[技术]Arizona眼睛模型 [复制链接]

简介 >0I\w$L  
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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。 `,)%<}  
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模型 idNg&'   
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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。 90!67Ap`x  
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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. 7DIFJJE'  
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光源 =xM:8 hm  
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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。 8Oo16LPD  
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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。 dU#}Tk  
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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。 w~WW2w  
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视网膜的散射 cGS7s 8U  
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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。 z460a[Wl  
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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。 oVeC@[U  
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脚本 Vi<F@ji  
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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： i" >kF@]c8  
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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。 a,KqTQB  
余下的脚本计算与屈光度有关的所有参数。 {[[/*1r|  
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分析 8U7X/L  
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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。 h"On9  
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脚本代码 n@y*~sG]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. $Ce;}sM  
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Dim entity As T_ENTITY 
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Dim op As T_OPERATION
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Dim mat As T_MODELMATERIAL = K3NKPUI  
Dim A As Double "E%3q3|"l  
Dim pupilDiam As Double _vr;cjMI  
Dim eID As Long 7r wNjY#  
Dim parID As Long NLF6O9  
Dim count As Integer Qs;MEt1  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]TIBy "3  
Dim tlens As Double, nlens As Double n_
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Dim curv As Double, conic As Double s:Io5C(  
Dim ok As Long n$y@a?al  
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Sub Main >PONu]^  
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    '用户输入对话框 $gysy!2}.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #w&N) c>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Wt
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 w~}.c:B  
        OKButton 40,91,90,21 }WEF*4B!  
        CancelButton 190,91,90,21 tzdh3\6F  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 41NVF_R6J  
        TextBox 220,49,40,21,.TextBox2 'default: 4 .yb=I6D;<3  
    End Dialog ?$Ii_.  
    Dim dlg As UserDialog {x<yDDIv_  
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    ok = Dialog (dlg) ioJr2wq6  
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    If ok=0 Then    'cancel button was pressed 0=V -{  
        Print "Execution cancelled." d{:0R9  
        End #Iwxt3K  
    End If *W$bhC'w  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,'>O#kD  
    If dlg.TextBox1 = "" Then &@/25Y2  
        A = 0           'Default accommodation &AhkP=Yw  
    Else Tb<}GcwJ  
        A = CDbl(dlg.TextBox1) %3mh'Z -[f  
    End If B):hm  
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    If dlg.TextBox2 = "" Then SRek:S,  
        pupilDiam = 4   'Default pupil diameter ]Ofs,U^  
    Else Qs7*_=+h  
        pupilDiam = CDbl(dlg.TextBox2) B8.uzX'p  
    End If #7|73&u(  
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    Print " " R;`C;Rbf  
    Print "Accommodation = " & A & " Diopters" Q+a"Z^Z|  
    Print "Pupil Diameter = " & pupilDiam & " mm" se&Q\!&M  
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    ' Calculate new parameters with accommodation a+PVi  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness k`h#.B J  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens p^*A&7d:P  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,#Mt
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens vfloha p  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *m*sg64Zw  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ,'&H`h54  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction osZ]R  
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    'Adjust parameters to account for accommodation P9jPdls  
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    '************************************************************************* 2./;i>H[u  
    'Aqueous thickness (Position of Lens) hD9b2KZv  
    '************************************************************************* ndS8p]P&o(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Usq.'y/o  
    GetCustomElement eID, entity -T{G8@V0I  
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    parID = FindFullName( "Geometry.Arizona Eye" ) njckPpyb@  
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    ' Delete any shift(s) in z VCQo3k5 {  
    count = 0 {B[ }}wX$  
    While GetOperationCount(eID)>count ubUVxYD?  
        GetOperation eID, count, op 6QAhVg: A  
        If op.Type="ShiftZ" Then f[wxt n'r  
            DeleteOperation eID,count VMH
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            count=count-1 ,)ZI&BL5  
        End If Kjt\A]R%  
        count=count+1 do:IkjU~  
    Wend }No8to  
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    'Set new shift in /X%+z5  
    op.Type = "ShiftZ" y3OF+;E  
    op.val1 = taq ^MO})C  
    op.parent = parID $rm/{i_7  
    AddOperation eID, op T,h9xl9i  
    Print "Set aqueous humor thickness = " & taq-0.55 il% u)NN  
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    '************************************************************************* A\<W x/  
    'Radius and conic constant of anterior lens pD;fFLvN  
    '************************************************************************* q5{h@}|M  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Go(Td++HS  
    GetConic eID, entity, curv, conic i>e?$H,/  
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    SetConic eID, entity, 1/Rant, CCant Y`rli  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant J?C:@Q  
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    '************************************************************************* fwNj@fl_,e  
    'Radius and conic constant of posterior lens X}H?*'-  
    '************************************************************************* '}$$0S.DC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 'OvM  
    GetConic eID, entity, curv, conic 0ZJj5<U  
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    SetConic eID, entity, 1/Rpost, CCpost PU8dr|!  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9e
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    '************************************************************************* [Qcht,\^v  
    'Lens thickness (Position of posterior lens surface) @Gt.J*!s/  
    '************************************************************************* J";4+wA7  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) fZrh_^yH  
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    ' Delete any z-shift(s) )]kxLf#  
    count = 0 "SRS{-p0  
    While GetOperationCount(eID)>count bEln.)  
        GetOperation eID, count, op _@W1?;yD  
        If op.Type="ShiftZ" Then p<3<Zk 7~0  
            DeleteOperation eID,count \440gH`  
            count=count-1 1)5$,+~lL  
        End If DTG-R>y^  
        count=count+1 k-^le|n9  
    Wend 51Vqbtj^  
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    'Set new z-shift iBI->xU[U  
    op.Type = "ShiftZ" UE/JV_/S;  
    op.val1 = tlens G"w [>m  
    op.parent = parID O_]hbXV0  
    AddOperation eID, op sUU[QP-  
    Print "Set lens thickness = " & tlens [+Fajo;0  
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    '************************************************************************* > l]Ble  
    'Lens index of refraction  TD%&9$F  
    '************************************************************************* )/)[}wN;j  
    eID = FindMaterial( "Lens" ) Em !%3C1r  
    GetModelMaterial eID, mat p6V#!5Q  
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    mat.Nd = nlens YxrMr9>l1  
    SetModelMaterial eID, mat %-a;HGbZn  
    Print "Set lens index of refraction = " & nlens @T:J<,  
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    '************************************************************************* hz*T"HJ]t  
    'Pupil diameter QO^V@"N  
    '************************************************************************* Qj|rNeM_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *ow`}Q  
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    'Adjust pupil diameter (trimming volume inner hole) R:$E'PSx  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }0tHzw=#%e  
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    ' Adjust pupil location to just in front of the lens KJ:z\N8eo  
    parID = FindFullName( "Geometry.Arizona Eye" ) 8|^&~Rl4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) X</Sl>[8  
    count = 0 7'
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    While GetOperationCount(eID)>count K_~kL0=4  
        GetOperation eID, count, op OGIv".~s4  
        If op.Type="ShiftZ" Then DP0@x+`k  
            DeleteOperation eID,count 1Dc
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            count=count-1 heL`"Y2'y>  
        End If `a83bF35  
        count=count+1 j#~~_VA~  
    Wend ^b$_I31D  
    op.Type = "ShiftZ" Wy}^5]R0E  
    op.val1 = taq-0.01 2x9.>nwhb  
    op.parent = parID @&Z^WN,x  
    AddOperation eID, op -gm5Eqi  
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    Print "Set pupil diameter = " & pupilDiam qxDMDMN  
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    'Update AZ Eye subassembly Description fgeh;cD  
    eID = FindFullName( "Geometry.Arizona Eye" ) >}\s-/  
    GetEntity eID, entity Le:C8^  
    entity.Description = "Accommodation = " & A & "D" |9=A"092{  
    SetEntity eID, entity \pfa\,rW  
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    Update 9:Oz-b  
    Print "DONE!" vi *A5  
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End Sub PPH;'!>s"  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： %~x?C4L8  
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Accommodation = 4 Diopters >mX6;6FF  
Pupil Diameter = 4 mm icIn>i<m  
Set aqueous humor thickness = 2.81 |=*)a2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 KILX?Pt[7  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 f)j*P<V  
Set lens thickness = 3.927 %~PcJhz  
Set lens index of refraction = 1.42672 | bRU=dg  
Set pupil diameter = 4 cz1+ XpU  
DONE! NS2vA>n8R