[技术]Arizona眼睛模型 [复制链接]

简介 _X,[]+ziu%  
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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。 Hyq@O8  
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模型 _4.]A3;}  
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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。 F}6DB*  
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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. MG7 ?N #  
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光源 ,?xLT2>J_  
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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。 O6m.t%*  
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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。 V>b2b5QAH,  
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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。 &=F-moDD  
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视网膜的散射 lZ|L2Yg3uB  
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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。 mR{CVU  
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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。 fD1?z"lo  
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脚本 \~JNQ&_o  
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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： 8YuJ8KC  
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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。 ~I{EE[F>qL  
余下的脚本计算与屈光度有关的所有参数。 D Irgq|8  
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分析 c_ La^HS  
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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。 ?Bo?JMV  
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脚本代码 1HMUHZT  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. '.?^uM  
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Dim entity As T_ENTITY ` ^DjEdUN  
Dim op As T_OPERATION Q,{^S,s<  
Dim mat As T_MODELMATERIAL $}t=RW  
Dim A As Double 3Jk[/.h  
Dim pupilDiam As Double k`Nyi)AGe  
Dim eID As Long 9YB2e84j  
Dim parID As Long 9B /s  
Dim count As Integer qu_)`wB  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double geksjVwP
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Dim tlens As Double, nlens As Double 93j{.0]X  
Dim curv As Double, conic As Double 5sCFzo<=vh  
Dim ok As Long !O|ql6^;  
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Sub Main U4BqO :sd  
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    '用户输入对话框 EIr@g  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $B\ H  
        TextBox 220,21,40,21,.TextBox1 'default: 0 tJNIr5o  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 YutQ]zYA.  
        OKButton 40,91,90,21 H$!+A  
        CancelButton 190,91,90,21 GF8 -_X  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .}q]`<]ze  
        TextBox 220,49,40,21,.TextBox2 'default: 4 fAGctRGH  
    End Dialog OF[?Z  
    Dim dlg As UserDialog K UKACUL  
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    ok = Dialog (dlg) #uSK#>H_!  
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    If ok=0 Then    'cancel button was pressed AEY$@!8  
        Print "Execution cancelled." [#Y' dFQ  
        End VPt9QL(  
    End If >{C\H.N  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Tzzq#z&F  
    If dlg.TextBox1 = "" Then WK0C  
        A = 0           'Default accommodation p~&BChBl!=  
    Else =7%oE[  
        A = CDbl(dlg.TextBox1) WF2NG;f=  
    End If }g|nz8
  
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    If dlg.TextBox2 = "" Then .Pe9_ZH$W  
        pupilDiam = 4   'Default pupil diameter sYqgXE.  
    Else <_Eg?ePW#  
        pupilDiam = CDbl(dlg.TextBox2) :P$#MC  
    End If P`S@n/}  
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    Print " " Ts9ktPlm  
    Print "Accommodation = " & A & " Diopters" x&Cp> +i  
    Print "Pupil Diameter = " & pupilDiam & " mm" o%`Xa#*Ly  
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    ' Calculate new parameters with accommodation <P_ea/5:|  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x({H{'9?  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens fuUm}N7  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens gd7^3q[$h  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens S QY"OBo<e  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4nqoZk^R  
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    tlens = 3.767 + 0.04*A                  'Lens thickness !2tW$
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L?5f+@0.  
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    'Adjust parameters to account for accommodation UG;Y^?Ppe5  
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    '************************************************************************* ]]0,|My7  
    'Aqueous thickness (Position of Lens) R"AUSO|{  
    '************************************************************************* :7g=b%;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) x%N\5 V1  
    GetCustomElement eID, entity ~rD={&0  
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    parID = FindFullName( "Geometry.Arizona Eye" ) t<j^q`;@v  
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    ' Delete any shift(s) in z cXnKCzSxZq  
    count = 0 wQ+8\ s=  
    While GetOperationCount(eID)>count {Qv>q$Q  
        GetOperation eID, count, op Km#pX1]>e  
        If op.Type="ShiftZ" Then $t~@xCi]S  
            DeleteOperation eID,count | ?yo 3  
            count=count-1 3;[DJ5  
        End If l?8M p$M  
        count=count+1 r?/A?DMe  
    Wend S4CbyXW  
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    'Set new shift in $wB^R(f@  
    op.Type = "ShiftZ" (X[CsaXt  
    op.val1 = taq q.#[TI ^  
    op.parent = parID S
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    AddOperation eID, op \x{;U#B[3>  
    Print "Set aqueous humor thickness = " & taq-0.55 )B# ,  
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    '************************************************************************* Pmg)v!"  
    'Radius and conic constant of anterior lens a
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    '************************************************************************* :1ecx$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) uX/$CM  
    GetConic eID, entity, curv, conic JAjmrX  
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    SetConic eID, entity, 1/Rant, CCant oR1
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Y-mK+12  
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    '************************************************************************* lv&mp0V+  
    'Radius and conic constant of posterior lens O,2~"~kF  
    '************************************************************************* g7V8D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?>c=}I#Ui-  
    GetConic eID, entity, curv, conic F>je4S;  
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    SetConic eID, entity, 1/Rpost, CCpost -|k)tvAm  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `:m!~  
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    '************************************************************************* =J-5.0Q\_\  
    'Lens thickness (Position of posterior lens surface) J7D}%  
    '************************************************************************* cJo\#cr  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) >_dx_<75&  
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    ' Delete any z-shift(s) E/&Rb*3  
    count = 0 9E2j!  
    While GetOperationCount(eID)>count >(w2GD?  
        GetOperation eID, count, op FWue;pw3  
        If op.Type="ShiftZ" Then W7"{r)7  
            DeleteOperation eID,count
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            count=count-1 3f" %G\  
        End If PWRy7d  
        count=count+1 VErv;GyV  
    Wend n\Fp[9+Z\  
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    'Set new z-shift .:p2Tbo  
    op.Type = "ShiftZ" hz;|NW{u  
    op.val1 = tlens XC 7?VE  
    op.parent = parID
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    AddOperation eID, op ]5~s"fnG  
    Print "Set lens thickness = " & tlens ?Xdak|?i  
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    '************************************************************************* 9a\nszwa  
    'Lens index of refraction Xs&TJ8a  
    '************************************************************************* [,n c  
    eID = FindMaterial( "Lens" ) :j|IP)-f  
    GetModelMaterial eID, mat ES~^M840f  
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    mat.Nd = nlens nJ4@I7Sk;  
    SetModelMaterial eID, mat ? J}r  
    Print "Set lens index of refraction = " & nlens CQel3Jtt.  
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    '************************************************************************* Mb3}7@/[  
    'Pupil diameter /@AEJ][$  
    '************************************************************************* xtPLR/Z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) +_XmlX A3Z  
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    'Adjust pupil diameter (trimming volume inner hole) 26X+ }^52  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" PH"hn
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    ' Adjust pupil location to just in front of the lens m9U"[Huv1E  
    parID = FindFullName( "Geometry.Arizona Eye" ) x^Yl*iq  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) V f-a'K&  
    count = 0 9/+Nj/  
    While GetOperationCount(eID)>count y/e2l  
        GetOperation eID, count, op DAo~8H  
        If op.Type="ShiftZ" Then b:qY gg  
            DeleteOperation eID,count #r PP*  
            count=count-1 m<L;  
        End If D\<y)kh  
        count=count+1 NmMIQ
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    Wend gP+fN$5'd  
    op.Type = "ShiftZ" +,~zWv1v  
    op.val1 = taq-0.01 VG/3xR&y  
    op.parent = parID AiD[SR  
    AddOperation eID, op BpX6aAx  
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    Print "Set pupil diameter = " & pupilDiam \{Q?^E  
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    'Update AZ Eye subassembly Description XqM3<~$  
    eID = FindFullName( "Geometry.Arizona Eye" ) =^H4Yck/5  
    GetEntity eID, entity fgihy  
    entity.Description = "Accommodation = " & A & "D" r`c_e)STO  
    SetEntity eID, entity R/"x}B1d  
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    Update 0]HYP;E"U  
    Print "DONE!" WyP W*  
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End Sub e#/E~r&  
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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： ?\8?%Qk  
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Accommodation = 4 Diopters 1-RIN}CSd  
Pupil Diameter = 4 mm EyY.KxCB  
Set aqueous humor thickness = 2.81 ]kG(G%r|M  
Set anterior lens radius = 10.4 and conic constant = -2.375869 zE;bBwy&  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 E^U0f/5 m  
Set lens thickness = 3.927 ?5kHa_^  
Set lens index of refraction = 1.42672 !mXxAo  
Set pupil diameter = 4 |yo\R{&6  
DONE! Y.^=]-n,