[技术]Arizona眼睛模型 [复制链接]

简介 \[L|  
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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。  :X 9_~  
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模型 AHet,N  
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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。 #Q/xQ`+|.  
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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. O{Y*a )"  
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光源 2#X>^LH  
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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。 .#LvvAeh  
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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。 o!zo%#0;#)  
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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。 SI/3Dz[  
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视网膜的散射 |?\2F   
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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。 7ZFd;-  
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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。 s]Z++Lh<{  
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脚本 B~`:?f9ny5  
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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： b q8nV  
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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。 \Wb3JQ)  
余下的脚本计算与屈光度有关的所有参数。 * & : J  
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分析 n!L}4Nmp  
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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。 !_?#f|  
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脚本代码 &?^"m\K4J*  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6JD~G\$  
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Dim entity As T_ENTITY e|4U2\&3y  
Dim op As T_OPERATION `FByME  
Dim mat As T_MODELMATERIAL sM@1Qyv&0  
Dim A As Double g3c,x kaO  
Dim pupilDiam As Double cD9.L  
Dim eID As Long e
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Dim parID As Long &,'CHBM  
Dim count As Integer }T"&4Rvs2R  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double B1va]=([)W  
Dim tlens As Double, nlens As Double rGQY  
Dim curv As Double, conic As Double G3gEL)b*  
Dim ok As Long h! wd/jR  
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Sub Main ^F87gow%`B  
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    '用户输入对话框 V BjA$.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Q$x 3uH\@  
        TextBox 220,21,40,21,.TextBox1 'default: 0 1(qL),F;  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 q}hHoSG]=  
        OKButton 40,91,90,21 XyD*V;.E  
        CancelButton 190,91,90,21 a>egH og  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,j%f
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        TextBox 220,49,40,21,.TextBox2 'default: 4 ;& zBNj  
    End Dialog gqDSHFm:  
    Dim dlg As UserDialog BCt>P?,UO  
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    ok = Dialog (dlg) ?'^yw C`  
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    If ok=0 Then    'cancel button was pressed #{zF~/Qq  
        Print "Execution cancelled." `}#n
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        End 34t[]v|LD  
    End If Z+ )<FX  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 8xYeaK  
    If dlg.TextBox1 = "" Then *P+8^t#Vp  
        A = 0           'Default accommodation TchByN6oN<  
    Else ,ZvlKN  
        A = CDbl(dlg.TextBox1) Zi.
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    End If GoPK. E$  
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    If dlg.TextBox2 = "" Then CFG(4IMx  
        pupilDiam = 4   'Default pupil diameter {#&j
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    Else <4%PT2R  
        pupilDiam = CDbl(dlg.TextBox2) PGA `R  
    End If }PzHtA,V  
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    Print " " ]%[.>mR  
    Print "Accommodation = " & A & " Diopters" L4{+@T1A[  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1_z~<d @?;  
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    ' Calculate new parameters with accommodation P*kC>lvSv  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [W=6NAd  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens qIk(ei  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [wcp2g3Px  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $rH}2  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens =p&uQ6.i+  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Yn8aTg[J  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction c)zwyBz  
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    'Adjust parameters to account for accommodation }Pj;9ivz  
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    '************************************************************************* 6<9gVh<=w  
    'Aqueous thickness (Position of Lens) C^ Oy.s  
    '************************************************************************* R9InUX"k  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5Pd^Sew  
    GetCustomElement eID, entity z=Khbh  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Vn6]h|vm  
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    ' Delete any shift(s) in z ]/odp/jm  
    count = 0 qfyuq]  
    While GetOperationCount(eID)>count #80M+m  
        GetOperation eID, count, op z:JJ>mxV  
        If op.Type="ShiftZ" Then }RZN3U=  
            DeleteOperation eID,count M[?0 ^ FBx  
            count=count-1 ?V4bz2#!1O  
        End If yQquGu  
        count=count+1 rIJd(=  
    Wend Uw->5   
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    'Set new shift in nmUMg  
    op.Type = "ShiftZ" QP!0I01  
    op.val1 = taq ,\D*=5  
    op.parent = parID Vnnl~|Xx  
    AddOperation eID, op SsQg8d  
    Print "Set aqueous humor thickness = " & taq-0.55 "%K[kA6  
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    '************************************************************************* ![{0Yw D  
    'Radius and conic constant of anterior lens Wh1'?#  
    '************************************************************************* 6_O3/   
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Yk yB  
    GetConic eID, entity, curv, conic 7/6%92T/B  
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    SetConic eID, entity, 1/Rant, CCant g)^g_4  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N_f>5uv  
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    '************************************************************************* Y]H,rO  
    'Radius and conic constant of posterior lens ]xN)>A2  
    '************************************************************************* $;B0x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) qruv^#_l  
    GetConic eID, entity, curv, conic I.u[9CI7HU  
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    SetConic eID, entity, 1/Rpost, CCpost w*B4>FYg  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Q a3+9  
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    '************************************************************************* f"0?_cG{%  
    'Lens thickness (Position of posterior lens surface) ,")/R/d  
    '************************************************************************* poVtg}n  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) HHg[6aw  
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    ' Delete any z-shift(s) `6 ?.ihV  
    count = 0 2t`d.s=  
    While GetOperationCount(eID)>count z;6,,  
        GetOperation eID, count, op _vr;cjMI  
        If op.Type="ShiftZ" Then tqicyNL  
            DeleteOperation eID,count  R]"3^k*  
            count=count-1 's 'H&sa  
        End If 3Tz~DdB  
        count=count+1 n_
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    Wend s:Io5C(  
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    'Set new z-shift ::2(pgH  
    op.Type = "ShiftZ" >PONu]^  
    op.val1 = tlens Y@Ti2bI`v  
    op.parent = parID C,nU.0  
    AddOperation eID, op n+:}pD  
    Print "Set lens thickness = " & tlens *#Hw6N0#  
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    '*************************************************************************
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    'Lens index of refraction 1eMz"@Q9  
    '************************************************************************* `rZS\A  
    eID = FindMaterial( "Lens" ) (K3eb  
    GetModelMaterial eID, mat G~KYFNHr  
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    mat.Nd = nlens QT7PCHP  
    SetModelMaterial eID, mat x$=""?dd  
    Print "Set lens index of refraction = " & nlens Z^r? MX/  
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    '************************************************************************* -1c{Jo  
    'Pupil diameter aF%V  
    '************************************************************************* <-F[q'!C1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) NAh^2X
 
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    'Adjust pupil diameter (trimming volume inner hole) eGQ-Ht,N  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" N=~aj7B%  
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    ' Adjust pupil location to just in front of the lens hLF;MH@  
    parID = FindFullName( "Geometry.Arizona Eye" ) ayh=@7*  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) l&oc/$&|[
 
    count = 0 FgTWym_  
    While GetOperationCount(eID)>count y]b&3&  
        GetOperation eID, count, op OGAC[s~V  
        If op.Type="ShiftZ" Then #0'%51Jcl  
            DeleteOperation eID,count V
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            count=count-1 l{4rK
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        End If p@iU9K\,  
        count=count+1 sG8G}f  
    Wend JpC_au7CX  
    op.Type = "ShiftZ" 2tI,`pSU  
    op.val1 = taq-0.01 ^s_7-p])(  
    op.parent = parID x f<wM]
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    AddOperation eID, op 0=Mu|G|Z  
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    Print "Set pupil diameter = " & pupilDiam ,#Mt
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    'Update AZ Eye subassembly Description sglH=0MP  
    eID = FindFullName( "Geometry.Arizona Eye" ) aKC,{}f$m  
    GetEntity eID, entity %hCd*[Z}j  
    entity.Description = "Accommodation = " & A & "D" G*%:"qleT$  
    SetEntity eID, entity JUdQ Q  
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    Update Lf+"Gp  
    Print "DONE!" ^vha4<'-qG  
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End Sub V?&P).5)  
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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： /MZ^;XG  
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Accommodation = 4 Diopters W.Z`kH *B  
Pupil Diameter = 4 mm &l?AC%a5  
Set aqueous humor thickness = 2.81 M$U
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Set anterior lens radius = 10.4 and conic constant = -2.375869 t$g@+1p4  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 v:?l C<,  
Set lens thickness = 3.927 D-4{9[  
Set lens index of refraction = 1.42672 y7| 3]>Z  
Set pupil diameter = 4 y85R"d  
DONE! ($'5xPb