[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 5qfKV&D  
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。 NWwtq&pz2  
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模型 /~huTKA}  
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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。 '<D}5u72  
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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. #&c;RPac!6  
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光源 |/\1nWD  
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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。 c O>: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。 L(P:n-
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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。 }eFUw  
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视网膜的散射 q ? TI,  
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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。 >Mw =}g@P  
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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。 z( [$,e\  
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脚本 P,=J"%a-  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： >.~k?_Of  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 3edK$B51;  
余下的脚本计算与屈光度有关的所有参数。
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分析 *.Hnt\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。 R!xc$`N  
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脚本代码 HV(*6b
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. q`zR6  
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Dim entity As T_ENTITY vu >@_hv  
Dim op As T_OPERATION ~36XJ  
Dim mat As T_MODELMATERIAL uRhH_c-6C  
Dim A As Double Ll48)P{+}V  
Dim pupilDiam As Double v3#47F)  
Dim eID As Long vB4qJ{f  
Dim parID As Long P"<ad kr  
Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double iAhRlQ{Qu  
Dim tlens As Double, nlens As Double 1H@F>}DP  
Dim curv As Double, conic As Double -q|M=6gOs  
Dim ok As Long KO$8lMm$  
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Sub Main 9j9?;3;  
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    '用户输入对话框 K*RRbtb  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Ut@)<N  
        TextBox 220,21,40,21,.TextBox1 'default: 0 n&&y\?n  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ?q`mr_x%?  
        OKButton 40,91,90,21 +O6@)?pI  
        CancelButton 190,91,90,21 {'C74s  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ga%77t|jm3  
        TextBox 220,49,40,21,.TextBox2 'default: 4 l).Ijl}AH;  
    End Dialog %&GQ]pmcY  
    Dim dlg As UserDialog ZH:X4!  
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    ok = Dialog (dlg) %)]RM/e8  
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    If ok=0 Then    'cancel button was pressed |V]E8Qt  
        Print "Execution cancelled." $nWmoe)  
        End ]
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    End If _: x$"i  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ZrBxEf$f  
    If dlg.TextBox1 = "" Then ${3
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        A = 0           'Default accommodation RzRLrfV  
    Else n_hD  
        A = CDbl(dlg.TextBox1) d~%Rnic6*  
    End If af{K4:I  
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    If dlg.TextBox2 = "" Then beoMLHp  
        pupilDiam = 4   'Default pupil diameter ) 'KHUa9  
    Else D1 z3E;:  
        pupilDiam = CDbl(dlg.TextBox2) {D8IA3w  
    End If .=
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    Print " " A 78{b^0
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    Print "Accommodation = " & A & " Diopters" i"@?eq#h  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1??RX}8[L+  
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    ' Calculate new parameters with accommodation kPe9G  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness c$;enAf@  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ap!<8N  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d=XhOC$  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6(=:j"w0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens k:.c(_2M  
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    tlens = 3.767 + 0.04*A                  'Lens thickness dewu@  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction B~IOM  
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    'Adjust parameters to account for accommodation {3>^nMv@e  
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    '************************************************************************* }PJ:9<G y  
    'Aqueous thickness (Position of Lens) :|g{gi  
    '************************************************************************* as8<c4:v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mB\|<2  
    GetCustomElement eID, entity y;H 3g#  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ZmDr$iU~  
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    ' Delete any shift(s) in z y[vjqfdmU  
    count = 0 )yk LUse+  
    While GetOperationCount(eID)>count i F Ab"VA  
        GetOperation eID, count, op |(fWT}tg  
        If op.Type="ShiftZ" Then E=E  
            DeleteOperation eID,count mAMKCxz,  
            count=count-1 T&%>/7I>  
        End If &uM?DQ`o8  
        count=count+1 S@_GjCpn
 
    Wend mP-+];gg  
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    'Set new shift in S=Zjdbd  
    op.Type = "ShiftZ" V}*b^<2o5  
    op.val1 = taq TBpW/wz/  
    op.parent = parID $8Zw<aEJ  
    AddOperation eID, op wRKGJ
  
    Print "Set aqueous humor thickness = " & taq-0.55 "o1/gV  
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    '************************************************************************* rRMC<.=  
    'Radius and conic constant of anterior lens $]9d((u4  
    '************************************************************************* 2Y,s58F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) qxq ~9\My  
    GetConic eID, entity, curv, conic ;Wr$hDt^  
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    SetConic eID, entity, 1/Rant, CCant q+z,{K  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ~7*HZ:.  
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    '************************************************************************* +um; eL7  
    'Radius and conic constant of posterior lens jooh`| `P  
    '************************************************************************* |Q{l]D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) "_^FRz#h  
    GetConic eID, entity, curv, conic #M
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    SetConic eID, entity, 1/Rpost, CCpost kys?%Y1  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost kn!J`"b  
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    '************************************************************************* p7z#4 GW  
    'Lens thickness (Position of posterior lens surface) ]fR 3f  
    '************************************************************************* )2a
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) P<bA~%<7"[  
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    ' Delete any z-shift(s) 
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    count = 0 *e^ZH  
    While GetOperationCount(eID)>count % R'eV<  
        GetOperation eID, count, op ]xuq2MU,l  
        If op.Type="ShiftZ" Then {#7t(:x  
            DeleteOperation eID,count ALFw[1X  
            count=count-1 fx*Swv%r  
        End If U-k6ZV3&8  
        count=count+1 ohwQ%NDl  
    Wend A
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    'Set new z-shift '0[l'Dt'  
    op.Type = "ShiftZ" 4kx#=MLt
 
    op.val1 = tlens /({5x[  
    op.parent = parID TiH(HW|:  
    AddOperation eID, op 7UMsKE-  
    Print "Set lens thickness = " & tlens p.zU9rID  
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    '************************************************************************* &vLZj  
    'Lens index of refraction `P'{HT  
    '************************************************************************* P afmHXx  
    eID = FindMaterial( "Lens" ) aFhsRE?YC=  
    GetModelMaterial eID, mat sO6+L #!  
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    mat.Nd = nlens Wc(?ezn  
    SetModelMaterial eID, mat Nz2}M
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    Print "Set lens index of refraction = " & nlens q+SDJ?v  
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    '*************************************************************************  Wkf)4!  
    'Pupil diameter >b/Yg:t  
    '************************************************************************* olh|.9Kdj}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) :V`q;g  
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    'Adjust pupil diameter (trimming volume inner hole) P4s:wuJ^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ww=< =  
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    ' Adjust pupil location to just in front of the lens r0_3`;H  
    parID = FindFullName( "Geometry.Arizona Eye" ) o6'`W2P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &bTadd%0  
    count = 0 ZQ@^(64  
    While GetOperationCount(eID)>count E-l>z%  
        GetOperation eID, count, op >&p_G0
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        If op.Type="ShiftZ" Then ;5oY)1  
            DeleteOperation eID,count -Ndd6O[ a5  
            count=count-1 ?9/%K45  
        End If @aI`ru+a  
        count=count+1 C}wmoYikV  
    Wend I/fERnHM/+  
    op.Type = "ShiftZ" 7 pp[kv;!G  
    op.val1 = taq-0.01 &EZ28k"x  
    op.parent = parID %$S.4#G2  
    AddOperation eID, op Hz28L$  
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    Print "Set pupil diameter = " & pupilDiam I8e{%PK  
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    'Update AZ Eye subassembly Description ZCV&v47\p_  
    eID = FindFullName( "Geometry.Arizona Eye" ) mR?OSeeB  
    GetEntity eID, entity ."cC^og  
    entity.Description = "Accommodation = " & A & "D" g5_]^[upw  
    SetEntity eID, entity izOtt^#DZt  
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    Update vA"yy"B+ V  
    Print "DONE!" (7&[!PS  
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End Sub iwrS>Sm  
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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： Ig*!0(v5$  
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Accommodation = 4 Diopters Vtr0=-m&  
Pupil Diameter = 4 mm ]#KZ W)M  
Set aqueous humor thickness = 2.81 J!~?}Fq/z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 >4b-NS/}0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `TBau:ElI  
Set lens thickness = 3.927 [iB`- dE,  
Set lens index of refraction = 1.42672 Qgf\gTF$r+  
Set pupil diameter = 4 P
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DONE! P
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