[技术]Arizona眼睛模型 [复制链接]

简介 (V9h2g&8L  
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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。 ,U=E[X=
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模型 n2'|.y}Um:  
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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。 6VR[)T%  
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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/ry)2Y=  
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光源 FAtWsk*pgY  
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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。 otnV-7)@  
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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。 /djACA  
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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。 ^x3EotQ\  
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视网膜的散射 x]'H jTqX  
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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。 V.j#E1P  
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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。 BhkAQEsWTQ  
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脚本 
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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： -
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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。 '\'7yN'  
余下的脚本计算与屈光度有关的所有参数。 +{^'i P  
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分析 J~'~[,K  
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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。 4w9F+*-  
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脚本代码 8E-Ip>{>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. U,d2DAvt  
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Dim entity As T_ENTITY iz(m3k:w  
Dim op As T_OPERATION ,i;9[4QMX  
Dim mat As T_MODELMATERIAL R/rcXX7%  
Dim A As Double *V<)p%l.  
Dim pupilDiam As Double GJ>ypEWo  
Dim eID As Long x' ?.~  
Dim parID As Long /rOnm=P+Q  
Dim count As Integer +>^[W~[2  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i _8zjj7  
Dim tlens As Double, nlens As Double "d:.*2Z2  
Dim curv As Double, conic As Double ~Ji>[#W K  
Dim ok As Long H!#5!m&  
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Sub Main %Au T8  
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    '用户输入对话框 U#iT<#!l2  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 sq48#5Tc^r  
        TextBox 220,21,40,21,.TextBox1 'default: 0 35}P0+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 nHE+p\  
        OKButton 40,91,90,21 ^|r`"gOJ3  
        CancelButton 190,91,90,21 tRkrV]K  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 vg5E/+4gp%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 O${r^6Hh  
    End Dialog #'#4hJ*YC  
    Dim dlg As UserDialog P mC82"  
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    ok = Dialog (dlg) $=7H1 w  
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    If ok=0 Then    'cancel button was pressed Hc>([?P%t  
        Print "Execution cancelled." +$'e4EwqV  
        End l(.7t'  
    End If Mi<*6j0  
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    'Assign accommodation and pupil diameter & use defaults if field left empty X3<SP  
    If dlg.TextBox1 = "" Then 20n%o&kG]8  
        A = 0           'Default accommodation Qz'O{f  
    Else  h=:*7>}  
        A = CDbl(dlg.TextBox1) Qb@BV&^y&  
    End If l DgzM3  
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    If dlg.TextBox2 = "" Then NT'Ie]|  
        pupilDiam = 4   'Default pupil diameter bx1G CD  
    Else >h|UCJ1 `  
        pupilDiam = CDbl(dlg.TextBox2) UnJi& ~O  
    End If TeOFAIU  
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    Print " " HW^{;'kH~  
    Print "Accommodation = " & A & " Diopters" oC5gME"2  
    Print "Pupil Diameter = " & pupilDiam & " mm" $hC~af6  
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    ' Calculate new parameters with accommodation A[K:/tB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &mCs%l  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?SBh^/zf  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens hLu&lY  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^XtHF|%0T  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $[WN[J  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 7MR:X#2v>  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction O<gP)ZW~  
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    'Adjust parameters to account for accommodation F^4*|g  
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    '************************************************************************* CR} >  
    'Aqueous thickness (Position of Lens) r9U[-CX:"  
    '************************************************************************* 0]f?Dx/8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) \UVT_=Y  
    GetCustomElement eID, entity <h)deB+}  
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    parID = FindFullName( "Geometry.Arizona Eye" ) #MmmwPB_  
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    ' Delete any shift(s) in z ={e#lC  
    count = 0 FZ;YvdX6  
    While GetOperationCount(eID)>count j(wY/Hl  
        GetOperation eID, count, op :/I={)5  
        If op.Type="ShiftZ" Then H{p[Ghp  
            DeleteOperation eID,count vLVSZX
 
            count=count-1 p]atH<^;K  
        End If s2,`eV  
        count=count+1 #$9U=^Z[  
    Wend 0nF>zOmc  
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    'Set new shift in f)!{y>Q  
    op.Type = "ShiftZ" ^/4{\3  
    op.val1 = taq f?oI'5R41  
    op.parent = parID + xkMW%e<  
    AddOperation eID, op G5C#i7cpm  
    Print "Set aqueous humor thickness = " & taq-0.55 4jI*Y6Wkz  
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    '************************************************************************* PDa0
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    'Radius and conic constant of anterior lens _A# x&<c  
    '************************************************************************* r)*_,Fo|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) tFb|y+  
    GetConic eID, entity, curv, conic TU^tW  
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    SetConic eID, entity, 1/Rant, CCant m"ki*9]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant  Wl}G[>P  
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    '************************************************************************* vM$#m1L?  
    'Radius and conic constant of posterior lens #EwRb<'Em  
    '************************************************************************* s?z=q%-p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) pD)/-Dgdm  
    GetConic eID, entity, curv, conic OmQuAG ^\x  
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    SetConic eID, entity, 1/Rpost, CCpost 0o\=0bH&s  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost y[Fw>g1`q  
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    '************************************************************************* iz$v8;w  
    'Lens thickness (Position of posterior lens surface) uvAy#,
  
    '************************************************************************* dh7)N}2  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3vEjf  
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    ' Delete any z-shift(s) |Cxip&e>  
    count = 0 }tg:DG  
    While GetOperationCount(eID)>count YQw/[  
        GetOperation eID, count, op ?PH}b?f4  
        If op.Type="ShiftZ" Then =&<$I  
            DeleteOperation eID,count s`7 _J9  
            count=count-1 tue%L]hc  
        End If -t706(#k  
        count=count+1 g#bfY=C  
    Wend ]f+D& qZ B  
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    'Set new z-shift .>\>F{#~  
    op.Type = "ShiftZ" =FC;d[U  
    op.val1 = tlens 0DP%44Cv9  
    op.parent = parID q=L* 99S  
    AddOperation eID, op c&iK+qvh{  
    Print "Set lens thickness = " & tlens &t@6qi`d  
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    '************************************************************************* clU3#8P!=  
    'Lens index of refraction kkuQ"^<J  
    '************************************************************************* &B>uPZ]
 
    eID = FindMaterial( "Lens" ) [n@!=T  
    GetModelMaterial eID, mat 2ucsTh@  
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    mat.Nd = nlens I@3c QxI  
    SetModelMaterial eID, mat 6d?2{_},  
    Print "Set lens index of refraction = " & nlens bm]dz;ljh  
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    '************************************************************************* @=| b$E  
    'Pupil diameter }sN9QgE  
    '************************************************************************* %BP)m(S7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) eDMwY$J  
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    'Adjust pupil diameter (trimming volume inner hole) {83He@  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" h[v3G<C~r  
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    ' Adjust pupil location to just in front of the lens {UVm0AeUq  
    parID = FindFullName( "Geometry.Arizona Eye" ) H<}Fk9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @nW(KF  
    count = 0 d"$oV~>P|  
    While GetOperationCount(eID)>count hF%~iqd  
        GetOperation eID, count, op FT?1Q'  
        If op.Type="ShiftZ" Then ?9ho|  
            DeleteOperation eID,count o[+|n[aT)3  
            count=count-1 Nb,H8;
 
        End If )|1JcnNSa  
        count=count+1 R~?;KJ  
    Wend o_^d>Klb8  
    op.Type = "ShiftZ" ezy5Jqk5%  
    op.val1 = taq-0.01 NGeeD?2~  
    op.parent = parID uEO2,1+  
    AddOperation eID, op >^)5N<t?  
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    Print "Set pupil diameter = " & pupilDiam 4 ~|TKd{  
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    'Update AZ Eye subassembly Description ~;4k UJD  
    eID = FindFullName( "Geometry.Arizona Eye" ) Pw0KQUs  
    GetEntity eID, entity QZq9$;>dW  
    entity.Description = "Accommodation = " & A & "D" v\tbf  
    SetEntity eID, entity Zkep7L   
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    Update $Lbe5d?\  
    Print "DONE!" Br$PL&e~  
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End Sub |MR?8A^"  
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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： 8 =Lv7G%  
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Accommodation = 4 Diopters ]6[d-$#^ko  
Pupil Diameter = 4 mm #\;w
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Set aqueous humor thickness = 2.81 ]|BSX-V.%i  
Set anterior lens radius = 10.4 and conic constant = -2.375869 (#"s!!b  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 DyTk<L  
Set lens thickness = 3.927 ~F6gF7]z  
Set lens index of refraction = 1.42672 ?
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Set pupil diameter = 4 ^W05Z!}  
DONE!
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