[技术]Arizona眼睛模型 [复制链接]

简介 E "}@SaB-  
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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。 uBa<5YDF  
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模型 cl2_"O  
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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。 (=Cb)/s0  
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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. &<]f-  
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光源 1.F&gP)9  
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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。 /oHCV0!0  
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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。 gCb+hQq\  
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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。 3- Kgz  
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视网膜的散射 Z^&G9I#  
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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。 Swhz\/u9  
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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。 wf\"&xwh?  
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脚本 pux IJ  
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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： F}_b7|^  
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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。 =0g!Q  
余下的脚本计算与屈光度有关的所有参数。 = j1Jl^[  

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分析 /mex{+p>tO  
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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。 Jl~ *@0(  
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脚本代码 /+Z*)q+SbT  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. .4+Rac  
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Dim entity As T_ENTITY <YaTr9%w  
Dim op As T_OPERATION ?\V#^q-  
Dim mat As T_MODELMATERIAL W8d-4')|  
Dim A As Double o$No@~%v  
Dim pupilDiam As Double DDeU:  
Dim eID As Long aK_5@8+ZD  
Dim parID As Long E-z5mX.2  
Dim count As Integer G}nJ3  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double XY"b90  
Dim tlens As Double, nlens As Double gNCS*a  
Dim curv As Double, conic As Double = lo.LFV  
Dim ok As Long xuioU  
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Sub Main Ob$``31{s  
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    '用户输入对话框 ,2FK$:M\  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 b>-DX  
        TextBox 220,21,40,21,.TextBox1 'default: 0 6<lo0PQ"Z  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 EvT$|#FY  
        OKButton 40,91,90,21 QOWGQl%!  
        CancelButton 190,91,90,21 bZ`v1d (r  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?NMk|+  
        TextBox 220,49,40,21,.TextBox2 'default: 4 TLwxP"  
    End Dialog ,L<JG  
    Dim dlg As UserDialog $k~TVm Yex  
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    ok = Dialog (dlg) :&BPKqKp  
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    If ok=0 Then    'cancel button was pressed -XBZ1q  
        Print "Execution cancelled." ]C \+b<  
        End M$K%e  
    End If n>
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    'Assign accommodation and pupil diameter & use defaults if field left empty P $`1}  
    If dlg.TextBox1 = "" Then hr vTFJ  
        A = 0           'Default accommodation &_L@hsm  
    Else 0Ui.nz j  
        A = CDbl(dlg.TextBox1) o}AXp@cqi  
    End If Y
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    If dlg.TextBox2 = "" Then X$kLBG_  
        pupilDiam = 4   'Default pupil diameter "| '~y}v_  
    Else Wdd}y`lS  
        pupilDiam = CDbl(dlg.TextBox2) rL5=8l  
    End If Zl>SeTjB-  
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    Print " " /M2in]oH  
    Print "Accommodation = " & A & " Diopters" m212 gc0u  
    Print "Pupil Diameter = " & pupilDiam & " mm" Y'/6T]a  
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    ' Calculate new parameters with accommodation Gk:fw#R  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j7!u;K^c  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens +<E#_)}`D6  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /?81Ypt  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens S#ryEgc]  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MHwfJ{"zo  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 'o&d!  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction o)I)I/v  
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    'Adjust parameters to account for accommodation ;lmg0dtJ  
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    '************************************************************************* 8u*<GbKGI  
    'Aqueous thickness (Position of Lens) q^[t</_N  
    '************************************************************************* ~<k>07  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) i[z 2'tx4  
    GetCustomElement eID, entity @
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    parID = FindFullName( "Geometry.Arizona Eye" ) wH"9N+82M  
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    ' Delete any shift(s) in z 7~2_'YX>:  
    count = 0 7nPg2K&  
    While GetOperationCount(eID)>count !w7/G  
        GetOperation eID, count, op DVd8Ix<  
        If op.Type="ShiftZ" Then 7#JnQ| ]  
            DeleteOperation eID,count _4oAk @A  
            count=count-1 5=;cN9M@  
        End If ltOS()[X  
        count=count+1 ]O;*Y{:Y  
    Wend /J^dzvH  
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    'Set new shift in e\~nqKCb  
    op.Type = "ShiftZ" &/m^}x/_W  
    op.val1 = taq 7bYwh8  
    op.parent = parID TJYhgna  
    AddOperation eID, op :G6CWE  
    Print "Set aqueous humor thickness = " & taq-0.55 ~;?mD/0k  
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    '************************************************************************* yoGG[l2k>s  
    'Radius and conic constant of anterior lens XR]bd  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *& w/*h$!  
    GetConic eID, entity, curv, conic .+(ED  
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    SetConic eID, entity, 1/Rant, CCant pcv\|)&}  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N?c~AEk9U  
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    '************************************************************************* <LZ#A@]71  
    'Radius and conic constant of posterior lens WS6Qp`c)e  
    '************************************************************************* ,fiV xnQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ) YB'W_  
    GetConic eID, entity, curv, conic .
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    SetConic eID, entity, 1/Rpost, CCpost #-b}QhxH  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost aAP86MHO  
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    '************************************************************************* 7*K2zu3  
    'Lens thickness (Position of posterior lens surface) 3ut<o-
 
    '************************************************************************* `_.:O,^n^  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) c0l?+:0M  
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    ' Delete any z-shift(s) ^[R/W VNk  
    count = 0 9s!R_R&W.  
    While GetOperationCount(eID)>count  ngJ{az  
        GetOperation eID, count, op [OPF3W3z  
        If op.Type="ShiftZ" Then Y_C6*T%  
            DeleteOperation eID,count fHwS12SB  
            count=count-1 jZ"j_=o@  
        End If yX
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        count=count+1 PB*G#2W  
    Wend )x?)v#k  
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    'Set new z-shift X]2x0  
    op.Type = "ShiftZ" :_F 8O  
    op.val1 = tlens DTsD<o  
    op.parent = parID #N|JC d_  
    AddOperation eID, op NBBR>3nt  
    Print "Set lens thickness = " & tlens mBB"e
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    '************************************************************************* -glGOTk  
    'Lens index of refraction SY:ISzB}  
    '************************************************************************* u^Ktz DmL  
    eID = FindMaterial( "Lens" ) r? }|W2^%  
    GetModelMaterial eID, mat ?I+$KjE+  
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    mat.Nd = nlens $tc1te  
    SetModelMaterial eID, mat *c%{b3T_  
    Print "Set lens index of refraction = " & nlens ~e)"!r  
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    '************************************************************************* RFSwX*!  
    'Pupil diameter f;OB"p  
    '************************************************************************* Ek_<2
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) o9C#5%9  
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    'Adjust pupil diameter (trimming volume inner hole) cf^i!X0  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" IAN={";p  
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    ' Adjust pupil location to just in front of the lens Jk7 Am-.0  
    parID = FindFullName( "Geometry.Arizona Eye" ) (u='&ka  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 0%q H=do6  
    count = 0 'n\PS,[1R  
    While GetOperationCount(eID)>count r1}1lJ>7H  
        GetOperation eID, count, op 9%"\s2T  
        If op.Type="ShiftZ" Then C(8!("tU  
            DeleteOperation eID,count ( *K)D$y  
            count=count-1 f87XE";:A  
        End If N_Zd.VnY  
        count=count+1 IGlyx'\_  
    Wend W:9l"'  
    op.Type = "ShiftZ" )iK:BL*Nw  
    op.val1 = taq-0.01 !"-.D4*r  
    op.parent = parID &h!O<'*2  
    AddOperation eID, op .!i`YT*jF
 
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    Print "Set pupil diameter = " & pupilDiam I36%oA  
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    'Update AZ Eye subassembly Description WB<MU:.Vc  
    eID = FindFullName( "Geometry.Arizona Eye" ) PyK!Cyq  
    GetEntity eID, entity \j BA4?(S  
    entity.Description = "Accommodation = " & A & "D" ~_F;>N~  
    SetEntity eID, entity H5 :,hrZY  
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    Update ^SsnCn-e  
    Print "DONE!" {{>,c}O /  
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End Sub kUT^o  
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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： 6X?:mn'%QF  
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Accommodation = 4 Diopters 5ug|crX  
Pupil Diameter = 4 mm Iu5 9W>  
Set aqueous humor thickness = 2.81 o~L(;A]yN  
Set anterior lens radius = 10.4 and conic constant = -2.375869 F#RNm5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?$uF(>LD  
Set lens thickness = 3.927 . &`Y
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Set lens index of refraction = 1.42672 [u^ fy<jdp  
Set pupil diameter = 4 JRZp'Ln  
DONE! Dv`"3