[技术]Arizona眼睛模型 [复制链接]

简介 2s}G6'xE]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。 9U3.=J  
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模型 R0K{wY58  
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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。 j|{ n?  
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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. PJ,G_+b!  
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光源 m= %KaRI  
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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。 gUYTVp Vf  
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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。 :_Iz( 2hV  
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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。 9%riB/vkrF  
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视网膜的散射 Jgy6!qUn_  
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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。 m8INgzVTC  
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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。 [Sc
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脚本 h7S; 4]  
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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： ;CuL1N#I  
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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。 a(uQGyr[k1  
余下的脚本计算与屈光度有关的所有参数。 9l,8:%X_  
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分析 oWggh3eXk  
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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。 BWr!K5w>i  
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脚本代码 >b~Q%{1  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ]SN5&S  
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Dim entity As T_ENTITY 1yeD-M"w  
Dim op As T_OPERATION 5Gz~,_  
Dim mat As T_MODELMATERIAL !Wy&+H*0  
Dim A As Double w)h"?'m~  
Dim pupilDiam As Double K k^!P*#  
Dim eID As Long 3Qp6$m  
Dim parID As Long G$~hAZ  
Dim count As Integer GT3}'`f B  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tq*{Hil>P`  
Dim tlens As Double, nlens As Double i6i;{\tc  
Dim curv As Double, conic As Double R5 EC/@  
Dim ok As Long [p)2!]y  
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Sub Main :]* =f].  
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    '用户输入对话框 syb$%  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]ij:>O@{$  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Eb8z`@p  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |+=ctpx9&  
        OKButton 40,91,90,21 (unJwh{7Q  
        CancelButton 190,91,90,21 avqJ[R  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 4Cvo^k/I  
        TextBox 220,49,40,21,.TextBox2 'default: 4 W\e!rq  
    End Dialog @VsK7Eo  
    Dim dlg As UserDialog 0b2;  
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    ok = Dialog (dlg) " j:15m5  
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    If ok=0 Then    'cancel button was pressed /!y3ZzL  
        Print "Execution cancelled." 1z3I^gI*i  
        End NE Z ]%  
    End If ]O~/k~f  
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    'Assign accommodation and pupil diameter & use defaults if field left empty y|WOw(#  
    If dlg.TextBox1 = "" Then ,UD5>Ai  
        A = 0           'Default accommodation ~>}7+p ?;  
    Else WW~QK2o-@  
        A = CDbl(dlg.TextBox1) `$[`C/h  
    End If ML X: S?  
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    If dlg.TextBox2 = "" Then b*< *,Ds/G  
        pupilDiam = 4   'Default pupil diameter lpefOnO[  
    Else hPUYq7B  
        pupilDiam = CDbl(dlg.TextBox2) ,q Bu5t  
    End If J-Fqw-<aFJ  

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    Print " " xCm`g{  
    Print "Accommodation = " & A & " Diopters" uC1
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    Print "Pupil Diameter = " & pupilDiam & " mm" e#4 iue7U  
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    ' Calculate new parameters with accommodation 1;+(HB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {>#4{D00  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens jyjK~!0  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens !q*]_1  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens /?:]f  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Yc V*3`  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @nF#\  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9{{CNy p  
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    'Adjust parameters to account for accommodation 4_?*@L1  

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    '************************************************************************* _l.kbfp@  
    'Aqueous thickness (Position of Lens) 'I)E.DoF  
    '************************************************************************* e@{8G^o>D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5nG$6Hw  
    GetCustomElement eID, entity C)Hb=  
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    parID = FindFullName( "Geometry.Arizona Eye" ) XZ&q5]PJI  
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    ' Delete any shift(s) in z }^B=f_Ag  
    count = 0 xBMhk9b^0  
    While GetOperationCount(eID)>count M7n|Z{?(  
        GetOperation eID, count, op :+|os"  
        If op.Type="ShiftZ" Then <rFY$ ?x  
            DeleteOperation eID,count _p=O*$b.  
            count=count-1 uCpk1d  
        End If Z(-@8=0  
        count=count+1 [z`m`9Aq  
    Wend m.N/g,  
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    'Set new shift in [.`#N1-@M  
    op.Type = "ShiftZ" Y>[u(q&09O  
    op.val1 = taq AW:WDNQh8n  
    op.parent = parID {sL(PS.z  
    AddOperation eID, op 9l:Bum)9  
    Print "Set aqueous humor thickness = " & taq-0.55 l %{$CmG\  
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    '************************************************************************* efF>kcIC  
    'Radius and conic constant of anterior lens ?yt"  
    '************************************************************************* KBo/GBD]|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) h $}&N  
    GetConic eID, entity, curv, conic
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    SetConic eID, entity, 1/Rant, CCant n/5)}( }K
 
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !jxz
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    '************************************************************************* 9L'R;H?L  
    'Radius and conic constant of posterior lens JY tM1d  
    '************************************************************************* +9mnxU>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?5!>k^q  
    GetConic eID, entity, curv, conic Ue<Y ~A  
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    SetConic eID, entity, 1/Rpost, CCpost IU`&h2KZ.  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost agFWye  
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    '************************************************************************* tc'`4O]c8  
    'Lens thickness (Position of posterior lens surface) xA9{o+  
    '************************************************************************* p}NIZ)]$  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .^S#h (A  
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    ' Delete any z-shift(s) Y&k6Xhuao  
    count = 0 <tbsQ3  
    While GetOperationCount(eID)>count tF<|Eja*  
        GetOperation eID, count, op .)>DFGb>H  
        If op.Type="ShiftZ" Then l1\/ `  
            DeleteOperation eID,count dkC[
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            count=count-1 ~',<7eW  
        End If }w&+H28.#  
        count=count+1 u"\HBbBx  
    Wend GyO
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    'Set new z-shift lk6*?EJ  
    op.Type = "ShiftZ" HUtuUX  
    op.val1 = tlens }F1|& A  
    op.parent = parID ]3C&l+m$ot  
    AddOperation eID, op ~/6m|k  
    Print "Set lens thickness = " & tlens k4+
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    '************************************************************************* !'No5  
    'Lens index of refraction uJ4RjLM`  
    '************************************************************************* R)"Y40nW  
    eID = FindMaterial( "Lens" ) A`4j=OF\  
    GetModelMaterial eID, mat Z;aQ/n[`  
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    mat.Nd = nlens c_]$UM[7L  
    SetModelMaterial eID, mat ^<R*7mB*  
    Print "Set lens index of refraction = " & nlens $Blo`'  
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    '************************************************************************* Kv[,!P"Y  
    'Pupil diameter `7P4O   
    '************************************************************************* @O<kjR<b  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) sY=fS2b#)  
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    'Adjust pupil diameter (trimming volume inner hole) 2yhtJ9/  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y%b 5{1  
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    ' Adjust pupil location to just in front of the lens "PBUyh-Z  
    parID = FindFullName( "Geometry.Arizona Eye" ) 93yJAao9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) nKJJ7'$'3  
    count = 0 9N|O*h1;u  
    While GetOperationCount(eID)>count xQC.ap  
        GetOperation eID, count, op u2^oXl  
        If op.Type="ShiftZ" Then (u-i{<   
            DeleteOperation eID,count m&DDz+g  
            count=count-1 Pq~"`-h7:  
        End If <L@0w8i`  
        count=count+1 >A|6kzC  
    Wend DNdwMSwp
 
    op.Type = "ShiftZ" 9}Tf9>qP>M  
    op.val1 = taq-0.01 W$@q ~/E  
    op.parent = parID 2>#Pt^R:C  
    AddOperation eID, op |n3PznV  
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    Print "Set pupil diameter = " & pupilDiam n*%<!\gJ  
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    'Update AZ Eye subassembly Description }`4o+  
    eID = FindFullName( "Geometry.Arizona Eye" ) %-|Po:6  
    GetEntity eID, entity 0 ]U ;5  
    entity.Description = "Accommodation = " & A & "D" Xvm.Un<N  
    SetEntity eID, entity A"k6n\!n;  
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    Update Deq
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    Print "DONE!" {j[[E/8N!y  
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End Sub Qv,|*bf  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： +/7UM x1  
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Accommodation = 4 Diopters 9ulJZ\cQ  
Pupil Diameter = 4 mm =L9sb!  
Set aqueous humor thickness = 2.81 ;Aiuy{<  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &h-d\gMJ  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ~Rk%M$E9  
Set lens thickness = 3.927 a_m P$4T  
Set lens index of refraction = 1.42672 F'W{\4  
Set pupil diameter = 4 9k ]$MR  
DONE! qr$=oCqa