[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 \5DOp-2  
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。 Y]neTX [ef  
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模型 M0K+Vz=  
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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。 1X-fiQJe  
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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. 5Y#~+Im=[@  
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光源 `nv82v  
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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。 q[
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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。 QLD
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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。 <2ymfL-q  
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视网膜的散射 Z"5ew
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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。 |m>{< :  
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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。 &pN/+,0E  
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脚本 q%hxU.h  
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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： eG08Xt|lc  
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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。 |P`:NAf2  
余下的脚本计算与屈光度有关的所有参数。 B`/p

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分析 ZuVes?&j  
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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。 gQlL0jAV  
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脚本代码 #9u2LK  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Uv%?
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Dim entity As T_ENTITY  HV\l86}  
Dim op As T_OPERATION 65AG#O5R  
Dim mat As T_MODELMATERIAL D>m!R[!o  
Dim A As Double {/K_NSg+h  
Dim pupilDiam As Double y)D7!s  
Dim eID As Long ^gd[UC-"w  
Dim parID As Long Yxd&hr  
Dim count As Integer /><+[\q4LM  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double MNVOloA  
Dim tlens As Double, nlens As Double g4NbzU[I  
Dim curv As Double, conic As Double d,*#yzO  
Dim ok As Long KQ2jeJ/pj  
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Sub Main ht5eb"c+8  
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    '用户输入对话框 %eQw\o,a  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 e sDd>W  
        TextBox 220,21,40,21,.TextBox1 'default: 0 #b5V/)K  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6ujePi <U  
        OKButton 40,91,90,21 ~CQTPR  
        CancelButton 190,91,90,21 <imIgt|`2  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 $Oi@B)=4d+  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (|_N2R!  
    End Dialog 61=D&lb  
    Dim dlg As UserDialog a534@U4,  
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    ok = Dialog (dlg) iw?*Wp25  
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    If ok=0 Then    'cancel button was pressed e QGhX(  
        Print "Execution cancelled." `2.2; Vk  
        End '/v@q]!  
    End If a^QyYX}\qR  
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    'Assign accommodation and pupil diameter & use defaults if field left empty J-)9>~[E<  
    If dlg.TextBox1 = "" Then X0e#w?  
        A = 0           'Default accommodation y;1l].L  
    Else <yz&> +9,  
        A = CDbl(dlg.TextBox1) < rqFBq8  
    End If VMb r@9  
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    If dlg.TextBox2 = "" Then WC *e#QP  
        pupilDiam = 4   'Default pupil diameter +ew9%={zB  
    Else ;8J+Q0V  
        pupilDiam = CDbl(dlg.TextBox2) xIb^x=|h  
    End If TX7]$Wj  
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    Print " " o:8*WCiqrN  
    Print "Accommodation = " & A & " Diopters" YH^h?s  
    Print "Pupil Diameter = " & pupilDiam & " mm" Tye[iJ  
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    ' Calculate new parameters with accommodation :UDT! 5FNO  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness MPI=^rc2  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens <C6*-j1oz  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens L]ce
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens F|3iKK022  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens oP 4z>  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 4A@77#:J5  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction vk]vtjf&%  
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    'Adjust parameters to account for accommodation o2vBY]Tj  
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    '************************************************************************* k;W`6:Kjp  
    'Aqueous thickness (Position of Lens) S#wy+*  
    '************************************************************************* QFYO_$1Y)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) *%,{<C,Y  
    GetCustomElement eID, entity %=GF  
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    parID = FindFullName( "Geometry.Arizona Eye" ) jJOs`'~Q\  
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    ' Delete any shift(s) in z
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    count = 0 M7JQw/,xs  
    While GetOperationCount(eID)>count dqu+-43I|  
        GetOperation eID, count, op 4Cn% h)w  
        If op.Type="ShiftZ" Then cEc_S42Z  
            DeleteOperation eID,count K,'v{wSr  
            count=count-1 quGvq"Y>  
        End If GL<u#[  
        count=count+1 zXRq) ;s  
    Wend CW)JS3}W"  
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    'Set new shift in rrL gBeQa  
    op.Type = "ShiftZ" Tb@r@j:V  
    op.val1 = taq ^}PG*h|  
    op.parent = parID Jv+N/+M47  
    AddOperation eID, op 1q7Y,whp  
    Print "Set aqueous humor thickness = " & taq-0.55 o&Vti"fpC  
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    '************************************************************************* |0Y: /uL#)  
    'Radius and conic constant of anterior lens UG5AFZ\  
    '************************************************************************* {#o0vWS>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >&g^ `  
    GetConic eID, entity, curv, conic m2|%AD  
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    SetConic eID, entity, 1/Rant, CCant k/;%{@G)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Vw>AD<Rl  
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    '************************************************************************* lH#C:n  
    'Radius and conic constant of posterior lens
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    '************************************************************************* uihU)]+@t/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %/:0x:ns  
    GetConic eID, entity, curv, conic f2f2&|7  
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    SetConic eID, entity, 1/Rpost, CCpost Wp2$L-T&$  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >=+:lD  

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    '************************************************************************* c`E0sgp  
    'Lens thickness (Position of posterior lens surface) |@*3 nb8  
    '************************************************************************* rQb=/@-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) t|jp]Vp  
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    ' Delete any z-shift(s) yRyUOTK  
    count = 0 FBP'AL|  
    While GetOperationCount(eID)>count km,I75o.  
        GetOperation eID, count, op p`I[3/$3  
        If op.Type="ShiftZ" Then )kpNg:2p  
            DeleteOperation eID,count C4H$w:bVk  
            count=count-1 f]C`]qg  
        End If qOs'Ljx6l  
        count=count+1 "pInb5F  
    Wend h; "pAE  
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    'Set new z-shift + \jn$>E  
    op.Type = "ShiftZ" \~BYY|UB;W  
    op.val1 = tlens 7RZ HU+  
    op.parent = parID pAtt=R,Ht  
    AddOperation eID, op 3o^~6A  
    Print "Set lens thickness = " & tlens B"Hz)-MW  
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    '************************************************************************* F6Ne?[b  
    'Lens index of refraction |QHIB?C?`  
    '************************************************************************* UY}EW`$#m  
    eID = FindMaterial( "Lens" ) s^R$u"pFs  
    GetModelMaterial eID, mat m8Y>4:Nw  
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    mat.Nd = nlens 7I=vgT1F  
    SetModelMaterial eID, mat ^9zlxs`<d  
    Print "Set lens index of refraction = " & nlens j^)=<+Q;=  
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    '************************************************************************* #DA,*  
    'Pupil diameter Ov~vK\  
    '************************************************************************* 7:'5q]9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) S|  
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    'Adjust pupil diameter (trimming volume inner hole) u$rSM0CJ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" U7xKu75G1  
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    ' Adjust pupil location to just in front of the lens [5;_XMj%  
    parID = FindFullName( "Geometry.Arizona Eye" ) Aj{G=AT  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ?Ll1B3f  
    count = 0 '>:%n  
    While GetOperationCount(eID)>count `1i\8s&O6@  
        GetOperation eID, count, op ;-quK%VO!  
        If op.Type="ShiftZ" Then #:E^($v  
            DeleteOperation eID,count 'byao03  
            count=count-1 ,Yu2K`  
        End If Q;k D Jo  
        count=count+1 (vPE?^}b  
    Wend 7?]wAH89  
    op.Type = "ShiftZ" 4bq+(CI6  
    op.val1 = taq-0.01 xA>3]<O  
    op.parent = parID {`+:!X  
    AddOperation eID, op q22@ZRw  
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    Print "Set pupil diameter = " & pupilDiam IXU~&5&J  
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    'Update AZ Eye subassembly Description c|F26$rv  
    eID = FindFullName( "Geometry.Arizona Eye" ) |]'gd)%S\  
    GetEntity eID, entity 3^`.bm4 ^  
    entity.Description = "Accommodation = " & A & "D" e/Y&d9` I  
    SetEntity eID, entity F> b<t.yV  
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    Update mMtva}=*  
    Print "DONE!" :1gcLsF  
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End Sub ',s{N9  
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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： qz }PTx  
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Accommodation = 4 Diopters ]8|peo{  
Pupil Diameter = 4 mm F>ps&h  
Set aqueous humor thickness = 2.81 :9W)CwZ)V  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &t@|/~%[  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 6BObV/S Jg  
Set lens thickness = 3.927 ~-BIUZ;  
Set lens index of refraction = 1.42672 X({R+  
Set pupil diameter = 4 Dw&_6\F@  
DONE! *?!A  
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