[技术]Arizona眼睛模型 [复制链接]

简介 @Y*ONnl  
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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。 swuW6p  
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模型 EP7L5GZ-a  
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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。 SZH,I&8  
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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. $+zev$f  
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光源 )Z0pU\  
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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。 k61Ot3  
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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。 TIlcdpwXf  
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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。 K[PIw}V$?:  
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视网膜的散射 3,e^;{w  
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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。 i1ur>4Ns  
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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。 {e0cc1Up}  
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脚本 ,95Nj h  
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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： `] ;*k2  
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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。 xq-R5(k  
余下的脚本计算与屈光度有关的所有参数。 fmY=SqQG-  
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分析 ihBlP\C  
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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。 (S* T{OgO  
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脚本代码 i]a 5cn  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &]3_ .C  
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Dim entity As T_ENTITY TZTi:\nS  
Dim op As T_OPERATION b=horvs/!  
Dim mat As T_MODELMATERIAL Hly2{hokq  
Dim A As Double ='a[(C&Y  
Dim pupilDiam As Double yt}Ve6 m  
Dim eID As Long L,M=ogdb  
Dim parID As Long pca `nN!  
Dim count As Integer Vb az#I  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ZH;VEX  
Dim tlens As Double, nlens As Double sxinA8  
Dim curv As Double, conic As Double zs:OHEZw  
Dim ok As Long ET;YAa*  
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Sub Main .(^KA{  
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    '用户输入对话框 .w/w] Eq  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 3&:Us|}  
        TextBox 220,21,40,21,.TextBox1 'default: 0 n*{aN}auJ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 q}p&<k  
        OKButton 40,91,90,21 A-x; ai]  
        CancelButton 190,91,90,21 | s%--W  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 S#_g/3w  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ad1I2  
    End Dialog m1H_kJ  
    Dim dlg As UserDialog L|pMq!@J  
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    ok = Dialog (dlg) W{:^P0l  
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    If ok=0 Then    'cancel button was pressed _rt+OzZ*L  
        Print "Execution cancelled." zrVw l\&  
        End 2%P{fJbwd  
    End If r0t4\d_&  
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    'Assign accommodation and pupil diameter & use defaults if field left empty AGu#*,K  
    If dlg.TextBox1 = "" Then $X<O\Kna  
        A = 0           'Default accommodation "`HkAW4GZa  
    Else 'Dw+k;RH  
        A = CDbl(dlg.TextBox1) qM78s>\-h  
    End If (37dD!  
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    If dlg.TextBox2 = "" Then kT)[<`
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        pupilDiam = 4   'Default pupil diameter NV\t%/ ?  
    Else l7#5.%A  
        pupilDiam = CDbl(dlg.TextBox2) 1oU/gm$7\q  
    End If xe?!UCUb@  
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    Print " " 0x BO5[w,Y  
    Print "Accommodation = " & A & " Diopters" %PA#x36
 
    Print "Pupil Diameter = " & pupilDiam & " mm" !2L?8oP-z  
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    ' Calculate new parameters with accommodation ^f6pw!  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 1.Kun !w  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `%S 35x9  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3 UUOB.  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens oP>+2.i  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (~S=DFsP  
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    tlens = 3.767 + 0.04*A                  'Lens thickness x -;tV=E}  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9u[^9tL+D  
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    'Adjust parameters to account for accommodation .cks){\  
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    '************************************************************************* U]Y</>xGI  
    'Aqueous thickness (Position of Lens) *G rYB6MT  
    '************************************************************************* $?P5A E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7:/gO~gI  
    GetCustomElement eID, entity |k.%e4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ymvd3>_  
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    ' Delete any shift(s) in z +/+>:  
    count = 0 p~Wy`g-  
    While GetOperationCount(eID)>count 2WO5Af%  
        GetOperation eID, count, op lKdd3W"o  
        If op.Type="ShiftZ" Then +H{TV#+r  
            DeleteOperation eID,count 4og/y0n,l"  
            count=count-1 
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        End If
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        count=count+1 >U\1*F,Om,  
    Wend ^sVr#T  
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    'Set new shift in l+nT$IPF  
    op.Type = "ShiftZ" VW`SqU
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    op.val1 = taq _DouVv>  
    op.parent = parID RCqd2$K"J+  
    AddOperation eID, op J?#Xy9dz  
    Print "Set aqueous humor thickness = " & taq-0.55 5Z@0XI  
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    '************************************************************************* AZ.$g?3w  
    'Radius and conic constant of anterior lens 2A=q{7s  
    '************************************************************************* 3N[Rrxe2  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *fCmZ$U:{  
    GetConic eID, entity, curv, conic Gf=3h4  
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    SetConic eID, entity, 1/Rant, CCant (b;Kl1Ql]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @}\i`H1s  
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    '************************************************************************* %?hvN  
    'Radius and conic constant of posterior lens H)k V8wU  
    '************************************************************************* $GR rTC!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ID: tTltcc  
    GetConic eID, entity, curv, conic +OI<0  
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    SetConic eID, entity, 1/Rpost, CCpost $\+x7"pI  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost s*Nb=v.e9  
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    '************************************************************************* YP Qix  
    'Lens thickness (Position of posterior lens surface) 1}_4C0h\'  
    '************************************************************************* W{%X1::q$  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,!40\"A  
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    ' Delete any z-shift(s) p#%
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    count = 0 OdbXna  
    While GetOperationCount(eID)>count |}?H$d  
        GetOperation eID, count, op %M3L<2  
        If op.Type="ShiftZ" Then &,P; 7R  
            DeleteOperation eID,count .07"I7  
            count=count-1 = GyABK  
        End If G@KDRv  
        count=count+1 G^sx/H76J  
    Wend C*}PL  
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    'Set new z-shift k;B[wEW@  
    op.Type = "ShiftZ" ;W T<]  
    op.val1 = tlens qSGM6kb  
    op.parent = parID Pr:\zI  
    AddOperation eID, op hVz] wKP  
    Print "Set lens thickness = " & tlens H:|.e)$i  
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    '************************************************************************* %AN,cE*  
    'Lens index of refraction iZLy#5(St  
    '************************************************************************* t`="2$NO  
    eID = FindMaterial( "Lens" ) P!"{-m'
  
    GetModelMaterial eID, mat A%2B3@1'q  
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    mat.Nd = nlens X}xf_3N "  
    SetModelMaterial eID, mat 5E]
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    Print "Set lens index of refraction = " & nlens h% KEg667  
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    '************************************************************************* zYP6m3n  
    'Pupil diameter $KQ q~|  
    '************************************************************************* `KtP;nG  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \WBO(,]V  
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    'Adjust pupil diameter (trimming volume inner hole) ?=LT ^Zp`  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Zf1 uK(6X  
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    ' Adjust pupil location to just in front of the lens x|yJCs>  
    parID = FindFullName( "Geometry.Arizona Eye" ) < =~=IZ)  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) j^5YFUwsQg  
    count = 0 eKy!Pai  
    While GetOperationCount(eID)>count z{|0W!nHJ  
        GetOperation eID, count, op B~E">}=!  
        If op.Type="ShiftZ" Then }S8aR:'  
            DeleteOperation eID,count \gA<yz-;N  
            count=count-1 L}CU"  
        End If 8R%<~fq r  
        count=count+1 0TaI"/ai  
    Wend %g:'6%26  
    op.Type = "ShiftZ" dOKp:|9G  
    op.val1 = taq-0.01 KJV8y"^=Q  
    op.parent = parID IA<>+NS  
    AddOperation eID, op Lu{/"&)  
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    Print "Set pupil diameter = " & pupilDiam ^8EW/$k  
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    'Update AZ Eye subassembly Description pbEWnx_  
    eID = FindFullName( "Geometry.Arizona Eye" ) :o'|%JE  
    GetEntity eID, entity Ea&NJ]& g  
    entity.Description = "Accommodation = " & A & "D" 6`7tTn?n  
    SetEntity eID, entity .CnZMw{'  
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    Update 9DJ&J{2W  
    Print "DONE!" *1Bq>h:  
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End Sub *~g*J^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： \wD/TLS}  
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Accommodation = 4 Diopters bS;_xDXd  
Pupil Diameter = 4 mm %-yzU/`JF  
Set aqueous humor thickness = 2.81 *ma w`1
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]}PXN1(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 X5YOxMq  
Set lens thickness = 3.927 >zqaV@T  
Set lens index of refraction = 1.42672 4P[MkMoC  
Set pupil diameter = 4 WM`3QJb  
DONE! sBB[u'h!