[技术]Arizona眼睛模型 [复制链接]

简介 /1MmOB  
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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。 <mQXS87  
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模型 ?>Sv_0  
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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。 =}0Uw4ub(u  
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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. ;.V/ngaj  
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光源 QQBh)5F  
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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。 8@;]@c)m  
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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。 -N8r
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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。 -g@!\{  
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视网膜的散射 mux/\TII  
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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。 ECOJ .^  
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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。 d5$D[,`1  
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脚本 eX+36VG\  
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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： W:_-I4q~
 
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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。 (QDKw}O2b  
余下的脚本计算与屈光度有关的所有参数。 7%y$^B7{  
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分析 Ix-Mp   
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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。  >Uw:cq  
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脚本代码 z`zz8hK.  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Vu3DP+u|i  
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Dim entity As T_ENTITY V|8'3=Z=
 
Dim op As T_OPERATION P8eCaZg?(3  
Dim mat As T_MODELMATERIAL  6:zPWJB  
Dim A As Double 3vY-;&  
Dim pupilDiam As Double ?9`j1[0  
Dim eID As Long w:5?ofC  
Dim parID As Long ON,[!pc  
Dim count As Integer W/qXQORv  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double cnu&!>8V  
Dim tlens As Double, nlens As Double o701RG~)  
Dim curv As Double, conic As Double j%6p:wDl  
Dim ok As Long 731Lz*IFg  
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Sub Main dKzG,/1W[m  
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    '用户输入对话框 NM{)liP ;8  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Xq?>a+B  
        TextBox 220,21,40,21,.TextBox1 'default: 0 M& ZKc
 
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Xdn&%5rI  
        OKButton 40,91,90,21 b j&!$')  
        CancelButton 190,91,90,21 U#z"t&o=L  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (Ceruo S  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Ui'v' $  
    End Dialog if*V-$[I  
    Dim dlg As UserDialog )]fsl_Yq  
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    ok = Dialog (dlg) JWNN5#=fQ  
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    If ok=0 Then    'cancel button was pressed T8S&9BM7  
        Print "Execution cancelled." ]3 "0#Y  
        End %p 6Ms  
    End If zDvV%+RW)  
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    'Assign accommodation and pupil diameter & use defaults if field left empty f)Qln[/  
    If dlg.TextBox1 = "" Then p/{%%30ke  
        A = 0           'Default accommodation tK3$,9+  
    Else
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        A = CDbl(dlg.TextBox1) j,OA>{-$  
    End If *$A`+D9  
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    If dlg.TextBox2 = "" Then |Yli~Qx  
        pupilDiam = 4   'Default pupil diameter I'5[8  
    Else wq?"NQ?O<  
        pupilDiam = CDbl(dlg.TextBox2) \'2rs152  
    End If && ]ix3  
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    Print " " RvR.t"8  
    Print "Accommodation = " & A & " Diopters" -C2!`/
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    Print "Pupil Diameter = " & pupilDiam & " mm" jRsl/dmy  
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    ' Calculate new parameters with accommodation )<QX2~m<  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ]!TE  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens /`M#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens JZ}zXv  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Z66Xj-o  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens wqG#jC!5  
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    tlens = 3.767 + 0.04*A                  'Lens thickness vd%AV(]<LJ  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction X@kgc&`0  
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    'Adjust parameters to account for accommodation _n:RA)4*  
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    '************************************************************************* Ar)EbGId  
    'Aqueous thickness (Position of Lens) qlM<X?  
    '************************************************************************* ,=e.QAF!"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :i{M1z I  
    GetCustomElement eID, entity k{r<S|PK0  
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    parID = FindFullName( "Geometry.Arizona Eye" ) }k.yLcXM  
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    ' Delete any shift(s) in z :?UcD_F  
    count = 0 >)D=PvGlmp  
    While GetOperationCount(eID)>count Ko&4{}/  
        GetOperation eID, count, op W$X/8K bn  
        If op.Type="ShiftZ" Then 3D6&0xTq  
            DeleteOperation eID,count &j~9{ C  
            count=count-1 '9QEG
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        End If R?1Z[N  
        count=count+1 .$s']' =  
    Wend fTpG>*{p  
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    'Set new shift in g(zeOS]q}  
    op.Type = "ShiftZ" ^zTe9:hz/\  
    op.val1 = taq r\QV%09R  
    op.parent = parID iuj%.}  
    AddOperation eID, op |fyzb=Lg  
    Print "Set aqueous humor thickness = " & taq-0.55 xbi\KT`~  
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    '************************************************************************* H*G(`Zl}  
    'Radius and conic constant of anterior lens ;o'>`=Y  
    '************************************************************************* >-V632(/{o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yT:2*sZRc
 
    GetConic eID, entity, curv, conic P$z%:Q  
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    SetConic eID, entity, 1/Rant, CCant PK|qiu-O&*  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N( 7(~D=)B  
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    '************************************************************************* )o:sDj`b]  
    'Radius and conic constant of posterior lens &bq1n_  
    '************************************************************************* Y'0
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) khjdTq\\  
    GetConic eID, entity, curv, conic <r <{4\%}  
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    SetConic eID, entity, 1/Rpost, CCpost 13 h,V]ak  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &*o4~6pQ#  

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    '************************************************************************* %h(%M'm?  
    'Lens thickness (Position of posterior lens surface) N?t*4Y  
    '************************************************************************* WL(Y1>|j  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) QDj%m%Xd  
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    ' Delete any z-shift(s) #qk=R7"Q  
    count = 0 MA_YMxP.'  
    While GetOperationCount(eID)>count VMF?qT3Nd  
        GetOperation eID, count, op Q7e4MKy7  
        If op.Type="ShiftZ" Then q.R(>Zc
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            DeleteOperation eID,count #
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            count=count-1 vn*K\,  
        End If ;o)'dK  
        count=count+1 s)E8}-v  
    Wend YJ6:O{AL1  

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    'Set new z-shift >&fD:y'&  
    op.Type = "ShiftZ" SVZ@'X\[M  
    op.val1 = tlens 8&HBR #  
    op.parent = parID &\ca ? #  
    AddOperation eID, op lH?jqp
  
    Print "Set lens thickness = " & tlens <V}q8k  
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    '************************************************************************* zOA~<fhT  
    'Lens index of refraction %CYo, e  
    '************************************************************************* D1+1j:m  
    eID = FindMaterial( "Lens" ) @i> r(
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    GetModelMaterial eID, mat I9L3Y@(f6m  
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    mat.Nd = nlens FZ%h7Oe  
    SetModelMaterial eID, mat &Jb$YKt  
    Print "Set lens index of refraction = " & nlens /~s<@<1!X  
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    '************************************************************************* Lp"OXJ*es  
    'Pupil diameter \VEnP=*:W  
    '************************************************************************* >Vx_Xv`Jwb  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %Iflf]l  
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    'Adjust pupil diameter (trimming volume inner hole) &n8Ja@Y]  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" LCS.C(n,  
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    ' Adjust pupil location to just in front of the lens OY(CB(2N  
    parID = FindFullName( "Geometry.Arizona Eye" ) Jlb{1B$7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s* u1n+Zq  
    count = 0 &+(D< U  
    While GetOperationCount(eID)>count #J3}H  
        GetOperation eID, count, op _:NQF7X#ug  
        If op.Type="ShiftZ" Then #wT6IU1  
            DeleteOperation eID,count f*"T]AX0  
            count=count-1 OA6i/3 #8  
        End If k7@QFw4 j  
        count=count+1 ha;fxM]  
    Wend @",
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    op.Type = "ShiftZ" !%}n9vr!}\  
    op.val1 = taq-0.01 ^S;{;c+'  
    op.parent = parID !^y;|9?O  
    AddOperation eID, op 9XQE5^  
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    Print "Set pupil diameter = " & pupilDiam 
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    'Update AZ Eye subassembly Description Q[#8ErUY  
    eID = FindFullName( "Geometry.Arizona Eye" ) S?`0,F  
    GetEntity eID, entity h*y+qk-!\g  
    entity.Description = "Accommodation = " & A & "D" stfniV  
    SetEntity eID, entity z]hRc8g}d  
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    Update o~y{9Q  
    Print "DONE!" 2DsP "q79k  
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End Sub k ?6d\Q  
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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： IQC[ewk  
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Accommodation = 4 Diopters 'l!\2Wv2  
Pupil Diameter = 4 mm \WnTpl>B  
Set aqueous humor thickness = 2.81 S]%,g%6i  
Set anterior lens radius = 10.4 and conic constant = -2.375869 SX'NFdY  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 C[%&;\3S@  
Set lens thickness = 3.927 ]D5Maid+  
Set lens index of refraction = 1.42672 VFF5Tp  
Set pupil diameter = 4 CDtL.a\  
DONE! 3t.!5L