[技术]Arizona眼睛模型 [复制链接]

简介 =W(Q34  
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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。 8'HEms  
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模型 Ua
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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。 r8`ffH  
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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. Z9v31)q(  
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光源 3#LlDC_WC  
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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。 y8]B:_iU9  
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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。 Xr,1&"B&t  
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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。 s:n6rG  
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视网膜的散射 'p^t^=dQ  
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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。 g_;\iqxL  
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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。 ]vAz  
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脚本 eb?x9h  
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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： bTI|F]^!  
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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。 ,V7nzhA2  
余下的脚本计算与屈光度有关的所有参数。 -M\<nx  
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分析 9=s<Ld  
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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。 AzPu)  
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脚本代码 _5w]a 2  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 2_>N/Z4T  
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Dim entity As T_ENTITY 1v y*{D  
Dim op As T_OPERATION )j6~Wy@4  
Dim mat As T_MODELMATERIAL n3WlZ!$  
Dim A As Double .7J#_*NV  
Dim pupilDiam As Double %mW{n8W3{  
Dim eID As Long !M(xG%M-V  
Dim parID As Long Ao 'l"-  
Dim count As Integer rm7ANMB:  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double EAUEQk?9  
Dim tlens As Double, nlens As Double X;$+,&M"  
Dim curv As Double, conic As Double e+EQ]<M  
Dim ok As Long )+#` CIv  
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Sub Main GC-5X`Sq  
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    '用户输入对话框 hDDn,uzpd  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 9+|$$)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 /WcG{Wdp  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6bg ;q(*7  
        OKButton 40,91,90,21 hW<%R]^|  
        CancelButton 190,91,90,21 YP oSRA L  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Lj({[H7D!  
        TextBox 220,49,40,21,.TextBox2 'default: 4 cZ,b?I"Q%  
    End Dialog !
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    Dim dlg As UserDialog $ Gf(38[w  
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    ok = Dialog (dlg) &C_j\7Dq  
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    If ok=0 Then    'cancel button was pressed AI2)g1m  
        Print "Execution cancelled." hPB9@hT$  
        End kdiM5l70  
    End If h
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    'Assign accommodation and pupil diameter & use defaults if field left empty lf|FWqqV  
    If dlg.TextBox1 = "" Then 4
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        A = 0           'Default accommodation !)f\%lb  
    Else `7E;VL^Y1  
        A = CDbl(dlg.TextBox1) ,>a&"V^k  
    End If [(i  
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    If dlg.TextBox2 = "" Then kt#fMd$  
        pupilDiam = 4   'Default pupil diameter dFxIF;C>/  
    Else l:~/<`o  
        pupilDiam = CDbl(dlg.TextBox2) k=$TGqQY?  
    End If q>_.[+6  
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    Print " " BKCiIfkZ  
    Print "Accommodation = " & A & " Diopters" s[>,X#7 y  
    Print "Pupil Diameter = " & pupilDiam & " mm" [\eeDa  
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    ' Calculate new parameters with accommodation +HpA:]#Y  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5{WE~8$  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens QE+g j8  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `,(4]tlL  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens x;.Jw6g  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens rBzuKQK}J  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ?=msH=N<l  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s]0{a.Cpv  
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    'Adjust parameters to account for accommodation _yx>TE2e  
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    '************************************************************************* oCv.Ln1;Z  
    'Aqueous thickness (Position of Lens) R%WCH?B<}  
    '************************************************************************* 5V~oIL  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;4\2.*s  
    GetCustomElement eID, entity ?zMHP#i  
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    parID = FindFullName( "Geometry.Arizona Eye" ) O:R*rJ  
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    ' Delete any shift(s) in z PdFKs+Z`  
    count = 0 EJ.SW5  
    While GetOperationCount(eID)>count 2jItq2.>  
        GetOperation eID, count, op 2zA4vZkbcw  
        If op.Type="ShiftZ" Then p4rL}Jm&  
            DeleteOperation eID,count \:'/'^=#|  
            count=count-1 M/'sl;  
        End If r,3DTBe  
        count=count+1 {<p?2E  
    Wend )EuvRLo{S7  
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    'Set new shift in eK=xrk  
    op.Type = "ShiftZ" mDABH@R  
    op.val1 = taq ah&D%8E  
    op.parent = parID `AtBtjs RV  
    AddOperation eID, op X7MM2V  
    Print "Set aqueous humor thickness = " & taq-0.55 U$.@]F4&  
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    '************************************************************************* 4[r0G+  
    'Radius and conic constant of anterior lens xrz,\eTb  
    '************************************************************************* /SR*W5#s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) dq6m>;`  
    GetConic eID, entity, curv, conic $9#H04.x  
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    SetConic eID, entity, 1/Rant, CCant sf qL|8  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6vo;!V6  
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    '************************************************************************* t#})Awy^R  
    'Radius and conic constant of posterior lens ]@c+]{  
    '************************************************************************* L|+~"'l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) bHYy}weZ  
    GetConic eID, entity, curv, conic Yui3+}Ms  
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    SetConic eID, entity, 1/Rpost, CCpost iL&fgF"'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O, wJR  
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    '************************************************************************* TDKki(o=~  
    'Lens thickness (Position of posterior lens surface) l`{\"#4  
    '************************************************************************* &j`}vg  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #e1>H1eU  
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    ' Delete any z-shift(s) X1|njJGO1  
    count = 0 drP=A~?&:  
    While GetOperationCount(eID)>count U^%Q}'UYym  
        GetOperation eID, count, op ;O6;.5q&  
        If op.Type="ShiftZ" Then gQg"j)  
            DeleteOperation eID,count K~{$oD7!  
            count=count-1 ~d4 )/y  
        End If )gIKH{JYL  
        count=count+1 Ad8n<zt|  
    Wend =F~S?y  
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    'Set new z-shift }Yzco52  
    op.Type = "ShiftZ" I\{ 1u  
    op.val1 = tlens Q5`*3h6p=  
    op.parent = parID ~{g [<Qi  
    AddOperation eID, op @7]yl&LZ  
    Print "Set lens thickness = " & tlens 5E;qM|Ns  
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    '************************************************************************* xb~yM%*c  
    'Lens index of refraction EStB#V^  
    '************************************************************************* ,X-bJA@(  
    eID = FindMaterial( "Lens" ) O)*+="Rg  
    GetModelMaterial eID, mat zuad~%D<I  
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    mat.Nd = nlens 9igiZmM  
    SetModelMaterial eID, mat /{aj}M0kN  
    Print "Set lens index of refraction = " & nlens b9J_1Gl]  
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    '************************************************************************* Fn;SF4KOm  
    'Pupil diameter V)HG(k  
    '************************************************************************* @ $ ;q;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) QUc= &5 %  
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    'Adjust pupil diameter (trimming volume inner hole) %KhI>O<  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" vXf!G`D  
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    ' Adjust pupil location to just in front of the lens qZtzO2Mt  
    parID = FindFullName( "Geometry.Arizona Eye" ) |!3DPA(_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ZF9z~9  
    count = 0 t
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    While GetOperationCount(eID)>count 8B K(4?gC  
        GetOperation eID, count, op xQ-<WF1i  
        If op.Type="ShiftZ" Then %~H-)_d20  
            DeleteOperation eID,count |O\s
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            count=count-1 '4+ ur`  
        End If EReZkvseC  
        count=count+1 W.f/pu  
    Wend 30#s aGV  
    op.Type = "ShiftZ" #uG%j  
    op.val1 = taq-0.01 XFHYQ2ME2  
    op.parent = parID %+W
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    AddOperation eID, op pk$l+sNZ=  
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    Print "Set pupil diameter = " & pupilDiam eC
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    'Update AZ Eye subassembly Description S"bg9o  
    eID = FindFullName( "Geometry.Arizona Eye" ) ~F|+o}a`  
    GetEntity eID, entity A@!qv#'  
    entity.Description = "Accommodation = " & A & "D" b.Ju
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    SetEntity eID, entity ) <[XtK  
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    Update N]Yd9tn{  
    Print "DONE!" P6'1.R  
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End Sub 8yR.uMI$/  
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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： / |;RV"  
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Accommodation = 4 Diopters r"3=44St  
Pupil Diameter = 4 mm FF`T\&u  
Set aqueous humor thickness = 2.81 VX0 %a@ur  
Set anterior lens radius = 10.4 and conic constant = -2.375869 z1 |TC  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 urs,34h  
Set lens thickness = 3.927 wY{-BuXv  
Set lens index of refraction = 1.42672 +aCv&sg  
Set pupil diameter = 4 TTX5EDCrC  
DONE! hc(#{]].