[技术]Arizona眼睛模型 [复制链接]

简介 c_z/At;4  
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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。 e.}3OK  
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模型 hdf8U  
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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/h:&B:;  
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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. }r~v,KDb  
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光源 V8nz-DL{  
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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:zLjtp  
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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。 8tV=fSHd  
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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。 co<2e#p;  
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视网膜的散射 Ko$ $dkSE  
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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。 +Mk*{A t  
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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。 QH7V_#6bKP  
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脚本 YW?7*go'Z  
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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： j}rgO
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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。 $f<eq7rRe  
余下的脚本计算与屈光度有关的所有参数。 "ibK1}-  
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分析 L _vblUDq  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 nd$H 3sf  
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脚本代码 ?(5o@Xq  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. aUypt(dv  
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Dim entity As T_ENTITY =@
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Dim op As T_OPERATION IvEMg2f}  
Dim mat As T_MODELMATERIAL ]regi- LGU  
Dim A As Double y2z{rd  
Dim pupilDiam As Double H!unIy|  
Dim eID As Long tt+>8rxF:;  
Dim parID As Long " Sc5qG  
Dim count As Integer )ZT6:)  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 'ox0o:  
Dim tlens As Double, nlens As Double |. J,8~x  
Dim curv As Double, conic As Double - *:p.(c  
Dim ok As Long SX1X<9  
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Sub Main
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    '用户输入对话框 hMNJ'i}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 bH'S.RWp=  
        TextBox 220,21,40,21,.TextBox1 'default: 0 mSU@UD|'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ;M}i
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        OKButton 40,91,90,21 7V~ "x&Eu  
        CancelButton 190,91,90,21 fA"<MslKLK  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 h7bPAW=(  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Of-C  
    End Dialog 7)B&(2D&  
    Dim dlg As UserDialog @)o0GHNP  
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    ok = Dialog (dlg) z'7#"D  
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    If ok=0 Then    'cancel button was pressed 7sXy`+TZ->  
        Print "Execution cancelled." X.s*>'  
        End sB?2*S"X)<  
    End If *R5`.j =  
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    'Assign accommodation and pupil diameter & use defaults if field left empty RTK}mhnV  
    If dlg.TextBox1 = "" Then p`d XqW  
        A = 0           'Default accommodation py]KTRzy  
    Else gh TcB  
        A = CDbl(dlg.TextBox1) LyGUvi  
    End If ]53O}sH>  
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    If dlg.TextBox2 = "" Then T_eJ}(p  
        pupilDiam = 4   'Default pupil diameter @zo7.'7P  
    Else (@+h5@J[`I  
        pupilDiam = CDbl(dlg.TextBox2) #S%4?  
    End If G@9u:\[l  
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    Print " " @!e~G'j%VD  
    Print "Accommodation = " & A & " Diopters" os[ZIHph  
    Print "Pupil Diameter = " & pupilDiam & " mm" d]8_l1O  
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    ' Calculate new parameters with accommodation q%>7L<r  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness qB:AkMd&  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [cDbaq,T  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~F;CE"3A  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :V-k'hm &  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens "#2pT H~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness \^
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction T'.[F  
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    'Adjust parameters to account for accommodation L x.jrF|&  
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    '************************************************************************* vs+QbI6>-  
    'Aqueous thickness (Position of Lens) .$Y? W<  
    '************************************************************************* s O=4IBE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZZ("-#?  
    GetCustomElement eID, entity i E9\_MA  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ?W!ry7gXO  
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    ' Delete any shift(s) in z \]8VwsP  
    count = 0 xdZ<| vMR  
    While GetOperationCount(eID)>count @.gPJMA  
        GetOperation eID, count, op ]boE{R!I  
        If op.Type="ShiftZ" Then n3$gx,KL  
            DeleteOperation eID,count \,R!S/R#  
            count=count-1 [/cIUQ  
        End If [(ygisqt  
        count=count+1 s)ky/ce  
    Wend H@D;e  
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    'Set new shift in #dxvz^2V.3  
    op.Type = "ShiftZ" q jz3<`7-  
    op.val1 = taq |gv{z"  
    op.parent = parID DtI$9`~  
    AddOperation eID, op u]E.iXp  
    Print "Set aqueous humor thickness = " & taq-0.55 1HbFtU`y~  
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    '************************************************************************* NEVp8)w  
    'Radius and conic constant of anterior lens >3PMnI  
    '************************************************************************* <7'&1=%r  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6{=_718l`  
    GetConic eID, entity, curv, conic P
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    SetConic eID, entity, 1/Rant, CCant #!})3_Qc(y  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant JoJukoy}F  
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    '************************************************************************* ubbnFE&PD  
    'Radius and conic constant of posterior lens OCNPi4  
    '************************************************************************* 9x?'}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) &94W-zh  
    GetConic eID, entity, curv, conic E^wyD-ii/  
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    SetConic eID, entity, 1/Rpost, CCpost o=_c2m   
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ()\jCNLT  
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    '************************************************************************* Kkv<"^H  
    'Lens thickness (Position of posterior lens surface) "IFgRaP=  
    '************************************************************************* .z-UOyer  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) bL`eiol6  
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    ' Delete any z-shift(s) dv!r.  
    count = 0 BzN@gQo  
    While GetOperationCount(eID)>count >o/95xk2  
        GetOperation eID, count, op pRi<cO  
        If op.Type="ShiftZ" Then 4 1t
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            DeleteOperation eID,count PeTA$Yl  
            count=count-1 kOjf #@c  
        End If UyiJU~r1  
        count=count+1 -RMi
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    Wend <)U4Xz?  
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    'Set new z-shift &
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    op.Type = "ShiftZ" )`+YCCa6F  
    op.val1 = tlens |"]PCb)!  
    op.parent = parID >jTp6tu,  
    AddOperation eID, op dRaOGm)  
    Print "Set lens thickness = " & tlens +Xy*?5E;C  
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    '************************************************************************* :iPym}CE  
    'Lens index of refraction Riry_   
    '************************************************************************* rs-,0'z,7  
    eID = FindMaterial( "Lens" ) I#G0, &Gv  
    GetModelMaterial eID, mat fU+Pn@'  
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    mat.Nd = nlens Q5a)}6-5  
    SetModelMaterial eID, mat nwmW.(R4  
    Print "Set lens index of refraction = " & nlens }}r> K}  
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    '************************************************************************* X+82[Y,mB.  
    'Pupil diameter $`J_:H%  
    '************************************************************************* #hw>tA6
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (gXN%rsY  
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    'Adjust pupil diameter (trimming volume inner hole) Um.qRZ?  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ",Cr,;]  
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    ' Adjust pupil location to just in front of the lens ytAWOt}`  
    parID = FindFullName( "Geometry.Arizona Eye" ) ~E5z"o6$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) hdma=KqZ(  
    count = 0 %)(Cp-b!  
    While GetOperationCount(eID)>count  Mps5Vv  
        GetOperation eID, count, op L.'}e{ldW  
        If op.Type="ShiftZ" Then fV\]L4%  
            DeleteOperation eID,count s!B/WsK  
            count=count-1 ~bK9R0|<  
        End If vVxD!EL  
        count=count+1 G}nO@  
    Wend cr;`Tl~}s  
    op.Type = "ShiftZ" ^Q}eatEn  
    op.val1 = taq-0.01 ec3<%+0f  
    op.parent = parID S<wj*"|.s  
    AddOperation eID, op YN/}9.  
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    Print "Set pupil diameter = " & pupilDiam EHf\L  
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    'Update AZ Eye subassembly Description #q\x$  
    eID = FindFullName( "Geometry.Arizona Eye" ) %;xOB^H^  
    GetEntity eID, entity 5Wx~ZQZ  
    entity.Description = "Accommodation = " & A & "D" mN_Z7n;^eh  
    SetEntity eID, entity 0Q5^C!K  
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    Update k@mVxnC  
    Print "DONE!" TFQ!7'xk)  
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End Sub Fr2N[\>s  
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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： zCaT tb|@  
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Accommodation = 4 Diopters }f}}A=  
Pupil Diameter = 4 mm PJ4(}a  
Set aqueous humor thickness = 2.81 i5}
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Set anterior lens radius = 10.4 and conic constant = -2.375869 *iA4:EIP  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 \*t~==WB
 
Set lens thickness = 3.927 _HOIT  
Set lens index of refraction = 1.42672 `{v?6:G:Q  
Set pupil diameter = 4 sBX-X$*N  
DONE! 2BXy<BM @