[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 6FB0g8  
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。 qez
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模型 A0{xt*g   
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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。 n8,%<!F^  
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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. lx`?n<-X  
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光源 aq?bI:>8  
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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。 7P{= Pv+  
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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。 j7P49{  
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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。 Oc)n,D)0  
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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。 @fd<  
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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。  <$nPGz)}  
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脚本 Q4mtfpiDx  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ~D5 -G?%$"  
余下的脚本计算与屈光度有关的所有参数。 Gb^63.}  
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分析 as:=
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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。 X0*+]tRg  
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脚本代码 i?_Q@uA~<:  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 8mr fs%_  
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Dim entity As T_ENTITY +HE,Q6-A  
Dim op As T_OPERATION CX#d  
Dim mat As T_MODELMATERIAL puOMtCI  
Dim A As Double MKtI3vi?  
Dim pupilDiam As Double 8z93ETv7`  
Dim eID As Long oX6Cd:c-  
Dim parID As Long pll5m7[  
Dim count As Integer lR?1,yLp  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double @.e4~qz\  
Dim tlens As Double, nlens As Double  o]0E  
Dim curv As Double, conic As Double <_/etw86Z  
Dim ok As Long GUQ3X
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Sub Main ,$]m1|t@z  
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    '用户输入对话框 T#E{d  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [<+T
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        TextBox 220,21,40,21,.TextBox1 'default: 0 ~U<j_j)z4.  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Fmn_fW6  
        OKButton 40,91,90,21
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        CancelButton 190,91,90,21 2Jo|P A`9  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Ez <YD  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ''2:ZXX  
    End Dialog i%
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    Dim dlg As UserDialog #~Kno@  
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    ok = Dialog (dlg) YloE4PAY7  
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    If ok=0 Then    'cancel button was pressed P'}E
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        Print "Execution cancelled." ZrYRLg  
        End uT
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    End If *h?*RUQ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ddYb=L+_b  
    If dlg.TextBox1 = "" Then 1%@i4  
        A = 0           'Default accommodation :t;\`gQoS  
    Else Y}vV.q  
        A = CDbl(dlg.TextBox1) =)#XZ[#F  
    End If kH06Cb  
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    If dlg.TextBox2 = "" Then %PVu>^  
        pupilDiam = 4   'Default pupil diameter 1\TkI=N3  
    Else HELTL$j,
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        pupilDiam = CDbl(dlg.TextBox2) @$b7 eu  
    End If {s@&3i?ZiC  
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    Print " " dn5t7D^x  
    Print "Accommodation = " & A & " Diopters" hzV%QDUpe  
    Print "Pupil Diameter = " & pupilDiam & " mm" sI)jqHZG  
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    ' Calculate new parameters with accommodation @ /e{-Q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .j!:Hp(z}  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Dmtsu2o  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens RZvRV?<bR  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens S{cK~sZj  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens qE^u{S4Z@  
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    tlens = 3.767 + 0.04*A                  'Lens thickness w
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction s4 Uk5<  
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    'Adjust parameters to account for accommodation c*8k _o,  
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    '************************************************************************* %F*h}i  
    'Aqueous thickness (Position of Lens) B3u:D"
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    '************************************************************************* n%dh|j2u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) e<{Ani0  
    GetCustomElement eID, entity LZPLz@=&]  
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    parID = FindFullName( "Geometry.Arizona Eye" ) EU7mP MxJ  
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    ' Delete any shift(s) in z XQ k,xQ  
    count = 0 F-?s8RD  
    While GetOperationCount(eID)>count CJLfpvV  
        GetOperation eID, count, op _'r&'s;<z  
        If op.Type="ShiftZ" Then Daf;; w  
            DeleteOperation eID,count CwzDkr&QC_  
            count=count-1 5DeAH;  
        End If "CQ:<$|$  
        count=count+1 _nW#Cl~  
    Wend ID=^497  
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    'Set new shift in cr{f*U6`  
    op.Type = "ShiftZ" BG20R=p  
    op.val1 = taq 9<!Ie^o?  
    op.parent = parID
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    AddOperation eID, op 4q^'MZm1  
    Print "Set aqueous humor thickness = " & taq-0.55 /`B:F5r  
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    '************************************************************************* , rc %#eF  
    'Radius and conic constant of anterior lens ON3~!Q)  
    '************************************************************************* G C3G=DTt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .{#J2}+[_}  
    GetConic eID, entity, curv, conic &qFy$`"  
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    SetConic eID, entity, 1/Rant, CCant +,ZQ( ZW  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ^{fA:N=  
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    '************************************************************************* LZ*ZXFIg  
    'Radius and conic constant of posterior lens ER$qL"H U  
    '************************************************************************* GZqy.AE,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6<C|O-  
    GetConic eID, entity, curv, conic 9rhl2E  
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    SetConic eID, entity, 1/Rpost, CCpost -]~vEfq+T  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >a2i%j/T  
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    '************************************************************************* !@kwHJkv  
    'Lens thickness (Position of posterior lens surface) iwnFCZVS  
    '************************************************************************* 3N5b3F  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) qm=N@@R&  
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    ' Delete any z-shift(s) s:\FlQ0  
    count = 0 ?T <2Cl'C  
    While GetOperationCount(eID)>count BO)Q$*G~JD  
        GetOperation eID, count, op m'.y,@^B  
        If op.Type="ShiftZ" Then #Rcb iV*M  
            DeleteOperation eID,count _"0Bg3Y  
            count=count-1 LL^WeD_Y  
        End If h#rziZ(  
        count=count+1 DNl'}K1W  
    Wend 6#/v:;bF  
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    'Set new z-shift g/6>>p`J  
    op.Type = "ShiftZ" xF8^#J6>  
    op.val1 = tlens gG6j>%y  
    op.parent = parID 3=~0m  
    AddOperation eID, op i@p0Jnh|  
    Print "Set lens thickness = " & tlens iSg^np  
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    '************************************************************************* )4BLm  
    'Lens index of refraction '6zD`Q  
    '************************************************************************* TY6Q;BTU  
    eID = FindMaterial( "Lens" ) #?EmC]N7  
    GetModelMaterial eID, mat &;]KntxB  
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    mat.Nd = nlens w5uOkz #  
    SetModelMaterial eID, mat RO+N>Wkt  
    Print "Set lens index of refraction = " & nlens %RS8zN  
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    '************************************************************************* qmx4hs8sh  
    'Pupil diameter FH}2wO~_  
    '************************************************************************* hFp\,QSx  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7dbGUbT  
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    'Adjust pupil diameter (trimming volume inner hole) J
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q=~*oYR  
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    ' Adjust pupil location to just in front of the lens 2jiH&'@  
    parID = FindFullName( "Geometry.Arizona Eye" ) qzt.k^'-^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 84eqT[I'  
    count = 0 [DzZ:8  
    While GetOperationCount(eID)>count u?B9zt%$-m  
        GetOperation eID, count, op +<1MY'>y  
        If op.Type="ShiftZ" Then 1ms(03dp  
            DeleteOperation eID,count z[~ph/
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            count=count-1 kzuI<DW  
        End If vQ",rP%  
        count=count+1 vle`#c.  
    Wend |s$w i>7l  
    op.Type = "ShiftZ" kt;uB X3  
    op.val1 = taq-0.01 bs9X4n5  
    op.parent = parID 6(0ME$  
    AddOperation eID, op y8arFG  
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    Print "Set pupil diameter = " & pupilDiam "F+m}GJ=a  
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    'Update AZ Eye subassembly Description 2Mo oqJp  
    eID = FindFullName( "Geometry.Arizona Eye" ) [ qx[ 0  
    GetEntity eID, entity )~[rb<:)b  
    entity.Description = "Accommodation = " & A & "D" QRKr2:o{  
    SetEntity eID, entity vnS;T+NZSC  
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    Update NwbX]pDT  
    Print "DONE!" > t~2  
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End Sub f5o##ia7:  
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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： V krjs0  
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Accommodation = 4 Diopters *P0sl( &  
Pupil Diameter = 4 mm fIwG9cR  
Set aqueous humor thickness = 2.81 jH~VjE>  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Ml
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 wMvAm%}+  
Set lens thickness = 3.927 V3v/hV:  
Set lens index of refraction = 1.42672 >%1mx\y^  
Set pupil diameter = 4 'M!*Ge  
DONE! q)rxv7Iu\  
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