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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 1'ts>6b  
    b8Gu<Q1k  
    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。 },<(VhP  
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    模型 R"%zmA@o=  
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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。 4+Aht]$hC  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 6Q\0v  
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    光源 cCOw7<  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 RN2^=$'.  
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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。 84(NylZ  
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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。 o3C7JG  
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    图2. 字母F光源的设定方法光 `b.KMOn  
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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 W&MZ5t,k=  
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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。 Jc8^m0_  
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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。 LdAWCBLS  
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    图5. 视网膜重点采样规格设定
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    脚本 ( x)}k&B;  
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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: aL?+# j^"  
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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。 jg)+]r/hS  
    余下的脚本计算与屈光度有关的所有参数。 \ B \G=Y  
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    分析 {S l#z }@s  
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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。 VK)vb.:  
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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 A[7\!bq5  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. As}3VBd  
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    Dim entity As T_ENTITY ?**9hu\BG  
    Dim op As T_OPERATION ./7*<W:  
    Dim mat As T_MODELMATERIAL r]+/"~a  
    Dim A As Double ^pc?oDPSg  
    Dim pupilDiam As Double |!Uul0O  
    Dim eID As Long }F B]LLi  
    Dim parID As Long T<a/GE/  
    Dim count As Integer ZBY*C;[)*P  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double s* ;rt  
    Dim tlens As Double, nlens As Double s!g06F  
    Dim curv As Double, conic As Double FN+x<VXo(  
    Dim ok As Long " J4?Sb<  
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    Sub Main ;#/Uo8  
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        '用户输入对话框 p~A6:"8s`=  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 +|K/*VVn`  
            TextBox 220,21,40,21,.TextBox1 'default: 0 S\poa:D`  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 nSSj&q-O  
            OKButton 40,91,90,21 S Bo i|  
            CancelButton 190,91,90,21 {SRv=g  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 j9sLR  
            TextBox 220,49,40,21,.TextBox2 'default: 4 &Hj1jM'  
        End Dialog #;(Q \  
        Dim dlg As UserDialog xRrKrs&eE  
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        ok = Dialog (dlg) "KHe6otmi_  
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        If ok=0 Then    'cancel button was pressed N5F+h94z]  
            Print "Execution cancelled." yhsbso,5 a  
            End Ib}~Q@?2  
        End If 1nZ7xCDK98  
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        'Assign accommodation and pupil diameter & use defaults if field left empty Q2LAXTF]y  
        If dlg.TextBox1 = "" Then IxU#x*  
            A = 0           'Default accommodation p!o+8Xz5  
        Else DQy;W  ov  
            A = CDbl(dlg.TextBox1) u-k!h  
        End If e_ h`x+\:  
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        If dlg.TextBox2 = "" Then y**>l{!!  
            pupilDiam = 4   'Default pupil diameter b8O }XB  
        Else vO 3-B   
            pupilDiam = CDbl(dlg.TextBox2) 8h{;*Wr-  
        End If b/g~;| <  
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        Print " " Y{`hRz`  
        Print "Accommodation = " & A & " Diopters" W*Gp0pX  
        Print "Pupil Diameter = " & pupilDiam & " mm" /zTx+U.\I  
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        ' Calculate new parameters with accommodation _h1:{hF  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness FNHJHuTe  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens QG]*v=Z  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens '(fCi  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zz[[9Am!  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 3BK_$Fy  
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        tlens = 3.767 + 0.04*A                  'Lens thickness <,+6:NmT  
    'l41];_  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction yoVN|5  
    LT:*K!>NOL  
        'Adjust parameters to account for accommodation NVG`XL  
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        '************************************************************************* n1@ Or=5  
        'Aqueous thickness (Position of Lens) wg{Y6X yH  
        '************************************************************************* 9 :FzSD  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) jKhj 7dR  
        GetCustomElement eID, entity A,f%0 eQR  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 1+NmiGKg  
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        ' Delete any shift(s) in z V1>>]]PS  
        count = 0 TM$Ek^fQ.  
        While GetOperationCount(eID)>count %q5iy0~P  
            GetOperation eID, count, op ba"a!#wA  
            If op.Type="ShiftZ" Then v}^ f8nVR  
                DeleteOperation eID,count 90]{4]y;  
                count=count-1 !|;w(/  
            End If 3I.0uLjg^  
            count=count+1 K$Yc!4M  
        Wend '$5o5\  
    J6*B=PX=(  
        'Set new shift in Bg0 aLU)[  
        op.Type = "ShiftZ" $C?G7Vs  
        op.val1 = taq ~zA{=|I2  
        op.parent = parID :>GT<PPD;  
        AddOperation eID, op _=oNQ  
        Print "Set aqueous humor thickness = " & taq-0.55 {1j[RE  
    :fE*fU@  
        '************************************************************************* h | +(  
        'Radius and conic constant of anterior lens O-K!Bv^ Q  
        '************************************************************************* ) bPF@'rF2  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n\D3EP<s  
        GetConic eID, entity, curv, conic z0m[25FQG  
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        SetConic eID, entity, 1/Rant, CCant TAn.5 wH9t  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ^iwM(d]#5  
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        '************************************************************************* mca9 +v  
        'Radius and conic constant of posterior lens L u?)Rya  
        '************************************************************************* vXi}B  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Q|W!m0XO  
        GetConic eID, entity, curv, conic e{x|d?)8  
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        SetConic eID, entity, 1/Rpost, CCpost C JNz J(  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4D\+_Ic3  
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        '************************************************************************* hrr;=q$  
        'Lens thickness (Position of posterior lens surface) ,w/f :-y  
        '************************************************************************* 6uH1dsD  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @tLoU%  
    8Bnw//_pT  
        ' Delete any z-shift(s) V6ioQx=K#  
        count = 0 fKY1=3  
        While GetOperationCount(eID)>count WPM<Qv L  
            GetOperation eID, count, op !OJSQB,  
            If op.Type="ShiftZ" Then K!9rH>`\  
                DeleteOperation eID,count Z0e+CEzq  
                count=count-1 m 5NF)eL  
            End If TIa`cU`  
            count=count+1 f-tV8  
        Wend 9h6xli  
    rHtT>UE=  
        'Set new z-shift h;KI2k_^  
        op.Type = "ShiftZ" r_Rjjo  
        op.val1 = tlens ^JMSe-  
        op.parent = parID /z4xq'<  
        AddOperation eID, op VM3H&$d(h  
        Print "Set lens thickness = " & tlens cF[[_  
    Eu )7@  
        '************************************************************************* ^IGTGY]s  
        'Lens index of refraction m`c(J1Et  
        '************************************************************************* "A:wWb<m  
        eID = FindMaterial( "Lens" ) 9CWUhS   
        GetModelMaterial eID, mat NoJo-vo*  
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        mat.Nd = nlens lm&C!{K  
        SetModelMaterial eID, mat Dg#Ab8  
        Print "Set lens index of refraction = " & nlens 3RRZVc* ^  
    ^aZ Wu|p  
        '************************************************************************* Z3R..vy8  
        'Pupil diameter *qG=p`  
        '************************************************************************* `z3?ET  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) o0wep&@  
    CFZ= !s)B  
        'Adjust pupil diameter (trimming volume inner hole) ;<q@>p[  
    't{=n[  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" AX1'.   
    @Ds?  
        ' Adjust pupil location to just in front of the lens ,[bcyf  
        parID = FindFullName( "Geometry.Arizona Eye" ) SAG) vmm  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -JZl?hY(  
        count = 0 fINM$ 6  
        While GetOperationCount(eID)>count oUw-l_M]  
            GetOperation eID, count, op 7B% @f9g  
            If op.Type="ShiftZ" Then #OWwg`AWv  
                DeleteOperation eID,count !4jS=Lhe>  
                count=count-1 <$D)uY K  
            End If aXC`yQ?  
            count=count+1 q{7s.m >  
        Wend 2%W(^Lj  
        op.Type = "ShiftZ" e`$v\7K  
        op.val1 = taq-0.01 {=g-zsc]K  
        op.parent = parID 4kg9R^0  
        AddOperation eID, op 6g$04C3tHi  
     b9y E  
        Print "Set pupil diameter = " & pupilDiam  ]NAPvw#p  
    RFK N,oB  
        'Update AZ Eye subassembly Description 2 yP#:T/z  
        eID = FindFullName( "Geometry.Arizona Eye" ) )X^nzhZ2O"  
        GetEntity eID, entity Gs?W7}<$  
        entity.Description = "Accommodation = " & A & "D" q]Qgg  
        SetEntity eID, entity !Q7   
    ?$n<vF>  
        Update j9u-C/Q\r  
        Print "DONE!" (tq)64XVz  
         =_yOX=g|  
    End Sub \R-u+ci$ZY  
    x(b&r g.-0  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: %okEN !=  
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    Accommodation = 4 Diopters *Nt6 Ufq6  
    Pupil Diameter = 4 mm >M1/m=a  
    Set aqueous humor thickness = 2.81 pb{P[-f  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 AN~1E@"  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 E?XA/z !  
    Set lens thickness = 3.927 _ _)Z Q  
    Set lens index of refraction = 1.42672 ,OasT!Sr  
    Set pupil diameter = 4 Oy|9po  
    DONE! +Zr03B  
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    QQ:2987619807 W;-Qze\D  
     
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