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    [分享]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: 2020-12-09
    简介 #]q<fhJhr$  
    ,H'O`oV!1E  
    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。 @ {j'Pf'  
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    模型 *ukE"Aj  
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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。 pMHY2t  
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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. .ss/E  
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    光源 A=Q"IdK  
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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。 bu1O<*  
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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。 wwF]+w%lOw  
    .\7R/cP}{A  
    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。 ]/XNfb  
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    图2. 字母F光源的设定方法光 #6[FGM  
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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 22a$//}E  
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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。 ZX sm9  
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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。 #*:y2W%H  
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    图5. 视网膜重点采样规格设定
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    脚本 we9R4 *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: L5 Rj;qhi  
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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。 $ &M"Ji  
    余下的脚本计算与屈光度有关的所有参数。 2~AGOx  
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    分析 6 :K~w<mMJ  
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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。 ):E4qlB  
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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 5 5>^H1M  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. &ok2Xw  
    3de<H=H'  
    Dim entity As T_ENTITY v?F~fRH  
    Dim op As T_OPERATION } :P/eY  
    Dim mat As T_MODELMATERIAL H.qp~-n  
    Dim A As Double ZP61T*n  
    Dim pupilDiam As Double NdZv*  
    Dim eID As Long (0g@Z `r  
    Dim parID As Long w+(bkqz]  
    Dim count As Integer +FRXTku(  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^P >; %  
    Dim tlens As Double, nlens As Double `ySLic`  
    Dim curv As Double, conic As Double X!V@jo9?  
    Dim ok As Long .e%PK  
    m!L&_ Z|j  
    Sub Main  T},Nqt<  
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        '用户输入对话框 ,d'x]&a  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 48nZ H=(Eh  
            TextBox 220,21,40,21,.TextBox1 'default: 0 P#-Ye<V~J(  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6cQh8_/>{#  
            OKButton 40,91,90,21 1nhC! jDD  
            CancelButton 190,91,90,21 p@!{Sh  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u snbGkq  
            TextBox 220,49,40,21,.TextBox2 'default: 4 T|`nw_0  
        End Dialog }D j W  
        Dim dlg As UserDialog @U08v_,  
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        ok = Dialog (dlg) ORHs1/L`j  
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        If ok=0 Then    'cancel button was pressed ,r!_4|\  
            Print "Execution cancelled." #u`i4  
            End m?VA 1  
        End If & F\HR  
    NPF"_[RoeV  
        'Assign accommodation and pupil diameter & use defaults if field left empty p3>p1tC  
        If dlg.TextBox1 = "" Then s ki'I  
            A = 0           'Default accommodation =S7Xj`/  
        Else H5j6$y|I|N  
            A = CDbl(dlg.TextBox1) qKag'0e  
        End If -}Vnr\f  
    v#J 2yg  
        If dlg.TextBox2 = "" Then w}nc^6qH  
            pupilDiam = 4   'Default pupil diameter ~{lSc/SP|  
        Else IIcG+zwx  
            pupilDiam = CDbl(dlg.TextBox2) <XG&f  
        End If ZT;$aNy  
    #InuN8sI  
        Print " " g.$a]pZz  
        Print "Accommodation = " & A & " Diopters" 6wK>SW)#&j  
        Print "Pupil Diameter = " & pupilDiam & " mm" w ;+x g  
    U7i WYdt$  
        ' Calculate new parameters with accommodation YQGVQ[P  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =?hGa;/rb  
    =wbgZr^2  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ;cKN5#7  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^ z!g3  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens x{y}pH"H  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens =Ji+GJ <,9  
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        tlens = 3.767 + 0.04*A                  'Lens thickness b?S,%  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction t&m 8 V$Q  
    mcbvB5U  
        'Adjust parameters to account for accommodation &/)2P#u  
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        '************************************************************************* {yFCGCs  
        'Aqueous thickness (Position of Lens) x -CTMKX  
        '************************************************************************* ;\1/4;m  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) R.nAD{>h*  
        GetCustomElement eID, entity kF{'?R5 w  
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        parID = FindFullName( "Geometry.Arizona Eye" ) oN3DM;  
    Ed">$S  
        ' Delete any shift(s) in z W&MZ5t,k=  
        count = 0 j~DTvWg<Jl  
        While GetOperationCount(eID)>count Jc8^m0_  
            GetOperation eID, count, op Wgp}v93  
            If op.Type="ShiftZ" Then -;T!d  
                DeleteOperation eID,count rf@Cz%xDD  
                count=count-1 B8J_^kd  
            End If &|6 A 8,  
            count=count+1 oW[];r  
        Wend ~1xfE C/  
    `4GEq2%  
        'Set new shift in zoh%^8? o  
        op.Type = "ShiftZ" ')G, +d^  
        op.val1 = taq 5t('H`,2  
        op.parent = parID 4th*=ku  
        AddOperation eID, op ,hO*W-a% 1  
        Print "Set aqueous humor thickness = " & taq-0.55 ^~dBO %M^  
    Mk=M)d`  
        '************************************************************************* (3. B\8s  
        'Radius and conic constant of anterior lens /sU~cn^D5  
        '************************************************************************* z?Hi u6c-  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >oD,wSYV~  
        GetConic eID, entity, curv, conic ([g[\c,H  
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        SetConic eID, entity, 1/Rant, CCant ICvl;Q  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3haR/Y N  
    ^$>Q6.x?*)  
        '************************************************************************* e^ Aw%t  
        'Radius and conic constant of posterior lens A-6><X's6  
        '************************************************************************* ,_wpYTl*X  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6VUkZKc  
        GetConic eID, entity, curv, conic @XJzM]*w&  
    =\ek;d0Tqb  
        SetConic eID, entity, 1/Rpost, CCpost Yo-$Z-ud  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ,`Yx(4!rR  
    ;xXD2{q  
        '************************************************************************* vz~`M9^  
        'Lens thickness (Position of posterior lens surface) Z=KHsMnB  
        '************************************************************************* FN+x<VXo(  
    &eA!h  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) f)_k_<  
    Kb$6a'u7  
        ' Delete any z-shift(s) [@_IUvf^.  
        count = 0 |XrGf2P9u  
        While GetOperationCount(eID)>count )i^+=TZq  
            GetOperation eID, count, op {9c_T!c  
            If op.Type="ShiftZ" Then r9 5hW  
                DeleteOperation eID,count f,(@K%  
                count=count-1 C CDO8  
            End If 0F5QAR O  
            count=count+1 Efa3{ 7>{  
        Wend C#l9MxZE  
    NScUlR"nE  
        'Set new z-shift Z@ dS,M*  
        op.Type = "ShiftZ" n/ CP2A  
        op.val1 = tlens :OKU@l|  
        op.parent = parID -s_=4U,  
        AddOperation eID, op N5F+h94z]  
        Print "Set lens thickness = " & tlens e~1$x`DH  
    Hw\hTTK  
        '************************************************************************* hfL8]d-  
        'Lens index of refraction ETQL,t9m  
        '************************************************************************* b~td ^  
        eID = FindMaterial( "Lens" ) Y$4dqn  
        GetModelMaterial eID, mat D/`b ~Yl  
    .4%6_`E  
        mat.Nd = nlens Ir?ehA  
        SetModelMaterial eID, mat +ab#2~,)  
        Print "Set lens index of refraction = " & nlens m`!Vryf  
    .t9*wz  
        '************************************************************************* /4Sul*{hc  
        'Pupil diameter +'`I]K>  
        '************************************************************************* 5M= S7B3=  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) PBY;S G ~  
    Y{`hRz`  
        'Adjust pupil diameter (trimming volume inner hole) # n\|Q\W  
    ;/~%D(  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @~j- -L  
    'iikcf*)C  
        ' Adjust pupil location to just in front of the lens A5 <T7~U  
        parID = FindFullName( "Geometry.Arizona Eye" ) JPmZ%]wA  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) qG8-UOUDt  
        count = 0 +V,Ld&r  
        While GetOperationCount(eID)>count w<m e(!-'  
            GetOperation eID, count, op )%Lgo${[;  
            If op.Type="ShiftZ" Then mKZ^FgG  
                DeleteOperation eID,count W:y'a3~  
                count=count-1 ]D\p<4uepM  
            End If I`KBj6n  
            count=count+1 wrEYbb  
        Wend |>Wi5h{6X  
        op.Type = "ShiftZ" lFc4| _c g  
        op.val1 = taq-0.01 an` GY&  
        op.parent = parID v>' mW  
        AddOperation eID, op mF@D O$  
    W}.p,d  
        Print "Set pupil diameter = " & pupilDiam G}0fk]%\:  
    E|BiK  
        'Update AZ Eye subassembly Description n||!/u)*  
        eID = FindFullName( "Geometry.Arizona Eye" ) J%ue{PL7  
        GetEntity eID, entity F^}n7h=qk  
        entity.Description = "Accommodation = " & A & "D" fS- 31<?  
        SetEntity eID, entity -^<`v{}Dn  
    mqv!"rk'w  
        Update QP[`*X  
        Print "DONE!" :taRCh5  
         1`I#4f  
    End Sub fH[:S9@  
    G[[NDK  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: #Cz6c%yK  
    9KLhAYaq  
    Accommodation = 4 Diopters +H8;*uZ|k,  
    Pupil Diameter = 4 mm xrky5[XoD  
    Set aqueous humor thickness = 2.81 gKay3}w  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 m8ydX6~max  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 H=k`7YN  
    Set lens thickness = 3.927 ?.&?4*u  
    Set lens index of refraction = 1.42672 +gsk}>"  
    Set pupil diameter = 4 n\D3EP<s  
    DONE! z0m[25FQG  
    9,;+B8-A  
    M"$TXXe  
    QQ:2987619807 gH zjI[WI  
     
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