[分享]Arizona眼睛模型 [复制链接]

简介 FJvY`zqB  
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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。 &nEL}GM)E  
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模型 wfo,r 7  
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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。 /A{ Zf'DI  
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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. &y!?R$?b  
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光源 &=lc]sk  

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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。 $tZ {>!N  
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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。 @R&d<^I&M  
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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。 ceUe*}\cr  
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视网膜的散射 C]

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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。 ^_]ZZin  
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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。 <- \|>r Q  
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脚本 v~mVf.j1  
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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： !1l~UB_  
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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。 D0Q9A]bD;  
余下的脚本计算与屈光度有关的所有参数。 ^8 VW$}  
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分析 ?~o`
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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。 T]tP!a;K  
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脚本代码 t\,Y<9{w  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. JX&
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Dim entity As T_ENTITY WZ'Z"'  
Dim op As T_OPERATION 7DAP_C  
Dim mat As T_MODELMATERIAL ^`cv6;)  
Dim A As Double ${T/b(NM  
Dim pupilDiam As Double h4]^~stI  
Dim eID As Long `\( ?^]WLa  
Dim parID As Long 2F2Hl  
Dim count As Integer 0=>$J WF  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Xl4}S"a  
Dim tlens As Double, nlens As Double
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Dim curv As Double, conic As Double j!4{+&Laq  
Dim ok As Long :qE.(k1@5  
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Sub Main h7#\]2U$[5  
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    '用户输入对话框 4kL6aSqT  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^("b~-cJ  
        TextBox 220,21,40,21,.TextBox1 'default: 0 A
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *q6XK_  
        OKButton 40,91,90,21 -m^-p  
        CancelButton 190,91,90,21 <1*kXTN(  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xUn"XkhP  
        TextBox 220,49,40,21,.TextBox2 'default: 4 boojq{cvYA  
    End Dialog 4v_Ac;2m&  
    Dim dlg As UserDialog lrE"phYk  
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    ok = Dialog (dlg) OJm ]gb7  
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    If ok=0 Then    'cancel button was pressed toA}0MI(:  
        Print "Execution cancelled." FxlH;'+Q  
        End 8c) eaDu  
    End If ]$g07 7o  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Sqa9+' [  
    If dlg.TextBox1 = "" Then 3S3 a|_+%  
        A = 0           'Default accommodation @g#5d|U);  
    Else ! yJ0Am>  
        A = CDbl(dlg.TextBox1) 6_%Cd`4Z  
    End If Un]wP`  
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    If dlg.TextBox2 = "" Then ykC3Z<pI.  
        pupilDiam = 4   'Default pupil diameter qU#A,%kcV  
    Else Q>$B.z  
        pupilDiam = CDbl(dlg.TextBox2) X
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    End If qiet<F  
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    Print " " J!om"h  
    Print "Accommodation = " & A & " Diopters"
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    Print "Pupil Diameter = " & pupilDiam & " mm" -Mr_Ao`E  
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    ' Calculate new parameters with accommodation WHx#;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &KMI C  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens a &tWMxBr  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -Y524   
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (K[e=0Rf  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens UnDCC_ud  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }36AeJ7L  
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    'Adjust parameters to account for accommodation *w;?&)8%  
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    '************************************************************************* >\K=)/W2  
    'Aqueous thickness (Position of Lens) N&G'i.w/  
    '************************************************************************* v/ Ge+o0K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~0,v Q   
    GetCustomElement eID, entity 2:|v
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    parID = FindFullName( "Geometry.Arizona Eye" )
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    ' Delete any shift(s) in z 6{;6~?U  
    count = 0 O^\:J2I(  
    While GetOperationCount(eID)>count 4Yvz-aSyO  
        GetOperation eID, count, op 9U;  
        If op.Type="ShiftZ" Then .=YV  
            DeleteOperation eID,count zx<t{e7  
            count=count-1 u)h {"pP  
        End If ^GV'Y  
        count=count+1 ,JI]Eij^  
    Wend \ C:Gx4K  
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    'Set new shift in {3KY:%6qj  
    op.Type = "ShiftZ" :g$"Xc8Zn  
    op.val1 = taq 0fstEExw  
    op.parent = parID =xkaF)AW&v  
    AddOperation eID, op o.r D  
    Print "Set aqueous humor thickness = " & taq-0.55 ue3 ].:  
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    '************************************************************************* r]LP=K1  
    'Radius and conic constant of anterior lens ;F1y!h67<  
    '************************************************************************* ^}2!fRKAmo  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >A{e,&  
    GetConic eID, entity, curv, conic Btznms'  
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    SetConic eID, entity, 1/Rant, CCant waz5+l28  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ag T)J  
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    '************************************************************************* zATOFV  
    'Radius and conic constant of posterior lens |}^u<S8X  
    '************************************************************************* YCP D+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) F ]X<q uuL  
    GetConic eID, entity, curv, conic [3=Y 9P:  
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    SetConic eID, entity, 1/Rpost, CCpost z
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost d. d J^M  
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    '************************************************************************* >lmqPuf  
    'Lens thickness (Position of posterior lens surface) 'O 7
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    '************************************************************************* 1d!s8um;  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) OE[7fDe'  
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    ' Delete any z-shift(s) V*JqC  
    count = 0 tMdSdJ8  
    While GetOperationCount(eID)>count R%LFFMVn  
        GetOperation eID, count, op IA}vN3  
        If op.Type="ShiftZ" Then 5fs,UH  
            DeleteOperation eID,count noaR3)  
            count=count-1 }x$@
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        End If "<Di  
        count=count+1 C:&Sk\   
    Wend Ax|'uvVAPT  
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    'Set new z-shift mGg/F&G9  
    op.Type = "ShiftZ" !m=Js"  
    op.val1 = tlens B
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    op.parent = parID q%bFR[p<*  
    AddOperation eID, op K_t >T)K  
    Print "Set lens thickness = " & tlens [A,!3BN  
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    '************************************************************************* B.?F^m@zS  
    'Lens index of refraction Qu/f>tJN;  
    '************************************************************************* _)LXD,LA  
    eID = FindMaterial( "Lens" ) s hq +  
    GetModelMaterial eID, mat 3P75:v  
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    mat.Nd = nlens k
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    SetModelMaterial eID, mat Mx0~^l
 
    Print "Set lens index of refraction = " & nlens l`6.(6  
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    '************************************************************************* 3J8>r|u;1'  
    'Pupil diameter IuFr:3(  
    '************************************************************************* RI<smt.Ng  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _8SB+s*  
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    'Adjust pupil diameter (trimming volume inner hole) B(FM~TVZ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y$,++wx  
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    ' Adjust pupil location to just in front of the lens `o9:6X?RA  
    parID = FindFullName( "Geometry.Arizona Eye" ) T6?03cSE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) E>#@
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    count = 0 IEM{?  
    While GetOperationCount(eID)>count Bk~lM'  
        GetOperation eID, count, op kwww5p ["  
        If op.Type="ShiftZ" Then npytb*[|c  
            DeleteOperation eID,count fGH
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            count=count-1 <tO@dI$~>  
        End If
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        count=count+1 "Ar|i8^G3  
    Wend "`S?q G  
    op.Type = "ShiftZ" s LDEa  
    op.val1 = taq-0.01 04-@c  
    op.parent = parID XdzC/{G  
    AddOperation eID, op iBWEZw)  
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    Print "Set pupil diameter = " & pupilDiam iz[IK%K  
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    'Update AZ Eye subassembly Description ^K8XY@{&  
    eID = FindFullName( "Geometry.Arizona Eye" ) xe.f]a  
    GetEntity eID, entity V2;Nv\J\  
    entity.Description = "Accommodation = " & A & "D" <%|u1cn~!v  
    SetEntity eID, entity @qWClr{`  
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    Update } nIYNeP?D  
    Print "DONE!" a
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End Sub Xmb##:  
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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： ?J+*i d  
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Accommodation = 4 Diopters ~U]%>Zf  
Pupil Diameter = 4 mm qauvwAMuX  
Set aqueous humor thickness = 2.81 <Nloh+n=  
Set anterior lens radius = 10.4 and conic constant = -2.375869  SN}3  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 1n*"C!q  
Set lens thickness = 3.927 G7GKO  
Set lens index of refraction = 1.42672 c8_,S[W  
Set pupil diameter = 4 ,s}7KE  
DONE! "WPWMQ+  
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