[技术]Arizona眼睛模型 [复制链接]

简介 N0U/u'J!g  
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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。 B~Q-V&@o  
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模型 XX;4A  
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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。 h$>F}n j  
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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. I-7LT?r  
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光源 ~,'{\jDrS  
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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。 8Of
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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。 s>rR\`  
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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。 lG*Rw-?a  
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视网膜的散射 *P()&}JK  
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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。 XGlt^<`  
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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。 *2X6;~  
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脚本 61\u{@
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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： #GsOE#*>T  
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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。 Q&m85'r5X  
余下的脚本计算与屈光度有关的所有参数。 Re%[t9F&  
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分析 [f6uwp  
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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。 ,OZ  
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脚本代码 ROO*/OOd  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. {f*Y}/@  
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Dim entity As T_ENTITY DF%d/a{]  
Dim op As T_OPERATION I-v} DuM  
Dim mat As T_MODELMATERIAL  ` Xc7b  
Dim A As Double :XKYfc_y  
Dim pupilDiam As Double Z0|5VLk,<{  
Dim eID As Long ,(jJOFf  
Dim parID As Long 01bCP  
Dim count As Integer ~f QrH%@  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $CcjuPsK  
Dim tlens As Double, nlens As Double <,.$U\W  
Dim curv As Double, conic As Double T+8Yd(:hX  
Dim ok As Long j:9M${~  
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Sub Main 6iFlz9XiI  
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    '用户输入对话框 p^l#Wq5  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7T[~~V^x  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !E
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Q+CJd>B  
        OKButton 40,91,90,21  /SvhOi  
        CancelButton 190,91,90,21 |T#cq!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 F)P:lvp<r  
        TextBox 220,49,40,21,.TextBox2 'default: 4 iAd&o`C  
    End Dialog 9#E *o~1  
    Dim dlg As UserDialog gl
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    ok = Dialog (dlg) #%,X),%-  
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    If ok=0 Then    'cancel button was pressed gt4GN`-k  
        Print "Execution cancelled." K5>3  
        End O[X*F2LC4  
    End If dT`nR"  
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    'Assign accommodation and pupil diameter & use defaults if field left empty F`}'^>  
    If dlg.TextBox1 = "" Then yoE-
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        A = 0           'Default accommodation DJ ru|2  
    Else 8lQ/cGAc  
        A = CDbl(dlg.TextBox1) LpHGt]|D  
    End If IRW0.'Dn  
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    If dlg.TextBox2 = "" Then ;W0J  
        pupilDiam = 4   'Default pupil diameter bGh&@&dHr  
    Else N'1I6e"  
        pupilDiam = CDbl(dlg.TextBox2) 2BY|Cp4R  
    End If deVd87;@7[  
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    Print " " ]4rmQAS7"  
    Print "Accommodation = " & A & " Diopters" as07~Xvp-  
    Print "Pupil Diameter = " & pupilDiam & " mm" $W._FAAJ#  
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    ' Calculate new parameters with accommodation q NGR6i  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness kHg|!  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens z$<=8ox8e  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]36SF5<0r  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens mQj#\<*  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens #v c+;`X  
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    tlens = 3.767 + 0.04*A                  'Lens thickness R ENCk(  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction zU5@~J  
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    'Adjust parameters to account for accommodation %6ckau1_;  
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    '************************************************************************* AFt- V  
    'Aqueous thickness (Position of Lens) .M6.]H  
    '************************************************************************* {\Pk;M{Y&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1I;q@g0  
    GetCustomElement eID, entity GzEw~JAs  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 4'faE="1)S  
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    ' Delete any shift(s) in z h(WlJCln  
    count = 0 e`Yj}i*bx]  
    While GetOperationCount(eID)>count 8YSvBy  
        GetOperation eID, count, op qMaO1cE\  
        If op.Type="ShiftZ" Then ,|f=2t+5X  
            DeleteOperation eID,count c{'Z.mut  
            count=count-1 M:O*_>KF  
        End If N\|B06X  
        count=count+1 n3e,vP? R  
    Wend e"@r[pq-{u  
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    'Set new shift in c[J 2;"SP  
    op.Type = "ShiftZ" (~@.9&cBD  
    op.val1 = taq hn.(pI1  
    op.parent = parID Iq|h1ie m+  
    AddOperation eID, op {UH45#Ua  
    Print "Set aqueous humor thickness = " & taq-0.55 ?`TQ!m6y  
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    '************************************************************************* :F d1k Jm  
    'Radius and conic constant of anterior lens QXI~Toddj  
    '************************************************************************* [KUkv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) t{,$?}  
    GetConic eID, entity, curv, conic 1uo
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    SetConic eID, entity, 1/Rant, CCant 7L+Wj }m  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant w !kk(QMV  
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    '************************************************************************* Ov"wcJ  
    'Radius and conic constant of posterior lens Wz^;:6F  
    '************************************************************************* xK8m\=#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) `+=Zq :0  
    GetConic eID, entity, curv, conic oVqx)@$
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    SetConic eID, entity, 1/Rpost, CCpost ,T;sWl  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost dLQp"vs$  
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    '************************************************************************* ^PdD-t
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    'Lens thickness (Position of posterior lens surface) =$}`B{(H  
    '************************************************************************* t<`wK8)  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }?b\/l<  
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    ' Delete any z-shift(s) !B[Y?b:  
    count = 0 |yNy
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    While GetOperationCount(eID)>count 4JBfA,  
        GetOperation eID, count, op oCwep^P(v  
        If op.Type="ShiftZ" Then $_%  
            DeleteOperation eID,count ?:q"qwt$F  
            count=count-1 gISA13  
        End If H/f}tw  
        count=count+1 8<Nz34Y  
    Wend c[1{>z{G  
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    'Set new z-shift =5:vKL j  
    op.Type = "ShiftZ" 2!f'l'}  
    op.val1 = tlens 6 y"r'  
    op.parent = parID E.'6p \  
    AddOperation eID, op yyPj!<.MGP  
    Print "Set lens thickness = " & tlens =M{&g  
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    '************************************************************************* r?`nc6$0|  
    'Lens index of refraction E=v4|/['N  
    '************************************************************************* `,  |l  
    eID = FindMaterial( "Lens" ) uA?a DjA  
    GetModelMaterial eID, mat >iJxq6!  
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    mat.Nd = nlens 48gpXc
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    SetModelMaterial eID, mat U;4;
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    Print "Set lens index of refraction = " & nlens "{{@N4^  
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    '************************************************************************* _#<l -R`  
    'Pupil diameter p<VW;1bt5  
    '************************************************************************* <!u(_Bxw/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) B^1jd!m  
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    'Adjust pupil diameter (trimming volume inner hole) Rlr[uU_  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +SRM?av  
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    ' Adjust pupil location to just in front of the lens I1ibrn  
    parID = FindFullName( "Geometry.Arizona Eye" ) 'u[cT$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) d{^K8T3  
    count = 0 I#yd/d5^  
    While GetOperationCount(eID)>count [o'}R`5)  
        GetOperation eID, count, op or`"{wop  
        If op.Type="ShiftZ" Then ]sI{+$~:c  
            DeleteOperation eID,count wRWKem=  
            count=count-1  `Q^Vm3h  
        End If @XF/hhGE_y  
        count=count+1 ,g)9ZP.F  
    Wend KrECAc  
    op.Type = "ShiftZ" =2wy;@f  
    op.val1 = taq-0.01 &kOb#\11u  
    op.parent = parID FLlL0Gu  
    AddOperation eID, op qmpU{fs  
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    Print "Set pupil diameter = " & pupilDiam 7"_gX  
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    'Update AZ Eye subassembly Description %8L5uMx  
    eID = FindFullName( "Geometry.Arizona Eye" ) LZ9IE>sj  
    GetEntity eID, entity cW $~86u"C  
    entity.Description = "Accommodation = " & A & "D" PI")
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    SetEntity eID, entity wa9{Q}wSa  
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    Update |z%*}DPrpa  
    Print "DONE!" *r3u=oWb  
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End Sub "2/VDB4!FG  
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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： dv\oVD  
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Accommodation = 4 Diopters b+}*@xhl  
Pupil Diameter = 4 mm HaamLu  
Set aqueous humor thickness = 2.81 yYTiAvN  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ;c>Rjg&[  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 P(r}<SM  
Set lens thickness = 3.927 Z.0^:rVp~  
Set lens index of refraction = 1.42672 k}Vu!+cz  
Set pupil diameter = 4 ?3i-wpzMp  
DONE! hAZ
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