[技术]Arizona眼睛模型 [复制链接]

简介 | WJ]7C  
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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}2  
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模型 tgCp2`n  
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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。 wxK71OH  
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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. b*S,8vE]  
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光源 ,2Ed^!`  
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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。 t*Ro2QZ  
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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。 'MYKAnZ-i  
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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。 XN t` 4$L  
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视网膜的散射 P]}:E+E<.I  
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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。 kb~ s,@p  
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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。 +|S)Mm8-  
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脚本 /o$6"~t  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： +K'YVB U}  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ={o4lFe3v(  
余下的脚本计算与屈光度有关的所有参数。 /-lW$.+{?  
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分析 -u~:Gd*l0  
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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。 U"@p3$2QW  
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脚本代码 SLkgIb~'X  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Bf^K?:r"V  
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Dim entity As T_ENTITY j4@6`[n:  
Dim op As T_OPERATION mBrZ{hqS  
Dim mat As T_MODELMATERIAL Qt'3v"S>)  
Dim A As Double G^<m0ew|  
Dim pupilDiam As Double H 9/m6F  
Dim eID As Long 1GR|$E  
Dim parID As Long w"M!**bP  
Dim count As Integer Ls|)SiXrY  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double %ByqkY{5F  
Dim tlens As Double, nlens As Double rjfWty%6pX  
Dim curv As Double, conic As Double Yqu/_6wLx  
Dim ok As Long Xsb.xxK.  
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Sub Main }|=Fnyj  
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    '用户输入对话框 NV}fcZ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 a&mL Dh/  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9XS>;<"2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 o4rf[.z  
        OKButton 40,91,90,21 }{J>kgr6  
        CancelButton 190,91,90,21  W>x.*K  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 's"aPqF?  
        TextBox 220,49,40,21,.TextBox2 'default: 4 E'+z.~+  
    End Dialog 4|jPr J  
    Dim dlg As UserDialog :[_k .1-+  
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    ok = Dialog (dlg) NQ '|M  
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    If ok=0 Then    'cancel button was pressed NS
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        Print "Execution cancelled." vls+E o]  
        End !YM:?%B  
    End If iy8Ln,4z(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?v+el,  
    If dlg.TextBox1 = "" Then .)t*!$5=N  
        A = 0           'Default accommodation #x6wM~  
    Else z^KBV^n  
        A = CDbl(dlg.TextBox1) |F=.NY  
    End If .nA9irc  
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    If dlg.TextBox2 = "" Then se_Oi$VZ{  
        pupilDiam = 4   'Default pupil diameter oC!z
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    Else xf:|lQf  
        pupilDiam = CDbl(dlg.TextBox2) nob}}w]~C  
    End If ?|hYtV  
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    Print " " ~^3U@(:  
    Print "Accommodation = " & A & " Diopters" (f"LD8MJ/  
    Print "Pupil Diameter = " & pupilDiam & " mm" $U^ Ms!'L  
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    ' Calculate new parameters with accommodation 1q*=4O  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness a8y*Jz-E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ; jJ%<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens {|q(4(f"Iu  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens DnB :~&Dw  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens dP/1E6*m  
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    tlens = 3.767 + 0.04*A                  'Lens thickness nG| NRp  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction oHethk  
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    'Adjust parameters to account for accommodation Is ( Ji  
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    '************************************************************************* .Ax]SNZ+:A  
    'Aqueous thickness (Position of Lens) 9iK%@k  
    '************************************************************************* u>03l(X6f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) W_]onq6  
    GetCustomElement eID, entity n8)eC2A  
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    parID = FindFullName( "Geometry.Arizona Eye" ) A9y3B^\*  
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    ' Delete any shift(s) in z {@X)=.Zf  
    count = 0 ~2 J!I^J  
    While GetOperationCount(eID)>count ? C6tYd  
        GetOperation eID, count, op [jKhC<t}  
        If op.Type="ShiftZ" Then y>JSo9[@  
            DeleteOperation eID,count cs Gd}2V
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            count=count-1 /onZ14  
        End If ",45p@  
        count=count+1 ]M
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    Wend @t#Ju1Y  
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    'Set new shift in (5=B^9{R  
    op.Type = "ShiftZ" z dUSmb  
    op.val1 = taq ALp|fZ\vp  
    op.parent = parID EUuk%<q7C(  
    AddOperation eID, op ?Lquf&`vP  
    Print "Set aqueous humor thickness = " & taq-0.55 f;a55%3c  
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    '************************************************************************* iq`caoi  
    'Radius and conic constant of anterior lens ys}I~MK-  
    '************************************************************************* 6tBe,'*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) N?mQ50o~C  
    GetConic eID, entity, curv, conic Ibu  5  
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    SetConic eID, entity, 1/Rant, CCant Uf\U~wM<  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant y9Q.TL>=[  
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    '************************************************************************* M:.0]'[s5  
    'Radius and conic constant of posterior lens )SWLX\b  
    '************************************************************************* _G^Cc}X  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) O g!SFg*  
    GetConic eID, entity, curv, conic X32{y973hT  
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    SetConic eID, entity, 1/Rpost, CCpost ]R]%c*tA  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @*5(KIeeC>  
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    '************************************************************************* ~>>^7oq  
    'Lens thickness (Position of posterior lens surface) 3V0^v  
    '************************************************************************* yey]#M[y  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) l !:kwF  
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    ' Delete any z-shift(s) h~u|v[@{J  
    count = 0 $VUX?ii$7=  
    While GetOperationCount(eID)>count !4(QeV-=  
        GetOperation eID, count, op ix_&<?8  
        If op.Type="ShiftZ" Then _'Hw`0}s  
            DeleteOperation eID,count Q?{^8?7  
            count=count-1 7Nlk:f)*-  
        End If jF0>wm  
        count=count+1 5T]dQ3[v4  
    Wend XWq@47FR  
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    'Set new z-shift ! +XreCw  
    op.Type = "ShiftZ" N<T@GQwkS  
    op.val1 = tlens Z6IWQo,)Rh  
    op.parent = parID 0K^?QM|S  
    AddOperation eID, op sc$I,|d2  
    Print "Set lens thickness = " & tlens ugS  
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    '************************************************************************* ;><m[l6  
    'Lens index of refraction j},3@TFh  
    '************************************************************************* #]@|mf q  
    eID = FindMaterial( "Lens" ) /G= ?E]^  
    GetModelMaterial eID, mat Qe
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    mat.Nd = nlens j. mla  
    SetModelMaterial eID, mat OzAxnd\.N  
    Print "Set lens index of refraction = " & nlens 5odXT *n  
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    '************************************************************************* V$3`y=8  
    'Pupil diameter YU/?AQg  
    '************************************************************************* kt7x}F(?<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 63Z^ k(  

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    'Adjust pupil diameter (trimming volume inner hole) 5Tq*]ZE  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cr~.],$Om  
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    ' Adjust pupil location to just in front of the lens zQaD&2 q  
    parID = FindFullName( "Geometry.Arizona Eye" ) l;}3J3/qq]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) t {H{xd  
    count = 0 du_~P"[  
    While GetOperationCount(eID)>count Ih)4.lLcKn  
        GetOperation eID, count, op 5Kw?#  
        If op.Type="ShiftZ" Then |G/WS0  
            DeleteOperation eID,count 1h?QEZ,6a  
            count=count-1 qIvnPaYW  
        End If D 3Tqk^5  
        count=count+1 8~y&"  \  
    Wend vL8Rg} Jh4  
    op.Type = "ShiftZ" y+nX(@~f
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    op.val1 = taq-0.01 u9N/9  
    op.parent = parID +`uNO<$~f  
    AddOperation eID, op 63/a 0Yn  
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    Print "Set pupil diameter = " & pupilDiam i@mS8%|l  
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    'Update AZ Eye subassembly Description q1Mt5O}  
    eID = FindFullName( "Geometry.Arizona Eye" ) P|t2%:_  
    GetEntity eID, entity fGoJP[ae  
    entity.Description = "Accommodation = " & A & "D" :Q8*MJ3&V  
    SetEntity eID, entity n0g8B  
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    Update ojc.ykP$  
    Print "DONE!" U7HfDDh  
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End Sub Ko0?c.l  
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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： g)7@EU2  
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Accommodation = 4 Diopters L8(2or  
Pupil Diameter = 4 mm <!F".9c@A  
Set aqueous humor thickness = 2.81 }m&\I  
Set anterior lens radius = 10.4 and conic constant = -2.375869 8.Ufw. 5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 c#TV2@  
Set lens thickness = 3.927 6sG5n7E-A  
Set lens index of refraction = 1.42672 ),Hr  
Set pupil diameter = 4 '}IGV`c  
DONE! u~PZK.Uf0