[技术]Arizona眼睛模型 [复制链接]

简介 B>JRta;hj  
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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。 _RAPXU~ 6-  
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模型 G"C'/  
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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。 L-q.Q  
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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. /5SBLp
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光源 0b4QcfB1[  
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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。 3>-^/  
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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。 GsxrqIaD  
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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。 f7\$rx  
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视网膜的散射 QYDSE  
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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。 tpU[KR[
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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。 ]~GwZB'M  
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脚本 >6KuZ_  
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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： COZ<^*=A#p  
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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。 V+(1U|@~  
余下的脚本计算与屈光度有关的所有参数。 +coVE^/w  
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分析 >;LXy  
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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。 ]MKW5
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脚本代码  At@H  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Zi/tax9C  
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Dim entity As T_ENTITY C8W#$a  
Dim op As T_OPERATION #rD0`[pz  
Dim mat As T_MODELMATERIAL JZ3CCf  
Dim A As Double }>]V_}h  
Dim pupilDiam As Double H|JPqBNRh  
Dim eID As Long _)XQb1]  
Dim parID As Long IOhJL'r  
Dim count As Integer F>RL&i  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double '"qTmo!  
Dim tlens As Double, nlens As Double ])`w_y(>  
Dim curv As Double, conic As Double ~.7/o0'+  
Dim ok As Long e ?sMOBPlv  
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Sub Main |Tv}leJF  
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    '用户输入对话框 `1 A,sXfa  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 t/%{R.1MN  
        TextBox 220,21,40,21,.TextBox1 'default: 0 5nF46c  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4}.PQ{  
        OKButton 40,91,90,21 /<C}v~r  
        CancelButton 190,91,90,21 wIQ~a  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =>3wI'I  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ( f]@lNmx  
    End Dialog E.LD1Pm0  
    Dim dlg As UserDialog WVZ](D8Gc]  
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    ok = Dialog (dlg) H?oBax:  
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    If ok=0 Then    'cancel button was pressed L)(JaZyV5  
        Print "Execution cancelled." hQ7-m.UZw  
        End /{Mo'.=Z  
    End If 27J!oin$  
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    'Assign accommodation and pupil diameter & use defaults if field left empty `)y<X#[8  
    If dlg.TextBox1 = "" Then nwS @r  
        A = 0           'Default accommodation `)~]3z
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    Else Z=Z
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        A = CDbl(dlg.TextBox1) QQI,$HId  
    End If Fc&3tw"g  
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    If dlg.TextBox2 = "" Then Ms=5*_J2Jk  
        pupilDiam = 4   'Default pupil diameter 2JdzeJb  
    Else @6lw_E_5  
        pupilDiam = CDbl(dlg.TextBox2) |qs8( 5z0  
    End If kI?+\k\V`  
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    Print " " 6;:z?Q  
    Print "Accommodation = " & A & " Diopters" 2x5^kN7  
    Print "Pupil Diameter = " & pupilDiam & " mm" z( \4{Y  
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    ' Calculate new parameters with accommodation ^/~ZP?%]  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness b1TIVK3m  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 9epMw-)k  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ej,)<*  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o;TS69|D  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens _lG|t6
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    tlens = 3.767 + 0.04*A                  'Lens thickness "hmLe(jo}  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ]4ib^R~Z  
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    'Adjust parameters to account for accommodation **V8a-@  
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    '************************************************************************* <Hf3AB;#4  
    'Aqueous thickness (Position of Lens) a,|Hn  
    '************************************************************************* 5rb<u>e{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) I A%ZCdA;  
    GetCustomElement eID, entity %*zV&H   
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    parID = FindFullName( "Geometry.Arizona Eye" ) 38 ]}+Bb  
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    ' Delete any shift(s) in z %9 3R/bx  
    count = 0 o:'@|(&<  
    While GetOperationCount(eID)>count =Vm3f^  
        GetOperation eID, count, op t`1M}}.  
        If op.Type="ShiftZ" Then Oq^t[X'  
            DeleteOperation eID,count /3#h]5Y"T  
            count=count-1 C$0rl74Wi  
        End If enx+,[  
        count=count+1 eQz.N<f"  
    Wend GrUpATIx  
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    'Set new shift in [_eT{v2B4  
    op.Type = "ShiftZ" hg%iv%1B'  
    op.val1 = taq l 88n*O  
    op.parent = parID #<~oR5ddlb  
    AddOperation eID, op ;Fo7 -kK  
    Print "Set aqueous humor thickness = " & taq-0.55 **$kWbS  
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    '************************************************************************* ,.kmUd  
    'Radius and conic constant of anterior lens /Xq|SO  
    '************************************************************************* s#'Vasu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) k8\KCKql  
    GetConic eID, entity, curv, conic L@'2}7N1%  
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    SetConic eID, entity, 1/Rant, CCant cTW$;Fpc+  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {qGXv@ I6  
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    '************************************************************************* {Q>4zepN!  
    'Radius and conic constant of posterior lens o|u4C{j  
    '************************************************************************* ce;$)Ff\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) =),O;M  
    GetConic eID, entity, curv, conic a~ RY 8s  
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    SetConic eID, entity, 1/Rpost, CCpost LGw-cX #  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost NT2XG&$W>  
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    '************************************************************************* VDro(?p8Z  
    'Lens thickness (Position of posterior lens surface) =;GmLi3A  
    '************************************************************************* A;5_/ 2  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZeY|JH1  
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    ' Delete any z-shift(s) C=CZtjUt  
    count = 0 (-Q~@Q1  
    While GetOperationCount(eID)>count ju5o).!bg  
        GetOperation eID, count, op =`*@OJHH  
        If op.Type="ShiftZ" Then Y}xM&%  
            DeleteOperation eID,count pHx$  
            count=count-1 M)ao}m>  
        End If VFM!K$_  
        count=count+1 Tay$::V  
    Wend ]8R@2L3s  
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    'Set new z-shift </Y(4Xwf=  
    op.Type = "ShiftZ" *P5\T4!+d  
    op.val1 = tlens k]C k%[d  
    op.parent = parID 8KN3|)  
    AddOperation eID, op -+u}u
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    Print "Set lens thickness = " & tlens ,;hpqu
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    '************************************************************************* 
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    'Lens index of refraction Z"'*A\r2  
    '************************************************************************* r`"T{o\e   
    eID = FindMaterial( "Lens" ) PjX V.gz  
    GetModelMaterial eID, mat *iY:R  
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    mat.Nd = nlens
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    SetModelMaterial eID, mat {qlcTc  
    Print "Set lens index of refraction = " & nlens U}4I29M  
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    '************************************************************************* ?-%(K^y4r  
    'Pupil diameter tBfmjxv  
    '************************************************************************* FfxD=\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) rW|%eT*/'A  
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    'Adjust pupil diameter (trimming volume inner hole) Cg?Mk6i  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" O9-`e  
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    ' Adjust pupil location to just in front of the lens [3qH?2&  
    parID = FindFullName( "Geometry.Arizona Eye" ) h_ccE6]t  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) v&(=^A\eN  
    count = 0 wsQ],ZE  
    While GetOperationCount(eID)>count I^( pZ9  
        GetOperation eID, count, op 4X*U~}  
        If op.Type="ShiftZ" Then &o7PB`(l  
            DeleteOperation eID,count J_7@d]0R  
            count=count-1 U,p'<rmS  
        End If XkkzY5rxOc  
        count=count+1 /;w(sU  
    Wend '(C+qwdRv  
    op.Type = "ShiftZ" F!g1.49""  
    op.val1 = taq-0.01 i$p2am
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    op.parent = parID RM,aG}6M)M  
    AddOperation eID, op ;-JFb$m  
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    Print "Set pupil diameter = " & pupilDiam rr2!H%:
 
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    'Update AZ Eye subassembly Description M;b3- i  
    eID = FindFullName( "Geometry.Arizona Eye" ) NOwd'iU  
    GetEntity eID, entity 9G2rVk  
    entity.Description = "Accommodation = " & A & "D" q2J
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    SetEntity eID, entity Q0Do B  
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    Update DnJ `]r  
    Print "DONE!" y\uBVa<B  
    
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End Sub n"aF#HR?0d  
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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： VD@$y^!H  
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Accommodation = 4 Diopters 8x)i{>#i  
Pupil Diameter = 4 mm b/qK/O8J  
Set aqueous humor thickness = 2.81 ?D2a"a$^  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ~GX ]K H  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Yq51+\d  
Set lens thickness = 3.927 +>1?ck  
Set lens index of refraction = 1.42672 c1i:m'b_5  
Set pupil diameter = 4 GTTEg{  
DONE! u&c%L0)E&