[分享]Arizona眼睛模型 [复制链接]

简介 &[}bHX/  
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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。 5\V>Sj(  
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模型 +dcBh Dq  
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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。 [84ss;.$  
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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. <<
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光源 8hZ+[E}  
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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。 LWuciHfd+  
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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。 A'HFpsa  
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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。 OZ3iH%  
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视网膜的散射 I !=ew |  
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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。 iqm]sC`  
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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。 ul$k xc=N  
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脚本 n@xC?D:t*  
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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： A[:0?Ez=  
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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。 p5`iq~e9
 
余下的脚本计算与屈光度有关的所有参数。 @lpo$lN0R  
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分析 C{(&Yy"  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 x7\b-EC  
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脚本代码 N~H!6N W  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =rz7x  
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Dim entity As T_ENTITY QS7<7+  
Dim op As T_OPERATION <O:}dXqZ  
Dim mat As T_MODELMATERIAL 1eHU!{<fqm  
Dim A As Double )Fk*'6  
Dim pupilDiam As Double &:Q^j:  
Dim eID As Long y5/frJ  
Dim parID As Long AXnRAW  
Dim count As Integer 6Qtyv  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double O2xbHn4  
Dim tlens As Double, nlens As Double `1Ui  
Dim curv As Double, conic As Double NM FgCL  
Dim ok As Long dfy]w4ETB  
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Sub Main 'q>2WP|UY9  
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    '用户输入对话框 X~UrAG}_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 XLHi  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }2xgm9j<  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 df\^uyD;  
        OKButton 40,91,90,21 W%ml/ 4  
        CancelButton 190,91,90,21 UHyGW$B  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V.w L  
        TextBox 220,49,40,21,.TextBox2 'default: 4 CFK{.{d]B  
    End Dialog &{4KymB:  
    Dim dlg As UserDialog Cb4.N8  
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    ok = Dialog (dlg) <C1w?d$9I  
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    If ok=0 Then    'cancel button was pressed cr,fyAvX  
        Print "Execution cancelled." J497 >w[  
        End B:)PUBb  
    End If kz0pX-@b  
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    'Assign accommodation and pupil diameter & use defaults if field left empty H0(.p'eN  
    If dlg.TextBox1 = "" Then hy&WG&qf  
        A = 0           'Default accommodation ?,}:)oA_  
    Else KWS\iu  
        A = CDbl(dlg.TextBox1) ]hMs:$}  
    End If >O]u4G!  
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    If dlg.TextBox2 = "" Then mX2X.ww(4  
        pupilDiam = 4   'Default pupil diameter Vp$<@Y  
    Else }
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        pupilDiam = CDbl(dlg.TextBox2) :(Ak:  
    End If r\A|fiL  
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    Print " " n\GN}?4  
    Print "Accommodation = " & A & " Diopters" ^*G UcQ$  
    Print "Pupil Diameter = " & pupilDiam & " mm" ?`= <*{_o  
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    ' Calculate new parameters with accommodation /&N\#;kK?b  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ddh  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,UYe OM2Ao  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /z m+  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &t U&Z
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens &E]<KbVx  
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    tlens = 3.767 + 0.04*A                  'Lens thickness fBb:J+  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction yxtfyf|9 '  
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    'Adjust parameters to account for accommodation e%km}m
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    '************************************************************************* *5u3d`bW  
    'Aqueous thickness (Position of Lens) }#q0K  
    '************************************************************************* ')T*cLQ><  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) vL#I+_ 2  
    GetCustomElement eID, entity 1! j^  
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    parID = FindFullName( "Geometry.Arizona Eye" ) lDL(,ZZS`  
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    ' Delete any shift(s) in z J8B0H1  
    count = 0 5g`J}@"k  
    While GetOperationCount(eID)>count qgs:9V xF  
        GetOperation eID, count, op R2==<"gq  
        If op.Type="ShiftZ" Then Jt:)(&-t  
            DeleteOperation eID,count 8%`h:f
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            count=count-1 z5_jx&^Z  
        End If BXNC(^  
        count=count+1 TyvUdU  
    Wend \qDY0hIv t  
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    'Set new shift in th{ie2$  
    op.Type = "ShiftZ" nf-6[dg  
    op.val1 = taq )8taMC:H^  
    op.parent = parID 9e7):ZupO  
    AddOperation eID, op ewdcAF5  
    Print "Set aqueous humor thickness = " & taq-0.55 BM9:|}\J65  
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    '************************************************************************* sDvy(5  
    'Radius and conic constant of anterior lens 2J Wp5  
    '************************************************************************* iOk`_LG#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /g1;`F(MS/  
    GetConic eID, entity, curv, conic f[*g8p  
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    SetConic eID, entity, 1/Rant, CCant \'X-><1  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9 ge'Mo  
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    '************************************************************************* a# Uk:O!  
    'Radius and conic constant of posterior lens LWxP}? =  
    '************************************************************************* ^U^K\rq 1u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @7t*X-P.;-  
    GetConic eID, entity, curv, conic qP+%ui5xR  
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    SetConic eID, entity, 1/Rpost, CCpost z
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #4AqWyp#f  
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    '************************************************************************* _QtW)\)5\  
    'Lens thickness (Position of posterior lens surface) ,D.@6bJW  
    '************************************************************************* 3W[Ps?G  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) X;{U?`b-  
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    ' Delete any z-shift(s) #UnGU,J  
    count = 0 :2lM7|@/  
    While GetOperationCount(eID)>count QvzE:]pyi  
        GetOperation eID, count, op {\VmNnw  
        If op.Type="ShiftZ" Then 9S?b &]  
            DeleteOperation eID,count i7?OZh*f  
            count=count-1 U9Lo0K  
        End If 0Rn`63#  
        count=count+1 m;<5QK8f  
    Wend 9Z:pss@  
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    'Set new z-shift s{fL~}Yz  
    op.Type = "ShiftZ" Zf?jnDA  
    op.val1 = tlens rD>q/,X=\  
    op.parent = parID (DM8PtZg  
    AddOperation eID, op `)H| &!wT  
    Print "Set lens thickness = " & tlens ?YM0VB,y  
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    '************************************************************************* S3dcE"hg  
    'Lens index of refraction ,f .#-  
    '************************************************************************* LfsOGC  
    eID = FindMaterial( "Lens" ) CasFj9,  
    GetModelMaterial eID, mat 8yGo\\=T  
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    mat.Nd = nlens } ejc  
    SetModelMaterial eID, mat mW."lzIl  
    Print "Set lens index of refraction = " & nlens V/8yW3]Xy  
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    '************************************************************************* *%dWNvN4X  
    'Pupil diameter g1q%b%8T  
    '************************************************************************* n{E+r  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) -:V2Dsr6;  
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    'Adjust pupil diameter (trimming volume inner hole) Lw{'mtm  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" WoWBZ;+U  
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    ' Adjust pupil location to just in front of the lens WtbOm  
    parID = FindFullName( "Geometry.Arizona Eye" )  ePI)~  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) j"<F?k@`Q  
    count = 0 oSoU9_W  
    While GetOperationCount(eID)>count 28o!>*  
        GetOperation eID, count, op _MGhG{p7t  
        If op.Type="ShiftZ" Then x;/%`gKn8  
            DeleteOperation eID,count Oc^bbC  
            count=count-1 bhT:MW!  
        End If !%YV0O0  
        count=count+1 H{*R(S<I  
    Wend >c@1UEwkm  
    op.Type = "ShiftZ" p:qj.ukw  
    op.val1 = taq-0.01 9,Ug  
    op.parent = parID N:rnH:g+:  
    AddOperation eID, op PF-"^2&_  
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    Print "Set pupil diameter = " & pupilDiam B ? D|B  
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    'Update AZ Eye subassembly Description 2d-C}&}L\  
    eID = FindFullName( "Geometry.Arizona Eye" ) T8J[B( )L  
    GetEntity eID, entity W_G'wU
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    entity.Description = "Accommodation = " & A & "D" GwZ(3  
    SetEntity eID, entity mdIa`OZr  
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    Update jiAN8t*P  
    Print "DONE!" <7sGA{  
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End Sub v"smmQZik  
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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： "4qv yVOE  
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Accommodation = 4 Diopters R>. %0%iq  
Pupil Diameter = 4 mm k-\RdX)E  
Set aqueous humor thickness = 2.81 g"L$}#iTsl  
Set anterior lens radius = 10.4 and conic constant = -2.375869 -AxO1 qO  
Set posterior lens radius = -4.424557 and conic constant = -3.081019
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Set lens thickness = 3.927 = eDi8A*~  
Set lens index of refraction = 1.42672 ~uz4  
Set pupil diameter = 4 Sj<WiQ%<  
DONE! B@2VI 1%  
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