  
Set lens index of refraction = 1.42672 6"=e+V@  
Set pupil diameter = 4 T[;{AXLeI  
DONE! }h]:I'R!  
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