[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 4<#ItQ(  
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。 Hloe7+5UD  
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模型 p<r<Y%  
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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。
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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. kBR=a%kG  
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光源 YP02/*'  
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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。 ]
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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。 JU>~[yAP  
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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。 h.vy SwF"j  
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视网膜的散射 #,#_"  
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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。 n>v1<
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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。 zq</(5H  
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脚本 1-p#}VX  
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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： -KGJr  
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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。 gV@xu)l  
余下的脚本计算与屈光度有关的所有参数。 $JOz7j(  
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分析 i\IpS@/{-v  
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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。 */K[B(G  
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脚本代码 q<E7qY+  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Ja3#W K  
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Dim entity As T_ENTITY Lmjd,t  
Dim op As T_OPERATION $R#_c}  
Dim mat As T_MODELMATERIAL j4i$2ZT'  
Dim A As Double F4\:9ws  
Dim pupilDiam As Double 'QE8  
Dim eID As Long )2).kL>  
Dim parID As Long )$^xbC#j`3  
Dim count As Integer w]MI3_|'r(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #6@hVR.  
Dim tlens As Double, nlens As Double PNAvT$0LaZ  
Dim curv As Double, conic As Double [Z/P[370  
Dim ok As Long bq7+l4CGTv  
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Sub Main 6g-jhsW6  
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    '用户输入对话框 L?u{vX  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 |h $Gs2  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ^r}Uu~A>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 x}a
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        OKButton 40,91,90,21 wrJQkven-  
        CancelButton 190,91,90,21 ruagJS)+  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %. ((4 6)  
        TextBox 220,49,40,21,.TextBox2 'default: 4 nycJZ}f:wP  
    End Dialog ~*EipxhstJ  
    Dim dlg As UserDialog bP$e1I3`  
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    ok = Dialog (dlg) Aa1#Ew<r  
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    If ok=0 Then    'cancel button was pressed xqk(id\&  
        Print "Execution cancelled." /TbJCZ  
        End !"phz&E5ah  
    End If 6p;Pf9 f  
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    'Assign accommodation and pupil diameter & use defaults if field left empty tz65Tn_M  
    If dlg.TextBox1 = "" Then >%6j-:S  
        A = 0           'Default accommodation ("A45\5  
    Else L`M{bRl+1  
        A = CDbl(dlg.TextBox1) im<!JMI  
    End If suQ`a_zJ  
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    If dlg.TextBox2 = "" Then K'8o'S_bF  
        pupilDiam = 4   'Default pupil diameter >}.~Y#Ge  
    Else G{.=27  
        pupilDiam = CDbl(dlg.TextBox2) 7202N?a {  
    End If 8u[.s`^  
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    Print " " dT1UYG}>j  
    Print "Accommodation = " & A & " Diopters" s7E %Et  
    Print "Pupil Diameter = " & pupilDiam & " mm" q@1A2L\Om  
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    ' Calculate new parameters with accommodation "j`T'%EV  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xg%{p``  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `o_i+?E  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens RU.j[8N$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens tvJl-&'N  
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    tlens = 3.767 + 0.04*A                  'Lens thickness d?U,}tv  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mMZ=9 ?m  
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    'Adjust parameters to account for accommodation YedF%  
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    '************************************************************************* lh0G/8+C  
    'Aqueous thickness (Position of Lens) ?~^p:T  
    '************************************************************************* %,N-M]Jf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) KPK`C0mg@k  
    GetCustomElement eID, entity WVyq$p/V  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 4`CO>Q  
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    ' Delete any shift(s) in z *}r6V"pH~  
    count = 0 y#ON=8l  
    While GetOperationCount(eID)>count 99zMdo S  
        GetOperation eID, count, op cw BiT  
        If op.Type="ShiftZ" Then 6jal5<H  
            DeleteOperation eID,count |c]L]
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            count=count-1 tr 8Q{  
        End If >Y3zO2Cr  
        count=count+1 W70BRXe04D  
    Wend $H,9GIivD  
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    'Set new shift in 48GaZ@v  
    op.Type = "ShiftZ" cJ,`71xop,  
    op.val1 = taq 2zjY|g/  
    op.parent = parID + L5  
    AddOperation eID, op ]w8h#p  
    Print "Set aqueous humor thickness = " & taq-0.55 Xp|$z~  
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    '************************************************************************* a- /p/ I-%  
    'Radius and conic constant of anterior lens ,l)AYu!q4F  
    '************************************************************************* [/cJc%{N  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 8/9YR(H3H  
    GetConic eID, entity, curv, conic Mb%[Qp60  
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    SetConic eID, entity, 1/Rant, CCant :)
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant J:;nN-\j  
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    '************************************************************************* 7sJGB^vM  
    'Radius and conic constant of posterior lens 3t]0  
    '************************************************************************* ^\PNjj*C i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Sj'.)nz>  
    GetConic eID, entity, curv, conic \?k"AtL  
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    SetConic eID, entity, 1/Rpost, CCpost f2$<4Hhmm  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost j62oA$z  
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    '************************************************************************* u7u1lx>S  
    'Lens thickness (Position of posterior lens surface) ^6^A/]v  
    '************************************************************************* 4kLTKm:G  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^W,x  
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    ' Delete any z-shift(s) m3b?f B  
    count = 0 B\7 80p<  
    While GetOperationCount(eID)>count h6gtO$A|p=  
        GetOperation eID, count, op `XwKCI  
        If op.Type="ShiftZ" Then O$&4{h`  
            DeleteOperation eID,count u&Y1,:hiL  
            count=count-1 `>$l2
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        End If -+.-Ab7  
        count=count+1 oMZ|)(7C  
    Wend U[l{cRT   
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    'Set new z-shift P0szY"}  
    op.Type = "ShiftZ" o7 X5{  
    op.val1 = tlens WG*S:_?  
    op.parent = parID Os|
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    AddOperation eID, op /SYzo4(  
    Print "Set lens thickness = " & tlens ,HO@bCK  
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    '************************************************************************* RjQdlr6*  
    'Lens index of refraction !p"Ijz5  
    '************************************************************************* ]a=Bc~g91  
    eID = FindMaterial( "Lens" ) fyt`$y_E[  
    GetModelMaterial eID, mat ?9AtFT  
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    mat.Nd = nlens SQVyCxcX_  
    SetModelMaterial eID, mat fxk6q$'  
    Print "Set lens index of refraction = " & nlens ,
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    '************************************************************************* yE),GJ-m\<  
    'Pupil diameter O0#9D'{  
    '************************************************************************* _:,U$W  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _LSf )  
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    'Adjust pupil diameter (trimming volume inner hole) cn!Y7LVr  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" p^QB^HEV  
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    ' Adjust pupil location to just in front of the lens o5eFLJ6  
    parID = FindFullName( "Geometry.Arizona Eye" ) e!~x-P5M`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )
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    count = 0 ~,.}@XlgT.  
    While GetOperationCount(eID)>count r6eApKZ>f6  
        GetOperation eID, count, op }7jg>3ng(  
        If op.Type="ShiftZ" Then %7bZnK`C  
            DeleteOperation eID,count t{)J#8:g  
            count=count-1 BPzlt  
        End If ?rgk  
        count=count+1 )Dq/fW  
    Wend YV0K&d  
    op.Type = "ShiftZ" Fps.Fhm  
    op.val1 = taq-0.01 ?rn#S8nNx<  
    op.parent = parID 2r=A'  
    AddOperation eID, op l6EDl0~r  
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    Print "Set pupil diameter = " & pupilDiam <+c6CM$#}V  
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    'Update AZ Eye subassembly Description e7.!=R{6  
    eID = FindFullName( "Geometry.Arizona Eye" ) ;eeu 9_$  
    GetEntity eID, entity =-qv[;%&6  
    entity.Description = "Accommodation = " & A & "D" P7GF"/  
    SetEntity eID, entity (7g1e
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    Update x p#+{}  
    Print "DONE!" Ll L8Q  
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End Sub M(2c{TT  
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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： t~0}Emgp<(  
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Accommodation = 4 Diopters tCdgtZm  
Pupil Diameter = 4 mm -IB~lw
 
Set aqueous humor thickness = 2.81 W|FPj^*t  
Set anterior lens radius = 10.4 and conic constant = -2.375869 E}$K&<J'-  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &<P!o_+eb  
Set lens thickness = 3.927 v&EHp{8Qd  
Set lens index of refraction = 1.42672 @:s|X  
Set pupil diameter = 4 _YH)E^If  
DONE! YrR}55V,  
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