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    [技术]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: 2021-10-22
    简介 zaf%%  
    5Jlz$]f  
    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。 H0_hQ:K   
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    模型 dr'#  
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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。 22)2o lU  
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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. KpA iKe  
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    光源 s8Xort&   
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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。 y".uu+hL`  
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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。 bzz=8n  
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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。 tT>~;l%'  
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    图2. 字母F光源的设定方法光 wz3BtCx  
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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 RBd{1on  
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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。 -Zh`h8gX  
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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。  A M8bem~  
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    图5. 视网膜重点采样规格设定
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    脚本 )o-rg  
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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:  Gqvj  
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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。 Ju4={^#  
    余下的脚本计算与屈光度有关的所有参数。 L?T%;VdG'>  
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    分析 :yO.Te F  
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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。 ="hh=x.5J  
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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 U2l7@uDr;  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. m08:EX P  
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    Dim entity As T_ENTITY _PUgK\  
    Dim op As T_OPERATION ASME~]]?  
    Dim mat As T_MODELMATERIAL \} [{q  
    Dim A As Double )D?\ru H  
    Dim pupilDiam As Double qP@d)XRQ  
    Dim eID As Long @LZ'Qc }@  
    Dim parID As Long X~wkqI#d%E  
    Dim count As Integer %5.aC|^}  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }#va#Nb(,  
    Dim tlens As Double, nlens As Double Y?G\@ 6  
    Dim curv As Double, conic As Double B@XnHh5y  
    Dim ok As Long UZ#Yd|'PD  
    z=C'qF`  
    Sub Main H=b54.J8&  
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        '用户输入对话框 Rrh?0qWs  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  mkH {%7n  
            TextBox 220,21,40,21,.TextBox1 'default: 0 U"\$k&  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X-,scm  
            OKButton 40,91,90,21 :KY920/,  
            CancelButton 190,91,90,21 ernZfd{H  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 jzCSxuZ7O  
            TextBox 220,49,40,21,.TextBox2 'default: 4 evOy Tvc  
        End Dialog P6q`i<  
        Dim dlg As UserDialog GPP{"6q5'  
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        ok = Dialog (dlg) &-^|n*=g6  
     }NX9"}/  
        If ok=0 Then    'cancel button was pressed ti6\~SY  
            Print "Execution cancelled."  "";[U  
            End .u[hK  
        End If C/AqAW1  
    4wfT8CL  
        'Assign accommodation and pupil diameter & use defaults if field left empty RW19I,d  
        If dlg.TextBox1 = "" Then N0A PX4j  
            A = 0           'Default accommodation 2E]SKpJ  
        Else &%3$zgvR  
            A = CDbl(dlg.TextBox1)  Z|zyO-  
        End If M-> /vi  
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        If dlg.TextBox2 = "" Then ` @.  
            pupilDiam = 4   'Default pupil diameter 7)iB6RB K  
        Else P%HvL4R  
            pupilDiam = CDbl(dlg.TextBox2) Z#H] yG  
        End If MLD-uI10{  
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        Print " " t\YN\`XD  
        Print "Accommodation = " & A & " Diopters" 9nW/pv  
        Print "Pupil Diameter = " & pupilDiam & " mm" !=%E&e]  
    UG)J4ZX  
        ' Calculate new parameters with accommodation |.kYomJ   
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness d V+%x"[:  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens #XSs.i{  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens B<)c{kj  
    r0 %WGMk2  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 43_;Z| T  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens QEd>T"@g  
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        tlens = 3.767 + 0.04*A                  'Lens thickness m$glRs @  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction QiDf,$t|,  
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        'Adjust parameters to account for accommodation FFE IsB"9  
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        '************************************************************************* 8NY $Iw  
        'Aqueous thickness (Position of Lens) ;Y:_}kN8_  
        '************************************************************************* j9)WInYc:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %3v:c|r  
        GetCustomElement eID, entity $|0_[~0-n  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 3&*_5<t\X  
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        ' Delete any shift(s) in z ?_Sf  
        count = 0 'EsN{.l?  
        While GetOperationCount(eID)>count z'cK,psq(  
            GetOperation eID, count, op h@nNm30i  
            If op.Type="ShiftZ" Then +(>!nsf  
                DeleteOperation eID,count -w8c;5X  
                count=count-1 i21ybXA=Z  
            End If K@Z K@++  
            count=count+1 lZyxJDZ A  
        Wend e;LJdd  
    'G3;!xk$  
        'Set new shift in UzLe#3MU  
        op.Type = "ShiftZ" q2qbbQ6H  
        op.val1 = taq 4[@`j{  
        op.parent = parID fC!]MhA"i  
        AddOperation eID, op }lN@J,q  
        Print "Set aqueous humor thickness = " & taq-0.55 ,`<w#  
    V{51wnxT  
        '************************************************************************* [3Qu @;"&  
        'Radius and conic constant of anterior lens AEjkqG4qv  
        '************************************************************************* NzRpI5\.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) -8- BVU  
        GetConic eID, entity, curv, conic Ift @/A  
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        SetConic eID, entity, 1/Rant, CCant wd4wYk\  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WM8 Ce0E  
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        '************************************************************************* yHvF"4]  
        'Radius and conic constant of posterior lens /.leY$  
        '************************************************************************* D@[Mk"f  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2LpJxV  
        GetConic eID, entity, curv, conic KH4 5A'o  
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        SetConic eID, entity, 1/Rpost, CCpost n<C4-'^U[a  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ],rtSUO  
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        '************************************************************************* M[wd.\ %  
        'Lens thickness (Position of posterior lens surface) 9S"c-"y\#  
        '************************************************************************* zB6u%uWR  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }F=+*-SYZ  
    !P*1^8b`f  
        ' Delete any z-shift(s) v634{:'e  
        count = 0 d8 1u  
        While GetOperationCount(eID)>count EC6&#)g;CO  
            GetOperation eID, count, op ]e0yC  
            If op.Type="ShiftZ" Then h-rPLU;Bw  
                DeleteOperation eID,count ;g[C=yhK`C  
                count=count-1 w#v8a$tT  
            End If ,Lt+*!;m  
            count=count+1 zo*YPDEm"  
        Wend mmC&xZ5f  
    P 19nF[A  
        'Set new z-shift p"9a`/  
        op.Type = "ShiftZ" 1(V>8}zn  
        op.val1 = tlens &V;^xMO!  
        op.parent = parID ;k6>*wFl|!  
        AddOperation eID, op v3 $+ l1  
        Print "Set lens thickness = " & tlens >h3r\r\n3  
    v ?b9TE  
        '************************************************************************* VV/6~jy0  
        'Lens index of refraction m&)5QX  
        '************************************************************************* pDr%uL  
        eID = FindMaterial( "Lens" ) cr!6qv1  
        GetModelMaterial eID, mat 74*1|S <  
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        mat.Nd = nlens K-Bf=7F,  
        SetModelMaterial eID, mat b2;+a(  
        Print "Set lens index of refraction = " & nlens >t2E034_  
    Ux_tHyc/  
        '************************************************************************* 19od# d3+  
        'Pupil diameter neW_mu;~Z  
        '************************************************************************* e(/~;"r{  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) %GUu{n<6  
    A|sTnhp~  
        'Adjust pupil diameter (trimming volume inner hole) oY@4G)5  
    j-2`yR  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" wN,DTmtD  
    K5U=%z  
        ' Adjust pupil location to just in front of the lens FY%v \`@1*  
        parID = FindFullName( "Geometry.Arizona Eye" ) y7#$:+jQv  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b#p)bcz!I  
        count = 0 @NMFurm  
        While GetOperationCount(eID)>count ]PVPt,c  
            GetOperation eID, count, op ]=v_u9;  
            If op.Type="ShiftZ" Then mG[S"?C  
                DeleteOperation eID,count @vWC "W  
                count=count-1 \tFg10  
            End If d#:&Uw  
            count=count+1 3nt&Sf  
        Wend [KXxn>n  
        op.Type = "ShiftZ" SX)giQLU  
        op.val1 = taq-0.01 Vx_ lI #3  
        op.parent = parID |He,v/r  
        AddOperation eID, op 7 }`c:u~j  
    |ubDudzp  
        Print "Set pupil diameter = " & pupilDiam D$g|f[l  
    G1MuH%4  
        'Update AZ Eye subassembly Description ?vL\VI9  
        eID = FindFullName( "Geometry.Arizona Eye" ) )5Yv7x(K  
        GetEntity eID, entity )'8DK$.  
        entity.Description = "Accommodation = " & A & "D" 0;z-I"N  
        SetEntity eID, entity y3T- ^  
    dj*%^cI  
        Update t1p}   
        Print "DONE!" xz#;F ,`ZR  
         zI/)#^SQ  
    End Sub SdhdXVZ  
    ,]@K6  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: I}/o`oc  
    {GDMix  
    Accommodation = 4 Diopters dsP|j (y  
    Pupil Diameter = 4 mm 9`}Wp2  
    Set aqueous humor thickness = 2.81 U JG)-x  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Z qX  U  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 FUzIuz 6  
    Set lens thickness = 3.927 6GCwc1g  
    Set lens index of refraction = 1.42672 BQVpp,]  
    Set pupil diameter = 4 }OO(uC2  
    DONE! &T?>Kx  
     
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