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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 i}|jHlv  
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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  = ~*Vfx  
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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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    Table 1. AZ眼睛模型的定义
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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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    图1. 光源和提示信息使用
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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$ICOXA  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 EyV5FWb58  
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    图2. 字母F光源的设定方法光 T#H-GOY:  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 p7.~k1h  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ATV|M[B  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 6OtNWbB  
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    图5. 视网膜重点采样规格设定
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    脚本 M@pF[J/  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 16~5;u  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 zP$"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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    图7. 字母F在视网膜上颜色分析
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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  
    !Okl3 !fC  
    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  
    :4Y 5  
    Sub Main z;&J9r $`  
    <II>io ;  
        '用户输入对话框 Ma ]*Pled  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  {C%f~j  
            TextBox 220,21,40,21,.TextBox1 'default: 0 e,*@+E\4  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Jg6@)<n  
            OKButton 40,91,90,21 ]1q`N7  
            CancelButton 190,91,90,21 Ed#Hilk'  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~#=70  
            TextBox 220,49,40,21,.TextBox2 'default: 4 c$;Cpt@-j  
        End Dialog ]-w.x ]I  
        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 ,,h>_IA  
            Print "Execution cancelled." 22EI`}"J  
            End r <2&_$|  
        End If V~QOl=`K:  
    o"qG'\x  
        'Assign accommodation and pupil diameter & use defaults if field left empty 8?hj}}H  
        If dlg.TextBox1 = "" Then #*+$o<Q]9  
            A = 0           'Default accommodation kM7 6?M  
        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) b Kr73S9  
        End If &M #}?@!C  
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        Print " " t<SCrLbz  
        Print "Accommodation = " & A & " Diopters" z+j3j2  
        Print "Pupil Diameter = " & pupilDiam & " mm" %eJE@$  
    ^B(:Hv}G(:  
        ' Calculate new parameters with accommodation cXt]55"  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness N{K[sXCW  
    ,'@t .XP  
        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  
    ifadnl26 s  
        'Adjust parameters to account for accommodation bqQR";  
    }J_#N.y  
        '************************************************************************* 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" ) TL: 6Pe  
    G]gc*\4  
        ' 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$h }g  
                DeleteOperation eID,count d08:lYQ  
                count=count-1 Z (C0+A\  
            End If D8)6yPwE  
            count=count+1 KKNQ+'?  
        Wend 2@|,VN V6~  
    @ "/:Omh  
        'Set new shift in 0W]vK$\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  
    Si-Q'*Y=  
        '************************************************************************* 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  
    }[SYWJIc  
        '************************************************************************* 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  
    Sn[/'V^$a  
        ' 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 ,n &Lp  
        Wend I8{ mkh  
    =LKf.@]#  
        '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  
    )&qr2Cm*  
        '************************************************************************* Ht|"91ZC5  
        'Lens index of refraction Gyb|{G_  
        '************************************************************************* ~"r(PCa@  
        eID = FindMaterial( "Lens" ) $>rKm  
        GetModelMaterial eID, mat 5. +_'bF|  
    -x-EU#.G  
        mat.Nd = nlens \w)ddc!ZS  
        SetModelMaterial eID, mat ym'!f|9AA  
        Print "Set lens index of refraction = " & nlens Bv#?.0Ez;  
    g9j&\+h^  
        '************************************************************************* `bF4/iBW  
        'Pupil diameter RM>A9nv$\  
        '************************************************************************* $f+cd8j?o  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #dQFs]:F  
    5 hW#BB  
        'Adjust pupil diameter (trimming volume inner hole) F12$BK DH  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ubM  N  
    ?*'0;K13  
        ' 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" @T J  
        op.val1 = taq-0.01 Xh}G=1}  
        op.parent = parID 2?:'p[z"]  
        AddOperation eID, op H'Jz:6   
    yatZ Al(B  
        Print "Set pupil diameter = " & pupilDiam U^]@0vR  
    m$7C{Mr'  
        '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  
    j1=su~  
        Update 35L\  
        Print "DONE!" yT[=!M  
         plpb4> S  
    End Sub >ByqM{?  
    JF=T_SH^U  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: c/V0AKkS 8  
    u#NX`_  
    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  
     
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