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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 NcY0pAR*  
    fKK-c9F   
    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。 Z?j='/u>@  
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    模型 _F$t#.o  
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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。 zZjLt1  
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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. uP'w.nA&2  
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    光源 =K< I)2   
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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。 %JH_Nw.P  
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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。 ~FrkLP  
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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。 ?%fZvpn-  
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    图2. 字母F光源的设定方法光 'L+BkE6+%  
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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 ;7=J U^@D@  
    .AI'L|FQ%c  
    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。 H5MAN,`  
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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。 6XCX#4'i%  
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    图5. 视网膜重点采样规格设定
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    脚本 v^I%Wm  
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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: yNf=Kl  
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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。 7,VWvmWJex  
    余下的脚本计算与屈光度有关的所有参数。 NcMq>n  
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    分析 W ]MJ!4  
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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。 v5ddb)  
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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 G9":z|  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. rd~W.b_b  
    !td.ks0  
    Dim entity As T_ENTITY {h+E&u[zL  
    Dim op As T_OPERATION ;4#8#;  
    Dim mat As T_MODELMATERIAL NJ!#0[@C  
    Dim A As Double q x }fn/:  
    Dim pupilDiam As Double bjX$idL  
    Dim eID As Long i4C b&h^  
    Dim parID As Long `%I{l  
    Dim count As Integer _ShJ3\,K  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Y]0y -H  
    Dim tlens As Double, nlens As Double Nmq5Tv  
    Dim curv As Double, conic As Double PBnn,#  
    Dim ok As Long ;//q jo  
    vXZz=E AH  
    Sub Main u)]sJ1p  
    [zd-=.:+M[  
        '用户输入对话框 UimZ/\r  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 S.>9tV2Ca  
            TextBox 220,21,40,21,.TextBox1 'default: 0 6_><W"r:]  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 o*BI^4  
            OKButton 40,91,90,21 y9 ' 3vZ  
            CancelButton 190,91,90,21 ~m&oa@*=y  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 e(N <Mf  
            TextBox 220,49,40,21,.TextBox2 'default: 4 w' >v@`y  
        End Dialog )BrqE uX@"  
        Dim dlg As UserDialog L%Hm# eFx  
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        ok = Dialog (dlg) 0t0:soZ x  
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        If ok=0 Then    'cancel button was pressed 64s;6=  
            Print "Execution cancelled." 9}_f\Bs  
            End )fr\ V."  
        End If \~1+T  
    He23<hd!  
        'Assign accommodation and pupil diameter & use defaults if field left empty W5g!`f  
        If dlg.TextBox1 = "" Then \Nyxi7  
            A = 0           'Default accommodation _9 O'  
        Else mmK_xu~f28  
            A = CDbl(dlg.TextBox1) 'FXZ`+r|  
        End If EZW?(%b>H  
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        If dlg.TextBox2 = "" Then .r"?w  
            pupilDiam = 4   'Default pupil diameter KrzM]x  
        Else oI/ThM`=q  
            pupilDiam = CDbl(dlg.TextBox2) y~ LVK8  
        End If U\6DEnII?!  
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        Print " " >f/g:[  
        Print "Accommodation = " & A & " Diopters" #O ]IXo(5z  
        Print "Pupil Diameter = " & pupilDiam & " mm" dj]N59<  
    C"WZsF^3  
        ' Calculate new parameters with accommodation ^Y |s^N  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5E=Odep`  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens \}W.RQ^3  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens $ 7!GA9Bn  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c5pG?jr+d  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (5 hu W7v  
    u>#'Y+7  
        tlens = 3.767 + 0.04*A                  'Lens thickness (1vS)v $L  
    "(GeW286k  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =G6@:h=  
    nX'.'3  
        'Adjust parameters to account for accommodation !y.7"G*  
    r>o6}Mx$  
        '************************************************************************* :f:C*mYvu  
        'Aqueous thickness (Position of Lens) Z0KA4O$eL  
        '************************************************************************* KG@hjO  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (""&$BJQ|  
        GetCustomElement eID, entity s5e}X:  
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        parID = FindFullName( "Geometry.Arizona Eye" ) + >j_[O5Y  
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        ' Delete any shift(s) in z g^FH[(P[G  
        count = 0 ?=&*6H_v  
        While GetOperationCount(eID)>count )&K%Me  
            GetOperation eID, count, op |Sm/Uq(c  
            If op.Type="ShiftZ" Then KW\`&ki  
                DeleteOperation eID,count zT"#9"["  
                count=count-1 x`&W[AA4  
            End If 5 B6:pH6e  
            count=count+1 ,@xZuq+K<  
        Wend t[Q\T0E  
    1)y}.y5S  
        'Set new shift in Re_.<_$  
        op.Type = "ShiftZ" A[MEtI=Q J  
        op.val1 = taq A\>qoR!Y  
        op.parent = parID f{0PLFj  
        AddOperation eID, op l"/Os_4O  
        Print "Set aqueous humor thickness = " & taq-0.55 sKtH4d5)  
    GU`2I/R  
        '************************************************************************* :O2N'vl47A  
        'Radius and conic constant of anterior lens L 'y+^L|X  
        '************************************************************************* = 4L.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G(i/ @>l  
        GetConic eID, entity, curv, conic #%~wuCn<K  
    '4EJ_Vhztc  
        SetConic eID, entity, 1/Rant, CCant p{Uro!J,K  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant xp = ]J UQ  
    } 2KuY\5\i  
        '************************************************************************* :v`o="  
        'Radius and conic constant of posterior lens h1$,  
        '************************************************************************* \oyr[so(i  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) u-,=C/iU  
        GetConic eID, entity, curv, conic c{[WOrA~#  
    DwPl,@T_i\  
        SetConic eID, entity, 1/Rpost, CCpost :B im`mHl  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ``{xm1GK  
    ET4YoH>  
        '************************************************************************* NR" Xn7G  
        'Lens thickness (Position of posterior lens surface) }/=_  
        '************************************************************************* i{.!1i:  
    G"]'`2.m  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :|bPr_&U$  
    gU:jx  
        ' Delete any z-shift(s) Onao'sjY  
        count = 0 yd $y\pN=<  
        While GetOperationCount(eID)>count pnWDsC~)  
            GetOperation eID, count, op pV_2JXM~@  
            If op.Type="ShiftZ" Then ==& =3  
                DeleteOperation eID,count 09r.0Ks  
                count=count-1 nL9m{$Zv  
            End If /}Max@.`  
            count=count+1 PM{kiz^  
        Wend ]'{<O3:7  
    Lq:Z='Kc  
        'Set new z-shift tlE+G@|^  
        op.Type = "ShiftZ" :^K|u^_>P  
        op.val1 = tlens ;tO(,^  
        op.parent = parID =Z2sQQVS  
        AddOperation eID, op >Tw|SK+3  
        Print "Set lens thickness = " & tlens W1 E(( 2  
    z' @F@k6  
        '************************************************************************* =73wngw  
        'Lens index of refraction 7C=t19&R'  
        '************************************************************************* HghNI  
        eID = FindMaterial( "Lens" ) BQsy)H`4E  
        GetModelMaterial eID, mat % %*t{0!H+  
    w1[F]|  
        mat.Nd = nlens rQU;?[y  
        SetModelMaterial eID, mat J^U#dYd  
        Print "Set lens index of refraction = " & nlens \\_Qv  
    *+5AN306  
        '************************************************************************* uCx\Bt"VI  
        'Pupil diameter mhL,:UE  
        '*************************************************************************  vO 3fAB  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7 yK >  
    13Q|p,^R  
        'Adjust pupil diameter (trimming volume inner hole) M^a QH/=:"  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  QHOem=B  
    P7Kp*He)  
        ' Adjust pupil location to just in front of the lens C]82Mt  
        parID = FindFullName( "Geometry.Arizona Eye" ) _rOKif?5  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) M%Ov6u<I8  
        count = 0 c8A //  
        While GetOperationCount(eID)>count qm2  
            GetOperation eID, count, op fDf:Jec`[  
            If op.Type="ShiftZ" Then 0GEK xV\F  
                DeleteOperation eID,count A#*0mJ8IK  
                count=count-1 @wb V@  
            End If (h%!Kun  
            count=count+1 sa{X.}i%E  
        Wend t\X5B]EZ  
        op.Type = "ShiftZ" zgV{S Qo  
        op.val1 = taq-0.01 K_(o D O  
        op.parent = parID .M!HVq47m  
        AddOperation eID, op x,pzX(  
    ;kY'DKL(  
        Print "Set pupil diameter = " & pupilDiam )=#QTiJ  
    vn7<>k> dx  
        'Update AZ Eye subassembly Description S 7RB` I5  
        eID = FindFullName( "Geometry.Arizona Eye" ) 0@vSl%I+  
        GetEntity eID, entity !>TH#sU$  
        entity.Description = "Accommodation = " & A & "D" Gz@'W%6yaV  
        SetEntity eID, entity 5\lOZYHX  
    zrri&QDF<  
        Update 4 @ )|N'  
        Print "DONE!" (bY#!16C:  
         I8rtta  
    End Sub Nw* >$v  
    B[}#m'Lv  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: C[z5& x2  
    ]25 xX  
    Accommodation = 4 Diopters U:"E:Bxz;m  
    Pupil Diameter = 4 mm X H,1\J-S  
    Set aqueous humor thickness = 2.81 jNBvy1  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 4vQ]7`I.f  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019  $ac VJI?  
    Set lens thickness = 3.927 Q E1DTU  
    Set lens index of refraction = 1.42672 F6`$5%$M;?  
    Set pupil diameter = 4 |hk?'WGc`0  
    DONE! g)nsP  
     
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