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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 dqPJ 2j $\  
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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。 t+p-,ey^@  
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    模型 IRXpk 6|  
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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。 ; N!K/[p=  
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    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. !0E$9Xon  
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    光源 p8o%H-Xk  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 E$*I.i_m  
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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。 6 3Kec  
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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。 C[<&% =  
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    图2. 字母F光源的设定方法光 v]Pw]m5=U  
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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 F1gDeLmJ  
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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。 W=PDOzB>K  
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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。 SAly~(r?/  
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    图5. 视网膜重点采样规格设定
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    脚本 ;k(|ynXv  
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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: Sg')w1  
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    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。 sW|u}8`  
    余下的脚本计算与屈光度有关的所有参数。 |`_TVzA  
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    分析 A3!NEFBK  
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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。 Wb/@~!+i`  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码  //K]zu  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. =]U[   
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    Dim entity As T_ENTITY y#YCc{K [  
    Dim op As T_OPERATION |'Ve75 W6u  
    Dim mat As T_MODELMATERIAL E5-8tHV   
    Dim A As Double ^ chlAQz(  
    Dim pupilDiam As Double L$lo5  
    Dim eID As Long F2 >o"j2  
    Dim parID As Long e[>(L%QV+  
    Dim count As Integer |I85]'K9a  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2!{CNt.-  
    Dim tlens As Double, nlens As Double 8Bo'0  
    Dim curv As Double, conic As Double kX5v!pm[  
    Dim ok As Long yd#4b`8U`  
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    Sub Main x\I9J4Q  
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        '用户输入对话框 oV,>u5:B  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _aa3Qw x  
            TextBox 220,21,40,21,.TextBox1 'default: 0 78y4nRQ*  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 pZ OVD%  
            OKButton 40,91,90,21 ~wh8)rm  
            CancelButton 190,91,90,21 ~cU,3g  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |Z#) 1K  
            TextBox 220,49,40,21,.TextBox2 'default: 4 *kZJ  
        End Dialog [4PG_k[uTJ  
        Dim dlg As UserDialog B@.U\.  
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        ok = Dialog (dlg) mZMLDs:  
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        If ok=0 Then    'cancel button was pressed EDL<J1%  
            Print "Execution cancelled." f<0-'fGJd  
            End e,:@c3I  
        End If +#'exgGU^[  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ?Za1  b  
        If dlg.TextBox1 = "" Then .CwMxuW  
            A = 0           'Default accommodation 7}TjOWC  
        Else 0#XZ_(@%  
            A = CDbl(dlg.TextBox1) {IqbO>|"O_  
        End If B5J=q("P  
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        If dlg.TextBox2 = "" Then E xY ~.  
            pupilDiam = 4   'Default pupil diameter .NwHr6/s*  
        Else *8X: fq  
            pupilDiam = CDbl(dlg.TextBox2) FkKx~I:  
        End If nyTfTn  
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        Print " " LD]XN'?"W  
        Print "Accommodation = " & A & " Diopters" [A[vR7&S  
        Print "Pupil Diameter = " & pupilDiam & " mm" j.AAY?L  
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        ' Calculate new parameters with accommodation "m/0>UU0  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xjv?Z"X  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens M)Ogb '@#  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens  5Lm ?  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens s.Yywy  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens V4ayewVX  
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        tlens = 3.767 + 0.04*A                  'Lens thickness gQ,PG  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mA3C)V  
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        'Adjust parameters to account for accommodation ^EM##Ss_  
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        '************************************************************************* sh E>gTe  
        'Aqueous thickness (Position of Lens) b.;F)(  
        '************************************************************************* ~{RXc+  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) M nH4p  
        GetCustomElement eID, entity A GS?<6W-  
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        parID = FindFullName( "Geometry.Arizona Eye" ) G#3 O^,m  
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        ' Delete any shift(s) in z nuhKM.a{  
        count = 0 0 .t;i4  
        While GetOperationCount(eID)>count <E!M<!h  
            GetOperation eID, count, op R279=sO,J  
            If op.Type="ShiftZ" Then `?91Cw=`  
                DeleteOperation eID,count l9#M`x9  
                count=count-1 1Cp5a2{  
            End If $WrDZU 2z  
            count=count+1 @ 5|F:J  
        Wend PgxD?Oi8  
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        'Set new shift in /< h~d  
        op.Type = "ShiftZ" $(.[b][S  
        op.val1 = taq hSo\  
        op.parent = parID b":cj:mxL  
        AddOperation eID, op LIirOf~e;!  
        Print "Set aqueous humor thickness = " & taq-0.55 7 45Uo'  
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        '************************************************************************* cZ%weQa#N)  
        'Radius and conic constant of anterior lens  ()=  
        '************************************************************************* UR:cBr  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) GC~Tfrf=r  
        GetConic eID, entity, curv, conic jrZM  
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        SetConic eID, entity, 1/Rant, CCant a 0Hzf  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant |SQ5Sb  
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        '************************************************************************* kd9hz-*  
        'Radius and conic constant of posterior lens gGH<%nHW1  
        '************************************************************************* G>d@lt  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >z.o?F  
        GetConic eID, entity, curv, conic ~X*)gS-=  
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        SetConic eID, entity, 1/Rpost, CCpost bL]*K$  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 3?.3Z!H/  
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        '************************************************************************* ZG H2  
        'Lens thickness (Position of posterior lens surface) al(t-3`<  
        '************************************************************************* A"2k,{d  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :,]V 03  
    uIiE,.Uu}  
        ' Delete any z-shift(s) jDqe)uVvtV  
        count = 0 q6%jCt2'  
        While GetOperationCount(eID)>count 'Oyz/P(p  
            GetOperation eID, count, op cAC]%~orx  
            If op.Type="ShiftZ" Then hwSn?bkw  
                DeleteOperation eID,count wFnIM2a,  
                count=count-1 R%"wf   
            End If 9EIHcUXe  
            count=count+1 &CV%+  
        Wend [x kbzJ  
    :{E;*v_!v  
        'Set new z-shift W}50E.\#  
        op.Type = "ShiftZ" {AoH  
        op.val1 = tlens R0B\| O0Uv  
        op.parent = parID yCwBZ/C  
        AddOperation eID, op w[S2 ] <  
        Print "Set lens thickness = " & tlens )}0(7z Yu  
    4. 7m*  
        '************************************************************************* "M3R}<Vt  
        'Lens index of refraction t,gKN^P_  
        '************************************************************************* <7~HG(ks  
        eID = FindMaterial( "Lens" ) )+'FTz` c  
        GetModelMaterial eID, mat /59jkcA+  
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        mat.Nd = nlens "7(2m  
        SetModelMaterial eID, mat qL/4mM0  
        Print "Set lens index of refraction = " & nlens rwWs\~.H  
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        '************************************************************************* k1e0kxn  
        'Pupil diameter -NHA{?6r  
        '************************************************************************* Rq-BsMX!A  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (j@3=-%6G  
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        'Adjust pupil diameter (trimming volume inner hole) <7NY.zvwk]  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /o Q^j'v  
    8=Xy19<;t  
        ' Adjust pupil location to just in front of the lens 80TSE*  
        parID = FindFullName( "Geometry.Arizona Eye" ) .bE+dA6:v  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) />=)=CGv;  
        count = 0 %JF.m$-  
        While GetOperationCount(eID)>count iG()"^G  
            GetOperation eID, count, op aKkL0 D  
            If op.Type="ShiftZ" Then Q(=} PF  
                DeleteOperation eID,count i0; p?4`m  
                count=count-1 KSe `G;{  
            End If ZCsL%(  
            count=count+1 ZV=O oL t,  
        Wend $ lz\t e  
        op.Type = "ShiftZ" wl|cipy"  
        op.val1 = taq-0.01 `a2%U/U  
        op.parent = parID p uEu v6F  
        AddOperation eID, op BQmHYar  
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        Print "Set pupil diameter = " & pupilDiam JR>#PJ,N-  
    do@`(f3 g  
        'Update AZ Eye subassembly Description -T3 z@k  
        eID = FindFullName( "Geometry.Arizona Eye" ) \Jq$!foYx  
        GetEntity eID, entity pxy=edd  
        entity.Description = "Accommodation = " & A & "D" TJjcX?:(  
        SetEntity eID, entity 0/z=G!z\  
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        Update O75^(keW  
        Print "DONE!" E_k<EQ%r  
         ElLDSo@WvR  
    End Sub M+4>l\   
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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: 4&]Sb}  
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    Accommodation = 4 Diopters O1!hSu&  
    Pupil Diameter = 4 mm Jse;@K5y  
    Set aqueous humor thickness = 2.81 3Run.Gv\  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Y7{|iw(#  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]'+PJdA  
    Set lens thickness = 3.927 k<xPg5  
    Set lens index of refraction = 1.42672 b'F#Y9  
    Set pupil diameter = 4 {BB#Bh[  
    DONE! _gDEIoBp  
     
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