[技术]Arizona眼睛模型 [复制链接]

简介 AG><5 }  
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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。 3^5h:OaT  
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模型 RAWzQE}  
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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。 NxnaH!wS  
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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. udmLHc  
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光源 f3S 8
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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。 sf/m@425  
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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。 Lp/'-Y_  
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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。 %J Jp/I  
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视网膜的散射 <@[;IX`YN  
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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。 \iaZV.#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。 /GX
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脚本 Nu3gkIz5z-  
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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： ![$`Ivro`  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 7r^Cs#b+I  
余下的脚本计算与屈光度有关的所有参数。 )B+R|PZ,  
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分析 
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 &-{%G=5~e%  
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脚本代码 b8Z_oN5!  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. S=lCzL;j"  
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Dim entity As T_ENTITY dNY'uv&Y  
Dim op As T_OPERATION &@'%0s9g  
Dim mat As T_MODELMATERIAL ij#v_~g3  
Dim A As Double ,X1M!'  
Dim pupilDiam As Double cMF)2^w}  
Dim eID As Long Nsq=1) <  
Dim parID As Long uF1 4;  
Dim count As Integer Ly3!0P.<  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^*4#ZvpG2  
Dim tlens As Double, nlens As Double I\1"E y  
Dim curv As Double, conic As Double )P?Fni}  
Dim ok As Long YFPse.2$a  
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Sub Main n#Dy YVb  
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    '用户输入对话框 &WLN   
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 xb%Q[V_m  
        TextBox 220,21,40,21,.TextBox1 'default: 0 >
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 H ?9Bo!  
        OKButton 40,91,90,21 _ Pzgn@D  
        CancelButton 190,91,90,21
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^|6#Vx  
        TextBox 220,49,40,21,.TextBox2 'default: 4 -^yc<%U  
    End Dialog lP)n$?u  
    Dim dlg As UserDialog 74:( -vS  
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    ok = Dialog (dlg) :RukW.MR  
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    If ok=0 Then    'cancel button was pressed re/u3\S  
        Print "Execution cancelled." F):kF_ho  
        End Gey-8  
    End If H.]V-|U  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~Q Q1
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    If dlg.TextBox1 = "" Then ?lgE9I]  
        A = 0           'Default accommodation /DH`7E  
    Else ^H2TSaJ;  
        A = CDbl(dlg.TextBox1) Sin)]zG~0  
    End If 2]Cn<zJ  
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    If dlg.TextBox2 = "" Then y7CXE6Y  
        pupilDiam = 4   'Default pupil diameter l{.PyU5)  
    Else ~,};FI  
        pupilDiam = CDbl(dlg.TextBox2) 1|-C(UW>  
    End If frm[<-~w0  
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    Print " " lul  
    Print "Accommodation = " & A & " Diopters" Iurz?dt4w  
    Print "Pupil Diameter = " & pupilDiam & " mm" 4clCZ@\K^  
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    ' Calculate new parameters with accommodation 0vDvp`ie#4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "QS(4yw?jg  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens % q!i  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )BI%cD  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %La/E#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens N4
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    tlens = 3.767 + 0.04*A                  'Lens thickness >k@{N
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _X<V`, p  
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    'Adjust parameters to account for accommodation s nxwe  
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    '************************************************************************* rk&oKd_&i  
    'Aqueous thickness (Position of Lens) 2uY:p=DxG9  
    '************************************************************************* w^HI lA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) o](ORS$~  
    GetCustomElement eID, entity :4X,5X7tW=  
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    parID = FindFullName( "Geometry.Arizona Eye" ) @q]!C5  
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    ' Delete any shift(s) in z #=Xa(<t  
    count = 0 :mCGY9d4L  
    While GetOperationCount(eID)>count wod{C!  
        GetOperation eID, count, op n]5Pfg|a  
        If op.Type="ShiftZ" Then I 6<LKI/  
            DeleteOperation eID,count #3?"#),q
 
            count=count-1 >tL"8@z9  
        End If s:,fXg25J  
        count=count+1 a04S&ezj  
    Wend kaR55  
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    'Set new shift in E6G;fPd= E  
    op.Type = "ShiftZ" j9RpYz  
    op.val1 = taq F3Vvqt*2  
    op.parent = parID 6~s{HI!  
    AddOperation eID, op B@\0b|  
    Print "Set aqueous humor thickness = " & taq-0.55 [vY)y\W{  
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    '************************************************************************* B1i'Mzm-4  
    'Radius and conic constant of anterior lens GLV`IkU %  
    '************************************************************************* CSm(yB{|pC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) R5uz<  
    GetConic eID, entity, curv, conic 5/m*Lc+r  
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    SetConic eID, entity, 1/Rant, CCant Pff-eT+~m  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N;m62N  
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    '************************************************************************* u |$GOSD  
    'Radius and conic constant of posterior lens l`JKQk   
    '************************************************************************* hE2{m{^A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K~5(j{Kb8  
    GetConic eID, entity, curv, conic MI8c>5?  
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    SetConic eID, entity, 1/Rpost, CCpost \jkDRR[  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost c1f`?i}.  
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    '************************************************************************* &j{IG`Trl  
    'Lens thickness (Position of posterior lens surface) )@.ODW;`  
    '************************************************************************* ,Qe`(vU*s  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yaX%<KBa\  
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    ' Delete any z-shift(s) ?* dfIc  
    count = 0 *qIns/@  
    While GetOperationCount(eID)>count 9 &Od7Cn  
        GetOperation eID, count, op ,(#n8|q4  
        If op.Type="ShiftZ" Then 0R,Y[).U  
            DeleteOperation eID,count [vCZD8"Y8  
            count=count-1 zjx'nK{eI  
        End If xoE,3Sn  
        count=count+1 +n8,=}  
    Wend 0j'k%R[l  
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    'Set new z-shift `jDmbD +=  
    op.Type = "ShiftZ" -32.g\]  
    op.val1 = tlens =1F F2#zS  
    op.parent = parID q]*:RI?wGT  
    AddOperation eID, op ><;.vP
 
    Print "Set lens thickness = " & tlens N%?8Bm~dP  
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    '************************************************************************* UDa\*  
    'Lens index of refraction 04z2gAo  
    '************************************************************************* qjvIp-  
    eID = FindMaterial( "Lens" ) oX1{~lDJl  
    GetModelMaterial eID, mat W}oAgUd  
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    mat.Nd = nlens Wuji'sxTs  
    SetModelMaterial eID, mat ?DJ,YY9P  
    Print "Set lens index of refraction = " & nlens :cTwp K  
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    '************************************************************************* ((_v>{  
    'Pupil diameter TqMy">>  
    '************************************************************************* #1f8A5<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) B3Esfk  
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    'Adjust pupil diameter (trimming volume inner hole) D'Sdz\:4  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <0)@Ikhx  
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    ' Adjust pupil location to just in front of the lens K<tkNWasQ  
    parID = FindFullName( "Geometry.Arizona Eye" ) T k>N4yq  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #bLeK$  
    count = 0 I#hzU8Cc  
    While GetOperationCount(eID)>count l.i&.;f  
        GetOperation eID, count, op rB%acTCz=[  
        If op.Type="ShiftZ" Then lV!@h}mG  
            DeleteOperation eID,count 0IjQqI  
            count=count-1 =u`^QE  
        End If +EgQj*F*  
        count=count+1 .W%{j()op  
    Wend ;zvg]  %  
    op.Type = "ShiftZ" =2[cpF]  
    op.val1 = taq-0.01  kQm\;[R  
    op.parent = parID pfvNVu  
    AddOperation eID, op "%Eyb\V!  
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    Print "Set pupil diameter = " & pupilDiam X\1'd,V  
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    'Update AZ Eye subassembly Description $ p{Q]|ww  
    eID = FindFullName( "Geometry.Arizona Eye" ) j^~WAWbFh  
    GetEntity eID, entity N5[fwz w  
    entity.Description = "Accommodation = " & A & "D" nPUq+cXy]C  
    SetEntity eID, entity Lw.N3!e[  
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    Update vrIM!~*W  
    Print "DONE!" eESJk14  
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End Sub `+QrgtcEy4  
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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： BY$%gIB6>  
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Accommodation = 4 Diopters Jj'~\j  
Pupil Diameter = 4 mm vf(\?Js,  
Set aqueous humor thickness = 2.81 L+s,,k  
Set anterior lens radius = 10.4 and conic constant = -2.375869 X Jy]d/  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 . \fzK  
Set lens thickness = 3.927 DY{JA *N  
Set lens index of refraction = 1.42672 G?d28p',.  
Set pupil diameter = 4 :U<`iJwY  
DONE! }45&s9m=