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    [技术]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: 2021-10-22
    简介 4IZlUJ?j+c  
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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。 1]j^d  
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    模型 8W;2oQN7  
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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。 NvQ%J+  
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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. GMb(10T`  
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    光源 e2c1pgs&+  
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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。 #|Oj]bd(=  
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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。 cx{T '1  
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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。 ^;r+W -MQ  
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    图2. 字母F光源的设定方法光 `B:"6nW6  
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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 *_1[[~Aw  
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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。 \gItZ}+c4}  
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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。 h%TLD[[/jr  
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    图5. 视网膜重点采样规格设定
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    脚本 6):Xzx,  
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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: L\e>B>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。 {U"^UuU]  
    余下的脚本计算与屈光度有关的所有参数。 !8R@@,_v  
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    分析 HI`q1m.  
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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。 \4{2eU  
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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 !tXZ%BP.u  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. d-B7["z,  
    q'G,!];qL  
    Dim entity As T_ENTITY xx)-d,S  
    Dim op As T_OPERATION G[h(xp?,l  
    Dim mat As T_MODELMATERIAL `uo, __y  
    Dim A As Double h2w}wsb0l  
    Dim pupilDiam As Double {v` 2sB  
    Dim eID As Long hoQ7).>  
    Dim parID As Long S1J<9xqSQ8  
    Dim count As Integer B$vr'U   
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4woO;Gm  
    Dim tlens As Double, nlens As Double lA^+Flh  
    Dim curv As Double, conic As Double 1J}8sG2`  
    Dim ok As Long `f9gC3Hk  
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    Sub Main ~AZWds(,N  
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        '用户输入对话框 2c(aO[%h9  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @Uo6>-W F  
            TextBox 220,21,40,21,.TextBox1 'default: 0 L]d-33.c!H  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 "D][e'  
            OKButton 40,91,90,21 &dR=?bz-A  
            CancelButton 190,91,90,21 r$(~j^<s  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Hkd^-=]]no  
            TextBox 220,49,40,21,.TextBox2 'default: 4 hhI)' $  
        End Dialog (Yb[)m>fQ}  
        Dim dlg As UserDialog wy,p&g)>  
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        ok = Dialog (dlg) ',I0ih#Ls  
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        If ok=0 Then    'cancel button was pressed ][;G=oCT  
            Print "Execution cancelled." RA O`i>@  
            End 9z>z3,ftN  
        End If ]N{0:Va@D  
    o0It82?RN  
        'Assign accommodation and pupil diameter & use defaults if field left empty mQ~:Y  
        If dlg.TextBox1 = "" Then NbRn*nb/T  
            A = 0           'Default accommodation nBItO~l  
        Else $s5a G)?7  
            A = CDbl(dlg.TextBox1) E=]4ctK  
        End If *|#T8t,}n  
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        If dlg.TextBox2 = "" Then g I]GUD-  
            pupilDiam = 4   'Default pupil diameter >vbY<HGt  
        Else \ I`p|&vG  
            pupilDiam = CDbl(dlg.TextBox2) ^:=f^N=^  
        End If 9uk<&nqx  
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        Print " " ` `U^COD  
        Print "Accommodation = " & A & " Diopters" 13hE}g;.  
        Print "Pupil Diameter = " & pupilDiam & " mm" XT>.`, sv  
    qJ4T]FVN  
        ' Calculate new parameters with accommodation Zw1U@5}A  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rN)V[5R#M  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens [K/m  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens eLD|A=X?  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens *f%>YxF  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens N_pUv   
    !p/%lU65  
        tlens = 3.767 + 0.04*A                  'Lens thickness nC1zzFFJ  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \!]hU%Un  
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        'Adjust parameters to account for accommodation Iq7}   
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        '************************************************************************* }~K`/kvs  
        'Aqueous thickness (Position of Lens) \b=Pj!^gwb  
        '************************************************************************* WI> P-D  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .iMN,+qP  
        GetCustomElement eID, entity Cqii}  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 2 dp>Z",  
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        ' Delete any shift(s) in z B.r4$:+jb2  
        count = 0 uj>WgU  
        While GetOperationCount(eID)>count 1NQbl+w#I  
            GetOperation eID, count, op $$APgj"|<  
            If op.Type="ShiftZ" Then tVrY3)c  
                DeleteOperation eID,count 7\]E~/g  
                count=count-1 DGW+>\G  
            End If =@2FX&&E_  
            count=count+1 (+uj1z^  
        Wend xv{O^Ie+S  
    ML;*e"$  
        'Set new shift in =@,Q Dm]L  
        op.Type = "ShiftZ" m7EcnQf  
        op.val1 = taq -HSs^dP`  
        op.parent = parID r(d':LV  
        AddOperation eID, op g~V+4+  
        Print "Set aqueous humor thickness = " & taq-0.55 Z6\+  
    ~'37`)]z  
        '************************************************************************* 7dsefNPb  
        'Radius and conic constant of anterior lens WE]e m >  
        '************************************************************************* KL$bqgc(p3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 2(5ebe[  
        GetConic eID, entity, curv, conic HbP!KVHyk1  
    _@S`5;4x  
        SetConic eID, entity, 1/Rant, CCant m]i @ +C  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !EUan  
    z'T) =ycT  
        '************************************************************************* .ERO|$fv  
        'Radius and conic constant of posterior lens oh# \]c\f  
        '************************************************************************* bR@p<;G|  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ctE\ q  
        GetConic eID, entity, curv, conic ()&~@1U  
    }neY<{z  
        SetConic eID, entity, 1/Rpost, CCpost iq( )8nxi  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost r.7$&BCng  
    .bBdQpF-  
        '************************************************************************* jw-0M1B  
        'Lens thickness (Position of posterior lens surface) lHgs;>U$  
        '************************************************************************* quY:pqG38q  
    %HrAzM.QBF  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {G?N E  
    g}@OUG"D  
        ' Delete any z-shift(s) w$JvB5O  
        count = 0 l;o1 d-n]  
        While GetOperationCount(eID)>count >EY3/Go>  
            GetOperation eID, count, op D!7`CH+  
            If op.Type="ShiftZ" Then A}eOFu`  
                DeleteOperation eID,count 95el'K[R  
                count=count-1 I? ,>DHUX  
            End If lNSLs"x^  
            count=count+1 M4as  
        Wend |sJSN.8  
    j?'GZ d"B  
        'Set new z-shift bhniB@<  
        op.Type = "ShiftZ" '],J$ge  
        op.val1 = tlens >2~=)L  
        op.parent = parID ]+X@ 7  
        AddOperation eID, op a+n0|CvF  
        Print "Set lens thickness = " & tlens Gz .|]:1  
    UFMA:o,  
        '************************************************************************* AK@9?_D  
        'Lens index of refraction SL5Ai/X0N  
        '************************************************************************* | Bi!  
        eID = FindMaterial( "Lens" ) &jmRA';sK  
        GetModelMaterial eID, mat .V,@k7U,V  
    gEjdN.  
        mat.Nd = nlens d3xmtG {i  
        SetModelMaterial eID, mat J{Q|mD=  
        Print "Set lens index of refraction = " & nlens 0Vx.nUQ  
    EN/,5<S<,[  
        '************************************************************************* rW$[DdFA5{  
        'Pupil diameter 4<BjC[@~Z{  
        '************************************************************************* .SWlp2!M5  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <7~'; K  
    Zu7)gf  
        'Adjust pupil diameter (trimming volume inner hole) 7Op>i,HZk\  
    ui?  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5 sX+~Q  
    Hm*/C4B`  
        ' Adjust pupil location to just in front of the lens uA< n  
        parID = FindFullName( "Geometry.Arizona Eye" ) Hl,W=2N  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m;,N)<~  
        count = 0 1jcouD5?H  
        While GetOperationCount(eID)>count E 7{U |\  
            GetOperation eID, count, op V-BiF>+  
            If op.Type="ShiftZ" Then ;=MU';o  
                DeleteOperation eID,count y+NN< EY@  
                count=count-1 *}*FX+px)  
            End If A*\.NTM  
            count=count+1 ln6d<; M5  
        Wend F1yqxWHeo  
        op.Type = "ShiftZ" ,>%}B3O:Y=  
        op.val1 = taq-0.01 Vh4X%b$TV  
        op.parent = parID lgk  .CC  
        AddOperation eID, op lN Yt`xp  
    %xI p5h]  
        Print "Set pupil diameter = " & pupilDiam $| @ (  
    :/nj@X6  
        'Update AZ Eye subassembly Description "]} bFO7C  
        eID = FindFullName( "Geometry.Arizona Eye" ) ?Wlb3;  
        GetEntity eID, entity T{-CkHf9Q  
        entity.Description = "Accommodation = " & A & "D" bE !GJZ  
        SetEntity eID, entity ?82xdp g  
    "~|6tQLc  
        Update |IzPgC  
        Print "DONE!" rD 3v$B  
         Hquc o  
    End Sub 8.O8No:'&  
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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: 3`DQo%<  
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    Accommodation = 4 Diopters s;ls qQk  
    Pupil Diameter = 4 mm H&-zZc4\  
    Set aqueous humor thickness = 2.81 P/W XaE4  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 T4Pgbop  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 yb\_zE\  
    Set lens thickness = 3.927 GjvOM y  
    Set lens index of refraction = 1.42672 ?^al9D[:lz  
    Set pupil diameter = 4 UM"- nZ>[  
    DONE! 0AL=S$B)  
     
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