[技术]Arizona眼睛模型 [复制链接]

简介 n79DS(t
 
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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。 $'I$n  
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模型 ck4T#g;=  
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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。 fSQ3 :o  
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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. uN?O*h/(  
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光源 ?#{2?%_  
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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。 ]@j"0F/`  
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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。 GXvo't@N  
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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。 q0KXuMK  
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视网膜的散射 j/`qd(=B  
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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。 vS,G<V3B  
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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。 VA&OI;=ri  
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脚本 }SvWC8  
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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： #*aGzF  
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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。 j &[WE7wf  
余下的脚本计算与屈光度有关的所有参数。 %Fm;LQa ]  
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分析 =&g}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。 {3p7`h
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脚本代码 t=\[J+  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Mh/>qyS*2  
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Dim entity As T_ENTITY #1hz=~YO  
Dim op As T_OPERATION byxehJ6[V  
Dim mat As T_MODELMATERIAL o0+BQ&A)s*  
Dim A As Double <XcMc<h~  
Dim pupilDiam As Double ``)1`wx$  
Dim eID As Long $m0x8<7nu  
Dim parID As Long |l\/ {F  
Dim count As Integer 7a_n\]t465  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double fy-Z{  
Dim tlens As Double, nlens As Double v.&*z48  
Dim curv As Double, conic As Double {gHscj;SM  
Dim ok As Long ]f @LhC1x  
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Sub Main yl+)I  
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    '用户输入对话框 Dj&bHC5%  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 csA.3|rv  
        TextBox 220,21,40,21,.TextBox1 'default: 0 dX}dO)%m{  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 b
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        OKButton 40,91,90,21 v?=VZ~`O(  
        CancelButton 190,91,90,21 q@Yt`$VTN  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 JkDZl?x5  
        TextBox 220,49,40,21,.TextBox2 'default: 4 HD^~4\%  
    End Dialog !w\;Q8irN  
    Dim dlg As UserDialog f]65iE?x  
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    ok = Dialog (dlg) . pE
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    If ok=0 Then    'cancel button was pressed 9s6lt#?b  
        Print "Execution cancelled." T.N7`  
        End 2jBE+k"M  
    End If XFAt\g  
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    'Assign accommodation and pupil diameter & use defaults if field left empty #;\;F PuZ  
    If dlg.TextBox1 = "" Then w3UJw  
        A = 0           'Default accommodation rX d2[pp  
    Else ^`5Yxpz  
        A = CDbl(dlg.TextBox1) eL4@% ]o  
    End If g' U^fN  
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    If dlg.TextBox2 = "" Then Y[]t_o)  
        pupilDiam = 4   'Default pupil diameter ,qqV11P]  
    Else 0|vWwZ
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        pupilDiam = CDbl(dlg.TextBox2) hRcJ):Wyb  
    End If 9+|,aG s  
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    Print " " +6-!o,(  
    Print "Accommodation = " & A & " Diopters" =W^L8!BE'  
    Print "Pupil Diameter = " & pupilDiam & " mm" 2~'quA  
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    ' Calculate new parameters with accommodation Q'M Ez  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OB@t(KNx*P  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &y+*3,!n8  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5-po>1g'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens BJrNbo;T  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a-5$GvG  
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    tlens = 3.767 + 0.04*A                  'Lens thickness e-t`\5b
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction F+r6/e6a  
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    'Adjust parameters to account for accommodation 0P >dXd)T  
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    '************************************************************************* xq*yZ5:5Jo  
    'Aqueous thickness (Position of Lens) )ISTb  
    '************************************************************************* h:90K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #<3\}*/  
    GetCustomElement eID, entity %c{)'X  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 0~+k  
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    ' Delete any shift(s) in z |sAg@kM  
    count = 0 ,' B=eY,  
    While GetOperationCount(eID)>count [RuY'  
        GetOperation eID, count, op e/Y+S;a  
        If op.Type="ShiftZ" Then -l
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            DeleteOperation eID,count N`MQHQ1  
            count=count-1 ~`.%n7  
        End If J n/=v\K@  
        count=count+1 \}W.RQ^3  
    Wend $ 7!GA9Bn  
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    'Set new shift in c5pG?jr+d  
    op.Type = "ShiftZ" (5 hu W7v  
    op.val1 = taq u>#'Y+7  
    op.parent = parID (#lS?+w)  
    AddOperation eID, op OwUbm0)h^V  
    Print "Set aqueous humor thickness = " & taq-0.55 X=~QE}x  
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    '************************************************************************* ^u{$$.&  
    'Radius and conic constant of anterior lens &|eQLY #l  
    '************************************************************************* ,Nh X%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 1uMdgrJRR  
    GetConic eID, entity, curv, conic !}?]&[N=  
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    SetConic eID, entity, 1/Rant, CCant o~p^`5#  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4G ?k31,k  
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    '************************************************************************* g=Jfp$*[  
    'Radius and conic constant of posterior lens *fZ'#C~x  
    '************************************************************************* 2t<CAKBB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K~R{q+  
    GetConic eID, entity, curv, conic 6yqp<D0SP)  

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    SetConic eID, entity, 1/Rpost, CCpost \)*qW[C$a  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >{Djx  
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    '************************************************************************* C.O-iBVe#  
    'Lens thickness (Position of posterior lens surface) *d 4D9(  
    '************************************************************************* pm+[,u!i  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) d
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    ' Delete any z-shift(s) NT'Yh  
    count = 0 l]gfT&  
    While GetOperationCount(eID)>count Tec6] :  
        GetOperation eID, count, op X@rAe37h+  
        If op.Type="ShiftZ" Then NG ~sE&,7  
            DeleteOperation eID,count KC'{>rt7  
            count=count-1 va\cE*,@ns  
        End If -[z;y73]t  
        count=count+1 dL>ZL1.$  
    Wend A7se#"w  
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    'Set new z-shift XQ>m8K?\d  
    op.Type = "ShiftZ" *&s_u)b  
    op.val1 = tlens lOZZ-  
    op.parent = parID Jh1fM`kB5K  
    AddOperation eID, op A]1](VQ)4  
    Print "Set lens thickness = " & tlens Flsf5 Tr0  
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    '************************************************************************* H`sV\'`!}  
    'Lens index of refraction 0:nyOx(;  
    '************************************************************************* Nsb13mlY  
    eID = FindMaterial( "Lens" ) 'tekn
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    GetModelMaterial eID, mat L,$9)`j  
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    mat.Nd = nlens p)`JVq,H/B  
    SetModelMaterial eID, mat G9;WO*  
    Print "Set lens index of refraction = " & nlens :7gIm|2"]  
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    '************************************************************************* 5K0Isuu>>  
    'Pupil diameter $P$OWp?b  
    '************************************************************************* t5S S]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) N]3XDd|q  
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    'Adjust pupil diameter (trimming volume inner hole) ;TY
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" s&4Y+dk93  
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    ' Adjust pupil location to just in front of the lens czafBO6  
    parID = FindFullName( "Geometry.Arizona Eye" ) 3LG)s:p$/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) qbjRw!2?w  
    count = 0 9kcAMk1K  
    While GetOperationCount(eID)>count &W1c#]q@r  
        GetOperation eID, count, op !^w+<p  
        If op.Type="ShiftZ" Then "Mth<%i  
            DeleteOperation eID,count 3/iGSG`  
            count=count-1 278 6tZF,  
        End If @AJt/wPk  
        count=count+1 >
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    Wend K:mb$YJ&  
    op.Type = "ShiftZ" {=TD^>?  
    op.val1 = taq-0.01 <3'r&ks  
    op.parent = parID 8@ b83  
    AddOperation eID, op xRb-m$B}L  
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    Print "Set pupil diameter = " & pupilDiam n<MH\.!tM  
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    'Update AZ Eye subassembly Description s{!F@^a  
    eID = FindFullName( "Geometry.Arizona Eye" ) dI3U
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    GetEntity eID, entity EI'(  
    entity.Description = "Accommodation = " & A & "D" f5AK@]4G  
    SetEntity eID, entity )]'?yS"  
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    Update tR1 kn&w  
    Print "DONE!" :W
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End Sub 1Nv_;p.{  
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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： |dXmg13( -  
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Accommodation = 4 Diopters bX8Bn0#a+  
Pupil Diameter = 4 mm ~)ls.NXI  
Set aqueous humor thickness = 2.81 fDf:J
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Set anterior lens radius = 10.4 and conic constant = -2.375869 0GEK xV\F  
Set posterior lens radius = -4.424557 and conic constant = -3.081019
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Set lens thickness = 3.927 @wbV@  
Set lens index of refraction = 1.42672 (h%!Kun  
Set pupil diameter = 4 sa{X.}i%E  
DONE! ~!\n