Obrasci frekvencije disanja tijekom submaksimalnog i maksimalnog plivanjakraulom s ventilom za disanje i bez njega

VALVE The purpose of the present study was to ascertain the effect of a respiratory valve (RV) and tubes during three different swimming tests (submaximal and maximal 200m front crawl swim and front crawl swimming to exhaustion) on a breathing frequency, selected biomechanical parameters such as stroke rate and number of breaths, and parameters of blood acid-base status and blood lactate concentration. Twelve former competitive male swimmers performed each swimming test twice: first, with an RV, and second, without an RV. Swimming with an RV induced a slower maximal 200m front crawl swim and shorter front crawl swimming to exhaustion in comparison with swimming without an RV. Furthermore, patterns of the breathing frequency during the submaximal and maximal swimming tests also differed between swimming with an RV and swimming without an RV. Significant differences of [LA-] after maximal 200m front crawl swimming between swimming with an RV and swimming without an RV (p≤0.05) were found. Significant differences in [LA-] and [HCO3-] after swimming to exhaustion between swimming with an RV and swim-ming without an RV (p≤0.01 and p≤0.05, respectively) were also found. Therefore, it may be concluded that when an RV is used for measuring respiratory parameters during swimming, a different pattern of breathing (comparing to swimming without an RV) may occur.Uvod Precizna mjerenja primitka kisika i respiratornih parametara tijekom plivanja vrhunac su istraživanja uspješnosti u plivanju. U cilju poboljšanja valjanosti testiranja, Toussaint i suradnici (1987) razvili su respiratorni ventil i cijevi (RV), specifično oblikovan za mjerenje primitka kisika i respiratornih parametara tijekom plivanja. Ipak, utvrđivanje stupnja odgovarajuće valjanosti mjerenja disanja tijekom plivanja s korištenjem ventila u usporedbi s normalnim disanjem tijekom plivanja zahtijeva daljnja istraživanja. Disanje tijekom plivanja kraulom, prsnog plivanja i delfinom sinkronizirano je sa zaveslajima. Štoviše, frekvencija disanja (Bf) mora odgovarati frekvenciji zaveslaja. Upotreba ventila omogućuje plivaču da diše slobodno i bez prekida, tj. plivač ne mora pribjegavati posebnoj mehanici disanja koja se inače mora primijeniti pri specifičnom plivačkom zaveslaju i frekvenciji zaveslaja. Stoga je cilj ovog istraživanja bio utvrditi učinak korištenja respiratornog ventila na frekvenciju disanja, odabrane biomehaničke parametre, kao što su frekvencija zaveslaja i broj udisaja, parametre acidobaznog statusa krvi te koncentraciju laktata u krvi tijekom tri različita plivačka testa (submaksimalnog i maksimalnog pčivanja kraulom na 200 metara te testa plivanja kraulom do iscrpljenja pri zadanoj, prethodno utvrđenoj brzini). Metode Dvanaest nekadašnjih natjecatelja plivača (dob: 24 ± 3 godine, visina: 181,3 ± 9 cm, masa: 77,4 ± 13 kg) dobrovoljno je pristalo sudjelovati u istraživanju. Na početku su ispitanici dvaput otplivali 200 metara kraul maksimalnom brzinom, najprije s respiratornim ventilom, a u drugom pokušaju bez ventila. Zatim su plivači otplivali 200 metara kraul s ventilom i bez njega. Brzine su prethodno zadane na razinu od 90% maksimalne brzine postignute u testu 200 metara kraul, zasebno s respiratornim ventilom i bez njega. Konačno, plivači su otplivali (čak uz određivanje tempa) kraul do iscrpljenja, sa i bez ventila. Test plivanja do iscrpljenja uključivao je zadanu, prethodno određenu brzinu koja je predstavljala 110% tempa korištenog u testu 200 metara kraul, najprije s respiratornim ventilom, a zatim bez njega. Tijekom plivačkih testova s respiratornim ventilom, frekvencija disanja mjerena je kontinuirano (breath by breath), korištenjem prijenosnog sustava izmjene plinova (Metamax 2, Cortex, Ger-many). Tijekom plivačkih testova bez respiratornog ventila, broj udisaja tijekom preplivane dionice od 25 metara određen je uz pomoć snimljenih videovrpca. Izmjereni krvni parametri uključivali su koncentraciju laktata ([LA-]) i parametre acidobaznog statusa - Pco2, parcijalni tlak kisika u krvi (Po2), pH i koncentraciju bikarbonatnih iona ([HCO3-]) prije početka svakog testa i tijekom prvih 30 do 45 se-kunda nakon plivačkih testova. Rezultati, rasprava i zaključak Plivanje s ventilom uzrokovalo je nižu brzinu u maksimalnom testu 200 metara kraul (1,28 ± 0,1 m/s) u odnosu na veću brzinu (1,38 ± 0,1 m/s; p<0,01) u plivanju bez ventila. Isto tako, korištenje ventila rezultiralo je kraćom dionicom (114 ± 17 m; p<0,05) plivanja kraulom do iscrpljenja u odnosu na veću udaljenost prijeđenu u plivanju bez venti-la (129 ± 18 m; p<0,05). Nadalje, obrasci frekvencije disanja tijekom submaksimalnih i maksimalnih plivačkih testova također su se razlikovali između plivanja s respiratornim ventilom i bez njega. U plivanju s respiratornim ventilom, ispitanici su povećavali frekvenciju disanja u skladu s povećanim metaboličkim zahtjevima za učestalijim udisajima nametnutim visokim intenzitetom plivanja (maksimalni ili blizu maksimalnog). Nasuprot tome, plivanje bez ventila uzrokovalo je gotovo nepromijenjenu frekvenciju disanja tijekom plivačkih testova. Na temelju rezultata ovog istraživanja može se zaključiti da se pri korištenju ventila za mjerenje respiratornih parametara tijekom plivanja može pojaviti drugačiji obrazac disanja (u usporedbi s plivanjem bez ventila). Sljedeći krvni testovi ([LA-], [HCO3-], pH, Po2 i Pco2) su primijenjeni da bi se utvrdilo jesu li različiti obrasci disanja (ukoliko su nađeni) rezultirali tako-đer i razlikom u odabranim fiziološkim parametri-ma. Nađene su značajne razlike [LA-] nakon maksimalnog testa 200 metara kraul između plivanja s ventilom (12,7 ± 2,4 mmol/l) i plivanja bez ventila (14,3 ± 2,1 mmol/l; p≤0.05), kao i razlike u [LA-] i [HCO3-] nakon plivanja do iscrpljenja između pli-vanja s ventilom ([LA-] = 9,9 ± 1,5 mmol/l; [HCO3-] = 18 ± 2 mmol/l) i plivanja bez ventila ([LA-] = 12,6 ± 2,8 mmol/l; [HCO3-] = 16 ± 2 mmol/l) (p≤0,01 i p≤0,.05, prema redoslijedu)

Atemminutenvolumen-beurteilung während des schwimmens Mittels der Rückwärts-Extrapolation der Ventilationskurve nach dem Schwimmen

The purpose of the present study was to ascertain whether the backward extrapolation method can be used to calculate the pulmonary ventilation (VE) appropriate in two different breathing conditions during swimming: with and without reduced breathing frequency. Five trained swimmers swam 400 m front crawl at Onset of Blood Lactate Accumulation (OBLA) velocity taking a breath every stroke cycle (normal breathing - NB). Then they repeated 400-m front crawl at NB velocity and with NB stroke frequency taking a breath every second stroke cycle (restricted breathing - RB). The measures included the parameters of blood acid-base status (pH, Po2, Pco2, [HCO3-]) and pulmonary ventilation (VE). Pulmonary ventilation during swimming was obtained by the backward extrapolation method (VEe) and by a theoretical model (VEt). There was no significant difference between VEeand VEtin NB. But the paired t-test showed a significant (p<0,05) difference between these two parameters in RB. Pco2 was also significantly higher after RB than after NB. It may be concluded that the backward extrapolation method could be used to determine the VE during swimming without reduced breathing frequency. If exertion is caused by hypercapnia and/or acidosis (reduced breathing frequency during swimming) then the backward extrapolation method is questionable.Uvod Jedan od osnovnih problema koji se javlja pri izravnom mjerenju plućne ventilacije (VE) tijekom plivanja u bazenu ili u malom bazenu sa suprotnim protokom vode, veže se uz uporabu opreme za mjerenje koja povećava otpor tijela i mijenja položaj tijela prigodom testiranja. Uslijed toga se povećava energetska potrošnja za vrijeme plivanja. Kako bi se prevladao taj problem, mjerenje bi trebalo provoditi uz najmanji mogući utjecaj na plivanje i fiziološki odgovor plivača. Stoga, se vrijednosti VE mogu mjeriti za vrijeme oporavka, a uz pomoć naknadne ekstrapolacije mogu se izračunati vrijednosti VE koje su bile aktualne za vrijeme plivanja. Metoda naknadne ekstrapolacije pokazala se dobrom za izračunavanje parametara VO2za vrijeme aktivnosti na tlu (Leger, Seliger i Brassard, 1980; Sleivert i Traegar-Mackinnon, 1991), kao i za vrijeme plivanja (Monpetiti, Leger, Lavoie i Cazorla, 1981; Costill, Maglischo i Richardson, 1992). Svrha ovog istraživanja bila je utvrditi izračunava li metoda naknadne ekstrapolacije ispravno VE u dvama različitim uvjetima disanja za vrijeme plivanja: sa i bez reduciranja frekvencije disanja. Metode Ispitanici i postupak. Pet treniranih plivača plivalo je 400 m kraul na razini anaerobnog praga (OBLA) uzimajući zrak pri svakom zaveslaju (normalno disanje, normal breathing, NB). Potom su ponovili dionicu 400 m kraul istom brzinom i frekvencijom zamaha, ali ovaj put uzimajući zrak kod svakog drugog zaveslaja (ograničeno disanje, reduced breathing, RB). Izmjereni su parametri acido-baznog statusa (pH, Po2, Pco2, [HCO3 -]) i plućna ventilacija (VE). Plućna ventilacija utvrđena je na osnovi naknadne ekstrapolacije VE krivulje oporavka u nultoj točka oporavka (VEe) (Leger et al., 1980) i pomoću teorijskog modela (VEt). Teorijski model sastavljen je na temelju snimaka i laboratorijskog mjerenja plućnoga kapaciteta. Rezultati i rasprava Nije utvrđena statistički značajna razlika između V E i V Et na razini normalnog disanja (NB). Međutim, t-test za zavisne uzorke pokazao je značajnu razliku između tih parametara pri ograničenom disanju (RB) (p<0.05). Također je utvrđeno da je razina Pco2 bila znatno viša nakon plivanja uz ograničeno disanje nego nakon plivanja uz normalno disanje. Town i suradnici (1990) izvješćuju da VE opada i do 50% u uvjetima RB u usporedbi s plivanjem u uvjetima NB. Sličan pad VE u ovom istraživanju dobiven je i prema teorijskom modelu (VEt). Došlo je čak i do povećanja VEe u uvjetima RB. Takvi rezultati pokazuju da povećanje Pco2 u uvjetima RB dovodi do povećanja VE neposredno nakon plivanja. Zbog toga je vrijeme od završetka plivanja do početka mjerenja (maksimalno 14 sekundi) plivačima bilo predugo za zadržavanje \u27plivačke\u27 VE (koja je bila ograničena za vrijeme plivanja). VE za vrijeme plivanja uz normalno disanje nije bila toliko smanjena kao u uvjetima RB. Promjene u pH, Po2 i Pco 2 nakon plivanja u uvjetima NB bile su premalene da bi mogle utjecati na VE neposredno nakon plivanja. Smanjenje VE za vrijeme plivanja uz RB bilo je kompenzirano povećanim dišnim volumenom (VT) (Dicker i sur., 1980; Town i sur., 1990). Kako bi se zadržala VE u vodi, plivači su koristili veći VT za vrijeme plivanja nego za vrijeme trčanja ili hodanja uz submaksimalan napor (Holmer, Stein, Saltin, Ekblon i Åstrand, 1974). U ovom istraživanju procijenjeni VT korišten u teorijskom modelu VE bio je gotovo jednak u oba uvjeta disanja (oko 5,6 l), što je znatno više od vrijednosti (2,9 l) dobivene za potpuno slobodno plivanje u bazenu (Holmer i sur., 1974). Zaključak Može se zaključiti da se metoda naknadne ekstrapolacije može koristiti kako bi se odredio VE za vrijeme plivanja bez redukcije frekvencije disanja. Ako je iscrpljenost uzrokovana nagomilavanjem CO2 (reducirana frekvencija disanja za vrijeme plivanja), tada je upotreba metode naknadne ekstrapolacije upitna.Das Ziel dieser Studie war, zu bestimmen, ob die Methode der Rückwärts-Extrapolation das Atemminuten-volumen (VE) in zwei verschiedenen Atmungszuständen während des Schwimmens errechnen kann: mit oder ohne reduzierter Atmungsfrequenz. Fünf professionelle Schwimmer schwammen 400 m Kraul bei OBLA-Geschwindigkeit und atmeten ein bei jedem Zyklus (normale Atmung - NB). Danach wiederholten sie 400 m Kraul bei NB-Geschwindigkeit und mit NB-Armzugfrequenz und atmeten ein bei jedem zweiten Zyklus (beschränkte Atmung - RB). Messungen umfassten die Parameter des Säure-Basen-Status im Blut (pH, Po2, Pco2, [HCO3-]) und das Atemminutenvolumen (VE). Das Atemminutenvolumen während des Schwimmens wurde durch die Methode der Rückwärts-Extrapolation (VEe) und durch das theoretische Modell (VEt) erlangt. Die gepaarten T-Tests zeigten einen bedeutenden (p<0,05) Unterschied zwischen VEe und VRt bei RB. Es gab aber keinen bedeutenden Unterschied zwischen diesen beiden Parametern bei NB. Pco2 war auch bedeutend höher nach RB als nach NB. Daraus kann man erschließen, dass die Methode der Rückwärts-Extrapolation bei der Bestimmung der VE während des Schwimmens ohne reduzierter Atmungsfrequenz angewendet werden könnte. Wenn die Anstrengung durch Hyperkapnie und/oder Azidose (reduzierte Atmungsfrequenz während des Schwimmens) verursacht wurde, ist die Anwendung der Methode der Rückwärts-Extrapolation fraglich

Intelligent device to help persons with autistic spectrum disorders with recognising other peoples emotions and manage their own stress / Intelligent device to help persons with autistic spectrum disorders with recognising other peoples emotions and manage their own stress

Raziskovalno delo obsega oblikovalski proces napredne tehnološke rešitve na področju zdravstva in izobraževanja. Oblikovali smo nosljiv inteligentni pripomoček za podporo oseb z motnjami avtističnega spektra (MAS) pri izzivih povezanih z aleksitimijo in tesnobo. Koncept vsebuje pametna očala, ki s pomočjo umetne inteligence (UI) prepoznavajo čustva oseb, s katerimi je uporabnik v interakciji. Rezultate mu sočasno sporočajo preko aplikacije za pametno uro s pomočjo vizualne in haptične podpore. Za lajšanje tesnobe je vključen podporni sistem, ki spremlja variabilnost uporabnikovega srčnega utripa (VSU) in ga vodi pri izvedbi dihalnih vaj. Rezultat sta koncept pametnih očal in prototip uporabniškega vmesnika aplikacije za pametno uro. Magistrsko delo je nastalo v tesnem sodelovanju z društvom ASPI (Društvo za pomoč odraslim osebam z motnjami avtističnega spektra – Aspergerjev sindrom), ki je s svojimi člani ter strokovnimi sodelavci aktivno sodelovalo pri etnografski raziskavi in participatornem oblikovalskem procesu.The following thesis explores the design process of an advanced technological solution in the field of healthcare and education. An intelligent wearable device was designed to support persons affected by autism spectrum disorders with challenges related to alexithymia and anxiety. The concept consists of smart glasses, which use artificial intelligence to recognize emotions of persons the user is interacting with. The results are communicated to the user by a smart watch application offering visual and haptic support. Anxiety is addressed by a support system based on heart rate variability monitoring, which guides users through breathing exercizes. Results of the process are concept smart-glasses and a prototype user interface for the smart-watch application. The thesis was developed in close collaboration with ASPI (Association for helping adults with Asperger syndrome), their members and professional associates who were actively involved in ethnographic research and a participatory design process

Impact of weekly swimming training distance on the ergogenicity of inspiratory muscle training in well trained youth swimmers.

The aim of this study was to examine the impact of weekly swimming training distance upon the ergogenicity of inspiratory muscle training (IMT). Thirty-three youth swimmers were recruited and separated into a LOW and HIGH group based on weekly training distance ( 41 km.wk-1, respectively). The LOW and HIGH groups were further subdivided into control and IMT groups for a 6-week IMT intervention giving a total of four groups: LOWcon, LOWIMT, HIGHcon, HIGHIMT. Before and after the intervention period, swimmers completed maximal effort 100 m and 200 m front crawl swims, with maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) assessed before and after each swim. IMT increased PImax (but not PEmax) by 36% in LOWIMT and HIGHIMT groups (P < 0.05) but 100 m and 200 m swims were faster only in the LOWIMT group (3% and 7% respectively, P < 0.05). Performance benefits only occurred in those training up to 31 km.wk-1 and indicate that the ergogenicity of IMT is affected by weekly training distance. Consequently, training distances are important considerations, among others, when deciding whether or not to supplement swimming training with IMT.N/

Inspiratory muscle fatigue at the swimming tumble turns: its occurrence and effects on kinematic parameters of the turns

Introduction: The present study had two objectives: 1) to investigate the effects of tumble turns on the development of inspiratory muscle fatigue (IMF) and compare this to whole swimming, and 2) to evaluate the effects of pre-induced IMF on the kinematic parameters of tumble turns. Fourteen young club-level swimmers (13 ± 2 years of ages) completed three swim trials.Methods: The first trial was used to determine the 400-m front crawl swim time at maximal effort (400FC). The other two trials consisted of a series of 15 tumble turns at the 400FC pace. In one of the turn-only trials, IMF was pre-induced (TURNS-IMF), whereas in the other turn-only trial it was not (TURNS-C).Results: Compared with baseline values, the values for maximal inspiratory mouth pressure (PImax) at the end of the swim were significantly lower at all trials. However, the magnitude of inspiratory muscle fatigue was less after TURNS-C (PImax decreased by 12%) than after 400FC (PImax decreased by 28%). The tumble turns were slower during 400FC than during TURNS-C and TURNS-IMF. In addition, compared to TURNS-C, turns in the TURNS-IMF were performed with higher rotation times and shorter apnea and swim-out times.Discussion: The results of the present study suggest that tumble turns put a strain on the inspiratory muscles and directly contribute to the IMF observed during 400FC swimming. Furthermore, pre-induced IMF resulted in significantly shorter apneas and slower rotations during tumble turns. IMF therefore has the potential to negatively affect overall swimming performance, and strategies should be sought to reduce its effects

3D modeling and printing of speaker enclosure

Cilj diplomskega dela je bil izdelati funkcionalno 3D natisnjeno ohišje za zvočnik in ugotoviti, kako na njegove akustične lastnosti vpliva uporaba različnih materialov. V ta namen smo izdelali tri enako oblikovana ohišja iz treh različnih termoplastov in izmerili njihove frekvenčne odzive ter harmonična popačenja. Kot teoretično osnovo smo predstavili 3D-tisk s poudarkom na opisu tehnologije, ki deluje na osnovi ekstrudiranja materialov oziroma termoplastov. Isto tehnologijo smo uporabili tudi za tisk ohišij. Temu sledi kratka predstavitev 3D-modeliranja, predstavitev elektrodinamičnih zvočnikov in ohišij za zvočnike. Ob pripravi slednjih smo ugotovili, da imajo najboljše akustične lastnosti okrogla ohišja, kar smo kasneje tudi upoštevali pri oblikovanju. Nazadnje smo ob pregledu raziskav predstavili in opisali zanimive zvočnike s 3D natisnjenimi ohišji. V eksperimentalnem delu smo opisali postopek načrtovanja in modeliranja eliptičnega ohišja ter tisk ohišja s tremi različnimi termoplastičnimi materiali oziroma filamenti, in sicer na osnovi ABS, PLA in kompozitnega filamenta PLA z dodatkom lesnih vlaken. Pri tem smo uporabili dva namizna tiskalnika – CubePro Duo in Witbox. Za tisk vseh treh ohišij smo uporabili enake nastavitve. Najboljši rezultat tiska smo dosegli s filamentom PLA na tiskalniku CubePro Duo, največ napak pa je nastalo pri tisku lesnega filamenta na tiskalniku Witbox. V ohišja smo s pomočjo lesenega obroča začasno vgradili 4-inčni širokopasovni zvočnik, kar nam je omogočilo merjenje akustičnih lastnosti posameznih ohišij. Meritve smo izvedli s pomočjo profesionalne opreme v gluhi sobi Fakultete za elektrotehniko v Ljubljani. Pri tem smo ugotovili, da frekvenčni odziv od idealnega odstopa za približno +/&#87225 dB in da so harmonska popačenja pod mejo zaznave. Z vidika akustike med posameznimi ohišji nismo izmerili relevantnih razlik.The goal of this thesis was to create a functional 3D printed speaker enclosure and to determine how its acoustic properties are affected by the use of different materials. For this purpose three identically shaped enclosures from three different thermoplastics were created and their frequency responses and harmonic distortions weremeasured. In theoretical part, 3D printing is presented with special emphasis on describing the technologies based on material extrusion, namely the extrusion of thermoplastics, which we have used to print the enclosures. This is followed by a brief presentation of 3D-modeling and presentations of electrodynamic loudspeakers and speaker enclosures. When preparing the latter we have discovered that spherical enclosures have the best acoustic properties, which we have taken into account when creating the design. While examining the state of present research, we have presented and described interesting speakers with 3D printed enclosures. The experimental part contains a description of the design and modeling processes of an elyptical enclosure as well as printing of the enclosure with three different thermoplastic materials or filamentsbased on ABS, PLA, and a composite filament of PLA and wood fibres. Two desktop printers were used, namely CubePro Duo and Witbox. Same settings for all three prints were used. The best results were achieved when printing with PLA filament on CubePro Duo whilethosewith wood filament on Witbox were the worst. The speaker was first fixed onto a wooden ring and this assembly was then temporarily attached to each enclosure to study its acoustic properties. The measurementswere conducted in an anechoic chamber of the Faculty of Electrical Engineering in Ljubljana using professional equipment. Our frequency responses differedby approximately ±5 dB from those stated by manufacturer. Harmonic distortions were below the level of perception. No relevant acoustic differences between the three enclosures were found

CAN BLOOD GAS AND ACID-BASE PARAMETERS AT MAXIMAL 200 METERS FRONT CRAWL SWIMMING BE DIFFERENT BETWEEN FORMER COMPETITIVE AND RECREATIONAL SWIMMERS?

The aim of the present study was to ascertain whether maximal 200 m front crawl swimming strategies and breathing patterns influenced blood gas and acid-base parameters in a manner which gives advantage to former competitive swimmers in comparison with their recreational colleagues. Twelve former competitive male swimmers (the CS group) and nine recreational male swimmers (the RS group) performed a maximal 200 m front crawl swimming with self- selected breathing pattern. Stroke rate (SR) and breathing frequency (BF) were measured during the swimming test. Measures also included blood lactate concentration ([LA]) and parameters of blood acid-base status before and during the first minute after the swimming test. The CS group swam faster then the RS group. Both groups have similar and steady SR throughout the swimming test. This was not matched by similar BF in the CS group but matched it very well in the RS group (r = 0.89). At the beginning of swimming test the CS group had low BF, but they increased it throughout the swimming test. The BF at the RS group remained constant with only mirror variations throughout the swimming test. Such difference in velocity and breathing resulted in maintaining of blood Po2 from hypoxia and Pco2 from hypercapnia. This was similar in both groups. [LA] increased faster in the CS group than in the RS group. On the contrary, the rate of pH decrease remained similar in both groups. The former competitive swimmers showed three possible advantages in comparison to recreational swimmers during maximal 200 m front crawl swimming: a more dynamic and precise regulation of breathing, more powerful bicarbonate buffering system and better synchronization between breathing needs and breathing response during swimmin