[技术]Arizona眼睛模型 [复制链接]

简介 zaf%%  
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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。 H0_hQ:K   
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模型 dr'#  
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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。 22)2o
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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. KpA i
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光源 s8Xort&  
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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。 y".uu+hL`  
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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。 bzz=8n  
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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。 tT>~;l%'  
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视网膜的散射 RBd{1on  
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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。 -Zh`
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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。 A M8bem~  
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脚本 )o-rg  
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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： 
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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。 Ju4={^#  
余下的脚本计算与屈光度有关的所有参数。 L?T%;VdG'>  
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分析 :yO.Te F  
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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。 ="hh=x.5J  
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脚本代码 U2l7@uDr;  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m08:EXP  
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Dim entity As T_ENTITY _PUgK\  
Dim op As T_OPERATION ASME~]]?  
Dim mat As T_MODELMATERIAL \}[{q  
Dim A As Double )D?\ru H  
Dim pupilDiam As Double qP@d)XRQ  
Dim eID As Long @LZ'Qc }@  
Dim parID As Long X~wkqI#d%E  
Dim count As Integer %5.aC|^}  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }#va#Nb(,  
Dim tlens As Double, nlens As Double Y?G\@6  
Dim curv As Double, conic As Double B@XnHh5y  
Dim ok As Long UZ#Yd|'PD  
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Sub Main H=b54.J8&  
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    '用户输入对话框 Rrh?0qWs  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  mkH{%7n  
        TextBox 220,21,40,21,.TextBox1 'default: 0 U"\$k&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X-,scm  
        OKButton 40,91,90,21 :KY920/,  
        CancelButton 190,91,90,21 ernZfd{H  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 jzCSxuZ7O  
        TextBox 220,49,40,21,.TextBox2 'default: 4 evOyTvc  
    End Dialog P6q`i<  
    Dim dlg As UserDialog GPP{"6q5'  
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    ok = Dialog (dlg) &-^|n*=g6  
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    If ok=0 Then    'cancel button was pressed ti6\~SY  
        Print "Execution cancelled." "";[U  
        End .u[hK  
    End If C/AqAW1  
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    'Assign accommodation and pupil diameter & use defaults if field left empty RW19I,d  
    If dlg.TextBox1 = "" Then N0APX4j  
        A = 0           'Default accommodation 2E]SKpJ  
    Else &%3$zgvR  
        A = CDbl(dlg.TextBox1)  Z
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    End If M->/vi  
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    If dlg.TextBox2 = "" Then `@.  
        pupilDiam = 4   'Default pupil diameter 7)iB6RBK  
    Else P%HvL4R  
        pupilDiam = CDbl(dlg.TextBox2) Z#H] yG  
    End If MLD-uI10{  
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    Print " " t\YN\`XD  
    Print "Accommodation = " & A & " Diopters" 9nW/pv  
    Print "Pupil Diameter = " & pupilDiam & " mm" !=%E&e]  
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    ' Calculate new parameters with accommodation |.kYomJ   
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness dV+%x"[:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #XSs.i{  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens B<)c{kj  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 43_;Z| T  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens QEd>T"@g  
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    tlens = 3.767 + 0.04*A                  'Lens thickness m$glRs @  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction QiDf,$t|,  
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    'Adjust parameters to account for accommodation FFE IsB"9  
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    '************************************************************************* 8NY$Iw  
    'Aqueous thickness (Position of Lens) ;Y:_}kN8_  
    '************************************************************************* j9)WInYc:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %3v:c|r  
    GetCustomElement eID, entity $|0_[~0-n  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 3&*_5<t\X  
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    ' Delete any shift(s) in z ?_
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    count = 0 'EsN{.l?  
    While GetOperationCount(eID)>count z'cK,psq(  
        GetOperation eID, count, op h@nNm30i  
        If op.Type="ShiftZ" Then +(>!nsf  
            DeleteOperation eID,count -w8c;5X  
            count=count-1 i21ybXA=Z  
        End If K@ZK@++  
        count=count+1 lZyxJDZ A  
    Wend e;LJdd  
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    'Set new shift in UzLe#3MU  
    op.Type = "ShiftZ" q2qbbQ6H  
    op.val1 = taq 4[@`j{  
    op.parent = parID fC!]MhA"i  
    AddOperation eID, op }lN@J,q  
    Print "Set aqueous humor thickness = " & taq-0.55 ,`<w#  
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    '************************************************************************* [3Qu @;"&  
    'Radius and conic constant of anterior lens AEj
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    '************************************************************************* NzRpI5\.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) -8-BVU  
    GetConic eID, entity, curv, conic Ift @/A  
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    SetConic eID, entity, 1/Rant, CCant wd4
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WM8 Ce0E  
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    '************************************************************************* yHvF"4]  
    'Radius and conic constant of posterior lens /.leY$  
    '************************************************************************* D@[Mk
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2LpJxV  
    GetConic eID, entity, curv, conic KH4 5A'o  
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    SetConic eID, entity, 1/Rpost, CCpost n<C4-'^U[a  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ],rtSUO  
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    '************************************************************************* M[wd.\ %  
    'Lens thickness (Position of posterior lens surface) 9S"c-"y\#  
    '************************************************************************* zB6u%uWR  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }F=+*-SYZ  
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    ' Delete any z-shift(s) v634{:'e  
    count = 0 d8 1u  
    While GetOperationCount(eID)>count EC6&#)g;CO  
        GetOperation eID, count, op ]e0yC  
        If op.Type="ShiftZ" Then h-rPLU;Bw  
            DeleteOperation eID,count ;g[C=yhK`C  
            count=count-1 w#v8a$tT  
        End If ,Lt+*!;m  
        count=count+1 zo*YPDEm"  
    Wend mmC&xZ5f  
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    'Set new z-shift p"9
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    op.Type = "ShiftZ" 1(V>8}zn  
    op.val1 = tlens &V;^xMO!  
    op.parent = parID ;k6>*wFl|!  
    AddOperation eID, op v3 $+l1  
    Print "Set lens thickness = " & tlens >h3r\r\n3  
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    '************************************************************************* VV/6~jy0  
    'Lens index of refraction m&)5QX  
    '************************************************************************* pDr%uL  
    eID = FindMaterial( "Lens" ) cr!6qv1  
    GetModelMaterial eID, mat 74*1|S<  
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    mat.Nd = nlens K-Bf=7F,  
    SetModelMaterial eID, mat b2;+a(  
    Print "Set lens index of refraction = " & nlens >t2E034_  
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    '************************************************************************* 19od# d3+  
    'Pupil diameter neW_mu;~Z  
    '************************************************************************* e(/~;"r{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %GUu{n<6  
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    'Adjust pupil diameter (trimming volume inner hole) oY@4G)5  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" wN,DTmtD  
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    ' Adjust pupil location to just in front of the lens FY%v \`@1*  
    parID = FindFullName( "Geometry.Arizona Eye" ) y7#$:+jQv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b#p)bcz!I  
    count = 0 @NMFurm  
    While GetOperationCount(eID)>count ]PVPt,c  
        GetOperation eID, count, op ]=v_u9;  
        If op.Type="ShiftZ" Then mG[S"?C  
            DeleteOperation eID,count @vWC "W  
            count=count-1 \tFg10  
        End If d#:&Uw  
        count=count+1 3nt&Sf  
    Wend [KXxn>n  
    op.Type = "ShiftZ" SX)giQLU  
    op.val1 = taq-0.01 Vx_lI #3  
    op.parent = parID |He,v/r  
    AddOperation eID, op 7 }`c:u~j  
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    Print "Set pupil diameter = " & pupilDiam D$g|f[l  
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    'Update AZ Eye subassembly Description ?vL\VI9  
    eID = FindFullName( "Geometry.Arizona Eye" ) )5Yv7x(K  
    GetEntity eID, entity )'8DK$.  
    entity.Description = "Accommodation = " & A & "D" 0;z-I"N  
    SetEntity eID, entity y3T-^  
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    Update t1p}
  
    Print "DONE!" xz#;F ,`ZR  
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End Sub SdhdXVZ  
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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： I}/o`oc  
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Accommodation = 4 Diopters dsP|j(y  
Pupil Diameter = 4 mm 9`}Wp2  
Set aqueous humor thickness = 2.81 UJG)-x  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Z qX U  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 FUzIuz 6  
Set lens thickness = 3.927 6GCwc
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Set lens index of refraction = 1.42672 BQVpp,]  
Set pupil diameter = 4 }OO(uC2  
DONE! &T?>Kx