[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 =aZgq99  
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。 =]jc{Y%o  
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模型 vFm8T58 7  
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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。 *Z'*^Y1le  
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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. ln.'}P  
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光源 "=<T8M  
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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。 oS3'q\  
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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。 _wMxKM  
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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。 N?7MYP
 
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视网膜的散射 A$d)xq-]K  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 -;]m4R)z  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 K9-;-{qb  
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脚本 'k^d-Mh>h  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： _{Z!$q6,  
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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。  9t$#!2z  
余下的脚本计算与屈光度有关的所有参数。 aMv?D(Meb  
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分析 XotiKCk|Aq  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 vbA<=V*P  
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脚本代码 nR%ey"  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. /H (55^EMZ  
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Dim entity As T_ENTITY E5;6ks)  
Dim op As T_OPERATION z6'Cz}%EP'  
Dim mat As T_MODELMATERIAL a7Mn/ i.  
Dim A As Double pVm]<jO  
Dim pupilDiam As Double @n|Mr/PAj  
Dim eID As Long 1>yh`Bp\=  
Dim parID As Long z:Y Z]   
Dim count As Integer }H5~@c$  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double e:9s%|]T  
Dim tlens As Double, nlens As Double C4[)yJ  
Dim curv As Double, conic As Double pH9xyN[:a  
Dim ok As Long Fok%  
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Sub Main 
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    '用户输入对话框 jT'09r3P  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #zf,%IYF  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Q6 oM$qiM  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Tv[h2_+E  
        OKButton 40,91,90,21 zH5
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        CancelButton 190,91,90,21 n[KLY!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !-veL1r  
        TextBox 220,49,40,21,.TextBox2 'default: 4 !jQj1QZR`  
    End Dialog OH >#f6`[  
    Dim dlg As UserDialog 5FJ(x:k?z  
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    ok = Dialog (dlg) 4j1$1C{  
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    If ok=0 Then    'cancel button was pressed 79*f <Gr  
        Print "Execution cancelled." $xU)t&Df
 
        End Y&uwi:_g  
    End If A.9ZFFz  
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    'Assign accommodation and pupil diameter & use defaults if field left empty eF"k"Ckt'  
    If dlg.TextBox1 = "" Then | LXVf  
        A = 0           'Default accommodation ~tc,p  
    Else 1j*E/L  
        A = CDbl(dlg.TextBox1) n\i~H  
    End If '" 4;;(  
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    If dlg.TextBox2 = "" Then }`pxs  
        pupilDiam = 4   'Default pupil diameter ID]E3K  
    Else I}sb0 Q&  
        pupilDiam = CDbl(dlg.TextBox2) GYt|[GC  
    End If Kh8  
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    Print " " cC*H.N  
    Print "Accommodation = " & A & " Diopters" 7>V*gV?v  
    Print "Pupil Diameter = " & pupilDiam & " mm" .3'U(U  
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    ' Calculate new parameters with accommodation Xqy9D ZIn  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (PC)R9r5  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ES)@iM?5  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5{xK&[wR*  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {%oxzdPc  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens t2(vtxrt  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ny"z<N&}/  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $jOp:R&I^3  
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    'Adjust parameters to account for accommodation O+?vQ$
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    '************************************************************************* W)<t7q+  
    'Aqueous thickness (Position of Lens) ]1 jhy2j  
    '************************************************************************* []$L"?]0uk  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) TT oW>RP#  
    GetCustomElement eID, entity
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    parID = FindFullName( "Geometry.Arizona Eye" ) R2A#2{+H  
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    ' Delete any shift(s) in z C~IE_E&Q`  
    count = 0 !;UoZ~  
    While GetOperationCount(eID)>count t,u;"%go  
        GetOperation eID, count, op 7]_zWx,r  
        If op.Type="ShiftZ" Then "vX\Q rL  
            DeleteOperation eID,count CiV^bYi  
            count=count-1 Ro_jf

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        End If uD?Rs`  
        count=count+1 F1t+D)KA>  
    Wend ,h9?o  
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    'Set new shift in 7h.fT`  
    op.Type = "ShiftZ" +{#L,0t  
    op.val1 = taq 7GvMKtuSK  
    op.parent = parID p<<dj%  
    AddOperation eID, op ]v]tBVO$  
    Print "Set aqueous humor thickness = " & taq-0.55 c#f@v45  
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    '************************************************************************* lPD&Doa  
    'Radius and conic constant of anterior lens a2[r
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    '************************************************************************* \mL]xE-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) =Qf{  
    GetConic eID, entity, curv, conic T!I3.  
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    SetConic eID, entity, 1/Rant, CCant -Iis/Xw:  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gT(
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    '************************************************************************* v o4U%  
    'Radius and conic constant of posterior lens ,pY:kQ  
    '************************************************************************* kE:{#>[Uz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ExM VGe  
    GetConic eID, entity, curv, conic wD:2sri  
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    SetConic eID, entity, 1/Rpost, CCpost Dr76+9'i  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e<qfM&*  
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    '************************************************************************* l"7#(a  
    'Lens thickness (Position of posterior lens surface) RL)~J4Y  
    '************************************************************************* cvQAo|  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }KO <II  
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    ' Delete any z-shift(s) w IP4Z^  
    count = 0 {5fL!`6w  
    While GetOperationCount(eID)>count DN iH" 0%  
        GetOperation eID, count, op <k0/O  
        If op.Type="ShiftZ" Then mlPvF%Ba  
            DeleteOperation eID,count zkiwFEHA=  
            count=count-1 Abi(1nXdQ  
        End If >_\[C?8  
        count=count+1 "LSzF_mK  
    Wend 5fMlOP_  
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    'Set new z-shift pTB7k3g  
    op.Type = "ShiftZ" |fW_9={1kQ  
    op.val1 = tlens [9B1%W  
    op.parent = parID 0m=57c$O  
    AddOperation eID, op N:okt)q:%  
    Print "Set lens thickness = " & tlens T"aE]4_  
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    '************************************************************************* J .VZD  
    'Lens index of refraction i]s%tEZ1  
    '************************************************************************* HOF=qE*p  
    eID = FindMaterial( "Lens" ) jEwt1S V  
    GetModelMaterial eID, mat (,tu7u{  
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    mat.Nd = nlens ky-nP8L}  
    SetModelMaterial eID, mat 5KDCmw  
    Print "Set lens index of refraction = " & nlens fUGappb  
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    '************************************************************************* <5,|h3]-#  
    'Pupil diameter (Q @'fb9z  
    '************************************************************************* Q
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) !nvg:$.&  
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    'Adjust pupil diameter (trimming volume inner hole) kN78j  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %q~q,=H$]  
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    ' Adjust pupil location to just in front of the lens E4>}O;m0  
    parID = FindFullName( "Geometry.Arizona Eye" ) ~;a\S3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =<#G~8WYz  
    count = 0 RGs7Hc  
    While GetOperationCount(eID)>count ~#jiX6<I  
        GetOperation eID, count, op cJv/)hRaz  
        If op.Type="ShiftZ" Then P tLWFO  
            DeleteOperation eID,count d6ef)mw  
            count=count-1 \@WVeFr  
        End If HZZZ [km  
        count=count+1 \/?J)k3H.  
    Wend 5 7t.Ud  
    op.Type = "ShiftZ" *U]&a^N  
    op.val1 = taq-0.01 3l45(%g+  
    op.parent = parID lux g1>  
    AddOperation eID, op R ZQH#+*t}  
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    Print "Set pupil diameter = " & pupilDiam 1}c'UEr%)  
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    'Update AZ Eye subassembly Description ~59lkr8  
    eID = FindFullName( "Geometry.Arizona Eye" ) Um6}h@>  
    GetEntity eID, entity 'QxJU$  
    entity.Description = "Accommodation = " & A & "D" GCq4{_B\Q  
    SetEntity eID, entity X-_VuM_p  
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    Update 8cG`We8l&  
    Print "DONE!" m7g*zu2#  
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End Sub LUId<We  
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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： Y`(Ri-U4  
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Accommodation = 4 Diopters NWvIwt{  
Pupil Diameter = 4 mm !?0C(VL(:  
Set aqueous humor thickness = 2.81 n#b{  
Set anterior lens radius = 10.4 and conic constant = -2.375869 k]5tU\;Yw  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~{tO8 ]  
Set lens thickness = 3.927 ){w{#  
Set lens index of refraction = 1.42672 #jrlNg4(  
Set pupil diameter = 4 _^#eO`4"  
DONE! 7~XA92  
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