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    [分享]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 ; p+C0!B2  
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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。 j0F& WKk  
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    模型 -0'< 7FSQ  
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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。 ! qtj1.w  
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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. E-X02A  
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    光源 b;`MHEzw&q  
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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。 yqJ>Z%)hf  
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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。 T_\hhP~  
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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。 JBV 06T_4o  
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    图2. 字母F光源的设定方法光 '*U_!RmQ  
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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 QVb{+`.7  
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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。 dphWxB  
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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。 Rs'mk6+  
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    图5. 视网膜重点采样规格设定
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    脚本 4{$ L]toP  
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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: `'rvDaP  
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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。 ypvz&SzIh  
    余下的脚本计算与屈光度有关的所有参数。 4?`*# DPl  
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    分析 >b*}Td~J  
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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。 7%|HtBXv^  
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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 SQdK`]4  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7MX5hZF"  
    &7w*=f8I  
    Dim entity As T_ENTITY ZyrVv\'  
    Dim op As T_OPERATION pQCW6X  
    Dim mat As T_MODELMATERIAL x c?=fv  
    Dim A As Double _.GHtu/I  
    Dim pupilDiam As Double P.Qz>c^-C  
    Dim eID As Long D' h%.  
    Dim parID As Long @(m?j1!M  
    Dim count As Integer 3Q#3S  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ou\~^  
    Dim tlens As Double, nlens As Double l Ztw[c  
    Dim curv As Double, conic As Double JIMi~mEiN  
    Dim ok As Long Mgux (5`;  
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    Sub Main qc/)l~]?g{  
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        '用户输入对话框 nhB.>ReAi  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 97^)B4  
            TextBox 220,21,40,21,.TextBox1 'default: 0 \~:_ h#bW  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?fvK<0S`  
            OKButton 40,91,90,21 Gr|102  
            CancelButton 190,91,90,21 _3m\r*(vmQ  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 zRA,Yi4;+  
            TextBox 220,49,40,21,.TextBox2 'default: 4 6M6r&,yRu  
        End Dialog 6 $5SS#  
        Dim dlg As UserDialog %xN91j["  
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        ok = Dialog (dlg) s,8g^aF4  
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        If ok=0 Then    'cancel button was pressed DP &*P/  
            Print "Execution cancelled." oN.#q$\` k  
            End ;TCT%j`^o  
        End If jGKI|v4U(  
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        'Assign accommodation and pupil diameter & use defaults if field left empty TE@bV9a  
        If dlg.TextBox1 = "" Then C <q@C!A  
            A = 0           'Default accommodation <w0$0ku  
        Else ]= 9^wS  
            A = CDbl(dlg.TextBox1) 8'VcaU7Nh  
        End If HhT6gJWrU  
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        If dlg.TextBox2 = "" Then `>\>'V<&  
            pupilDiam = 4   'Default pupil diameter -Z&9pI(3R~  
        Else QR[i9'`<  
            pupilDiam = CDbl(dlg.TextBox2) 0`kaT ?>  
        End If Q|nGY:98  
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        Print " " _iZ9Ch\  
        Print "Accommodation = " & A & " Diopters" y (=$z/  
        Print "Pupil Diameter = " & pupilDiam & " mm" l#!6 tw+e?  
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        ' Calculate new parameters with accommodation Kd').w  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness eW;0{P  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7Ezy-x2h  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens S,^)\=v  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :eW`El  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8G|kKpX  
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        tlens = 3.767 + 0.04*A                  'Lens thickness J4q_}^/2w  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction W3 2]#M=  
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        'Adjust parameters to account for accommodation |E9iG  
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        '************************************************************************* U|)CZcM  
        'Aqueous thickness (Position of Lens) qI5`:PH%n  
        '************************************************************************* Ggp.%kS6F  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 05/'qf7P,U  
        GetCustomElement eID, entity NmZowh$M  
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        parID = FindFullName( "Geometry.Arizona Eye" ) N9gbj%+  
    @0U={qX  
        ' Delete any shift(s) in z Eh/Z4pzT  
        count = 0 !5=S 2<UX  
        While GetOperationCount(eID)>count nx'Yevi0$  
            GetOperation eID, count, op xjg(}w  
            If op.Type="ShiftZ" Then !t!\b9=  
                DeleteOperation eID,count &u~#bDh  
                count=count-1 YuKg|<WO  
            End If 7':qx}c#!1  
            count=count+1 <t"|wYAa_  
        Wend QK@[ b3-h1  
    db0]D\  
        'Set new shift in eeu;A, @U  
        op.Type = "ShiftZ" 9a3mN(<  
        op.val1 = taq j55;E E!  
        op.parent = parID o=y0=,:a?9  
        AddOperation eID, op E e 15Y$1  
        Print "Set aqueous humor thickness = " & taq-0.55 We?cRb  
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        '************************************************************************* k;xIo(:  
        'Radius and conic constant of anterior lens K *xca(6  
        '************************************************************************* XX[CTh?O%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _ 2E*  
        GetConic eID, entity, curv, conic }>< v7  
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        SetConic eID, entity, 1/Rant, CCant .p$tb2%r  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Xjs`iK=w  
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        '************************************************************************* }?^5L7n  
        'Radius and conic constant of posterior lens VFLW @  
        '************************************************************************* RSK5 }2  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) o%sx(g=q6  
        GetConic eID, entity, curv, conic ^M~Z_CQL2  
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        SetConic eID, entity, 1/Rpost, CCpost 8m"jd+  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost u;3wg`e  
    .LA?2N  
        '************************************************************************* >N8*O3  
        'Lens thickness (Position of posterior lens surface) \zM3{{mV/  
        '************************************************************************* 9L9qLF5 t  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x#c%+  
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        ' Delete any z-shift(s) x_$`#m{hL5  
        count = 0 EUjA-L(  
        While GetOperationCount(eID)>count wjc&S'[  
            GetOperation eID, count, op gOLN7K-)  
            If op.Type="ShiftZ" Then Vh'H =J  
                DeleteOperation eID,count W|4h;[w  
                count=count-1 Y=\:fa  
            End If G;Py%8  
            count=count+1 Y4Y~e p  
        Wend 8"yZS)09  
    WO!'("  
        'Set new z-shift B&>z&!}  
        op.Type = "ShiftZ" gi #dSd1\&  
        op.val1 = tlens |*n B2  
        op.parent = parID "< })X.t  
        AddOperation eID, op #6*20w_u  
        Print "Set lens thickness = " & tlens L6Io u  
    @RXkj-,eC#  
        '************************************************************************* IaT\ymm`  
        'Lens index of refraction ToX--w4  
        '************************************************************************* |qz&d=>  
        eID = FindMaterial( "Lens" ) Znd ,FqHk  
        GetModelMaterial eID, mat Yan}H}Oq  
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        mat.Nd = nlens _o7t| pl~  
        SetModelMaterial eID, mat bYBEh n  
        Print "Set lens index of refraction = " & nlens $0XR<D  
    \wF- [']N  
        '************************************************************************* X.+|o@G  
        'Pupil diameter `!Yd$=*c_&  
        '************************************************************************* IxaF *4JG  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %ty`Oa2  
    \![ p-mW{  
        'Adjust pupil diameter (trimming volume inner hole) Y49&EQ  
    +t%1FkI\  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3 #"!Hg  
    0Ua&_D"  
        ' Adjust pupil location to just in front of the lens Vw]!Kb7tA  
        parID = FindFullName( "Geometry.Arizona Eye" ) bs0[ a 1/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) lokKjs  
        count = 0 1pAcaJzf  
        While GetOperationCount(eID)>count otX/sg.B*  
            GetOperation eID, count, op  ZvwU  
            If op.Type="ShiftZ" Then Cy dV$!&mP  
                DeleteOperation eID,count qe 'RvBz  
                count=count-1 uHq;z{ 2GI  
            End If mDx=n.lIz  
            count=count+1 M+*K-zt0  
        Wend -9Dr;2\  
        op.Type = "ShiftZ" " v<O)1QT  
        op.val1 = taq-0.01 n8tw8o%&[  
        op.parent = parID r @}N6U~*  
        AddOperation eID, op  +;-ZU  
    ?|~KF:,#}  
        Print "Set pupil diameter = " & pupilDiam 7=/iFv[  
     &Ufp8[  
        'Update AZ Eye subassembly Description q%LjOPE V  
        eID = FindFullName( "Geometry.Arizona Eye" ) 0O[le*3b  
        GetEntity eID, entity ,0c]/Sd*p  
        entity.Description = "Accommodation = " & A & "D" V!l?FOSZ  
        SetEntity eID, entity %JgdLnQE  
    (&Rql7](8  
        Update b gxk:$E  
        Print "DONE!" 3N 5@<:2`  
         bh(} f.@ 9  
    End Sub \SoT^PW  
    nxB[T o*P  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: /b\c<'3NY  
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    Accommodation = 4 Diopters N0%q 66]1  
    Pupil Diameter = 4 mm 'E&tEbY  
    Set aqueous humor thickness = 2.81 `NTtw;%Y  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 CF 3V)3}  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ,}O33BwJp  
    Set lens thickness = 3.927 Si@ 6'sw  
    Set lens index of refraction = 1.42672 Wm}gnNwA  
    Set pupil diameter = 4 w3z'ZCcr;"  
    DONE! I{h KN V  
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    QQ:2987619807 P aeq  
     
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