[技术]Arizona眼睛模型 [复制链接]

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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。 N*-Z Jv  
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模型 1#uw^{n  
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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。 0_.hU^fP  
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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. QyQ8M1
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光源 1
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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。 pP&M]'  
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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。 <rF  
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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。 9mm(?O~'p  
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视网膜的散射 I-"{m/PEdg  
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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。 _%B`Y ?I`  
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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。 A@r,A?(  
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脚本 ;;5i'h~?]J  
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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： @d|9(,Q  
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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。 jEIL(0_H  
余下的脚本计算与屈光度有关的所有参数。 %#~Wk|8} Q  
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分析 (WvA9s{/  
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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。 XLT<,B}e  
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脚本代码 '>BHwc  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. %<t/xAge  
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Dim entity As T_ENTITY |Oe6OCPf  
Dim op As T_OPERATION e<K=Q$U.  
Dim mat As T_MODELMATERIAL R0[Gfq9M=  
Dim A As Double &3V4~L1aEg  
Dim pupilDiam As Double +8M{y D9#  
Dim eID As Long ojri~erJE?  
Dim parID As Long gN%R-e0  
Dim count As Integer f&'md  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double R#>E{[9  
Dim tlens As Double, nlens As Double [aC(Ga}  
Dim curv As Double, conic As Double tN~{Mt$-W  
Dim ok As Long Alz#zBGb  
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Sub Main 0/$sr;  
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    '用户输入对话框 trLs4o,  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vq}V0- <  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]CjODa  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 SW7%SX,xM  
        OKButton 40,91,90,21 DVd/OU  
        CancelButton 190,91,90,21 aO1cd_d6x_  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 W2RS G~|  
        TextBox 220,49,40,21,.TextBox2 'default: 4 P1<;:!8'  
    End Dialog |@RO&F  
    Dim dlg As UserDialog ^^m%[$nw&r  
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    ok = Dialog (dlg) 6x0>E^~  
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    If ok=0 Then    'cancel button was pressed 0^=S:~G  
        Print "Execution cancelled." \iFE,z  
        End J0IK=Y  
    End If hf[K\aAk  
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    'Assign accommodation and pupil diameter & use defaults if field left empty zv41Yv!x}  
    If dlg.TextBox1 = "" Then $aG'.0HW  
        A = 0           'Default accommodation WKG=d]5  
    Else (<12&=WxE  
        A = CDbl(dlg.TextBox1) f]Vz!hM~  
    End If 99 ["I:  
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    If dlg.TextBox2 = "" Then HwHI$IB  
        pupilDiam = 4   'Default pupil diameter f: Rh9  
    Else cMj<k8.{  
        pupilDiam = CDbl(dlg.TextBox2) ~'ovJ46tx  
    End If sEoS|"  
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    Print " " }~7>S5  
    Print "Accommodation = " & A & " Diopters" ^/c|s!U^  
    Print "Pupil Diameter = " & pupilDiam & " mm" .D :v0Zm}m  
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    ' Calculate new parameters with accommodation ZrTq)BZ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness HV}NT~
 
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Z1Ms~tch  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens E_
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T/H*Bo*=5  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens BjA|H  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 8w{V[@QLn  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction '!_o`t@  
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    'Adjust parameters to account for accommodation 3}"VUS0wh  
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    '************************************************************************* toF@@%  
    'Aqueous thickness (Position of Lens) k2xjcrg  
    '************************************************************************* LE7o[<>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) a@%FwfIu  
    GetCustomElement eID, entity qB8<(vBP+  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Cnn,$R=/s  
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    ' Delete any shift(s) in z _8bqk\m+  
    count = 0 ~sM334sQ  
    While GetOperationCount(eID)>count lY6U$*9c  
        GetOperation eID, count, op 5~\W!|j/  
        If op.Type="ShiftZ" Then 2+|[e_  
            DeleteOperation eID,count ;N)qNiJY  
            count=count-1 $hA[vi\5  
        End If 5bgx;z9  
        count=count+1 n|(Y?`(  
    Wend _3)~{dQ+  
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    'Set new shift in _N<8!(|w  
    op.Type = "ShiftZ" >:Rc%ILym  
    op.val1 = taq `/0FXb 8h  
    op.parent = parID -1fT2e  
    AddOperation eID, op AR&u9Y)I  
    Print "Set aqueous humor thickness = " & taq-0.55 ,#s}nJ4  
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    '************************************************************************* %R}}1
 
    'Radius and conic constant of anterior lens PyIIdTm  
    '************************************************************************* >ztv3^w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,UY],;ib  
    GetConic eID, entity, curv, conic (;!&RZ  
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    SetConic eID, entity, 1/Rant, CCant O%rjY  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X.g1 312~  
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    '************************************************************************* n`}vcVL;  
    'Radius and conic constant of posterior lens si)920?E&  
    '************************************************************************* la f
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Zsaz#z|xW  
    GetConic eID, entity, curv, conic i/~A7\:8%  
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    SetConic eID, entity, 1/Rpost, CCpost Dk/;`sXV  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost vX&Nh"0H&  
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    '************************************************************************* {G_ZEo#x8,  
    'Lens thickness (Position of posterior lens surface) K o,O!T.  
    '************************************************************************* =p$1v{L8  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) FhW\23OC  
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    ' Delete any z-shift(s) 7)z^*;x  
    count = 0 EZa
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    While GetOperationCount(eID)>count s-Bpd#G>/  
        GetOperation eID, count, op L= hPu#&/  
        If op.Type="ShiftZ" Then Q!MS_ #O  
            DeleteOperation eID,count Q R;Xj3]v  
            count=count-1 $GEY*uIOa  
        End If ,{7Z OzA  
        count=count+1 v-EcJj%  
    Wend B xq(+^T  
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    'Set new z-shift E\5t&jZr  
    op.Type = "ShiftZ" f8!*4Bw  
    op.val1 = tlens F:1w%#6av  
    op.parent = parID #D&eov?  
    AddOperation eID, op +,f|Y6L<  
    Print "Set lens thickness = " & tlens g7rn|<6FI  
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    '************************************************************************* W/L~&.'  
    'Lens index of refraction hxGZ}zq*S  
    '************************************************************************* ):31!IC  
    eID = FindMaterial( "Lens" ) .e~17}Ka}  
    GetModelMaterial eID, mat q0&g.=;  
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    mat.Nd = nlens :iP2e+j  
    SetModelMaterial eID, mat C0Z mv  
    Print "Set lens index of refraction = " & nlens a^>0XXr}Y  
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    '************************************************************************* |1uyJ?%B  
    'Pupil diameter 2c LIz@  
    '************************************************************************* B;@7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) k|'{$/n  
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    'Adjust pupil diameter (trimming volume inner hole) =`Pgo5A  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q,S~+bD(z  
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    ' Adjust pupil location to just in front of the lens Ko|nF-r_  
    parID = FindFullName( "Geometry.Arizona Eye" ) wsYvbI!  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~7IXJeon  
    count = 0 Q$^o
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    While GetOperationCount(eID)>count e3oHe1"hP  
        GetOperation eID, count, op yY_Zq\   
        If op.Type="ShiftZ" Then Z9,-FO{#3-  
            DeleteOperation eID,count %F_)!M;x  
            count=count-1 xp7`[.  
        End If rozp  
        count=count+1 | vL0}e  
    Wend NitsUg@<  
    op.Type = "ShiftZ" 4+"2K-]   
    op.val1 = taq-0.01 GH[ATL  
    op.parent = parID eg!s[1[_  
    AddOperation eID, op lA>^k;+>  
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    Print "Set pupil diameter = " & pupilDiam "H\1Z,P<m  
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    'Update AZ Eye subassembly Description 0h=NbLr|S-  
    eID = FindFullName( "Geometry.Arizona Eye" ) yq]=+X>(  
    GetEntity eID, entity jMr[U
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    entity.Description = "Accommodation = " & A & "D" kCRfO}wt3  
    SetEntity eID, entity UEHJ? }  
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    Update [@ >}  
    Print "DONE!" >%LZ|*U  
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End Sub 
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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： S\5%nz\  
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Accommodation = 4 Diopters 0])D)%B k  
Pupil Diameter = 4 mm j}u b  
Set aqueous humor thickness = 2.81 X\&CQiPS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 7W[+e&  
Set posterior lens radius = -4.424557 and conic constant = -3.081019  qHVZsZ  
Set lens thickness = 3.927 e7tp4M9!%  
Set lens index of refraction = 1.42672 pY.R?\  
Set pupil diameter = 4 +;,65j+n   
DONE! dmA#v:$1