[技术]Arizona眼睛模型 [复制链接]

简介 )t0b$<%  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 is?&%VY  
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模型 mF}k}0  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 g$"eI/o  
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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. \u_v7
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光源 ;]M67ma7C  
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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。 px>>]>ZMH  
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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。 TcLaWf!c5  
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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。 ~}0hN]*G  
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视网膜的散射 ?SOF n  
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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。 @*"<U]  
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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。 g} ~<!VpX  
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脚本 y]pN=<*h5  
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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： yFU2'pB  
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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。 G2+)R^FSC  
余下的脚本计算与屈光度有关的所有参数。 8P<UO  
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分析 ~2A$R'xb  
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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。 dI ZTLb"a  

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脚本代码 WQLHjGehe  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. n|mJE,N  
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Dim entity As T_ENTITY K!D_PxV  
Dim op As T_OPERATION -90ZI1O`  
Dim mat As T_MODELMATERIAL k|$"TFXx;  
Dim A As Double 8/>wgY  
Dim pupilDiam As Double 2.Eu+*UC  
Dim eID As Long itC *Z6^  
Dim parID As Long b?2X>QJ  
Dim count As Integer lGnql1(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q 9gFTLQ  
Dim tlens As Double, nlens As Double yrE,,N%I  
Dim curv As Double, conic As Double  ny  
Dim ok As Long V:F+HM
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Sub Main S1az3VJI\  
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    '用户输入对话框 L VU)W^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 -l40)^ E}  
        TextBox 220,21,40,21,.TextBox1 'default: 0 /_:T\`5uO  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 FU(}=5n  
        OKButton 40,91,90,21 4l%?mvA^m  
        CancelButton 190,91,90,21 tJh3$K\  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;vI*ThzdD  
        TextBox 220,49,40,21,.TextBox2 'default: 4 YM`:L  
    End Dialog ph8Jn
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    Dim dlg As UserDialog hP4)8>  
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    ok = Dialog (dlg) TJyH/C  
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    If ok=0 Then    'cancel button was pressed ! =\DC,-CB  
        Print "Execution cancelled." @`IXu$Wm(  
        End .o\;,l2  
    End If ;*wT,2;  
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    'Assign accommodation and pupil diameter & use defaults if field left empty M|[@znzR<  
    If dlg.TextBox1 = "" Then jHu,u|e0>S  
        A = 0           'Default accommodation yUD_w  
    Else _>gXNS r4u  
        A = CDbl(dlg.TextBox1) +(=0CA0GE  
    End If Mz/]DJ8  
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    If dlg.TextBox2 = "" Then DnG/ n  
        pupilDiam = 4   'Default pupil diameter B@"SOX  
    Else KJ0xp hf  
        pupilDiam = CDbl(dlg.TextBox2) (c(-E|u.  
    End If J8GXI:y  
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    Print " " i14[3bPLk!  
    Print "Accommodation = " & A & " Diopters" 9S:
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    Print "Pupil Diameter = " & pupilDiam & " mm" []A"]p  
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    ' Calculate new parameters with accommodation 4T
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness C=oM,[ESQ0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens fV.A=*1l#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens b(PHZCy#  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens =_$XP   
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens =~GE?}.o  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `y8 ?=  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Vl5SL{+D  
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    'Adjust parameters to account for accommodation ]dPVtk  
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    '************************************************************************* 2-vJv+-
 
    'Aqueous thickness (Position of Lens) '}U_D:o.b  
    '************************************************************************* Q!4i_)rM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) wF|0n t  
    GetCustomElement eID, entity ioB|*D<U2  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !cq=)xR  
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    ' Delete any shift(s) in z g\ErJ+i
 
    count = 0 P'a0CE%  
    While GetOperationCount(eID)>count 5SoZ$,a<e  
        GetOperation eID, count, op vOos*&  
        If op.Type="ShiftZ" Then ,sO:$  
            DeleteOperation eID,count Yw6DJ
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            count=count-1 AuoxZ?V  
        End If 5h_<R!jA  
        count=count+1 <lC]>
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    Wend ybo#
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    'Set new shift in VK@$JwdL  
    op.Type = "ShiftZ" gKmX^A5<  
    op.val1 = taq HG2N-<$  
    op.parent = parID El~-M`Gf  
    AddOperation eID, op :z B}z^8-  
    Print "Set aqueous humor thickness = " & taq-0.55 p]wP36<S!  
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    '************************************************************************* VLf g
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    'Radius and conic constant of anterior lens ?k [%\jq{a  
    '************************************************************************* (7IqY1W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C@*%A
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    GetConic eID, entity, curv, conic *f79=x  
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    SetConic eID, entity, 1/Rant, CCant zL9VR;q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .4wTjbO6  
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    '************************************************************************* -@rxiC:Q  
    'Radius and conic constant of posterior lens dSwm|kIa  
    '************************************************************************* sa_R$ /H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Ej' 7h~=v  
    GetConic eID, entity, curv, conic #MUiL=  
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    SetConic eID, entity, 1/Rpost, CCpost vKU`C?,L  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3AK(dC[ri  
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    '************************************************************************* , Hn7(^t  
    'Lens thickness (Position of posterior lens surface) ue@8voZhS/  
    '************************************************************************* wuKl-:S;Vs  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9ftN8Svw  
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    ' Delete any z-shift(s) B]1HS`*7  
    count = 0 ^"1TPd|  
    While GetOperationCount(eID)>count 5|{)Z]M%9  
        GetOperation eID, count, op O:1DOUYXs  
        If op.Type="ShiftZ" Then Y[Es  
            DeleteOperation eID,count ;;@IfZ ?j  
            count=count-1 So#dJ>  
        End If B#]_8svO  
        count=count+1
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    Wend ,*dzJT$k  
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    'Set new z-shift r=qLaPG  
    op.Type = "ShiftZ" }'lNi^"XL  
    op.val1 = tlens [G
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    op.parent = parID +jtA&1cf  
    AddOperation eID, op 9RxO7K  
    Print "Set lens thickness = " & tlens DF'8GF&Rp  

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    '************************************************************************* H>?F8R_iq  
    'Lens index of refraction _9NVE|c;  
    '************************************************************************* {7X#4o0  
    eID = FindMaterial( "Lens" ) NY@"&p'Q  
    GetModelMaterial eID, mat ]NtSu%u  
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    mat.Nd = nlens >Rt9xP  
    SetModelMaterial eID, mat ,-@5NY1q  
    Print "Set lens index of refraction = " & nlens :M j_2  
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    '************************************************************************* 1kmQX+f
  
    'Pupil diameter +yWR#[`n  
    '************************************************************************* o 7G> y#Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (S oo<.9~  
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    'Adjust pupil diameter (trimming volume inner hole) !%xP}{(7  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 55-D\n<  
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    ' Adjust pupil location to just in front of the lens nLy#|C  
    parID = FindFullName( "Geometry.Arizona Eye" ) [9V
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w(BH247`  
    count = 0 .$Bwb/a  
    While GetOperationCount(eID)>count `5'2Hg+  
        GetOperation eID, count, op m_*R.a  
        If op.Type="ShiftZ" Then ioV_oR9I  
            DeleteOperation eID,count dn,gZ"<  
            count=count-1 /APcL5:=  
        End If `tE^jqrke5  
        count=count+1 Fk1.iRVzi  
    Wend >|3a 9S  
    op.Type = "ShiftZ" )`8pd 7<.  
    op.val1 = taq-0.01 D|_V<'  
    op.parent = parID NP/>H9Q2%  
    AddOperation eID, op %6ub3PLw8  
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    Print "Set pupil diameter = " & pupilDiam 3]U]?h  
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    'Update AZ Eye subassembly Description 8~ #M{}  
    eID = FindFullName( "Geometry.Arizona Eye" ) @(:v_l  
    GetEntity eID, entity )ofm_R'q*  
    entity.Description = "Accommodation = " & A & "D" ? _<[T  
    SetEntity eID, entity }q!_!q,@  
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    Update ip``v0Nf  
    Print "DONE!" U,;xZe  
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End Sub '#Dg8/r!  
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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： !@g)10u  
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Accommodation = 4 Diopters 6)e5zKW!?  
Pupil Diameter = 4 mm kWL.ewTiex  
Set aqueous humor thickness = 2.81 Y)
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Set anterior lens radius = 10.4 and conic constant = -2.375869 ^0tw%6:  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 EO)%UrWnC  
Set lens thickness = 3.927 iOqk*EL_r\  
Set lens index of refraction = 1.42672 t`|,6qEG  
Set pupil diameter = 4 I,O#X)O|i  
DONE! PlCc8Zy