[技术]Arizona眼睛模型 [复制链接]

简介 ^IIy>  
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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。 &g^*ep~|#  
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模型 #+AQ:+  
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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*A-&9.p3  
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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. /9I/^i~  
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光源 {A
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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。 uXh:/KO  
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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。 gC/ e]7FNr  
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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。 tZKw(<am  
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视网膜的散射 :\His{%  
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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。 W_Y8)KxG:L  
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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。 uy3<2L#.  
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脚本 K=v:qY4Z  
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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： =ZIT!B?4  
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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。 \BXzmok  
余下的脚本计算与屈光度有关的所有参数。 CG=c@-"n/  
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分析 3$k#bC  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 +ZOiL[rS  
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脚本代码 x^f)I|t  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =79R;|5  
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Dim entity As T_ENTITY fq6%@M~  
Dim op As T_OPERATION [
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Dim mat As T_MODELMATERIAL Vi8A4  
Dim A As Double YNU}R/u6^  
Dim pupilDiam As Double "S%t\  
Dim eID As Long FI$:R  
Dim parID As Long ;Y`Y1  
Dim count As Integer tUJRNEg  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double |HAJDhM,l  
Dim tlens As Double, nlens As Double e /JQ #A  
Dim curv As Double, conic As Double ;[sW\Ou  
Dim ok As Long /8h=6"  
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Sub Main lrT2*$ w3  
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    '用户输入对话框 3`HK^((o  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 yJm"vN  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \beO5]KS<  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \WCQ>c?~  
        OKButton 40,91,90,21 0Z9DewwP  
        CancelButton 190,91,90,21 RwWg:4  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 8-#%l~dr  
        TextBox 220,49,40,21,.TextBox2 'default: 4 d,"LZ>hNY*  
    End Dialog l]R0r{{  
    Dim dlg As UserDialog zN4OrG0  
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    ok = Dialog (dlg) :o'XE|N  
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    If ok=0 Then    'cancel button was pressed \2i7\U  
        Print "Execution cancelled." Z',!LK!  
        End 0CrsZtX  
    End If wSTulo:9  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~7
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    If dlg.TextBox1 = "" Then ?['!0PF  
        A = 0           'Default accommodation Tu#< {'1$  
    Else ):D"LC  
        A = CDbl(dlg.TextBox1) =Ph8&l7~sp  
    End If Sjpx G@k  
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    If dlg.TextBox2 = "" Then -Aj)<KNx[  
        pupilDiam = 4   'Default pupil diameter V2YK T,5  
    Else 200yN+ec  
        pupilDiam = CDbl(dlg.TextBox2) "ZuuSi  
    End If *v>ZE6CL  
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    Print " " q+ $6D;9  
    Print "Accommodation = " & A & " Diopters" 3$$E0`7.  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1o_
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    ' Calculate new parameters with accommodation 1 DWoL}Z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness CLb6XnkcA\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens kI{DxuTad  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens yPm2??5MW>  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens C6_(j48&  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens vJkc/7  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Y::0v@&(  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^URCnJ67Se  
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    'Adjust parameters to account for accommodation kIrrbD  
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    '************************************************************************* [m t.2.  
    'Aqueous thickness (Position of Lens) s[1ao"sZ^  
    '************************************************************************* @=Kq99=\U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) '=\}dav!  
    GetCustomElement eID, entity `&$8/_`  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ;SR ESW  
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    ' Delete any shift(s) in z <#63tN9  
    count = 0 EP;/[O  
    While GetOperationCount(eID)>count XZ rI w  
        GetOperation eID, count, op L"L3n,%F  
        If op.Type="ShiftZ" Then c}x1-d8  
            DeleteOperation eID,count G7-BeA8  
            count=count-1 z`y9<+  
        End If CUA @CZ6{  
        count=count+1 +Q*`kg'  
    Wend 15$xa_w}L  
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    'Set new shift in .p`4>XA  
    op.Type = "ShiftZ" %B3~t>  
    op.val1 = taq R;& >PFmq  
    op.parent = parID H#-3  
    AddOperation eID, op KWwtL"3  
    Print "Set aqueous humor thickness = " & taq-0.55 Hh<H~s [  
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    '************************************************************************* d1/emwH  
    'Radius and conic constant of anterior lens 6Z/`p~e  
    '************************************************************************* ]`E+HLEQ'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Nz{dnV{&x;  
    GetConic eID, entity, curv, conic <G"cgN#]  
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    SetConic eID, entity, 1/Rant, CCant FoefBo?g65  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant bIKg>U'5d  
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    '************************************************************************* fSh5u/F!  
    'Radius and conic constant of posterior lens JFq wC=-  
    '************************************************************************* `h}eP[jA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?@V R%z  
    GetConic eID, entity, curv, conic $o6/dEKQ  
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    SetConic eID, entity, 1/Rpost, CCpost E'5*w6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost vNv?trw  
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    '************************************************************************* Ku;fZN[g  
    'Lens thickness (Position of posterior lens surface) l=^A41L_  
    '************************************************************************* WxdQ^#AE  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) f*ZU a  
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    ' Delete any z-shift(s) ]{-.?W*$  
    count = 0 4Nm>5*]  
    While GetOperationCount(eID)>count ?0b-fL^^+l  
        GetOperation eID, count, op z,HhSW?&^  
        If op.Type="ShiftZ" Then L aTcBcI  
            DeleteOperation eID,count c0Ug
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            count=count-1 owVvbC2<b(  
        End If \j)Evjw  
        count=count+1 J )1  
    Wend :,BAw ,  
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    'Set new z-shift 
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    op.Type = "ShiftZ" 3WV(Ok  
    op.val1 = tlens |%_C$s%  
    op.parent = parID {N(qS'N  
    AddOperation eID, op \BOoY#!a  
    Print "Set lens thickness = " & tlens n `j._G  
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    '*************************************************************************
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    'Lens index of refraction %lKw+D  
    '************************************************************************* GR,2^]<{  
    eID = FindMaterial( "Lens" ) -15e  
    GetModelMaterial eID, mat \u=d`}E  
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    mat.Nd = nlens ,CE/o7.FG  
    SetModelMaterial eID, mat =4ygbk  
    Print "Set lens index of refraction = " & nlens :cpj{v;s  
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    '************************************************************************* <y 4(!z"  
    'Pupil diameter WR+j?Fcf  
    '************************************************************************* u09Tlqh0 3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6#w>6g4V~R  
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    'Adjust pupil diameter (trimming volume inner hole) >OG189O  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $C16}^  
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    ' Adjust pupil location to just in front of the lens w,~*ead  
    parID = FindFullName( "Geometry.Arizona Eye" ) ,f03TBD}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) o'Bd. B  
    count = 0 W 4{ T<  
    While GetOperationCount(eID)>count ci,(]T+!  
        GetOperation eID, count, op h yrPu_  
        If op.Type="ShiftZ" Then +in)(a.  
            DeleteOperation eID,count $e^"Inhtqp  
            count=count-1 NP>v@jO  
        End If O[X*F2LC4  
        count=count+1 z$^d_)  
    Wend ZbRRDXk!  
    op.Type = "ShiftZ" F`}'^>  
    op.val1 = taq-0.01 yoE-
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    op.parent = parID DJ ru|2  
    AddOperation eID, op 8lQ/cGAc  
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    Print "Set pupil diameter = " & pupilDiam XY0kd&N8  
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    'Update AZ Eye subassembly Description pEB3qGA  
    eID = FindFullName( "Geometry.Arizona Eye" ) *h^->+0n  
    GetEntity eID, entity &oL"AJU  
    entity.Description = "Accommodation = " & A & "D" y"?`MzcJ0  
    SetEntity eID, entity G<Z}G8FW^  
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    Update @Z]0c=-+  
    Print "DONE!" ]0i[=  
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End Sub Rtf<UhUn  
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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： hB?#b`i^  
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Accommodation = 4 Diopters +o+f\!  
Pupil Diameter = 4 mm He_O+[sc  
Set aqueous humor thickness = 2.81 ]t[%.^5#  
Set anterior lens radius = 10.4 and conic constant = -2.375869 mQj#\<*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 #v c+;`X  
Set lens thickness = 3.927 8~y!X0Ov!  
Set lens index of refraction = 1.42672 R ENCk(  
Set pupil diameter = 4 cT(nKHL  
DONE! zU5@~J