[技术]Arizona眼睛模型 [复制链接]

简介 L]wk Ba  
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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。 j]'ybpMT"  
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模型 8iUYZF  
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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。 9}$'q$0R]  
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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. c

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光源 SQ-CdpT<  
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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。 D9%t67s  
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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。 FJ] ?45  
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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。 W.nr&yiQ  
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视网膜的散射 5%]O'h  
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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。 KJi8LM  
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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。 r1[#_A`Yn  
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脚本 e'2w-^7  
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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。 ?*:BgaR_  
余下的脚本计算与屈光度有关的所有参数。 ^?S 
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分析 r#B{j$Rw   
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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。 ]SUW"5L-  
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脚本代码 y*T@_on5  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 5`)
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Dim entity As T_ENTITY kiu#THF  
Dim op As T_OPERATION 8gJg7RxL  
Dim mat As T_MODELMATERIAL $k^& X `  
Dim A As Double +,UuJ6[n  
Dim pupilDiam As Double x,Z:12H0  
Dim eID As Long ,'byJlw_pv  
Dim parID As Long \RmU6(;IQ  
Dim count As Integer 3j\Py'};  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &H/3@A3  
Dim tlens As Double, nlens As Double l}W"> yQ0  
Dim curv As Double, conic As Double p~z\&&0U0  
Dim ok As Long vu3zZMl  
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Sub Main &:#"APX  
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    '用户输入对话框 pt%Y1<9Eh?  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 wp<f{^ et  
        TextBox 220,21,40,21,.TextBox1 'default: 0 USV;j%U4*  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 t:%u4\nZ;  
        OKButton 40,91,90,21 TE-(Zil\  
        CancelButton 190,91,90,21 W.>}5uVl6  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 @Uqcym.  
        TextBox 220,49,40,21,.TextBox2 'default: 4 @wh-.MD  
    End Dialog K Vnz{cx`  
    Dim dlg As UserDialog 6t'vzcQs  
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    ok = Dialog (dlg) mV|Z5=f  
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    If ok=0 Then    'cancel button was pressed Ur(< ]  
        Print "Execution cancelled." +K48c,gt?  
        End 3-_`x9u*  
    End If t]+h.  
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    'Assign accommodation and pupil diameter & use defaults if field left empty v K!vA-7  
    If dlg.TextBox1 = "" Then }VqCyJu&{  
        A = 0           'Default accommodation vY]7oX+  
    Else E2Ec
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        A = CDbl(dlg.TextBox1) rhC x&L  
    End If 8>'vzc/*>  
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    If dlg.TextBox2 = "" Then 
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        pupilDiam = 4   'Default pupil diameter i)@H  
    Else Dj{=Y`Tw  
        pupilDiam = CDbl(dlg.TextBox2) _@O.EksY3r  
    End If mBDzc(_\$'  
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    Print " " @|fT%Rwho<  
    Print "Accommodation = " & A & " Diopters" 4]no#lVRJ  
    Print "Pupil Diameter = " & pupilDiam & " mm" AizLzR$OG  
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    ' Calculate new parameters with accommodation a>egH og  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,j%f
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens gqDSHFm:  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens BCt>P?,UO  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens gNSsT])  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -qpe;=g&f  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `}#n
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Z+ )<FX  
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    'Adjust parameters to account for accommodation 8xYeaK  
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    '************************************************************************* 1  Lz  
    'Aqueous thickness (Position of Lens) g4GU
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    '************************************************************************* J+YoAf`hi  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) a t%qowt  
    GetCustomElement eID, entity mf\@
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    parID = FindFullName( "Geometry.Arizona Eye" ) <'vtnz  
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    ' Delete any shift(s) in z "*N]Y^6/A  
    count = 0 >C -N0H
 
    While GetOperationCount(eID)>count s;xErH@RA  
        GetOperation eID, count, op >H,PST  
        If op.Type="ShiftZ" Then jNW/Biy4u  
            DeleteOperation eID,count K4^mG  
            count=count-1 7QHrb'c  
        End If Y{2L[5_1  
        count=count+1 :@J.!dokF  
    Wend 3.@ir"vy  
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    'Set new shift in ig4mj47wJ  
    op.Type = "ShiftZ" <ugy-vSv  
    op.val1 = taq / a$B8,  
    op.parent = parID w>&g'  
    AddOperation eID, op )<_:%oB  
    Print "Set aqueous humor thickness = " & taq-0.55 >C/O >g  
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    '************************************************************************* pR3K~bx^  
    'Radius and conic constant of anterior lens U9h@1:  
    '************************************************************************* "PC9[i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) F,JqHa9  
    GetConic eID, entity, curv, conic  nw  
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    SetConic eID, entity, 1/Rant, CCant idNg&'   
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant n hGh5,  
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    '************************************************************************* UKf0cU  
    'Radius and conic constant of posterior lens K"VRHIhfg  
    '************************************************************************* %SwhNn  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Mgg m~|9)  
    GetConic eID, entity, curv, conic \(ju0qFqH  
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    SetConic eID, entity, 1/Rpost, CCpost I=&Kn
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost nH|7XY9"  
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    '************************************************************************* +P;&/z8i*g  
    'Lens thickness (Position of posterior lens surface) ^4{"h  
    '************************************************************************* P yN{  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) w~WW2w  
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    ' Delete any z-shift(s) P#qQde/y  
    count = 0  @+!u{  
    While GetOperationCount(eID)>count p-B |Gr|  
        GetOperation eID, count, op /t_AiM,(  
        If op.Type="ShiftZ" Then "i;"  
            DeleteOperation eID,count $ 1v'CT  
            count=count-1 q 1+{MPJ  
        End If 7SjWofv  
        count=count+1 zl@hg<n  
    Wend `_>44!M  
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    'Set new z-shift oPR?Ar  
    op.Type = "ShiftZ" YUQKy2  
    op.val1 = tlens N6%M+R/Q  
    op.parent = parID swG!O}29OX  
    AddOperation eID, op 'klYGp  
    Print "Set lens thickness = " & tlens #>O>=#Q  
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    '************************************************************************* vXeI)vFK  
    'Lens index of refraction +cC$4t0$^A  
    '************************************************************************* 9M1UkS$`@  
    eID = FindMaterial( "Lens" ) ,2lH*=m;  
    GetModelMaterial eID, mat obSLy Ed  
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    mat.Nd = nlens T#-U\C~o  
    SetModelMaterial eID, mat 5ii:93Hlj  
    Print "Set lens index of refraction = " & nlens yPVK>em5  
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    '*************************************************************************  El|Y]f  
    'Pupil diameter JId|LHf*P  
    '************************************************************************* TV*@h2C"i  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0i/!nke.  
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    'Adjust pupil diameter (trimming volume inner hole) 2t`d.s=  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _?a.S8LxJZ  
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    ' Adjust pupil location to just in front of the lens w4j,t  
    parID = FindFullName( "Geometry.Arizona Eye" ) xaW9Sj0ZM  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) dn:/8~B"X  
    count = 0 {}N=pL8MS  
    While GetOperationCount(eID)>count <
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        GetOperation eID, count, op T{zz3@2?  
        If op.Type="ShiftZ" Then b0 y*}  
            DeleteOperation eID,count A!^gF~5  
            count=count-1 s.XLC43Rs  
        End If @]X5g8h  
        count=count+1 
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    Wend P%Tffsl  
    op.Type = "ShiftZ" `nEe-w^9)I  
    op.val1 = taq-0.01 q,*([yX  
    op.parent = parID U$^$7g 3  
    AddOperation eID, op _e94  
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    Print "Set pupil diameter = " & pupilDiam  @t<KS&  
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    'Update AZ Eye subassembly Description %M u$0~ct"  
    eID = FindFullName( "Geometry.Arizona Eye" ) L5A?9zum/!  
    GetEntity eID, entity N_| '`]D  
    entity.Description = "Accommodation = " & A & "D" zE1=*zO`  
    SetEntity eID, entity gkL{]*9&%  
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    Update #Iwxt3K  
    Print "DONE!" *W$bhC'w  
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End Sub ,'>O#kD  
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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： _68{ {.  
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Accommodation = 4 Diopters E% d3}@  
Pupil Diameter = 4 mm GLr7sack  
Set aqueous humor thickness = 2.81 T7~Vk2o%(  
Set anterior lens radius = 10.4 and conic constant = -2.375869 D);w)`  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 j/uu&\e  
Set lens thickness = 3.927 o2W^!#]=
 
Set lens index of refraction = 1.42672 22FHD4  
Set pupil diameter = 4 G'f
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DONE! 0t(js_