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1、摘要題名:波前像差曲面擬合方法研究碩士姓名:張晶導(dǎo)師姓名:舒華忠學(xué)校名稱:東南大學(xué)近年來,波前像差的理論和檢測(cè)技術(shù)在眼科的應(yīng)用使得屈光領(lǐng)域的研究有了新的突破。I臨床實(shí)驗(yàn)結(jié)果表明,與常規(guī)的眼科手術(shù)相比,準(zhǔn)確的波前像差引導(dǎo)的眼科手術(shù)可以使眼科手術(shù)患者術(shù)后的視覺質(zhì)量有進(jìn)一步的改善。本文依據(jù)由角膜高度數(shù)據(jù)值計(jì)算眼睛波前像差的方法,采用正交徑向多項(xiàng)式擬合角膜高度曲面和波前像差曲面,從而得到精確的波前像差數(shù)據(jù)。在已有的應(yīng)用中,傳統(tǒng)的Zemike多項(xiàng)式被廣泛應(yīng)用在曲面擬合領(lǐng)域。D.R.Iskander通過實(shí)驗(yàn)證實(shí),另一類徑向多項(xiàng)式——傳統(tǒng)的Pseudo—Ze
2、rnike(BW)多項(xiàng)式相對(duì)于Zemike多項(xiàng)式表現(xiàn)出更加健壯的擬合性質(zhì)。本文試圖尋找其它的正交多項(xiàng)式,并期待它們的擬合性能比傳統(tǒng)的Zemike多項(xiàng)式和傳統(tǒng)的Pseudo.Zemike(BW)多項(xiàng)式更優(yōu)。在此基礎(chǔ)上,本文分別提出了應(yīng)用連續(xù)的擴(kuò)展的Zemike多項(xiàng)式和擴(kuò)展的Pseudo.Zemike多項(xiàng)式來進(jìn)行角膜高度曲面和波前像差曲面的擬合。角膜高度面實(shí)驗(yàn)數(shù)據(jù)分別采用兩個(gè)模擬正常人眼角膜的曲面(球面和橢球面)和用Keratron型角膜地形圖儀測(cè)量得到的真實(shí)角膜面;波前像差面實(shí)驗(yàn)數(shù)據(jù)則采用波前像差傳感器測(cè)量得到的數(shù)據(jù)。實(shí)驗(yàn)結(jié)果表明,擴(kuò)展的Zemi
3、ke多項(xiàng)式和擴(kuò)展的Pseudo.Zemike多項(xiàng)式在小尺寸的角膜曲面和波前像差曲面上具備更加穩(wěn)定的擬合性能。為了避免連續(xù)多項(xiàng)式在離散化后帶來的誤差和正交化過程,本文又結(jié)合離散Tchebichef多項(xiàng)式和離散Krawtchouk多項(xiàng)式,提出了離散徑向Tchebichef多項(xiàng)式和離散徑向Krawtchouk多項(xiàng)式,并且將其應(yīng)用到角膜高度曲面擬合和波前像差曲面擬合中。實(shí)驗(yàn)數(shù)據(jù)依舊采用上述的各個(gè)曲面,實(shí)驗(yàn)結(jié)果表明離散徑向Tchebiehef多項(xiàng)式和離散Krawtchouk多項(xiàng)式在角膜高度曲面和波前像差曲面擬合方面的性能優(yōu)于其它連續(xù)徑向多項(xiàng)式。關(guān)鍵詞:波
4、前像差擬合、角膜面擬合、擴(kuò)展的Zemike多項(xiàng)式、擴(kuò)展的Pseudo.Zemike多項(xiàng)式、Tchebichef多項(xiàng)式、Krawtchouk多項(xiàng)式AbstractTHESISTITLE:MethodstudyforthemodelingofwavefrontaberrationsurfaceMASTERNAME:ZHANGJingSUPERVISORNAME:SHUHua-zhongSCHOOLNAME:SoutheastUniversityInrecentyears,theapplicationofwavefrontaberrationtheo
5、ryanditstestingtechnologyinOphthalmologyhavemadesomenewbreakthroughsinthefieldofrefractive.Clinicalexperimentalresultsshowthatcomparedwithconventionaleyessurgery,thesurgery1cadsbyaccuratewavefrontaberrationcouldimprovethepost-surgeryvisualqualitysignificantly.Basedontheproce
6、duretoobtainthecomealaberrationsfromthecornealelevationdata,radialorthogonalpolynomialsaleusedtofitthecomealelevationsurfacesandcomealwavefrontaberrationsurfaces,SOthattheaccuratewavefrontdatacouldbegot.Sofar,traditionalZemikepolynomialshavebeenwidelyusedinthesurfacefittingf
7、ield.Anothersetofpolynomials—廿aditionalPseudo-Zemike餌W)polynomialsshowsmorerobustfiaingcapabilitythantheZemikePolynomials.Intllisthesis.newmethodsformodelingcornealelevationsurfaceandwavefrontaberrationstlrfacewithcontinuousGeneralizedZemikePolynomialsandcontinuousGeneralize
8、dPseudo—ZemikePolynomialsareproposed.Theexperimentaldataforthecomealelevati