[技术]Arizona眼睛模型 [复制链接]

简介 <xOv0B  
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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。
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模型 'BY{]{SL  
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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。 7O6VnKl  
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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. 2,.%]U  
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光源 fAMJFHW  
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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。 c5~d^  
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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。 # 3{g6[Y  
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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。 ^<L;"jl%  
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视网膜的散射 rN3i5.*/t  
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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。 4 I}xygV  
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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。 U'IJwGRP  
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脚本 -OLXRc=  
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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： n ,<`.^  
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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。 \<ohe w  
余下的脚本计算与屈光度有关的所有参数。 $)OUOv
 
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分析 Iq&S6l <0  
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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。 -BWkPq!  
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脚本代码 A=X2zm>9  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. xJ"CAg|
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Dim entity As T_ENTITY %I]?xe6  
Dim op As T_OPERATION f3h&K}x  
Dim mat As T_MODELMATERIAL R#Z1+&='  
Dim A As Double hv xvwV1  
Dim pupilDiam As Double 5- Q`v/w;  
Dim eID As Long )N QtjB$  
Dim parID As Long a7G0  
Dim count As Integer 4_,l[BhsQG  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q?C)5(  
Dim tlens As Double, nlens As Double #UREFwSL  
Dim curv As Double, conic As Double -C$Z%I7 0  
Dim ok As Long lu@#
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Sub Main W-Cf#o  
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    '用户输入对话框 AR\?bB~`c  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W%]sI n  
        TextBox 220,21,40,21,.TextBox1 'default: 0 [woR9azC  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g0.D36  
        OKButton 40,91,90,21 \K 01F  
        CancelButton 190,91,90,21 @URLFMFi  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 SEY  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ki6`d?  
    End Dialog }I7/FqrD  
    Dim dlg As UserDialog ?MhRdY  
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    ok = Dialog (dlg) 3mn0  
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    If ok=0 Then    'cancel button was pressed ^o't&  
        Print "Execution cancelled." +P6#7.p`Z  
        End f}bUuQrH-!  
    End If }+`W[h&u  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Yt*M|0bL  
    If dlg.TextBox1 = "" Then *?oQ6g(Nz  
        A = 0           'Default accommodation 6wzF6]@O  
    Else Yfy6o6*:  
        A = CDbl(dlg.TextBox1) |0w'+HaE~N  
    End If ] K7>R0  
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    If dlg.TextBox2 = "" Then =ox#qg.5  
        pupilDiam = 4   'Default pupil diameter e4NT  
    Else > 3JU  
        pupilDiam = CDbl(dlg.TextBox2) H<`[,t  
    End If <W,k$|w  
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    Print " " o]#Q6J  
    Print "Accommodation = " & A & " Diopters" TMG:fg&E~  
    Print "Pupil Diameter = " & pupilDiam & " mm" G;Y,C<)0k  
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    ' Calculate new parameters with accommodation ;:*o P(9k  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness }
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 6K P!o  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens VO(Ck\i}  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^iubqtT]  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens S^)r,cC  
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    tlens = 3.767 + 0.04*A                  'Lens thickness H'I|tPs  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !U>"H8}dv  
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    'Adjust parameters to account for accommodation J+\F)k>r  
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    '************************************************************************* sNvT0  
    'Aqueous thickness (Position of Lens) RYE::[O7  
    '************************************************************************* |[K7oa~#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) QC<(rx  
    GetCustomElement eID, entity QY+#Vp<`  
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    parID = FindFullName( "Geometry.Arizona Eye" ) +nuv?QB/  
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    ' Delete any shift(s) in z 8tA.d.8  
    count = 0 NG'VlT  
    While GetOperationCount(eID)>count o9wg<LP  
        GetOperation eID, count, op CG9X3%xO%  
        If op.Type="ShiftZ" Then lha)'
 
            DeleteOperation eID,count NH'RU`U)  
            count=count-1 `N(.10~  
        End If T|.Q81.NE  
        count=count+1 10#!{].#x  
    Wend ,zXL8T  
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    'Set new shift in qsvUJU  
    op.Type = "ShiftZ" h| UT/:  
    op.val1 = taq |B`-chK  
    op.parent = parID 18[f_0@ #  
    AddOperation eID, op i
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    Print "Set aqueous humor thickness = " & taq-0.55 h!K B%4V  
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    '************************************************************************* e!4akKw4wD  
    'Radius and conic constant of anterior lens Qmn5umd=?\  
    '************************************************************************* >.{ ..~"K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {Y/|7Cl0  
    GetConic eID, entity, curv, conic Ka_UVKwMro  
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    SetConic eID, entity, 1/Rant, CCant J+IW  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $#RD3#=?u  
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    '************************************************************************* ~|uCZ.;o  
    'Radius and conic constant of posterior lens On'3K+(_  
    '************************************************************************* J.<eX=<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i[\[xfk  
    GetConic eID, entity, curv, conic xh-[]Jz(
 
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    SetConic eID, entity, 1/Rpost, CCpost _5`M( ;hL2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :W1,s53  
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    '************************************************************************* )
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    'Lens thickness (Position of posterior lens surface) V)@MM2,  
    '************************************************************************* 5ef&Ih.3  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tjd"05"@:  
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    ' Delete any z-shift(s) :.35pp,0  
    count = 0 $AXz/fGV  
    While GetOperationCount(eID)>count {?!hUi+  
        GetOperation eID, count, op 19N:9;Ixz  
        If op.Type="ShiftZ" Then b]JN23IS2  
            DeleteOperation eID,count P);Xke  
            count=count-1 8^R>y  
        End If L}21[ N~ky  
        count=count+1 VuPET  
    Wend <khx%<)P  
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    'Set new z-shift z9'0&G L  
    op.Type = "ShiftZ" <
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    op.val1 = tlens _yoG<qI  
    op.parent = parID QE#$bCw  
    AddOperation eID, op (C3d<a\:  
    Print "Set lens thickness = " & tlens O,>&w5  
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    '************************************************************************* UpIf t=@P  
    'Lens index of refraction 7S1!|*/ I  
    '************************************************************************* Bjo&  
    eID = FindMaterial( "Lens" ) CYn}wkz  
    GetModelMaterial eID, mat b@X@5SJFW  
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    mat.Nd = nlens %om7h$D=`  
    SetModelMaterial eID, mat B_&PK7vA  
    Print "Set lens index of refraction = " & nlens .lFSFJ??  
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    '************************************************************************* ua[\npz5  
    'Pupil diameter !<LS4s;  
    '************************************************************************* qnS7z%H8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) z8!u6odu %  
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    'Adjust pupil diameter (trimming volume inner hole) *Qf}4a0  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <R(2 9QN  
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    ' Adjust pupil location to just in front of the lens 6wd]X-G++  
    parID = FindFullName( "Geometry.Arizona Eye" ) wMUnZHd{|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :I$2[K  
    count = 0 G6,8Xwk  
    While GetOperationCount(eID)>count 1CM1u+<iZ  
        GetOperation eID, count, op sWC"^ So  
        If op.Type="ShiftZ" Then ?
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            DeleteOperation eID,count CIDL{i8  
            count=count-1 KCT8Q!\  
        End If I;v`o{  
        count=count+1 V[mQ;:=  
    Wend :A'!u r=\  
    op.Type = "ShiftZ" &f yFUg  
    op.val1 = taq-0.01 bS'r}  
    op.parent = parID a82mC r  
    AddOperation eID, op xY S%dLE"  
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    Print "Set pupil diameter = " & pupilDiam ul?BKV+3E  
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    'Update AZ Eye subassembly Description ?>y-5B[K/(  
    eID = FindFullName( "Geometry.Arizona Eye" ) V~_nyjrJM  
    GetEntity eID, entity )1vojp 4Za  
    entity.Description = "Accommodation = " & A & "D" ~ YK<T+  
    SetEntity eID, entity #{M -3  
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    Update -!0LIr:"  
    Print "DONE!" vO_quQ[.  
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End Sub p.9v<I%0  
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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： LU{Z  
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Accommodation = 4 Diopters *r`Yz}  
Pupil Diameter = 4 mm 9^^#I~-  
Set aqueous humor thickness = 2.81 $dP)8_Z2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 %D r?.e  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 j0~3[dyqU  
Set lens thickness = 3.927 `X='g96C1  
Set lens index of refraction = 1.42672 `0i3"06lr  
Set pupil diameter = 4 '-IT@}  
DONE! f}X8|GlBo