[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 r CHl?J  
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。 d>&,9c%  
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模型 i2U{GV<K-r  
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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。 "3"V3w  

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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. &yTqZ*Yuk  
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光源 '8.r-`l(  
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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。 o>i4CCU+  
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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。 7P5)Z-K[  
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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。 cJ n=  
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视网膜的散射 y`5 9A  
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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。 c(m<h+2VL  
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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。 Al^d$FaF  
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脚本 *3FKt&v 0  
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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： Zw9FJ/Zn@  
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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。 
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余下的脚本计算与屈光度有关的所有参数。 
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分析 _
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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。 mb3"U"ohs  
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脚本代码 rJTa  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. eA?RK.e  
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Dim entity As T_ENTITY FUb\e-Q=  
Dim op As T_OPERATION nEy&>z  
Dim mat As T_MODELMATERIAL X-Kh(Z  
Dim A As Double <w9JRpFY  
Dim pupilDiam As Double @%uUiP0  
Dim eID As Long (gU!=F?#m  
Dim parID As Long MK~8}x2K  
Dim count As Integer g2ixx+`?|:  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double KqJs?Won  
Dim tlens As Double, nlens As Double KC6.Fr{  
Dim curv As Double, conic As Double L}b.ulkMD  
Dim ok As Long 9T9!kb  
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Sub Main 3M7/?TMw{6  
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    '用户输入对话框 itP,\k7>d  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 lNh70G8^p  
        TextBox 220,21,40,21,.TextBox1 'default: 0  'KL0@l  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 !;{7-
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        OKButton 40,91,90,21 C2I_%nU Z1  
        CancelButton 190,91,90,21 I6av6t}  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ie95rZp  
        TextBox 220,49,40,21,.TextBox2 'default: 4 0i>5<ej,f
 
    End Dialog ()?(I?I
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    Dim dlg As UserDialog 1(R}tRR7R  
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    ok = Dialog (dlg) _<V)-Y  
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    If ok=0 Then    'cancel button was pressed 7Q9 w?y~c  
        Print "Execution cancelled." MKk\ u9  
        End P3=G1=47U  
    End If t%)7t9j  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Hzz %3}E  
    If dlg.TextBox1 = "" Then pYEMmZ?L  
        A = 0           'Default accommodation X`K<>0.N  
    Else my1@41 H  
        A = CDbl(dlg.TextBox1) ET*SB  
    End If )2o?#8J  
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    If dlg.TextBox2 = "" Then f'RX6$}\1X  
        pupilDiam = 4   'Default pupil diameter ^[`%&uj!g  
    Else h,N?Ab'S  
        pupilDiam = CDbl(dlg.TextBox2) V1zmGy  
    End If Dx?,=~W9  
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    Print " " khxnlry  
    Print "Accommodation = " & A & " Diopters" &6!)jIWJ  
    Print "Pupil Diameter = " & pupilDiam & " mm" CK@@HSm}l  
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    ' Calculate new parameters with accommodation *?vCC+c  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness O0v}43J[  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 9.-S(ZO  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0[(8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens M7~2iU<#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens PC8Q"O  
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    tlens = 3.767 + 0.04*A                  'Lens thickness tDcT%D {:  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction JH9J5%sp  
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    'Adjust parameters to account for accommodation bAqA1y3=  
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    '************************************************************************* FW4<5~'  
    'Aqueous thickness (Position of Lens) DyQy^G'%l  
    '************************************************************************* ou
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ld~/u]K%V  
    GetCustomElement eID, entity (L&d!$,Dv  
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    parID = FindFullName( "Geometry.Arizona Eye" ) H7n>Vx:L-  
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    ' Delete any shift(s) in z =; Ff4aF  
    count = 0 v
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    While GetOperationCount(eID)>count F$]Pk|,  
        GetOperation eID, count, op -Q*gW2KmV  
        If op.Type="ShiftZ" Then b4kgFA  
            DeleteOperation eID,count CA~-rv  
            count=count-1 4D4j7  
        End If u6JM]kR
  
        count=count+1 U[MA)41  
    Wend &h/Xku&0  
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    'Set new shift in PJH&  
    op.Type = "ShiftZ" #\m<Sz5Gp#  
    op.val1 = taq #*
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    op.parent = parID VTE .^EK!  
    AddOperation eID, op Fx.=#bVX7  
    Print "Set aqueous humor thickness = " & taq-0.55 " H\k`.j  
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    '************************************************************************* B]tQ(s~  
    'Radius and conic constant of anterior lens e\L8oOk#r  
    '************************************************************************* iYy1!\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .ioEIsg  
    GetConic eID, entity, curv, conic F)eelPZ+,  
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    SetConic eID, entity, 1/Rant, CCant ;i+jJ4  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant &^jXEz;  
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    '************************************************************************* tWcHb #  
    'Radius and conic constant of posterior lens bk[!8-b/a  
    '************************************************************************* #ABZ&Z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @q)d  
    GetConic eID, entity, curv, conic 7%M_'P4 V  
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    SetConic eID, entity, 1/Rpost, CCpost M\BRcz  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =I_'
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    '************************************************************************* +NUG  
    'Lens thickness (Position of posterior lens surface) Nh44]*  
    '************************************************************************* R:qW;n%AF  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) S_H+WfIHV'  
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    ' Delete any z-shift(s) OjA,]Gv6  
    count = 0 5b7RYV  
    While GetOperationCount(eID)>count Ny/MJ#Lq  
        GetOperation eID, count, op z F;K  
        If op.Type="ShiftZ" Then 5z)~\;[ -  
            DeleteOperation eID,count J{G?-+`  
            count=count-1 A04U /;  
        End If @=u3ZVD  
        count=count+1 ]ZS OM\}  
    Wend Ow,b^|  
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    'Set new z-shift >H,*H;6  
    op.Type = "ShiftZ" GQ ;;bcj&  
    op.val1 = tlens YS_;OFsd  
    op.parent = parID e*1_8I#2  
    AddOperation eID, op Vxt+]5X  
    Print "Set lens thickness = " & tlens Z;"vW!%d  
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    '*************************************************************************
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    'Lens index of refraction \~wMfP8  
    '************************************************************************* W2!+z{:m  
    eID = FindMaterial( "Lens" ) GC'O[q+  
    GetModelMaterial eID, mat F:DrX_O%  
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    mat.Nd = nlens X}0cCdW  
    SetModelMaterial eID, mat q@2siI~W  
    Print "Set lens index of refraction = " & nlens %&bY]w  
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    '************************************************************************* TD_Oo-+\  
    'Pupil diameter V(*
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    '************************************************************************* 93hxSRw  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) bg0

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    'Adjust pupil diameter (trimming volume inner hole) Ek}A
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5@W j>:w  
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    ' Adjust pupil location to just in front of the lens ov
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    parID = FindFullName( "Geometry.Arizona Eye" ) +ck}l2&#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Gs[XJ 5%`~  
    count = 0 $ME)#(  
    While GetOperationCount(eID)>count Z?z.?ar  
        GetOperation eID, count, op vvOV2n.WD  
        If op.Type="ShiftZ" Then a[TMDU;(/4  
            DeleteOperation eID,count Z/J y'$x  
            count=count-1 5kXYeP3:  
        End If rrv%~giU  
        count=count+1 WX
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    Wend HpnWoDM  
    op.Type = "ShiftZ" KK &?gTa  
    op.val1 = taq-0.01 qIqM{#' ^  
    op.parent = parID 8\gjST*  
    AddOperation eID, op cN9t{.m  
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    Print "Set pupil diameter = " & pupilDiam xN%K^Tree  
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    'Update AZ Eye subassembly Description xkR0  
    eID = FindFullName( "Geometry.Arizona Eye" ) @s^-.z  
    GetEntity eID, entity 4E?Oky#}-  
    entity.Description = "Accommodation = " & A & "D" " 2Dngw  
    SetEntity eID, entity 0
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    Update Xn\jO>[Ef  
    Print "DONE!" 0qT%!ku&  
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End Sub lb1Xsgm{  
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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： C"enpc_C/  
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Accommodation = 4 Diopters {FTqu.  
Pupil Diameter = 4 mm ^zgo#J5O  
Set aqueous humor thickness = 2.81 xn|(9#1o  
Set anterior lens radius = 10.4 and conic constant = -2.375869 L&OwPd  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 4ss4kp_>  
Set lens thickness = 3.927 {kAc(  
Set lens index of refraction = 1.42672 RzusNS  
Set pupil diameter = 4 2dgd~   
DONE! n?K  
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