[技术]Arizona眼睛模型 [复制链接]

简介 }#Iqq9[  
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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。 p6)6Gcx  
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模型 5LU7}v~/  
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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。 $?VYHkX  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. "GJ.`Hj  
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光源 PpNG`_O  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 +JXn   
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 f'`y-]"V5)  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 {!wd5C@  
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视网膜的散射 bX5/xf$q  
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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。 - ku8n%u  
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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。 |V
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脚本 oJ#;XR  
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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： Eq8:[o  
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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。 ygK,t*T20  
余下的脚本计算与屈光度有关的所有参数。 xf|C{XV@H  
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分析 A,7* 52U  
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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。 lACS^(  
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脚本代码 9PaV*S(\TR  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. _U,Hi?b"$}  
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Dim entity As T_ENTITY y"K[#&,0  
Dim op As T_OPERATION li#ep?5h^  
Dim mat As T_MODELMATERIAL y`
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Dim A As Double G1I<B  
Dim pupilDiam As Double SWT)M1O2  
Dim eID As Long '?3
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Dim parID As Long Zl.,pcL  
Dim count As Integer S]4!uv^y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double wawJZ+V  
Dim tlens As Double, nlens As Double gXY]NWI  
Dim curv As Double, conic As Double kp6&e  
Dim ok As Long Ksk[sf?J&  
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Sub Main '=Acg"aT  
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    '用户输入对话框 X'xnJtk  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 e YiqTWn:  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ~{{7y]3M-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Ldy(<cN  
        OKButton 40,91,90,21 c;n\HYk  
        CancelButton 190,91,90,21 _d>{Hz2  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^t`0ul]c  
        TextBox 220,49,40,21,.TextBox2 'default: 4 X3~@U7DU  
    End Dialog /7ykmW  
    Dim dlg As UserDialog L_M(Lj  
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    ok = Dialog (dlg) crgVedx~}  
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    If ok=0 Then    'cancel button was pressed /#?!9c  
        Print "Execution cancelled." fd&>p  
        End u!t<2`:h  
    End If L9!\\U  
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    'Assign accommodation and pupil diameter & use defaults if field left empty xE*.,:,&  
    If dlg.TextBox1 = "" Then EbJc%%c  
        A = 0           'Default accommodation xgvwH?<  
    Else Q+O./1x*,  
        A = CDbl(dlg.TextBox1) z0&Y_Up+5  
    End If Ve xxdg  
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    If dlg.TextBox2 = "" Then *0_Q0SeE,o  
        pupilDiam = 4   'Default pupil diameter  LYyud  
    Else 4MCj*ok<  
        pupilDiam = CDbl(dlg.TextBox2) iAt&927  
    End If CbOCL~ "  
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    Print " " _KZTY`/*  
    Print "Accommodation = " & A & " Diopters" WM ]eb, 8q  
    Print "Pupil Diameter = " & pupilDiam & " mm" &#!1 Y[e^  
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    ' Calculate new parameters with accommodation Sf2xI'  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness v]
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens q RRvZhf  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :*YnH&  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |3`8$-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens VL
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    tlens = 3.767 + 0.04*A                  'Lens thickness Mt@Ma ]!  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction MHA_b^7?  
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    'Adjust parameters to account for accommodation FB %-$  
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    '************************************************************************* _n&#e r  
    'Aqueous thickness (Position of Lens) DHZ`y[&}|N  
    '************************************************************************* ZVrZkd`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |OuIQhoE  
    GetCustomElement eID, entity lAkg47i  
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    parID = FindFullName( "Geometry.Arizona Eye" ) e`Co ='  
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    ' Delete any shift(s) in z cM]ZYi
 
    count = 0 e$&n)>%  
    While GetOperationCount(eID)>count )4>7X)j>  
        GetOperation eID, count, op {]$)dz5  
        If op.Type="ShiftZ" Then #5iy^?N"w  
            DeleteOperation eID,count Kq(JHB+  
            count=count-1 B&<P>AZ  
        End If DcE4r>8B  
        count=count+1 JEF;Q  
    Wend $#(j2sL1  
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    'Set new shift in D  ,[yx='  
    op.Type = "ShiftZ" 9_ZGb"(Lj  
    op.val1 = taq D0>Pc9
 
    op.parent = parID }'K-1:  
    AddOperation eID, op -aV(6i*n  
    Print "Set aqueous humor thickness = " & taq-0.55 #w:nj1{_  
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    '************************************************************************* >*Ej2ex  
    'Radius and conic constant of anterior lens Eu%E2A|`I  
    '************************************************************************* UD9JE S,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) v8n^~=SH  
    GetConic eID, entity, curv, conic N|3#pHm@  
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    SetConic eID, entity, 1/Rant, CCant M+b?qw  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /Z[HU{4  
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    '************************************************************************* T6."j_  
    'Radius and conic constant of posterior lens
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    '************************************************************************* ^;tB,7:*V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) WdB\n/BWB  
    GetConic eID, entity, curv, conic i1'G_bo4F7  
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    SetConic eID, entity, 1/Rpost, CCpost Nr).*]g@~  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost LF#[$ so{i  
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    '************************************************************************* h4+*ssnYV  
    'Lens thickness (Position of posterior lens surface) 5=%KK3  
    '************************************************************************* {'z$5<|  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) p#_5w  
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    ' Delete any z-shift(s) hljKBx~  
    count = 0 7_jlNr7uk  
    While GetOperationCount(eID)>count :,g]Om^  
        GetOperation eID, count, op 29m$S7[  
        If op.Type="ShiftZ" Then Eggu-i(rD  
            DeleteOperation eID,count f1;@a>X  
            count=count-1 "_&c[VptWi  
        End If @#$(Cs*{]  
        count=count+1 e8#83|h  
    Wend M{)&SNI*C  
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    'Set new z-shift 7upWM~H^  
    op.Type = "ShiftZ" W/}_y8q  
    op.val1 = tlens +\)Y,@cw  
    op.parent = parID gNc;P[  
    AddOperation eID, op Nh}u]<B  
    Print "Set lens thickness = " & tlens |lZp5MOc  
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    '************************************************************************* &Yc'X+'4  
    'Lens index of refraction =p"ma83  
    '************************************************************************* _zi| GD  
    eID = FindMaterial( "Lens" ) &U7h9o H  
    GetModelMaterial eID, mat sriDta?Cz  
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    mat.Nd = nlens ek]nLN  
    SetModelMaterial eID, mat
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    Print "Set lens index of refraction = " & nlens s@{~8cHgU  
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    '************************************************************************* xSNGf@1b  
    'Pupil diameter K=nDC.  
    '************************************************************************* 2eA.04F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) p
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    'Adjust pupil diameter (trimming volume inner hole) S^|U"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" SbzJeaZv  
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    ' Adjust pupil location to just in front of the lens [t$ r)vX  
    parID = FindFullName( "Geometry.Arizona Eye" ) .Eb]}8/}E  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) R/*"N'nH-%  
    count = 0 ';My"/ Z-  
    While GetOperationCount(eID)>count j"aY\cLr t  
        GetOperation eID, count, op BV }CmU&DA  
        If op.Type="ShiftZ" Then E_DQ.!U!o  
            DeleteOperation eID,count c:&8B/  
            count=count-1 &q9=0So4\  
        End If }.Z`   
        count=count+1 t|hc`|  
    Wend 5E1`qof  
    op.Type = "ShiftZ" *Uj;a.  
    op.val1 = taq-0.01 :#35mBe}k  
    op.parent = parID %KkC1.yu<  
    AddOperation eID, op G2?#MO  
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    Print "Set pupil diameter = " & pupilDiam }!R*Q`m  
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    'Update AZ Eye subassembly Description Y:L[Iz95o  
    eID = FindFullName( "Geometry.Arizona Eye" )  _cj=}!I  
    GetEntity eID, entity _DT,iF*6  
    entity.Description = "Accommodation = " & A & "D" DR:DXJc  
    SetEntity eID, entity G5K?Q+n   
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    Update (GC5r#AnS  
    Print "DONE!" ,(zV~-:9  
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End Sub 8ih_S2Cd  
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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： N6\rjYx+7  
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Accommodation = 4 Diopters 9H/R@i[E  
Pupil Diameter = 4 mm |iX>hJSl  
Set aqueous humor thickness = 2.81 dcD#!v\0  
Set anterior lens radius = 10.4 and conic constant = -2.375869 D4|Ajeo;1  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]+3M\ ib  
Set lens thickness = 3.927 7aKI=;60.  
Set lens index of refraction = 1.42672 ge.>#1f}  
Set pupil diameter = 4 \k`9s q  
DONE! 6$=>ckP