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infotek 2023-04-27 08:29

Arizona眼睛模型

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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。 dqwCyYC  
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模型 nXHU|5.I  
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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。 _  dFZR  
Table 1. AZ眼睛模型的定义
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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. U~!yGjF  
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光源 "fWAp*nI3t  
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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。 i,HafY  
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图1. 光源和提示信息使用
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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。 OO)m{5r,{  
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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。 Glz)-hjJ:n  
图2. 字母F光源的设定方法光 3Z?"M  
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图3. 字母F在视网膜上位置点列图
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视网膜的散射 ?^TjG)e7  
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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。 .&Uu w  
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图4. 视网膜朗伯散射设定
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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。 ;dXQB>Za  
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图5. 视网膜重点采样规格设定
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脚本 AvW2)+6G  
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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: 0Q@ &z  
图6. 用户对话框的创建与编辑
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图7. 用户对话框编辑器
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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。 3+6s}u)  
余下的脚本计算与屈光度有关的所有参数。 d*7nz=0&$  
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分析 5<o8prt B  
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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。 F,2)Udim  
图7. 字母F在视网膜上颜色分析
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脚本代码 21Z}Zj  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. S1 22. I  
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Dim entity As T_ENTITY YGy.39@31  
Dim op As T_OPERATION )4oTA@wR  
Dim mat As T_MODELMATERIAL wLeP;u1  
Dim A As Double %E q} H  
Dim pupilDiam As Double mjdZ^  
Dim eID As Long (rfU=E  
Dim parID As Long |2mm@):  
Dim count As Integer ><o dBM-  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double UEeD Nl$^u  
Dim tlens As Double, nlens As Double YXCfP~i  
Dim curv As Double, conic As Double %{$iN|%J%$  
Dim ok As Long Wi3:;`>G<p  
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Sub Main Ps3wg=ni[  
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    '用户输入对话框 wfH#E2+pk  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w i,}sEoM  
        TextBox 220,21,40,21,.TextBox1 'default: 0 3DH} YAUU  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 >3R)&N  
        OKButton 40,91,90,21 }?zy*yL  
        CancelButton 190,91,90,21 E"p;  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 feOX]g#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 }E626d}uA  
    End Dialog =b{wzx}e  
    Dim dlg As UserDialog "F nH>g-  
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    ok = Dialog (dlg) Gh3b*O_,  
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    If ok=0 Then    'cancel button was pressed %3B0s?,I  
        Print "Execution cancelled." y7ng/vqM7  
        End .W[ 9G\  
    End If }GV5':W@WG  
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    'Assign accommodation and pupil diameter & use defaults if field left empty V/C":!;  
    If dlg.TextBox1 = "" Then QMUmPx&  
        A = 0           'Default accommodation Z_iVOctP  
    Else }=.:bwX5  
        A = CDbl(dlg.TextBox1) zo!e<>o  
    End If g\;&Z  
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    If dlg.TextBox2 = "" Then 1ztL._Td  
        pupilDiam = 4   'Default pupil diameter ''Lf6S`4X~  
    Else 2$G,pT1J  
        pupilDiam = CDbl(dlg.TextBox2) b#XY.+ *0  
    End If vUtA@  
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    Print " " HB+{vuN*L  
    Print "Accommodation = " & A & " Diopters" 2`2S94'  
    Print "Pupil Diameter = " & pupilDiam & " mm" ,OGXH2!h  
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    ' Calculate new parameters with accommodation /*v} .fH%  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness VZ69s{/.B  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens X:3W9`s )*  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens H_ecb;|mP  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens m]XG7:}V0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Dht,!LVb;  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Y/|wOm;|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ONc-jU^  
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    'Adjust parameters to account for accommodation i'6>_,\(  
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    '************************************************************************* &_1Ivaen6  
    'Aqueous thickness (Position of Lens) xzI?'?duC  
    '************************************************************************* L("zS%qr  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) b~5Q|3P9  
    GetCustomElement eID, entity cq?&edjP  
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    parID = FindFullName( "Geometry.Arizona Eye" ) R=/^5DZ}  
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    ' Delete any shift(s) in z *{#l0My  
    count = 0 8D)I~0\  
    While GetOperationCount(eID)>count <aScA`\B#  
        GetOperation eID, count, op S*0P[R  
        If op.Type="ShiftZ" Then BZdryk:S  
            DeleteOperation eID,count z]\CI:  
            count=count-1 Q,AM<\S  
        End If M~o\K'  
        count=count+1 7y/Pch  
    Wend -nsI5\]  
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    'Set new shift in 5VLJ:I?0O  
    op.Type = "ShiftZ" r6x"D3  
    op.val1 = taq '9w.~@7  
    op.parent = parID .3Ag6YI0N  
    AddOperation eID, op 3P&K<M#\  
    Print "Set aqueous humor thickness = " & taq-0.55 4/Wqeq,E8  
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    '************************************************************************* Fh3>y2 `/  
    'Radius and conic constant of anterior lens |Nfi y  
    '************************************************************************* xGU~FU  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .dr-I7&!  
    GetConic eID, entity, curv, conic r\x"nS  
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    SetConic eID, entity, 1/Rant, CCant AlH\IP  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Af V a[{E  
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    '************************************************************************* cc %m0p  
    'Radius and conic constant of posterior lens \A ?B{*  
    '************************************************************************* = ;!$Qw4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }qk8^W{  
    GetConic eID, entity, curv, conic Q^_*&},V  
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    SetConic eID, entity, 1/Rpost, CCpost 8=!BtMd"  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #K[UqJ+x  
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    '************************************************************************* L+rMBa  
    'Lens thickness (Position of posterior lens surface) l^ Q-KUI  
    '************************************************************************* GIyb0XjTw  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) qVpV ZH!  
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    ' Delete any z-shift(s) 7v8V0Gp  
    count = 0 ]3%( '8/  
    While GetOperationCount(eID)>count 5R?[My  
        GetOperation eID, count, op 5,;>b^gXY`  
        If op.Type="ShiftZ" Then 04u^Q  
            DeleteOperation eID,count Vo@gxC,  
            count=count-1 i 1{Lx)  
        End If LMF@-j%  
        count=count+1 oXQzCjX_   
    Wend L93PDp4v  
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    'Set new z-shift sX :)g>b   
    op.Type = "ShiftZ" Xqz\%&G  
    op.val1 = tlens 9;L5#/E  
    op.parent = parID nNN~Z'bG  
    AddOperation eID, op 19r4J(pV  
    Print "Set lens thickness = " & tlens HVq02 Z  
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    '************************************************************************* IO*}N"  
    'Lens index of refraction wOlnDQs  
    '************************************************************************* \$iU#Z  
    eID = FindMaterial( "Lens" ) +J`HI1  
    GetModelMaterial eID, mat d"P\ =`+  
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    mat.Nd = nlens X q"_^  
    SetModelMaterial eID, mat |\ZsoA  
    Print "Set lens index of refraction = " & nlens !bPsJbIo>  
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    '************************************************************************* JFJ_ PphvD  
    'Pupil diameter Gl4(-e'b  
    '************************************************************************* 5q.d$K |  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 5)T=^"IHXi  
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    'Adjust pupil diameter (trimming volume inner hole) BotGPk><c  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :3uCW1  
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    ' Adjust pupil location to just in front of the lens e]1&f.K  
    parID = FindFullName( "Geometry.Arizona Eye" ) l[MP|m#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -=tf)  
    count = 0 D.Q9fa&P  
    While GetOperationCount(eID)>count xD:t$~  
        GetOperation eID, count, op <~%e{F:[#  
        If op.Type="ShiftZ" Then AM[#AZv  
            DeleteOperation eID,count k^JV37;bl  
            count=count-1 \z~wm&  
        End If MHuQGc"e+4  
        count=count+1 d(=*@epjR  
    Wend Wk0"U V  
    op.Type = "ShiftZ" ja<!_^h=At  
    op.val1 = taq-0.01 ![>j`i  
    op.parent = parID v$P<:M M  
    AddOperation eID, op H}nPaw]G  
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    Print "Set pupil diameter = " & pupilDiam xT]|78h$   
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    'Update AZ Eye subassembly Description c,v?2*<  
    eID = FindFullName( "Geometry.Arizona Eye" ) r Ljb'\<*  
    GetEntity eID, entity rryC^Vma  
    entity.Description = "Accommodation = " & A & "D" 3eg)O34  
    SetEntity eID, entity Oi?+Z:lak  
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    Update |5;:3K+  
    Print "DONE!" GY%2EM(  
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End Sub ~"Q24I  
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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: Wv4x^nJ  
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Accommodation = 4 Diopters g5\EVcHkz  
Pupil Diameter = 4 mm =!~6RwwwY  
Set aqueous humor thickness = 2.81 5C G ,l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 U#X6KRZ~g  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 *!wBn  
Set lens thickness = 3.927 >$g+Gx\v4  
Set lens index of refraction = 1.42672 }(yX$ 3?`  
Set pupil diameter = 4 Q!T+Jc9N  
DONE!
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