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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 c qyh#uWe  
    G&3<rT3Ib  
    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。 ;l?(VqX_E  
    &.4_4"l(  
    模型 \)uad5`N  
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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。 0U*"OSpF  
    r8 >?-P  
    Table 1. AZ眼睛模型的定义
    ~(]DNXB8I`  
    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. IE f^.Z  
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    光源 G.e\#_RR?  
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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。 Z[bC@y[Wb  
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    图1. 光源和提示信息使用
    .Q)"F /  
    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。 k ,(:[3J  
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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。 ADz|Y~V!  
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    图2. 字母F光源的设定方法光  Vp^sER  
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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 }TL"v|ny6;  
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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。 dS=,. }  
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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。 dD<kNa}2  
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    图5. 视网膜重点采样规格设定
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    脚本 59 Y=VS  
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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: b;l%1x9r  
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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。 0eP~F2<bC  
    余下的脚本计算与屈光度有关的所有参数。 R"([Y#>m  
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    分析 v4aGL<SO  
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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。 ,-kZ5&r  
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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 E5Jk+6EcMa  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. )wd~639U  
    1j,Y  
    Dim entity As T_ENTITY <~w#sIh  
    Dim op As T_OPERATION =x>k:l~s  
    Dim mat As T_MODELMATERIAL 0in6 z  
    Dim A As Double WpZ^R;eK  
    Dim pupilDiam As Double (p!AX<=z  
    Dim eID As Long 7Y:s6R|  
    Dim parID As Long Rby7X*.-v  
    Dim count As Integer ]S ,GHPEN  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ?]N&H90^5  
    Dim tlens As Double, nlens As Double FG\?_G  
    Dim curv As Double, conic As Double C:{'0m*jKs  
    Dim ok As Long ,#l oVLy  
    iI0'z=J  
    Sub Main [4yQ-L)]e  
    =`H( `2  
        '用户输入对话框 (eP)>G]  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Nl _Jp:8s  
            TextBox 220,21,40,21,.TextBox1 'default: 0 e>.xXg6Zn  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ta(x4fP_  
            OKButton 40,91,90,21 + aF jtb  
            CancelButton 190,91,90,21 ps{(UYM=b  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r_m&Jl@4  
            TextBox 220,49,40,21,.TextBox2 'default: 4 3RUB2c4  
        End Dialog z16++LKmM  
        Dim dlg As UserDialog [-ecKPx  
    i^l;PvIF  
        ok = Dialog (dlg) FC#Q tu~J  
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        If ok=0 Then    'cancel button was pressed j;.&+.  
            Print "Execution cancelled." oP6G2@3P/  
            End f9$q.a*  
        End If ):@B1 yR  
    H@:@zD!G[  
        'Assign accommodation and pupil diameter & use defaults if field left empty qxx.f5 8H  
        If dlg.TextBox1 = "" Then RP9||PFS~~  
            A = 0           'Default accommodation 8J0tya"z  
        Else =[&Jxy>Y  
            A = CDbl(dlg.TextBox1) p\K5B,  
        End If i747( ^  
    yrX]w3kr%  
        If dlg.TextBox2 = "" Then p pq#5t^[)  
            pupilDiam = 4   'Default pupil diameter u[DV{o  
        Else -E1}mL}I`  
            pupilDiam = CDbl(dlg.TextBox2) &AVi4zV  
        End If B|&<  
    g d-fJ._1  
        Print " " ITV}f#  
        Print "Accommodation = " & A & " Diopters" q'q{M-U<  
        Print "Pupil Diameter = " & pupilDiam & " mm" Fwr,e;Z  
    53QP~[F8R]  
        ' Calculate new parameters with accommodation W=*\4B]  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X)~-MY*p  
    7^F?key?  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens jX%Q  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens xjYFTb}!  
    ?m6E@.{  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens EA\~m*k  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens w'!gLta  
    fu/c)D6u*m  
        tlens = 3.767 + 0.04*A                  'Lens thickness yT4|eHl  
    -]e@cevy  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &}r932  
    y[cAU:P?  
        'Adjust parameters to account for accommodation lQzrf"N'  
    /[OMpP  
        '************************************************************************* =ZQIpc  
        'Aqueous thickness (Position of Lens) n!p&.Mt  
        '************************************************************************* s5.2gu|"%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T1E=<q4  
        GetCustomElement eID, entity Z& %61jGK  
    ])`F$S  
        parID = FindFullName( "Geometry.Arizona Eye" ) 5>HI/QG  
    FD<~?-  
        ' Delete any shift(s) in z 8Y9mB #X  
        count = 0 TsQMwV_h  
        While GetOperationCount(eID)>count G4i&:0  
            GetOperation eID, count, op M@8(h=  
            If op.Type="ShiftZ" Then }7V/(K  
                DeleteOperation eID,count Buo1o&&  
                count=count-1 {9)f~EbM!  
            End If xiI!_0'  
            count=count+1 jHd~yCq  
        Wend G`pI{_-e  
    (n< xoV[e  
        'Set new shift in w*+rBp,f  
        op.Type = "ShiftZ" {XVSHUtw  
        op.val1 = taq Ul=`]@]]  
        op.parent = parID Y4_i=}\*vf  
        AddOperation eID, op g%Z;rDfi  
        Print "Set aqueous humor thickness = " & taq-0.55 &"BKue~q@p  
    */1z=  
        '************************************************************************* it.l;L_nW  
        'Radius and conic constant of anterior lens V{npK(  
        '************************************************************************* dG| iA]  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G/y< bPQ  
        GetConic eID, entity, curv, conic &(K*TB|Om  
    (HTVSC%=  
        SetConic eID, entity, 1/Rant, CCant 7(jt:V6V  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cIgF]My*D@  
    ' o 5,P/6  
        '************************************************************************* .JzO f[g5  
        'Radius and conic constant of posterior lens .(sT?M`\J  
        '************************************************************************* lY~xoHT;[  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \^+sgg{  
        GetConic eID, entity, curv, conic HJ2]xe09  
    kxKBI{L  
        SetConic eID, entity, 1/Rpost, CCpost h\1_$ac  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost QKVZ![Y!s  
    RGiA>Z:W  
        '************************************************************************* gAE}3//  
        'Lens thickness (Position of posterior lens surface) htaB! Q?V  
        '************************************************************************* Q>.-u6(&  
    39OZZaWL  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) NE(6`Wq`  
    #i~.wQ $1  
        ' Delete any z-shift(s) x>t:&Y M  
        count = 0 _+UD>u{  
        While GetOperationCount(eID)>count nI 6`/  
            GetOperation eID, count, op 'Ct+0X:D  
            If op.Type="ShiftZ" Then Tj>~#~  
                DeleteOperation eID,count pdE=9l'  
                count=count-1 ?-(E$ll  
            End If >iq^Ts  
            count=count+1 hX;xbl  
        Wend 4b4nFRnH  
    ZJ!/49c*>  
        'Set new z-shift #Z fg  
        op.Type = "ShiftZ" d/;oNC+  
        op.val1 = tlens zRB1V99k  
        op.parent = parID Gs-'  
        AddOperation eID, op s,0,w--=  
        Print "Set lens thickness = " & tlens w7O(I"  
    LaLA }1!  
        '************************************************************************* =6? 3c\  
        'Lens index of refraction 5:O"T  
        '************************************************************************* ]e+S~me  
        eID = FindMaterial( "Lens" ) {4#'`Eejj  
        GetModelMaterial eID, mat 4).q+{#k  
    @$Y`I{Xf  
        mat.Nd = nlens h8nJ$jg  
        SetModelMaterial eID, mat KSLyU1W  
        Print "Set lens index of refraction = " & nlens C7PHZ`<  
    >V NMQ  
        '************************************************************************* NC0x!tJ#7  
        'Pupil diameter C,K P!B{  
        '************************************************************************* 3C.bzw^  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) nE,"3X"   
    oZ!rK/qoA  
        'Adjust pupil diameter (trimming volume inner hole) Vk[m$  
    _pW\F(+8  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C#(4>'  
    H]YPMG<  
        ' Adjust pupil location to just in front of the lens c>I^SY(r%  
        parID = FindFullName( "Geometry.Arizona Eye" ) 3pm;?6i6  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) BjJ+~R  
        count = 0 rlW  
        While GetOperationCount(eID)>count !30BZM^  
            GetOperation eID, count, op xez~Yw2  
            If op.Type="ShiftZ" Then J8(v65  
                DeleteOperation eID,count {ImZ><xe/  
                count=count-1 ~g)gXPjke  
            End If Ao 1*a%-.  
            count=count+1 7+@:wX\  
        Wend RBiDU}j  
        op.Type = "ShiftZ" 3%'$AM}+s  
        op.val1 = taq-0.01 }F**!%4d  
        op.parent = parID s4t>/.;x  
        AddOperation eID, op Vhv<w O Ct  
    -cEjB%Neo  
        Print "Set pupil diameter = " & pupilDiam 2,'m]`;GNr  
    N }Z"$4  
        'Update AZ Eye subassembly Description }7k+tJ<   
        eID = FindFullName( "Geometry.Arizona Eye" ) I%;xMt Y1o  
        GetEntity eID, entity b=.Ikt+y  
        entity.Description = "Accommodation = " & A & "D" u9QvcD^'z  
        SetEntity eID, entity b?qtTce  
    d+Pfi)+(I  
        Update ABB4(_3E  
        Print "DONE!" :Q"]W!kCs  
         <Sb W QbN  
    End Sub $ ^m_M.1  
    X5'foFE'  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: U!TFFkX[  
    Il>!C\hU  
    Accommodation = 4 Diopters &p`RKD  
    Pupil Diameter = 4 mm }n oI2.-#  
    Set aqueous humor thickness = 2.81 ~M2w&g;1  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ;)~loa1\  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 %jim] ]<S[  
    Set lens thickness = 3.927 RT4ns+J1  
    Set lens index of refraction = 1.42672 f_7a) 'V4  
    Set pupil diameter = 4 *EvnN:  
    DONE! 5L%A5C&|  
     
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