[技术]Arizona眼睛模型 [复制链接]

简介 [9mL $;M W  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 cPn+<M#  
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模型 PoShQR<  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。  >0Ev#cX4  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. *~z#.63oZ  
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光源 2GWDEgI1o  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 {SG>'KXZ  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 jN/C'\QL  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ~fzuwz  
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视网膜的散射 u/AT-er;  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 m-1?\bs  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 V`fL%du,3  
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脚本 zTCP)x  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 3;$bS<>  
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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。 8?jxDW a  
余下的脚本计算与屈光度有关的所有参数。 p/|(,)'+jx  
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分析 x3p9GAd#  
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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。 EI`vVI  
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脚本代码 mf*Nr0L;J  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ySruAkw%  
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Dim entity As T_ENTITY l]vohLz 3!  
Dim op As T_OPERATION %yw=[]Vjze  
Dim mat As T_MODELMATERIAL ;?im(9h"v!  
Dim A As Double pv$tTWk  
Dim pupilDiam As Double 1*R_"#  
Dim eID As Long E\e]K !  
Dim parID As Long >_#)3K1y8  
Dim count As Integer +rQg7a}  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double u 2lXd'  
Dim tlens As Double, nlens As Double D=w9cKa  
Dim curv As Double, conic As Double SL*DK.  
Dim ok As Long <;KRj85"j  
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Sub Main lS{4dvr?w  
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    '用户输入对话框 cHn;}l!I  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 S1C^+Sla]  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ~x+Ykq0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 T#e4":A&x  
        OKButton 40,91,90,21 B/u*<k4  
        CancelButton 190,91,90,21 7ti<  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ]S]"`;Wh  
        TextBox 220,49,40,21,.TextBox2 'default: 4 a#R%8)  
    End Dialog XZBj=2~-3  
    Dim dlg As UserDialog 9L
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    ok = Dialog (dlg) ho|8U  
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    If ok=0 Then    'cancel button was pressed qnTi_c  
        Print "Execution cancelled." tBTJmih"  
        End )6C`&Mj  
    End If BGA%"b  
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    'Assign accommodation and pupil diameter & use defaults if field left empty vu>YH)N_h  
    If dlg.TextBox1 = "" Then v+7*R)/  
        A = 0           'Default accommodation >~>{;Wq(p+  
    Else 7n<#y;wo  
        A = CDbl(dlg.TextBox1) xrX?ZJ  
    End If /9TL&_A-T  
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    If dlg.TextBox2 = "" Then FB.!`%{  
        pupilDiam = 4   'Default pupil diameter ${CYDD"mdy  
    Else ){jqfkL  
        pupilDiam = CDbl(dlg.TextBox2) B{N=0 cSi  
    End If kYTOldfY2  
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    Print " " Flne=ij6g  
    Print "Accommodation = " & A & " Diopters" ->Q`'@'|P  
    Print "Pupil Diameter = " & pupilDiam & " mm" t0I>5#*WU  
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    ' Calculate new parameters with accommodation a]{uZGn@i  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness VEr 6uvB  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens hQP6@KIe)  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens QQSH +  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens PGMv(}%;  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens lJ("6aT?  
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    tlens = 3.767 + 0.04*A                  'Lens thickness sio)_8tp  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction % i%ew4  
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    'Adjust parameters to account for accommodation v hR twi  
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    '************************************************************************* JO}#f+w}  
    'Aqueous thickness (Position of Lens) ?'TA!MR  
    '************************************************************************* XX*'N+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <[/PyNYK  
    GetCustomElement eID, entity HDa~7wE  
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    parID = FindFullName( "Geometry.Arizona Eye" ) :QxL 9&"  
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    ' Delete any shift(s) in z 0zlM.rjEZ  
    count = 0 u'#`yTB6b  
    While GetOperationCount(eID)>count **Qe`}E:  
        GetOperation eID, count, op xI-=tib  
        If op.Type="ShiftZ" Then DN4fP-m-  
            DeleteOperation eID,count =W;
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            count=count-1 7=$+k]U8  
        End If v; je
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        count=count+1 L`<T'3G  
    Wend
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    'Set new shift in
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    op.Type = "ShiftZ" aW52.X z%8  
    op.val1 = taq 1}i&HIr!b  
    op.parent = parID ~uP r]#  
    AddOperation eID, op Y\+(rC27  
    Print "Set aqueous humor thickness = " & taq-0.55 -d$8WSI8  
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    '************************************************************************* ?|%\<h@;  
    'Radius and conic constant of anterior lens <`oCz Q1  
    '************************************************************************* D[?
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 'd|Q4RE+W  
    GetConic eID, entity, curv, conic }:,o Y<  
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    SetConic eID, entity, 1/Rant, CCant v9j4|
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "N?%mCPI  
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    '************************************************************************* VEFwqB1l  
    'Radius and conic constant of posterior lens aF;]7i@  
    '************************************************************************* `<l/GwtAJ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) icKg7-$N  
    GetConic eID, entity, curv, conic T% /xti5$!  
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    SetConic eID, entity, 1/Rpost, CCpost &cv@Kihq(  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost iBGS
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    '************************************************************************* u7<qaOzs?  
    'Lens thickness (Position of posterior lens surface) Q:-%3)g<<  
    '************************************************************************* xA[Wb'  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yV 9]_k  
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    ' Delete any z-shift(s) 7yqSt)/U  
    count = 0 AF9[2AH=Y  
    While GetOperationCount(eID)>count 4~MJ4:  
        GetOperation eID, count, op \-$bo=s.  
        If op.Type="ShiftZ" Then imJ[:E  
            DeleteOperation eID,count 7dM6;`V^  
            count=count-1 /ZIJ<#o[
 
        End If <WQ<<s@#pb  
        count=count+1 #f|NM7  
    Wend IF36K^K  
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    'Set new z-shift bo~{<UT  
    op.Type = "ShiftZ" CN8@c!mB  
    op.val1 = tlens *MnG-\{j  
    op.parent = parID ]RJb;  
    AddOperation eID, op (T%F!2i([U  
    Print "Set lens thickness = " & tlens +qh< Fj>  
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    '************************************************************************* niBjq#bJi  
    'Lens index of refraction =,>TpE  
    '************************************************************************* zDvP7hl  
    eID = FindMaterial( "Lens" ) 7 BnenHD  
    GetModelMaterial eID, mat [6&CloY3  
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    mat.Nd = nlens sw=JUfAhy  
    SetModelMaterial eID, mat Z}'F"}QI  
    Print "Set lens index of refraction = " & nlens R$T[%AGZ.  
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    '************************************************************************* @LWxz  
    'Pupil diameter [U3D`V$xD  
    '************************************************************************* c`$`0}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XRz%KVysp  
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    'Adjust pupil diameter (trimming volume inner hole) wEHAkc
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" *Sz{DE1U  
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    ' Adjust pupil location to just in front of the lens xT=kxyu  
    parID = FindFullName( "Geometry.Arizona Eye" ) )v!lPpe8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) mSk :7ozZ  
    count = 0 IioE<wS)  
    While GetOperationCount(eID)>count 'wB H
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        GetOperation eID, count, op <igx[2X  
        If op.Type="ShiftZ" Then a7v[l04  
            DeleteOperation eID,count AHMV@o`V  
            count=count-1 -'H+lrmv  
        End If ?D~SHcBaN  
        count=count+1 ,@'){V
 
    Wend -t~B@%  
    op.Type = "ShiftZ" i9EMi_%  
    op.val1 = taq-0.01 `6BS-AVO7  
    op.parent = parID "$E!_  
    AddOperation eID, op ev: !,}]w  
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    Print "Set pupil diameter = " & pupilDiam l5y#i7q  
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    'Update AZ Eye subassembly Description n;k97>m${x  
    eID = FindFullName( "Geometry.Arizona Eye" ) "<.  
    GetEntity eID, entity I>8@=V~  
    entity.Description = "Accommodation = " & A & "D" \'LCC-  
    SetEntity eID, entity t0V_ c'm  
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    Update NKUI! [  
    Print "DONE!" 5KH'|z  
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End Sub +/>YH-P=  
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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： JbC\l  
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Accommodation = 4 Diopters -SY:qG3?  
Pupil Diameter = 4 mm 6P*)rye  
Set aqueous humor thickness = 2.81 B]KLn?zt5  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ^Lfn3.M  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 9hs{uxwuEE  
Set lens thickness = 3.927 W];6u  
Set lens index of refraction = 1.42672 *ckrn>E{h  
Set pupil diameter = 4 FTYLMQ i  
DONE!  wpdEI(