Interpretation of the Biomedical Signals using the RBF-Type Neural Networks

Transcription

1 terpretto of the Boedc Sgs usg the RBF-Tpe Neur Networs ANDRZEJ ZWORSK, POTR BANA Deprtet of Autotcs, AGH Uverst of Scece d Techoog, A Mcewcz 30, Krow, POLAND Astrct: -The pper descred deterto of preters of Brste Evoed Audtor Potets (BAEP) regstrto usg coputto tegece ethods the reserch o the sste of utoted dgoss of the ptet's udtor sste the Rd Bss Fuctos (RBF) eur etwors hve ee pped The uthors hve so preseted terpretto of the detered etwor's weght coeffcets, whch eds to es evuto of the requred chrcterstcs of the BAEP regstrto Dgostc sstes sed the ss of BAEP sgs re curret dc deveopg fed of oectve reserch cocerg the hu udtor sste The phsc's terpretto usu cudes o the ptudes d tec perods of chrcterstc wves, the presece d te octo of whch, provdes ss for dgosg the ptet's herg tes Becuse of gret dverst of sgs, whch geer deped o the ge, sex d so o the stuus test, the evuto d eorto of uous dgoss ecoes qute dffcut for expereced phscs Therefore the uthors of the preset pper e ttept of costructg dgostc sste, whch coud e e to ete the ucertt eeet fro the process of evuto of herg tes, d woud e e to provde fu utooous operto, sed o cer, predefed crter Ke-Words: Coputto tegece, RBF Neur Networs, Brste Evoed Audtor Potets, Boedc Sg Processg troducto The BAEP sgs regstered the surfce eectrodes re dervtves of o-eectrc ctvt of the r d udtor cortex Eorto of the BAEP regstrto d ss techque offered the udoogsts posst of coo ppcto of oectve, eectro-phsoogc ethods for dgosg the hu udtor sste Those ethods hve ecoe rrepcee, prtcur the stces, where drect cooperto etwee the ptet d the phsc s ot posse, e the extos of ewors or gerers The exto of the herg threshod usg the ABR coprses regstrto of sequece of resposes for stu of vrg testes d frequeces d the the deterto of the wve detecto threshod The prr proe of the ABR threshod studes durg ss of the regstered ter s deterto of the wve threshod The resut of tht deterto s hgh depedet o the experece of the perso evutg the exto resuts Tpc regstrto of BAEP sg, eg suect of udoogc ss, usu cossts of sever respose sgs oted for coustc stu of vrous testes [Fg] Dgosg of the herg pret s usu sed o the ss of the recordg's orphoog d the ptudes d tec perods of prtcur wves the recordg The st two esures see to e uch eser for foruto the for of spe rues, whch ow drect cocuso, whether gve recordg c e cssfed s regur At preset t s ssued tht the ptudes d tec perods of prtcur wves shoud e coted wth stdrd ts, detered fro extos of cosdere uer of peope wth fu herg tes [4,]

2 t hs ee ssued tht the vues: f(x, x ) () where: x - te [s], x - test of the stuus [], x - -th te vue,, x - -th test of the stuus,,, - th spe of the BAEP recordg, ttruted to the x test, hve ee oted fro esureet of dscrete vues of uow fucto, represetg threedeso structure of the test seres Addto, ths fucto c e descred ere specfcto of the tec perods d ptudes of ts copoet sgs te [s] Fg Tpc BAEP sg recordg regstered for ptet wth or herg O the rght hd sde the test of the stutg sg hs ee red Wth decresg test of the stuus the ptudes of dvdu wves decrese, whe ther tec perods crese Modeg of the BAEP Sg Appcto of RBF Neur Networs Rd Bss Fuctos (RBF) eur etwors [6] provde uvers too for fucto pproxto the cse descred the weght coeffcets oted s resut of the RBF etwor's erg process cot the forto out ptudes d tec perods of prtcur wves A RBF etwor of dex s descred the foowg foru: r ( x) wϕ ( x v, σ ) + w0, () ξ ϕ( ξ, σ ) exp, σ The erg go for the -th RBF etwor s: ( ) r( x ),,, (3) W,, S, w0 whe: [ ] T W w, w,, w, T [ v, v,, v T S [ σ, σ,, σ ] The etwor hs ee ered the Leveerg- Mrqurdt gorth The etwor erg s strted fro the spe recorded for the hghest test of the stuus (eg 0 ) The W,, S, w 0, coeffcets provde strtg pot for the ext terto, e for the erg the etwor wth dex + Whe the W,, S, w 0 coeffcets re ow t s es to detere the tec perods d ptudes of prtcur wves The tec perod of the -st wve the -th terto s gve : L v, (4) d ts ptude s gve : A w ( v v, σ ) + w0 ϕ () Therefore foowg operto gorth c e proposed: ) Preset the put dt,

3 x - -th te vue,, x - -th test of the stuus,,,, - th BAEP recordg spe, ttruted to the x test, w 0, W S where the uers: T [ w, w,, w T [ v, v,, v T [ σ, σ,, σ ] ptudes of prtcur wves s fuctos of the stuus test The uers re coveet wrtte the trx for: L L A A L o r o, A o r o L L A A for whch the superscrpts descre the stuus test, d the suscrpts deote the wve uer The requred fucto depedeces of the ptude d tec perod vues o the stuus test c e pproxted thrdorder poo fuctos [Fg,3,4] [ 4 6], S [ ], W [ ], w hve ee seected o the ss of edc dt oted fro the dtse of sttute of Phsoog d Pthoog of Herg, Wrsw, Pod ) Sove the proe of erg the -th RBF etwor { Wˆ, ˆ, Sˆ, wˆ } rg ( ( x ) W,, S, w0 ) 0 r x [s] c) for detere L v ˆ, A wˆ ϕ (ˆ v vˆ, σˆ ) + wˆ 0 d) f STOP, otherwse susttute: +, W ˆ, ˆ, ˆ + W + S + S, w0, + wˆ 0 The executo of the gorth provdes sets of uers deterg the tec perods d x [s] Fg Approxto of BAEP sg recordg oted usg RBF etwors (red es), experet dt (c es) recordg for ptet wth or herg - recordg for ptet wth herg pret The zed sgs, oted oth fro the ptets wth or herg d wth herg

4 pthooges, hve ee suect to prer processg, whch reoved the er tred d the verge vue, d the the sgs hve ee fed s put dt to the gorth descred ove Fu procedure hs ee peeted the MATLAB evroet d t hs ee tested o 07 BAEP recordgs oted fro ptets wth herg prets d 3 recordgs fro ptets wth or herg tes or herg, - recordg fro ptet wth herg pret s s Fg 4 Aptudes of prtcur wves s fucto of stuus test detered the gorth (rer) d thrd-order poo pproxto (cotuous e) recordg fro ptet wth or herg, - recordg fro ptet wth herg pret Fg 3 Ltec perods of prtcur wves s fucto of stuus test, detered the gorth (rer) d the thrd-order poo pproxto (cotuous e) recordg fro ptet wth 3 Cocusos After copetg the whoe stud t hs ee foud the proposed gorth esures rpd

5 covergece of the requred preters to the vues estted speczed phsc (97%) for ptets wth or herg tes For the ptets wth pthooges the gorth dd ot provde uque preter ttruto, however t ws ws posse to fd out, tht the pthoog ws preset For those cses the cocordce wth the edc cssfcto ws so qute hgh (8%) Therefore the descred gorth c e used for estto of the herg stdrd ts d for prer dt processg for the eeds of cssfctos of herg prets The oted vues of tec perods d wve ptudes ow reducto the uer of put dt requred for eur etwors perforg cotext ss of the shpe d orphoog of BAEP sg recordg The oted prer resuts, descred the preset pper, shoud e cosdered s prosg The ext stges of the stud w cude costructo of etwors, whch w e worg o the put dt suppeeted ddto forto, regrdg the perso chrcterstcs of the ptet Refereces: [] R Tdeusewcz: Neur Networs, AOW RM, Wrszw, 993 ( Posh) [] J M Zurd: troducto to Artfc Neur Sstes, West Pushg Cop, St Pu, 99 [3] T Kohoe: Sef-Orgzto d Assoctve Meor, Sprger-erg, Ber, 984 [4] R E Degdo, O Ozdr: Autoted Audtor Brste Respose terpretto, EEE Egeerg Medce Ad Boog, Apr/M 994 [] S H: Neur Networs, Mc Coege Pushg Cop, 994 [6] MJ Aoff Eetrodgoss Cc Neuroog, Church Lvgstoe New Yor 986 [7] H JW:Audtor Brste Respose Audoetr Coege H Press c, S Dego, 984 [8] Nees O, Noer Sste detfcto, Sprger-erg, 00 [9] Woch, Buł J, Tdeusewcz R, B P, zwors A Deterto of dgostc preters utoted sste for ABR sg ss METMBS'0 : Proceedgs of the terto Coferece o Mthetcs d Egeerg Techques Medce d Boogc Sceces : Ls egs 00 [0] MATLAB docuetto: Users Gude, MthWors, Mss, [] MATLAB docuetto: Neur Networ Tooox Users Gude, MthWors, Mss, 999 [] MATLAB docuetto: Sg Processg Tooox Users Gude, MthWors, Mss, 999 [3] zwors A, Woch, Buł J: SOM eur etwors detecto of chrcterstc fetures of Brste Audtor Evoed Potets (BAEP), :Advces sstes theor, thetc ethods d ppctos / eds A Ze, N EMstors, WSEAS Press, 00, pp8 6 [4] zwors A, Tdeusewcz R, Srzńs H, Koche K, Bu J, Woch : Autotc Ass d Recogto of the Audtor Brste Respose Sgs, Proceedgs of the 8th terto Cogress o Acoustcs, Koto, Jp, 4-9 Apr 004, o, pp 7-78 Ths pper ws supported KBN/AGH grt 80386