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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 I_<XL<  
    L'e^D|  
    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。 /RxP:>hVv  
    =EP`,zqn$9  
    模型 </{Zb.  
    C7FQc {  
    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。 jr4xh {Z`  
    D=-}&w_T"  
    Table 1. AZ眼睛模型的定义
    dT|f<E/P  
    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. /h0bBP  
    ZwS:Te9-  
    光源 tk%f_"}  
    PC_!  
    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。 {h?pvH_>  
    Y[6T7eZ0g  
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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。 ep"[; $Eb  
    _J l(:r\%  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ]nhh|q9r{  
    #{8I FA  
    图2. 字母F光源的设定方法光 @f-X/q]P  
    ST*h{:u&A  
    图3. 字母F在视网膜上位置点列图
    :5NMgR.d  
    视网膜的散射 hpAdoy[  
    a;HAuy`M x  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 c* {6T}VZr  
    _RbfyyaN  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 exb} y  
    r<UVO$N  
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    图5. 视网膜重点采样规格设定
    ,MCTb'=G  
    脚本 =Zq6iMD  
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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: ~rb0G*R>  
    /t0L%jJZ  
    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
    ,9P-<P  
    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。 SyvoN, ;Q  
    余下的脚本计算与屈光度有关的所有参数。 Bu{Kjv  
    {@InOo!4w]  
    分析 ]@&X*~c^Z  
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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。 "\b>JV5  
    %Rk|B`ST  
    图7. 字母F在视网膜上颜色分析
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    脚本代码 \;{ ]YX  
    #fuUAbU0X  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. iq; | i!  
    {"ST hTZ  
    Dim entity As T_ENTITY I=0c\ U}  
    Dim op As T_OPERATION 8Qg10Yjy  
    Dim mat As T_MODELMATERIAL 54_}9_g  
    Dim A As Double *7!MG  
    Dim pupilDiam As Double '}Fe&%  
    Dim eID As Long NHd@s#@  
    Dim parID As Long *g(d}C!  
    Dim count As Integer ppAbG,7  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double h* S"]ye5  
    Dim tlens As Double, nlens As Double `n PdZ.  
    Dim curv As Double, conic As Double jx}&%p X  
    Dim ok As Long ZJ/528Ju  
    uavATnGO{B  
    Sub Main  +A3/^C0  
    5|H;%T 3_  
        '用户输入对话框 8}'iEj^e  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $C[z]}iOi  
            TextBox 220,21,40,21,.TextBox1 'default: 0 hi8q?4jE  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f8Hq&_Pn   
            OKButton 40,91,90,21 u[GZ~L  
            CancelButton 190,91,90,21 ^j<v~GT x+  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 *rq*li;  
            TextBox 220,49,40,21,.TextBox2 'default: 4 =6sP`:  
        End Dialog 7 Lm9I  
        Dim dlg As UserDialog 8+'}`  
    'Ea3(OsuXn  
        ok = Dialog (dlg) !l'nX  
    m%|\AZBA#  
        If ok=0 Then    'cancel button was pressed C[^VM$  
            Print "Execution cancelled." `^)`J  
            End _^<vp  
        End If &f.5:u%{b  
    u+)!C*ho  
        'Assign accommodation and pupil diameter & use defaults if field left empty KXPCkNIN!  
        If dlg.TextBox1 = "" Then fQoAdw  
            A = 0           'Default accommodation r^,_m,s'<  
        Else K?l|1jez(#  
            A = CDbl(dlg.TextBox1) tV++QC7@L  
        End If /uw@o9`~2-  
    yhH2b:nY(9  
        If dlg.TextBox2 = "" Then lS=YnMs6a  
            pupilDiam = 4   'Default pupil diameter ZX_QnSNZ?  
        Else :|j[{;asY  
            pupilDiam = CDbl(dlg.TextBox2) 3! P^?[p3  
        End If ktU:Uq  
    | R,dsBd  
        Print " " 8{4'G$6  
        Print "Accommodation = " & A & " Diopters" RRO@r}A!y  
        Print "Pupil Diameter = " & pupilDiam & " mm" >{^_]phlb  
    #aqnj+  
        ' Calculate new parameters with accommodation @[^ 3y C#  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X_PzK'#m  
    |r@;ulO  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens =-dnniKW4  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens f} c;s  
    Ec7xwPk  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U N?tn}`!  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens nDkG}Jk B!  
    G]B0LUT6c  
        tlens = 3.767 + 0.04*A                  'Lens thickness r'i99 ~  
    I gJu/{:y^  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s.z)l$  
    %jAc8~vW?  
        'Adjust parameters to account for accommodation _kD5pC =  
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        '************************************************************************* )QAYjW!Z  
        'Aqueous thickness (Position of Lens) as:=QMV  
        '************************************************************************* u8"s#%>N y  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H;=yR]E  
        GetCustomElement eID, entity hTBJ\1 -  
    ;8H&FsR  
        parID = FindFullName( "Geometry.Arizona Eye" ) u/tJ])~@  
    yK{P%oh)  
        ' Delete any shift(s) in z :$Cm]RZ  
        count = 0 i%yKyfD  
        While GetOperationCount(eID)>count Nr@,In|JS  
            GetOperation eID, count, op (0`rfYv5.R  
            If op.Type="ShiftZ" Then thPAD+u.3  
                DeleteOperation eID,count -IIrrY O  
                count=count-1 |mhKD#:  
            End If XzAXcxC6G  
            count=count+1 yc0 1\o  
        Wend #mH28UT  
    ejg!1*H@n  
        'Set new shift in |(~IfSE2  
        op.Type = "ShiftZ" 7:~3B-Tb  
        op.val1 = taq `y'%dY}$n  
        op.parent = parID _~Lu%   
        AddOperation eID, op z7fX!'3V  
        Print "Set aqueous humor thickness = " & taq-0.55 1dr g5  
    6X ]I`e  
        '************************************************************************* [<+T@"y  
        'Radius and conic constant of anterior lens ~U<j_j)z4.  
        '************************************************************************* Fmn_fW6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) UHJro9  
        GetConic eID, entity, curv, conic qA}l[:F+#  
    T c-fO /0  
        SetConic eID, entity, 1/Rant, CCant w[2E:Nj  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _WV13pnRu  
    m<Gd 6V5  
        '************************************************************************* C4E*q3[Y  
        'Radius and conic constant of posterior lens QP%AJ[3ea%  
        '************************************************************************* .yDR2 sW  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Njo.-k  
        GetConic eID, entity, curv, conic u}'m7|)8  
    dnANlNMk?  
        SetConic eID, entity, 1/Rpost, CCpost >>=zkPy  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9 'X"a  
    8U#14U5rS  
        '************************************************************************* }T%E;m-  
        'Lens thickness (Position of posterior lens surface) p+I`xyk  
        '************************************************************************* <MxA;A  
    a;i} <n7  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) P EzT|uY  
    &~"N/o  
        ' Delete any z-shift(s) 7WV"Wrl]  
        count = 0 "97sH_ ,  
        While GetOperationCount(eID)>count mv<cyWp  
            GetOperation eID, count, op fN`Prs A  
            If op.Type="ShiftZ" Then USE!  
                DeleteOperation eID,count (>Sy,  
                count=count-1 T+V:vuK  
            End If 45+kwo0  
            count=count+1 8yr-X!eF  
        Wend n`Ypv{+ {%  
    } BP.t$_  
        'Set new z-shift @ /e{-Q  
        op.Type = "ShiftZ" .j!:Hp(z}  
        op.val1 = tlens &sq q+&ao  
        op.parent = parID Dmtsu2o  
        AddOperation eID, op RZvRV?<bR  
        Print "Set lens thickness = " & tlens ylmVmHmc  
    p=Q o92 NH  
        '************************************************************************* @M*5q# s  
        'Lens index of refraction 2J(,Xf  
        '************************************************************************* .>5E 4^$%  
        eID = FindMaterial( "Lens" ) >wV2` 6  
        GetModelMaterial eID, mat NS4W!o;"  
    5t-(MY  
        mat.Nd = nlens %e: hVU  
        SetModelMaterial eID, mat P\X$fD  
        Print "Set lens index of refraction = " & nlens G!GGT?J  
    o`jVd,aj  
        '************************************************************************* YZ0Q?7l7  
        'Pupil diameter P; =,Q$e8  
        '************************************************************************* :JxuaM8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) A*{V%7hs&  
    K?wo AuY  
        'Adjust pupil diameter (trimming volume inner hole) EU7mP MxJ  
    U_0"1+jbq  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]gb?3a}A  
    B?XqH_=0L  
        ' Adjust pupil location to just in front of the lens -1F+,+m  
        parID = FindFullName( "Geometry.Arizona Eye" ) j&?@:Zg v  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) xirZ.wjW  
        count = 0 &W y9%  
        While GetOperationCount(eID)>count cZ/VMQEr  
            GetOperation eID, count, op mVyF M -`  
            If op.Type="ShiftZ" Then 3}?]G8iL?L  
                DeleteOperation eID,count LwCf}4u"  
                count=count-1 1`&"U[{  
            End If sU?%"q  
            count=count+1 SR'u*u!  
        Wend JLxAk14lc  
        op.Type = "ShiftZ"  cCy*?P@  
        op.val1 = taq-0.01 .ktyA+r8v  
        op.parent = parID [tz}H&  
        AddOperation eID, op x_KJCU  
    &FzZpH  
        Print "Set pupil diameter = " & pupilDiam 8<g9 ~L  
    X[iQ%Y$/n  
        'Update AZ Eye subassembly Description xcl8q:  
        eID = FindFullName( "Geometry.Arizona Eye" ) dxeLu  
        GetEntity eID, entity #ruL+- 8!<  
        entity.Description = "Accommodation = " & A & "D" n#5%{e>  
        SetEntity eID, entity "PY&NL?  
    1O;q|p'9  
        Update ^5*9BwH`  
        Print "DONE!" w'D=K_h  
         fnO>v/&B  
    End Sub |`6*~ciUV  
    Ut^ {4_EC  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 9r hl2E  
    KdtQJ:_`k  
    Accommodation = 4 Diopters t=(CCq_N,  
    Pupil Diameter = 4 mm >a2i%j/T  
    Set aqueous humor thickness = 2.81 L,wEUI  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ]PjJy/vkjj  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 iwnFCZVS  
    Set lens thickness = 3.927 3N5b3F  
    Set lens index of refraction = 1.42672 ;V\l, u  
    Set pupil diameter = 4 qm=N@@R&  
    DONE! UB1/0o  
     
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