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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 rbT)=-(  
    3:%QB9qc]'  
    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。 $,xnU.n  
    EBtLzbj  
    模型 \D>$aLO*?  
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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。 "U. ^lkN  
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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. K/ &?VIi`z  
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    光源 B*htN  
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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。 s] /tYJYl  
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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。 B12$I:x`  
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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。 C@N1ljXJT  
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    图2. 字母F光源的设定方法光 y]%w)4PS  
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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 :a:[.  
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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。 b]E|*  
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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。 T ^A b!O  
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    图5. 视网膜重点采样规格设定
    (BX83)  
    脚本 )hwV`2>l  
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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: [nxE)D  
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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。 X5YiFLH>y\  
    余下的脚本计算与屈光度有关的所有参数。 d@mo!zu  
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    分析 +Taa!hfys  
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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。 KC e13!  
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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 :5GZ\Z8F  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. N__H*yP  
    NGYyn`Lx  
    Dim entity As T_ENTITY 7dihVvL $  
    Dim op As T_OPERATION \EbbkN:D  
    Dim mat As T_MODELMATERIAL F2(q>#<_  
    Dim A As Double ]IJRnVp%  
    Dim pupilDiam As Double x0a.!  
    Dim eID As Long r%Rs0)$yj  
    Dim parID As Long {|9}+ @5Q1  
    Dim count As Integer }4c o)B"  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double y0v]N  
    Dim tlens As Double, nlens As Double lC 97_ T  
    Dim curv As Double, conic As Double *cWmS\h|  
    Dim ok As Long /EwGW  
    ;%J5=f%z)  
    Sub Main j:5%ppIY  
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        '用户输入对话框 [%HIbw J  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7#;vG>]  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ~;-9X|  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 O`FqD{@V  
            OKButton 40,91,90,21 $#o1MX  
            CancelButton 190,91,90,21 _i}wK?n  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 jW*1E *"  
            TextBox 220,49,40,21,.TextBox2 'default: 4 eX&Gw{U-f  
        End Dialog g1DmV,W-Q  
        Dim dlg As UserDialog m$>iS@R  
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        ok = Dialog (dlg) 8U~.\`H-PT  
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        If ok=0 Then    'cancel button was pressed ~Y5l+EF#  
            Print "Execution cancelled." x:K?\<  
            End BpAB5=M0  
        End If Z\X'd_1!  
    hJ%1   
        'Assign accommodation and pupil diameter & use defaults if field left empty gLj?Ys  
        If dlg.TextBox1 = "" Then %@& a7JOL  
            A = 0           'Default accommodation $%2_{m_K:p  
        Else s #:%x#  
            A = CDbl(dlg.TextBox1) t[.W$1=  
        End If k/Mp6<?C:  
    }|8*sk#[  
        If dlg.TextBox2 = "" Then g+q@i{Yn  
            pupilDiam = 4   'Default pupil diameter .I?@o8'x  
        Else A,i()R'I  
            pupilDiam = CDbl(dlg.TextBox2) ^. X[)U  
        End If U/MFhD(06  
    ~HLRfL?  
        Print " " 5?u[XAE  
        Print "Accommodation = " & A & " Diopters" 6=|&tE  
        Print "Pupil Diameter = " & pupilDiam & " mm" vg%QXaM  
    f%^'P"R  
        ' Calculate new parameters with accommodation <SXZx9A!  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >POO-8Q  
    ESQ!@G/n  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens .e[Tu|qo  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens D\L!F6taS  
    tR`S#rk  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens I{.HO<$7D}  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens H;vZm[\0N-  
    }*;EFR6'  
        tlens = 3.767 + 0.04*A                  'Lens thickness =v2%Vs\7k  
    \&|CM8A  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction MB$a82bY  
    f>iuHR*EXB  
        'Adjust parameters to account for accommodation 2PC5^Ni/9@  
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        '************************************************************************* 4^Qi2[w  
        'Aqueous thickness (Position of Lens) ^KHLBSc:  
        '************************************************************************* n`5WXpz4;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) g,lY ut  
        GetCustomElement eID, entity U~is-+Uq  
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        parID = FindFullName( "Geometry.Arizona Eye" ) wz#[:2  
    s"mFt{Y  
        ' Delete any shift(s) in z 1t~({Pl<>  
        count = 0 tW6#e(^l6  
        While GetOperationCount(eID)>count +mWjBY  
            GetOperation eID, count, op 4 eh=f!(+  
            If op.Type="ShiftZ" Then T&}Ye\%  
                DeleteOperation eID,count ?vbDB4  
                count=count-1 ofCVbn  
            End If  ]6~k4  
            count=count+1 OhWC}s  
        Wend iz x[  
    c>MY$-PD  
        'Set new shift in B3b,F#  
        op.Type = "ShiftZ" #tz8{o?ebN  
        op.val1 = taq qzdaN5  
        op.parent = parID fGO*% )  
        AddOperation eID, op E`E'<"{Yd  
        Print "Set aqueous humor thickness = " & taq-0.55 _Xh=&(/8@  
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        '************************************************************************* gduxA/aT  
        'Radius and conic constant of anterior lens ,VG9)K 1K  
        '************************************************************************* HYIRcY  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9eSRCLhgD  
        GetConic eID, entity, curv, conic *,jqE9:O  
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        SetConic eID, entity, 1/Rant, CCant y9 uVCR  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8&Wx@QI  
    F ?mA1T>x  
        '************************************************************************* Vu|dV\N0*  
        'Radius and conic constant of posterior lens ABiC9[Q0  
        '************************************************************************* b+$o4 l/x  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) kgc.8  
        GetConic eID, entity, curv, conic wO.B~`y  
    = o+7xom  
        SetConic eID, entity, 1/Rpost, CCpost 03"#J2b  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost WB;J1TpM7  
    sA2o2~AmM  
        '************************************************************************* E!YmcpCl  
        'Lens thickness (Position of posterior lens surface) E3tj/4:L  
        '************************************************************************* <j"O%y.  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) TAAR'Jz S  
    >Jiij  
        ' Delete any z-shift(s) ORtg>az\%  
        count = 0 ?1DUNZ6  
        While GetOperationCount(eID)>count GU#Q}L2  
            GetOperation eID, count, op [J:zE&aj  
            If op.Type="ShiftZ" Then wy\o*P9mG)  
                DeleteOperation eID,count CRd_}  
                count=count-1 B%(K0`G#X  
            End If }!knU3J  
            count=count+1 _DrnL}9I7  
        Wend B{4"$Mi  
    w*2^/zh  
        'Set new z-shift r'PE5xqF  
        op.Type = "ShiftZ" p}r yKW\cJ  
        op.val1 = tlens XWf7"]%SX  
        op.parent = parID ZU^Q1}</5  
        AddOperation eID, op !xJFr6G~8  
        Print "Set lens thickness = " & tlens [BE:+ ID3  
    q4zSS #]A  
        '************************************************************************* .Wh6(LDY(  
        'Lens index of refraction c}8 -/P=  
        '************************************************************************* {'&8`d  
        eID = FindMaterial( "Lens" ) \|Y{jG<cu  
        GetModelMaterial eID, mat mR6E]TuM  
    y,1S& k  
        mat.Nd = nlens 8}J(c=4Gk  
        SetModelMaterial eID, mat Ta,u-!/ I  
        Print "Set lens index of refraction = " & nlens ~|qXtds$  
    =X<)5IS3  
        '************************************************************************* k~ZBJ+ 94  
        'Pupil diameter Hc"N& %X[  
        '************************************************************************* [I_BCf  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6J]~A0vsi}  
    0rGj|@+;  
        'Adjust pupil diameter (trimming volume inner hole)  ,&4zKm  
    ul}4p{ m[  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 8[f8k 3g  
    i{4'cdr?  
        ' Adjust pupil location to just in front of the lens kS[Dy$AB/2  
        parID = FindFullName( "Geometry.Arizona Eye" ) w# xncH:1  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !+%Az*ik  
        count = 0 c;nx59w ]q  
        While GetOperationCount(eID)>count n JW_a&'  
            GetOperation eID, count, op r$Yh)rpt:  
            If op.Type="ShiftZ" Then m*OLoZVy  
                DeleteOperation eID,count '=-s1c@^  
                count=count-1 $)4GCP  
            End If qW+=g]x\  
            count=count+1 ;}$Z 80  
        Wend P~n8EO1r  
        op.Type = "ShiftZ" 6j?FRs  
        op.val1 = taq-0.01 r=xTs,xx  
        op.parent = parID _95- -\  
        AddOperation eID, op N,h1$)\B#  
    Dg1kbO=2  
        Print "Set pupil diameter = " & pupilDiam qAnA=/k`  
    @G7w(>_T3  
        'Update AZ Eye subassembly Description (ej:_w1  
        eID = FindFullName( "Geometry.Arizona Eye" ) d%S=$}o  
        GetEntity eID, entity <=#lRZW[z  
        entity.Description = "Accommodation = " & A & "D" 7AS.)Q#=x  
        SetEntity eID, entity X v`2hf  
    (9Fabo\SH  
        Update hg$qb eUl  
        Print "DONE!" s@.`"TF.7  
         5B8V$ X  
    End Sub A%.J%[MVz  
    +e&m#d  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: CM+F7#T?n  
    !hwzKm=%N  
    Accommodation = 4 Diopters GMVC&^  
    Pupil Diameter = 4 mm ey'pm\Z  
    Set aqueous humor thickness = 2.81 tn(?nQN3  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 T b5$  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 8<E!rn-  
    Set lens thickness = 3.927 GlXA-p<  
    Set lens index of refraction = 1.42672 $]Q*E4(kV9  
    Set pupil diameter = 4 BG(R=, 7  
    DONE! UrD=|-r`  
    vLi/'|7  
    /k4^&  
    QQ:2987619807 lQ=&jkw  
     
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