[技术]Arizona眼睛模型 [复制链接]

简介 i}
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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。 CqX*.j{  
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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。 {8;}y[R  
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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. VhnIr#L+  
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光源 :yw(Co]f  
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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[vFh0s"m  
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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。 E;k$ICOXA  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 EyV5FWb58  
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视网膜的散射 p7.~k1h  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ATV|M[B  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 6OtNWbB  
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脚本
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 16~5;u  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 zP$"6~.  
余下的脚本计算与屈光度有关的所有参数。 XWB#7;,R  
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分析 ki?V eFp  
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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。 =6qSo @  
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脚本代码 b: I0Zv6  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. !H9zd\wc  
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Dim entity As T_ENTITY h;OHpvk  
Dim op As T_OPERATION E7<l^/<2S+  
Dim mat As T_MODELMATERIAL ndvt $*  
Dim A As Double 8K\S]SZ  
Dim pupilDiam As Double _akpW  
Dim eID As Long K8v@)  
Dim parID As Long 0/~{,  
Dim count As Integer L*{E-m/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :?)q"hE  
Dim tlens As Double, nlens As Double HoZsDs.XZ  
Dim curv As Double, conic As Double 0.U- tg0  
Dim ok As Long $A98h-*x  

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Sub Main z;&J9r$`  
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    '用户输入对话框 Ma ]*Pled  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  {C%f~j  
        TextBox 220,21,40,21,.TextBox1 'default: 0 e,*@+E\4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1
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        OKButton 40,91,90,21 ]1q`N7  
        CancelButton 190,91,90,21 Ed#Hilk'  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
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        TextBox 220,49,40,21,.TextBox2 'default: 4 c$;Cpt@-j  
    End Dialog ]-w.x
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    Dim dlg As UserDialog @M(+YCi:e@  
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    ok = Dialog (dlg) w!Ii  
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    If ok=0 Then    'cancel button was pressed ,
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        Print "Execution cancelled." 22EI`}"J  
        End r <2&_$|  
    End If V~QOl=`K:  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 8?hj}}H  
    If dlg.TextBox1 = "" Then #*+$
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        A = 0           'Default accommodation kM
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    Else Ge*N%=MX8  
        A = CDbl(dlg.TextBox1) sGGi7%  
    End If 8y]{I^z}  
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    If dlg.TextBox2 = "" Then f3mQd}<L  
        pupilDiam = 4   'Default pupil diameter +"VXw2R_e  
    Else 8@KGc )k  
        pupilDiam = CDbl(dlg.TextBox2) bKr73
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    End If &M#}?@!C  
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    Print " " t<SCrLbz  
    Print "Accommodation = " & A & " Diopters" z+j3j2  
    Print "Pupil Diameter = " & pupilDiam & " mm"
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    ' Calculate new parameters with accommodation cXt]55"  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness N{K[sXCW  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 9gETWz(3I  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens uh3<%9#\k  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens if+97^Oy  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ots]y  
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    tlens = 3.767 + 0.04*A                  'Lens thickness bO }9/Ay  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ]KQBek#DD  
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    'Adjust parameters to account for accommodation bqQR";  
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    '************************************************************************* Wtp;se@#  
    'Aqueous thickness (Position of Lens) :\|<7n   
    '************************************************************************* {BD G;e  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =m?x5G^  
    GetCustomElement eID, entity OJ<V<=MYZ  
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    parID = FindFullName( "Geometry.Arizona Eye" )
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    ' Delete any shift(s) in z OsgjSJrf  
    count = 0 rC6{-42bb  
    While GetOperationCount(eID)>count EskD)Sl  
        GetOperation eID, count, op DP!~WkU~  
        If op.Type="ShiftZ" Then ,xy$h }g  
            DeleteOperation eID,count d08:lYQ  
            count=count-1 Z (C
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        End If D8)6yPwE  
        count=count+1 KKNQ+'?  
    Wend 2@|,VN V6~  
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    'Set new shift in 0W]vK$\F*  
    op.Type = "ShiftZ" />V& OX`  
    op.val1 = taq ??,/85lM  
    op.parent = parID J,t`ilT  
    AddOperation eID, op *m[[>wE  
    Print "Set aqueous humor thickness = " & taq-0.55 "_n})s f  
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    '************************************************************************* 8]xYE19=  
    'Radius and conic constant of anterior lens i?'|}tK  
    '************************************************************************* )^j62uv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) B<&g  
    GetConic eID, entity, curv, conic }KR"0G[f  
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    SetConic eID, entity, 1/Rant, CCant (E7C9U*  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +*x9$LSD  
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    '************************************************************************* yG,uD!N]|  
    'Radius and conic constant of posterior lens 6-f-/$B  
    '************************************************************************* RdLk85<n  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) af}JS2=$  
    GetConic eID, entity, curv, conic M,oRi;V  
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    SetConic eID, entity, 1/Rpost, CCpost O@`KGZEPY  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 8_T9[]7V8  
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    '************************************************************************* Z~ u3{  
    'Lens thickness (Position of posterior lens surface) !>)o&sM  
    '************************************************************************* )8_MkFQe  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /NQ PTr  
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    ' Delete any z-shift(s) @oQ"FLF.  
    count = 0 a.fdCI]%  
    While GetOperationCount(eID)>count Q 6dqFnz  
        GetOperation eID, count, op /?u]Fj  
        If op.Type="ShiftZ" Then #E#Fk3-ljQ  
            DeleteOperation eID,count N,4hh?  
            count=count-1 =kBN&v_(!  
        End If d^d+8R  
        count=count+1 
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    Wend I8{ mkh  
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    'Set new z-shift W>&!~9H  
    op.Type = "ShiftZ" ^m-w@0^z  
    op.val1 = tlens u]&+TR  
    op.parent = parID 6dhzx; A  
    AddOperation eID, op ]E#W[6'VtB  
    Print "Set lens thickness = " & tlens =4gPoS  
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    '************************************************************************* Ht|"91ZC5  
    'Lens index of refraction Gyb|{G_  
    '************************************************************************* ~"r(PCa@  
    eID = FindMaterial( "Lens" ) $>rKm  
    GetModelMaterial eID, mat 5. +_'bF|  
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    mat.Nd = nlens \w)ddc!ZS  
    SetModelMaterial eID, mat ym'!f|9AA  
    Print "Set lens index of refraction = " & nlens Bv#?.0Ez;  
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    '************************************************************************* `bF4/iBW  
    'Pupil diameter RM>A9nv$\  
    '************************************************************************* $f+cd8j?o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #dQFs]:F  
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    'Adjust pupil diameter (trimming volume inner hole) F12$BKDH  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ubMN  
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    ' Adjust pupil location to just in front of the lens A[m<xtm5K  
    parID = FindFullName( "Geometry.Arizona Eye" ) %JI*)K1WI  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) <Df2  
    count = 0 8WC_CAP  
    While GetOperationCount(eID)>count A0bR.*3  
        GetOperation eID, count, op {+V ]@sz  
        If op.Type="ShiftZ" Then AOef1^S=  
            DeleteOperation eID,count :KS"&h{SY  
            count=count-1 c[Z#q*Q  
        End If VzevOS  
        count=count+1 (,b\"Q  
    Wend yJMo/!DZ  
    op.Type = "ShiftZ" @TJ  
    op.val1 = taq-0.01 Xh}G=1}  
    op.parent = parID 2?:'p[z"]  
    AddOperation eID, op H'Jz:6   
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    Print "Set pupil diameter = " & pupilDiam U^]@0vR  
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    'Update AZ Eye subassembly Description |-z"6F r-  
    eID = FindFullName( "Geometry.Arizona Eye" ) *E+VcU  
    GetEntity eID, entity 8+H 0  
    entity.Description = "Accommodation = " & A & "D" U65oh8x  
    SetEntity eID, entity ^DVryeLD  
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    Update 35L\  
    Print "DONE!" yT[=!M  
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End Sub >ByqM{?  
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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： c/V0AKkS 8  
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Accommodation = 4 Diopters WJMmt XO  
Pupil Diameter = 4 mm Q7\j:.  
Set aqueous humor thickness = 2.81 s\p 1EL(  
Set anterior lens radius = 10.4 and conic constant = -2.375869 HVK0NI  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 KNR7Igw?}  
Set lens thickness = 3.927 "Y@q?ey[1  
Set lens index of refraction = 1.42672 00@F?|-j  
Set pupil diameter = 4 Lcf?VV}  
DONE! V Ds0+RC