[技术]Arizona眼睛模型 [复制链接]

简介 @zL)R b%P$  
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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。 Sf);j0G,D  
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模型 6vbWe@#U/  
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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。 zlF*F8>m  
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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. r(y1^S9!8  
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光源 g]EDL<b  
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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。 )xX(Et6+`  
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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。 7}OzTup  
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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。 >!s=f  
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视网膜的散射 h#'(i<5v  
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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。 )67_yHW  
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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。 .j:.?v  
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脚本 DeE-M"  
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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： `2c>M\c4U  
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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。 AVVL]9b_2  
余下的脚本计算与屈光度有关的所有参数。 [hTGWT3  
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分析 vZj^&/F$=g  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 2  *IF  
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脚本代码 sUN>uroi !  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. xnmIo? hC  
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Dim entity As T_ENTITY =A={Dpv[>  
Dim op As T_OPERATION [RCUP.  
Dim mat As T_MODELMATERIAL IG0$OtG  
Dim A As Double drP2%u  
Dim pupilDiam As Double &I:[ 'l!  
Dim eID As Long [Av#Z)R  
Dim parID As Long %[\: 8  
Dim count As Integer kF.!U/C  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^0"NcOzzxl  
Dim tlens As Double, nlens As Double JW9^C  
Dim curv As Double, conic As Double :b
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Dim ok As Long .NcoST9a  
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Sub Main 0l3v>ty  
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    '用户输入对话框 : Q X~bq  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Nv "R'Pps  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ATCFdtNc  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 @%&;V(  
        OKButton 40,91,90,21 ";}Lf1M9  
        CancelButton 190,91,90,21 GdG1e%y]z  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w]GoeIg({  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (rO_Vfaa  
    End Dialog 1}#v<b$  
    Dim dlg As UserDialog Be}e%Rk  
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    ok = Dialog (dlg) >JwdVy^  
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    If ok=0 Then    'cancel button was pressed <HM\ZDo@P  
        Print "Execution cancelled." &?>h#H222  
        End {PgB
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    End If (A O]f fBU  
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    'Assign accommodation and pupil diameter & use defaults if field left empty |0FRKD]  
    If dlg.TextBox1 = "" Then }HtP8F8!x  
        A = 0           'Default accommodation DLcfOOn1I  
    Else ,!t1( H  
        A = CDbl(dlg.TextBox1) -cs 4<  
    End If w]]`/`  
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    If dlg.TextBox2 = "" Then Ol H{!  
        pupilDiam = 4   'Default pupil diameter NCYN .@J  
    Else yLCqlK  
        pupilDiam = CDbl(dlg.TextBox2) I7TdBe-  
    End If {6Lkh  
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    Print " " 
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    Print "Accommodation = " & A & " Diopters" 11}sRu/  
    Print "Pupil Diameter = " & pupilDiam & " mm" !Sr^4R+Z  
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    ' Calculate new parameters with accommodation Je_Hj9#M\d  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 75i M_e\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !P/ ]o  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens S+H#^WS
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6-va;G9Fc  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens fZ$
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    tlens = 3.767 + 0.04*A                  'Lens thickness ;wND?:  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction q# gZ\V$I  
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    'Adjust parameters to account for accommodation Pd!;z=I  
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    '************************************************************************* u_
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    'Aqueous thickness (Position of Lens) fHvQ9*T  
    '************************************************************************* UT[nzbG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) +*,rOK`C  
    GetCustomElement eID, entity !+& NG&1  
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    parID = FindFullName( "Geometry.Arizona Eye" ) H^xrFXg~z  
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    ' Delete any shift(s) in z G&:[G>iSm^  
    count = 0 SdC505m0*  
    While GetOperationCount(eID)>count 'KpCPOhfR  
        GetOperation eID, count, op * 2[&26D  
        If op.Type="ShiftZ" Then xou7j  
            DeleteOperation eID,count W093rNF~  
            count=count-1 1~8F&  
        End If /k<*!H]KSg  
        count=count+1 T[xGF/
  
    Wend 8B;`9?CI  
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    'Set new shift in toPA@V  
    op.Type = "ShiftZ" XOa<R  
    op.val1 = taq Y?%MPaN:  
    op.parent = parID /' L20aN2  
    AddOperation eID, op PN/2EmwtC  
    Print "Set aqueous humor thickness = " & taq-0.55 qTC`[l  
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    '************************************************************************* g*t.g@B<2  
    'Radius and conic constant of anterior lens Dn$zwksSs  
    '************************************************************************* %8`zaa  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ( f8g}2  
    GetConic eID, entity, curv, conic .Y'kDuUu  
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    SetConic eID, entity, 1/Rant, CCant J&^r}6D  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 1
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    '************************************************************************* ]@l~z0^|[_  
    'Radius and conic constant of posterior lens SZg+5MD;X  
    '************************************************************************* S
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) GK/a^[f+'l  
    GetConic eID, entity, curv, conic /7@@CG6b  
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    SetConic eID, entity, 1/Rpost, CCpost M<
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost "
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    '************************************************************************* HG@!J>YaD  
    'Lens thickness (Position of posterior lens surface) vb: '%^v  
    '************************************************************************* IK{0Y#c  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) HT A-L>Cee  
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    ' Delete any z-shift(s) Y8.0R-:ZAN  
    count = 0 A42At]  
    While GetOperationCount(eID)>count r-]R4#z>
  
        GetOperation eID, count, op dge58A)Q  
        If op.Type="ShiftZ" Then Ul@ZCv+  
            DeleteOperation eID,count 9foQ0#R  
            count=count-1 'BAe>r_Pn  
        End If 4TG|  
        count=count+1 ;}f%bE  
    Wend /qI80KVnN  
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    'Set new z-shift G2a fHL<  
    op.Type = "ShiftZ" @pytHN8( $  
    op.val1 = tlens 7bsW7;C  
    op.parent = parID H=X>o.iVqi  
    AddOperation eID, op =Z#tZ{"  
    Print "Set lens thickness = " & tlens Tj0eW(<!s  
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    '************************************************************************* <py~(q  
    'Lens index of refraction $ }B"u;:SU  
    '************************************************************************* =AgY8cF!sl  
    eID = FindMaterial( "Lens" ) 68I4MZK>4  
    GetModelMaterial eID, mat @GnsW;$*~.  
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    mat.Nd = nlens wk9tJ#}  
    SetModelMaterial eID, mat ?N11R?8  
    Print "Set lens index of refraction = " & nlens lS?f?n^  
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    '************************************************************************* ::TUSz2/2  
    'Pupil diameter 7Fy^K;V"  
    '************************************************************************* Tj:+:B(HB  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) J\;~(: ~  
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    'Adjust pupil diameter (trimming volume inner hole) =[1W.Zt  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 2"__jp:(  
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    ' Adjust pupil location to just in front of the lens 7/*;rT  
    parID = FindFullName( "Geometry.Arizona Eye" ) E&&80[tN]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ;"Ot\:0  
    count = 0 ,R^Pk6m>  
    While GetOperationCount(eID)>count U4
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        GetOperation eID, count, op Do_L  
        If op.Type="ShiftZ" Then //LXbP3/  
            DeleteOperation eID,count "9WP^[  
            count=count-1 { @-Q1  
        End If Zfb:>J@h6  
        count=count+1 YRYrR|I  
    Wend [dzb{M6_  
    op.Type = "ShiftZ" |(P>'fat-p  
    op.val1 = taq-0.01 ]iz5V
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    op.parent = parID (|6qN  
    AddOperation eID, op jzPC9  
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    Print "Set pupil diameter = " & pupilDiam H/, tE0ZV  
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    'Update AZ Eye subassembly Description /(}V!0\?  
    eID = FindFullName( "Geometry.Arizona Eye" ) TTOd0a  
    GetEntity eID, entity U| N`X54  
    entity.Description = "Accommodation = " & A & "D" 6=')*_~/  
    SetEntity eID, entity 9*2hBNp+  
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    Update 6iC}%eU  
    Print "DONE!" "M:arP5f  
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End Sub `8y &  
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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： N{q'wep  
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Accommodation = 4 Diopters lN1zfM  
Pupil Diameter = 4 mm 72{kig9c  
Set aqueous humor thickness = 2.81 D8dTw{C  
Set anterior lens radius = 10.4 and conic constant = -2.375869 VJ$C)0xQA  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 aIfog+Lp  
Set lens thickness = 3.927 {:oZ&y)Ac  
Set lens index of refraction = 1.42672 M,#t7~t  
Set pupil diameter = 4 ,\qo  
DONE! S"eKiS,z