[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ;8ugI  
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。 C`DTPoXN  
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模型 `i<U;?=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。 b2ZKhS8  
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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. RU@`+6j+  
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光源 /9i2@#J}W1  
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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。 4D0"Y#&G  
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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。 g }5lGz4  
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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。 f BukrPsV  
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视网膜的散射 3g)pLW  
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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。 EW|bs#l  
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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。 YG$Y4h" @"  
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脚本 yd'>Mw  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： R8sj>.I9j  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 :!n_a*.{  
余下的脚本计算与屈光度有关的所有参数。 xhWWl(r`5  
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分析 V+(1U|@~  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 pxDkf|*  
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脚本代码 ]MKW5
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. iz.J._&  
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Dim entity As T_ENTITY ]r
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Dim op As T_OPERATION !:]CKbG  
Dim mat As T_MODELMATERIAL !{>'jvH  
Dim A As Double Y23- Im  
Dim pupilDiam As Double *eK\W00  
Dim eID As Long 0}$Zr*|;Y  
Dim parID As Long H`d595<=i;  
Dim count As Integer ^ ~'&K e  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double P{-j^'y  
Dim tlens As Double, nlens As Double Tr*3:J }  
Dim curv As Double, conic As Double C-u'Me)H  
Dim ok As Long 6V-u<FJ  
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Sub Main %Ya%R@b}  
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    '用户输入对话框 nvY%{Zf$}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ;UUpkOQO(  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lY -2e>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 3CcCcZ9I  
        OKButton 40,91,90,21 Gj!9#on$7R  
        CancelButton 190,91,90,21 VokIc&!Uz  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >>bsr#aJ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =S+*=jA  
    End Dialog oN({X/P2j  
    Dim dlg As UserDialog v]{F.N  
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    ok = Dialog (dlg) 6Ft?9 B(F:  
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    If ok=0 Then    'cancel button was pressed M$YU_RPl+  
        Print "Execution cancelled." lDsT?yHS`Z  
        End C-)mP- |8  
    End If ad)jw:n  
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    'Assign accommodation and pupil diameter & use defaults if field left empty #K#BNpG|  
    If dlg.TextBox1 = "" Then 2i0 .x  
        A = 0           'Default accommodation Cf
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    Else x%_VzqR`  
        A = CDbl(dlg.TextBox1) 0{Uc/  
    End If u1 Z;n  
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    If dlg.TextBox2 = "" Then pmwVVUEQ  
        pupilDiam = 4   'Default pupil diameter f |%II,!3  
    Else R`5g#  
        pupilDiam = CDbl(dlg.TextBox2) amTeTo]Tg  
    End If j)nL!":O  
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    Print " " 4t 5i9+h  
    Print "Accommodation = " & A & " Diopters" Jn7T5$p
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    Print "Pupil Diameter = " & pupilDiam & " mm" [x%[N)U3  
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    ' Calculate new parameters with accommodation )2sE9G,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~%chF/H
 
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens %8O1sF  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3#A4A0  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]SC|%B_*  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens cslZ;  
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    tlens = 3.767 + 0.04*A                  'Lens thickness O*7vmPy
 
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction %1oB!+tv  
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    'Adjust parameters to account for accommodation Kpg?' !I  
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    '************************************************************************* !F:ANoaS  
    'Aqueous thickness (Position of Lens) +0ALO%G;G"  
    '************************************************************************* `5Bv2wlIV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >^6|^rc  
    GetCustomElement eID, entity ;~-ZN?8   
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    parID = FindFullName( "Geometry.Arizona Eye" ) 5rb<u>e{  
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    ' Delete any shift(s) in z %*zV&H   
    count = 0 ?6Wv["%  
    While GetOperationCount(eID)>count v<@3&bot  
        GetOperation eID, count, op 3+l8VX&u!  
        If op.Type="ShiftZ" Then %9 3R/bx  
            DeleteOperation eID,count o:'@|(&<  
            count=count-1 KpBOmXE  
        End If w}]BJ<C  
        count=count+1 a&Qr7tTY"  
    Wend =2t=Zyp0Y  
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    'Set new shift in 7W'&v+\  
    op.Type = "ShiftZ" ZO!h!2*  
    op.val1 = taq &MZ{B/;;H  
    op.parent = parID 6gabnW3  
    AddOperation eID, op p/yz`m T'w  
    Print "Set aqueous humor thickness = " & taq-0.55 %iB,hGatE  
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    '************************************************************************* QQ`tSYgex  
    'Radius and conic constant of anterior lens L+m
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    '************************************************************************* Yy~xNj5OS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 4.Q[Tu  
    GetConic eID, entity, curv, conic 1N_T/I8_F  
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    SetConic eID, entity, 1/Rant, CCant 2TG2<wqvE  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Kton$%Li  
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    '************************************************************************* $Zr \$z2  
    'Radius and conic constant of posterior lens 4{Q$^wD+.  
    '************************************************************************* kbL7Xjk  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) g:O/~L0Xb  
    GetConic eID, entity, curv, conic {Q>4zepN!  
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    SetConic eID, entity, 1/Rpost, CCpost &zd@cr1  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^W(ue]j}o  
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    '************************************************************************* 9@ 4]t6h[  
    'Lens thickness (Position of posterior lens surface) p$G3<Z&7  
    '************************************************************************* 2ql)]Skg6  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tU$n3Bg  
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    ' Delete any z-shift(s) nrA 4N1  
    count = 0 y4! :l=E^  
    While GetOperationCount(eID)>count k( I
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        GetOperation eID, count, op BL~#-Mm<|l  
        If op.Type="ShiftZ" Then 6ddRFpe  
            DeleteOperation eID,count Pl!E$   
            count=count-1 5VpqDL~d  
        End If 'gXD?ARW  
        count=count+1 rg;4INs#  
    Wend Z t4q= Lr  
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    'Set new z-shift e$teh` p3  
    op.Type = "ShiftZ" p0y|pD  
    op.val1 = tlens skXzck  
    op.parent = parID >Tjl?CS  
    AddOperation eID, op 1;KJUf[N  
    Print "Set lens thickness = " & tlens *|j4>W\J  
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    '************************************************************************* m,"-/)  
    'Lens index of refraction N p*T[J  
    '************************************************************************* H)h^|A/vO  
    eID = FindMaterial( "Lens" ) BW6Ox
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    GetModelMaterial eID, mat Pr>05lg  
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    mat.Nd = nlens q6*i/"mN*  
    SetModelMaterial eID, mat #?+[|RS|  
    Print "Set lens index of refraction = " & nlens 6&5D4 V  
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    '************************************************************************* E|>-7k")  
    'Pupil diameter j!kJ@lbP  
    '************************************************************************* *zN~x(0{E  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mR
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    'Adjust pupil diameter (trimming volume inner hole) (,t[`z  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" z.\r7  
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    ' Adjust pupil location to just in front of the lens
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    parID = FindFullName( "Geometry.Arizona Eye" ) mI{Fs|9h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) j!NXNuy:  
    count = 0 Z9NN
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    While GetOperationCount(eID)>count +."|Y3a  
        GetOperation eID, count, op - f ^!R  
        If op.Type="ShiftZ" Then h_ccE6]t  
            DeleteOperation eID,count (J.Z+s$:2  
            count=count-1 0>Td4qr+u  
        End If I^( pZ9  
        count=count+1 4X*U~}  
    Wend %'i_iF8.  
    op.Type = "ShiftZ" ItvcN  
    op.val1 = taq-0.01 1<Mb@t  
    op.parent = parID |c8\alw  
    AddOperation eID, op JIw?]xa*  
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    Print "Set pupil diameter = " & pupilDiam AX%}ip[PC  
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    'Update AZ Eye subassembly Description j1qU 4#Y  
    eID = FindFullName( "Geometry.Arizona Eye" ) tFc<f7k  
    GetEntity eID, entity ! [1aP,  
    entity.Description = "Accommodation = " & A & "D" *k;bkd4x  
    SetEntity eID, entity Fbu4GRgJ3  
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    Update @[?ZwzY:9  
    Print "DONE!" :j .:t  
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End Sub kaQNcMcq  
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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： n{<}<SVY  
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Accommodation = 4 Diopters [ dVBsi  
Pupil Diameter = 4 mm AaxQBTB  
Set aqueous humor thickness = 2.81 Al6%RFt  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _b/zBF
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]|PTZ1?j  
Set lens thickness = 3.927 %qo.n v  
Set lens index of refraction = 1.42672 1\UU"  
Set pupil diameter = 4 $:oC\K6  
DONE! ~Gmt,l!b  
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