[技术]Arizona眼睛模型 [复制链接]

简介 $U"/.Mh\  
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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。 y|iZuHS}  
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模型 #C4  
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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。 M)Tv(7  
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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. Rm)vY}v  
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光源 m-> chOu~|  
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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。 x-CYG?-x  
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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。 _N9yC\  
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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。 fZxZ):7i  
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视网膜的散射 
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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。 $vlgiJ&f  
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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。 dSk\J[D  
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脚本 L.l%EcW=,  
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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： ~=Er= 0  
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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。 Y?ZTl762  
余下的脚本计算与屈光度有关的所有参数。 roj/GZAy"  
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分析 ;=*b:y Y  
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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。 #
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脚本代码 1fViW^l_  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >`'#4!}G5j  
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Dim entity As T_ENTITY pb_mW;JVu  
Dim op As T_OPERATION ruB&&C6)v  
Dim mat As T_MODELMATERIAL aE1h0`OT  
Dim A As Double &"Ua"H)  
Dim pupilDiam As Double Drk9F"J  
Dim eID As Long
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Dim parID As Long SO]x^+[  
Dim count As Integer b;9v.MZ4>g  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 1g2%f9G  
Dim tlens As Double, nlens As Double ;T-i+_  
Dim curv As Double, conic As Double .<rL2`
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Dim ok As Long im*QaO%a4  
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Sub Main }Jh!B|  
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    '用户输入对话框 q,QMvUK:  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 :==kC672  
        TextBox 220,21,40,21,.TextBox1 'default: 0 B/i,QBPF]  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ]rZ"5y  
        OKButton 40,91,90,21 D@>P%k$$s>  
        CancelButton 190,91,90,21 Xb)XV$0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 W_O,Kao  
        TextBox 220,49,40,21,.TextBox2 'default: 4 |X~T</{8i  
    End Dialog \P&'4y~PL  
    Dim dlg As UserDialog #++MoW}'g  
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    ok = Dialog (dlg) x>&1;g2r  
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    If ok=0 Then    'cancel button was pressed EOVHTDkKf  
        Print "Execution cancelled." $T1 D ?X  
        End 7:mM`0g!  
    End If 04WKAP'c N  
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    'Assign accommodation and pupil diameter & use defaults if field left empty E88_15'3D  
    If dlg.TextBox1 = "" Then qGl+KI
 
        A = 0           'Default accommodation <IK8Uc
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    Else 8 E.u3eS  
        A = CDbl(dlg.TextBox1) O`OntYwa>  
    End If +3]@0VM26;  
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    If dlg.TextBox2 = "" Then +]`MdOu  
        pupilDiam = 4   'Default pupil diameter k{y@&QNj  
    Else + 5sTGNG  
        pupilDiam = CDbl(dlg.TextBox2) Z&JW}''n|F  
    End If Zhz.8W  
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    Print " " YUM%3  
    Print "Accommodation = " & A & " Diopters" r}D`15IHJ  
    Print "Pupil Diameter = " & pupilDiam & " mm" ]c[80F-  
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    ' Calculate new parameters with accommodation KB*[b  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness G80d!*7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens uH65DI<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,)S|%tDW  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens oKA8)~Xqou  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $LFzpg  
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    tlens = 3.767 + 0.04*A                  'Lens thickness kTc'k  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  p&:RSO  
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    'Adjust parameters to account for accommodation l')?w]|  
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    '************************************************************************* `)1_^# k  
    'Aqueous thickness (Position of Lens) H5^'J`0\  
    '************************************************************************* Co[  r
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Tx`;y|  
    GetCustomElement eID, entity /NMd GKr  
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    parID = FindFullName( "Geometry.Arizona Eye" ) PZeVjL?E  
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    ' Delete any shift(s) in z ;}=v|Dr&I.  
    count = 0 5~aSkg,MD  
    While GetOperationCount(eID)>count `| L+a~~  
        GetOperation eID, count, op %]r@vjeyd  
        If op.Type="ShiftZ" Then :&&Ps4\Sq  
            DeleteOperation eID,count wrac\.  
            count=count-1 iW.8+?Xq&  
        End If 0rsdDME[  
        count=count+1 na(@`(j[  
    Wend B~jl1g|  
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    'Set new shift in m~(]\  
    op.Type = "ShiftZ" &N[~+"  
    op.val1 = taq _dmgNbs
  
    op.parent = parID "_}Hzpy5k  
    AddOperation eID, op tm#T8iF  
    Print "Set aqueous humor thickness = " & taq-0.55 ]wER&/v"  
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    '************************************************************************* [-{L@  
    'Radius and conic constant of anterior lens mI@E>VCV[  
    '************************************************************************* kbM4v G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #gUM%$  
    GetConic eID, entity, curv, conic 7K {/2k  
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    SetConic eID, entity, 1/Rant, CCant `~(KbH=]  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant l`[*b_ Xt  
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    '************************************************************************* 5m=3{lBi  
    'Radius and conic constant of posterior lens UyEyk$6SU  
    '************************************************************************* n;xtUw6\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Uj(,
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    GetConic eID, entity, curv, conic vp[~%~1(  
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    SetConic eID, entity, 1/Rpost, CCpost IgG@v9'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost )o SFHf  
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    '************************************************************************* .px*.e s  
    'Lens thickness (Position of posterior lens surface) 4u"V52  
    '************************************************************************* y4C_G?  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wHx1CXC  
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    ' Delete any z-shift(s) '<^%>R2  
    count = 0 #hH"g  
    While GetOperationCount(eID)>count kbI:}b7H  
        GetOperation eID, count, op 0>)('Kv  
        If op.Type="ShiftZ" Then )67Kd]  
            DeleteOperation eID,count J&@[=zBYw  
            count=count-1 gX{V>T(<  
        End If di "rvw;R  
        count=count+1 )^|zuYzN  
    Wend dp&4G6Y<A  
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    'Set new z-shift sc@v\J;k  
    op.Type = "ShiftZ" 53=VIN]  
    op.val1 = tlens V#ZF0a]  
    op.parent = parID INyreoMp  
    AddOperation eID, op $83TA><a  
    Print "Set lens thickness = " & tlens ull
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    '************************************************************************* 51*o&:eim  
    'Lens index of refraction >dUnk)7  
    '************************************************************************* r\F`xtR(  
    eID = FindMaterial( "Lens" ) N*|Mfpf  
    GetModelMaterial eID, mat %F3M\)jU  
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    mat.Nd = nlens l-Xxur5M'  
    SetModelMaterial eID, mat 17a'C  
    Print "Set lens index of refraction = " & nlens 8*V3g_z  
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    '************************************************************************* Z
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    'Pupil diameter t9
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    '************************************************************************* J)
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) +`r;3kH ..  
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    'Adjust pupil diameter (trimming volume inner hole) 7i`@`0   
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &y[Od{=  
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    ' Adjust pupil location to just in front of the lens ~gNa<t
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    parID = FindFullName( "Geometry.Arizona Eye" ) HpiP"Sl  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ? DWF7{1  
    count = 0 c_s=>z  
    While GetOperationCount(eID)>count 7H:1c=U  
        GetOperation eID, count, op u}W R1u[  
        If op.Type="ShiftZ" Then vj]-p=
 
            DeleteOperation eID,count uLD%M av  
            count=count-1 qt=gz6!  
        End If fil'._  
        count=count+1 wN-3@  
    Wend V:4]]z L}  
    op.Type = "ShiftZ" p~Fc*g[!  
    op.val1 = taq-0.01 c:.k2u  
    op.parent = parID EJ;:O1,6H  
    AddOperation eID, op +/'3=!oyd  
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    Print "Set pupil diameter = " & pupilDiam Wf^6:  
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    'Update AZ Eye subassembly Description .S>:-j'u  
    eID = FindFullName( "Geometry.Arizona Eye" ) c|  
    GetEntity eID, entity 56;lB$)"  
    entity.Description = "Accommodation = " & A & "D" cs `T7?>  
    SetEntity eID, entity '#mv-/<t*  
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    Update d[;Sn:B  
    Print "DONE!" h[b;_>7  
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End Sub &k*sxW'  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 8@^=k.5IK  
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Accommodation = 4 Diopters P!q!+g  
Pupil Diameter = 4 mm 2fM*6CaS  
Set aqueous humor thickness = 2.81 'gHa3:US  
Set anterior lens radius = 10.4 and conic constant = -2.375869 4loG$l+a1  
Set posterior lens radius = -4.424557 and conic constant = -3.081019  3=@94i  
Set lens thickness = 3.927 59A@~;.F  
Set lens index of refraction = 1.42672 ^"WrE(3  
Set pupil diameter = 4 G[z!;Zuf  
DONE! 1|_jV7`Mz