[技术]Arizona眼睛模型 [复制链接]

简介 aAbK{=/y_!  
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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。 ?lPn{oB9"  
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模型 ,<CFjtelO  
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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。 G(3wI}  
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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. b)[2t^zG  
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光源 gX%"Ki7.  
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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。 c%+_~iBUN  
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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。 sd5)We  
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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。 <-h[
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视网膜的散射 W; zzc1v  
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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。 %
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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。 96d&vm~m1  
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脚本 VZ]}9k  
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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： 0JXXJ:dB  
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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。 %D49A-R  
余下的脚本计算与屈光度有关的所有参数。 ~='}(Fg:  
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分析 F|&
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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。 (XNd]G  
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脚本代码 7P:/ (P  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. GQ0(
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Dim entity As T_ENTITY @;X#/dZe  
Dim op As T_OPERATION 0C4Os p  
Dim mat As T_MODELMATERIAL C'6c,  
Dim A As Double RN2z/FUf  
Dim pupilDiam As Double "#8I &xZK  
Dim eID As Long w$0*5n>)  
Dim parID As Long (7C$'T-ZK  
Dim count As Integer |)OC1=As  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double z
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Dim tlens As Double, nlens As Double f{-,"6Y1  
Dim curv As Double, conic As Double )Vo%}g?6!  
Dim ok As Long JYnyo$m/  
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Sub Main D^S"6v"z  
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    '用户输入对话框 eB9F35[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 i(YR-vYK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \rY\wa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 i(4.7{*  
        OKButton 40,91,90,21 bD=R/yA  
        CancelButton 190,91,90,21 ;;N#'.xD  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 I9h{fB  
        TextBox 220,49,40,21,.TextBox2 'default: 4 3uL$+F  
    End Dialog LX}|%- iv  
    Dim dlg As UserDialog %edTW[C`  
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    ok = Dialog (dlg) em2Tet  
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    If ok=0 Then    'cancel button was pressed t$PJ*F67M  
        Print "Execution cancelled." ;?Q0mXr  
        End {<zE}7/2-  
    End If _6->D[dB  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ]YY4{E(9d  
    If dlg.TextBox1 = "" Then ^97[(89G9  
        A = 0           'Default accommodation i "aQm  
    Else .*?)L3n+t  
        A = CDbl(dlg.TextBox1) Lr Kx  
    End If _8 l=65GW  
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    If dlg.TextBox2 = "" Then 4M;S&LA  
        pupilDiam = 4   'Default pupil diameter 1pqYB]*u_  
    Else GuF-HP}xM  
        pupilDiam = CDbl(dlg.TextBox2) b/4gs62{k  
    End If bd3>IWihp  
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    Print " " z=4E#y`?U  
    Print "Accommodation = " & A & " Diopters" @h5Q?I  
    Print "Pupil Diameter = " & pupilDiam & " mm" z'zC  
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    ' Calculate new parameters with accommodation kdMB.~(K=  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xM>dv5<E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens KF7d`bRe  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )5TX3#=;(G  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens BbI),iP  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?[ D6|gp  
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    tlens = 3.767 + 0.04*A                  'Lens thickness
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &WdP=E"  
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    'Adjust parameters to account for accommodation FYK}AR<=  
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    '************************************************************************* :0Fwaw9PH"  
    'Aqueous thickness (Position of Lens) )EG-
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    '************************************************************************* ik0w\*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5d|+c<  
    GetCustomElement eID, entity )Y?E$=M+B  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 7RgnL<t~:8  
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    ' Delete any shift(s) in z l`];CALA4  
    count = 0 3iiOxg?j  
    While GetOperationCount(eID)>count ezd@>(hJ  
        GetOperation eID, count, op lqKwjJtX  
        If op.Type="ShiftZ" Then ]o_E]5"jO  
            DeleteOperation eID,count B^hK  
            count=count-1 *1}vn%wvn  
        End If Vb2")+*:  
        count=count+1 j MA%`*r  
    Wend w2tkJcQ3  
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    'Set new shift in qj?I*peK)  
    op.Type = "ShiftZ" U3w*z6OG  
    op.val1 = taq OL[_2m*;9p  
    op.parent = parID 1z[blNs&  
    AddOperation eID, op >2)!w  
    Print "Set aqueous humor thickness = " & taq-0.55 I3?:KVa  
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    '************************************************************************* 3*b!]^d:D  
    'Radius and conic constant of anterior lens < YuI}d~'  
    '************************************************************************* K9Pw10g'  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g/,O51f'  
    GetConic eID, entity, curv, conic .]Z,O>N
 
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    SetConic eID, entity, 1/Rant, CCant q}5&B=2pM  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #60<$HO:Z  
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    '************************************************************************* 4U:+iumy2  
    'Radius and conic constant of posterior lens !!t@H\  
    '************************************************************************* n1c Q#u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) fKT(.VNq5  
    GetConic eID, entity, curv, conic fI0L\^b%  

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    SetConic eID, entity, 1/Rpost, CCpost on1mu't_;  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e3>k"  
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    '************************************************************************* k4%> F  
    'Lens thickness (Position of posterior lens surface) G,i%:my7  
    '************************************************************************* ,K[B/tD{j  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) z'X_s.9F  
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    ' Delete any z-shift(s) l@YpgyqaL  
    count = 0 ]t3 NA*mM  
    While GetOperationCount(eID)>count Sq==)$G  
        GetOperation eID, count, op JXnPKAN  
        If op.Type="ShiftZ" Then gf2w@CVF>=  
            DeleteOperation eID,count *)d|:q3  
            count=count-1 z*>CP  
        End If ^q$vyY   
        count=count+1 ss3fq}  
    Wend J0|}u1?l  
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    'Set new z-shift i]LK,'  
    op.Type = "ShiftZ" "$8<\k$LGT  
    op.val1 = tlens osX23T~-  
    op.parent = parID LGCL*Qbsg  
    AddOperation eID, op .< vg[  
    Print "Set lens thickness = " & tlens T}]Ao  
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    '************************************************************************* (^Do#3  
    'Lens index of refraction Lou4M  
    '************************************************************************* qkUr5^1  
    eID = FindMaterial( "Lens" ) NI s4v(!  
    GetModelMaterial eID, mat cCV"(Oo[H|  
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    mat.Nd = nlens y!!+IeReS  
    SetModelMaterial eID, mat Q84KU8?d  
    Print "Set lens index of refraction = " & nlens A1ebXXD)  
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    '************************************************************************* ,n!xzoX_  
    'Pupil diameter 0XYO2k  
    '************************************************************************* rrwsj`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 3Ob"r`  
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    'Adjust pupil diameter (trimming volume inner hole) JcVq%~{M  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" JN KZ'9  
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    ' Adjust pupil location to just in front of the lens Z%OSW  
    parID = FindFullName( "Geometry.Arizona Eye" ) NxX1_d  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /l$noaskX  
    count = 0 xf]4!zE  
    While GetOperationCount(eID)>count -X}R(.}x  
        GetOperation eID, count, op ]VYl Eqe  
        If op.Type="ShiftZ" Then a@jP^VVk  
            DeleteOperation eID,count !Z'm@,+  
            count=count-1 M7>\Qk  
        End If Csc2yI%3  
        count=count+1 ,6buo~?W:  
    Wend GKd>AP_  
    op.Type = "ShiftZ" 3CHte*NL=  
    op.val1 = taq-0.01 F_Pd\Aq8  
    op.parent = parID #129 i2  
    AddOperation eID, op 86I*
 
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    Print "Set pupil diameter = " & pupilDiam Go67VqJr  
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    'Update AZ Eye subassembly Description P%lLKSA  
    eID = FindFullName( "Geometry.Arizona Eye" ) B&$89]gs|  
    GetEntity eID, entity 8Z!ea3kAT  
    entity.Description = "Accommodation = " & A & "D" _/=ZkI5  
    SetEntity eID, entity 0Yjy  
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    Update sq^"bLw  
    Print "DONE!" QE}@|H9xs  
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End Sub o<'gM
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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： Vi|jkyC8  
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Accommodation = 4 Diopters *3K"Kc2  
Pupil Diameter = 4 mm Mww]l[1'EL  
Set aqueous humor thickness = 2.81 D/Wuan?yPN  
Set anterior lens radius = 10.4 and conic constant = -2.375869 +J4t0x  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 u~kwNN9t3  
Set lens thickness = 3.927 mN*P2*  
Set lens index of refraction = 1.42672 w8i!Qi#y5D  
Set pupil diameter = 4 @6!JW(,]\  
DONE! I{PN6bn{>