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The aim of this study is to develop a new, computationally-efficient, anatomically-realistic 3D bidomain cardiac electrical activity model using widely available software and standard low-cost hardware. The model incorporates whole-heart embedded in a human torso, spontaneous activation of sinoatrial node and specialized conduction system with heterogeneous action potential morphologies. The model is capable of generating realistic body surface electrocardiograms (ECGs) and is proposed as a useful tool for investigating some major issues in heart pathophysiology and in stimulation; such as simulating and optimizing synchronized electrical cardioversion, defibrillation and pacing stimulation., Cilj studije je razviti računalno efikasan, anatomski realističan 3D model električne aktivnosti cijelog ljudskog srca na široko dostupnoj računalnoj opremi. Model uključuje cijelo srce okruženo plućima i postavljeno unutar ljudskog torza, sa spontanom aktivacijom sinus-atrijskog čvora i specijaliziranim vodljivim putevima s heterogenim morfologijama akcijskih potencijala. Model omogućuje simuliranje elektrokardiograma (EKG) realističnog oblika te ga je moguće koristiti za istraživanje srčanih patofiziologija, simuliranje i optimizaciju sinkronizirane električne kardioverzije, defibrilacije ili simulacije različitih srčanih stimulacija.

Medicine and health care have changed dramatically in the past few decades and they depend on high technology for prevention, diagnosis and treatment of diseases, and for patient rehabilitation. Modern biomedical research and health care are provided by multidisciplinary teams in which biomedical engineers contribute to the advancement of knowledge equally as medical professions. Biomedical engineering represents one (out of two) the most rapidly growing branches of industry in the developed world [1] (the other are sustainable and renewable energy sources). The new knowledge gained by basic biomedical engineering research (at gene, molecular, cellular, organ and system level) has high impact on the growth of new medical products and boosts industries, including small and medium size enterprises (SMEs). SMEs are expected to bring to the market new products and services for health care delivery [2]. Health is the major theme of the specific Programme on Cooperation under the European Seventh Framework Programme, with a total budget of e6.1 billion over the duration of FP7. The objective of health research under FP7 is to improve the health of European citizens and stir up the competitiveness of health-related industries and businesses, while addressing global health issues, life improving and develop life saving technologies. Hospitals and other medical institutions have a commitment to take care of all kinds of high technology devices including the hospital information systems, networks and their safety and security. Growing technological participation in health services enforces the support of technologically specialized personnel, trained clinical engineers. Worldwide, the educational system has adopted the curricula of biomedical engineering and of clinical engineering. Professional organizations are building certification system for biomedical and clinical engineers and the continuous education (life long learning) structures. The development of biomedical enginee, Medicina i zdravstvena zaštita su se dramatično promijenile u posljednjih nekoliko desetljeća, i ovise o visokoj tehnologiji za prevenciju, dijagnostiku i liječenje bolesti, i za rehabilitaciju pacijenata. Moderna biomedicinska istraživanja i zdravstvena zaštita osigurava se multidisciplinarnim timovima u kojima biomedicinski inženjeri doprinose unapređenju znanja jednako kao i medicinski stručnjaci. Biomedicinsko inženjerstvo predstavlja jedno (od dvije) najbrže rastuće grane industrije u razvijenom svijetu [1] (druga grana su održivi i obnovljivi izvori energije). Nova znanja stečena temeljnim istraživanjima u biomedicinskom inženjerstvu (na razini gena, molekula, stanice, organa i na razini sustava) imaju velik utjecaj na razvoj novih medicinskih proizvoda i jačanje industrije, uključujući i mala i srednja poduzeća (MSP). Očekuje se da mala i srednja poduzeća na tržište donesu nove proizvode i usluge za zdravstvenu skrb [2]. Zdravlje je glavna tema specifičnog programa o suradnji u okviru europskog sedmog okvirnog programa (FP7), s ukupnim proračunom od 6,1 milijarde eura tijekom trajanja FP7. Cilj istraživanja u području zdravstva u okviru FP7 je poboljšati zdravlje europskih građana i povećati konkurenciju u okviru zdravstvene djelatnosti i industrije, a istovremeno voditi računa o globalnim zdravstvenim problemima, poboljšanju života i razvoju tehnologija za spašavanje života. Bolnice i druge medicinske ustanove imaju obvezu voditi brigu o svim vrstama uređaja visoke tehnologije, uključujući bolničke informatičke sustave, mreže i te o njihovoj sigurnosti. Povećanje udjela tehnologije u zdravstvu proizvelo je potrebu za tehnološki specijaliziranim osobljem, kliničkim inženjerima. Diljem svijeta, obrazovni sustav je usvojio visokoškolske programe biomedicinskog inženjerstva i kliničkog inženjerstva. Profesionalne organizacije su izgradile sustav potvrđivanja za biomedicinske i kliničke inženjere i za njihovo kontinuirano obrazovanje (cjeloživotno učenje). Razvoj

In patients undergoing Coronary Artery Bypass G rafting (CABG) surgery postoperative atrial fibrillation (AF) occurs with prevalence of up to 40%. The highest incidence is between the second and third day after the operation. Following cardiac surgery AF causes various complications, hemodynamic instability, and can cause heart attack, cerebral and other thromboemolisms. AF increases morbidity, duration and expense of medical treatment. This study aims to identify patients at high risk of postoperative AF. An early prediction of AF would provide a timely prophylactic treatment and would reduce incidence of arrhythmia. Patients at low risk of postoperative AF could be excluded from the side effects of anti-arrhythmic drugs. The investigation included 50 patients in whom lead II electrocardiograms were continuously recorded for 48 hours following CABG. Univariate statistical analysis was used in the search of signal features that might predict AF. The most promising identified features were: P wave duration, RR interval duration and PQ segment level. On the basis of these a nonlinear multivariate prediction model was made deploying a Support Vector Machine (SVM) classifier. The prediction accuracy was found uprising over the time. At 48 hours following CABG; the measured best average sensitivity was 95 . 9% and specificity 93. 4% . The positive and negative predictive accuracy were 88. 9% and 98. 8% , respectively and the overall accuracy was 94. 6% . In regard to the prediction accuracy, the risk assessment and prediction of postoperative A F are optimal to be done in the period between 24 and 48 hours following CABG., Postoperacijska fibrilacija atrija (AF) pojavljuje se u oko 40% pacijenata podvrgnutih operaciji aortokoronarnog premoštenja (CABG), s najvećom učestalosti pojavljivanja oko trećeg dana nakon operacije. Postoperacijska AF može stvoriti brojne komplikacije poput hemodinamske nestabilnosti, srčanog udara, cerebralnih i drugih tromboembolija; povećava morbiditet, trajanje i troškove liječenja. S tudija ima za cilj rano otkrivanje pacijenta sa visokim rizikom razvoja postoperacijske AF, što bi osiguralo pravovremenu profilaktičku terapiju i smanjilo učestalost aritmije, dok bi pacijenti sa niskim rizikom razvoja postoperacijske AF bili pošteđeni nuspojava antiaritmičkih lijekova. Podatkovni skup uključuje 50 pacijenata, snimanih II standardnim odvodom elektrokardiografa, kontinuirano u razdoblju od 48 sati nakon operacije. Univarijatna statistička analiza korištena je za određivanje parametara signala koji bi mogli predvidjeti AF, te su kao najznačajniji određeni: trajanje P vala, trajanje RR intervala i razina PQ spojnice; na temelju kojih je izveden nelinearni multivarijatni predikcijski model zasnovan na SVM klasifikatoru. Ukupna predikcijska točnost modela povećava se s vremenom. U 48 . satu nakon operacije najbolje prosječne značajke iznosile su: osjetljivost 95 , 9%, specifičnost 93, 4% , pozitivna prediktivnost 88, 9% , negativna prediktivnost 98 , 8% te ukupna točnost 94, 6% . Prema rezultatima predikcijske točnosti, procjenu rizika i predikciju postoperacijske AF optimalno bilo bi načiniti u periodu između 24-tog i 48-og sata nakon operacije ugradnje aortokoronarnih premosnica.

Mean voltages of right and left temporal and mass eter muscle (RAT, LAT, RM, LM) during maximum voluntary clenching in maximal intercuspal position (MI), retruded contact position (RCP) and incisal position (IP) were examined. There was no significant difference between sexes in any of the examined positions (p>0.05). For the symmetric positions of the lower jaw (MI,P,RCP) there was slightly higher muscle activity on the right side, although not significant (p>0.05). The biggest reduction of the activity of masseter muscle was observed in RCP and the biggest reduction of the activity of temporal muscle was observed in IP, indicating that masseter muscle is more responsible for the protrusive isometric contraction and temporal muscle is more responsible for the retrusive isometric activity. Greater inhibitory input was observed on the masseter motoneurons than on the motoneurons of the temporal muscle in RCP, while greater inhibitory input was observed on the motoneurons of the temporal muscle than on the motoneurons of the masseter muscle in IP, indicating that various receptors might be responsible for the reduction of maximal voluntary clenching efforts: spatial receptors in temporomandibular joints and muscle tendon organs, as well as the receptors in periodontal membrane o f the anterior and posterior teeth., Istraživana je aktivnost desnog m. temporalisa i massetera (RAT, RM) i lijevog m. temporalisa i massetera (LAT, LM) u različitim simetričnim okluzijskim položajima mandibule: u maksimalnoj interkuspidaciji (MI), incizalnom položaju (IP) i retrudiranome kontaktnom položaju (RCP). Nije bilo značajne razlike u mioelektričnoj aktivnosti mišića između muškoga i ženskoga spola (p>0,05). U simetričnim okluzijskim položajima postojala je naznatno veća aktivnost mišića na desnoj strani, premda ne i signifikantna (p>0,05). Najveće smanjenje aktivnosti massetera bilo je u RCP, a temporalisa u IP, što pokazuje da je masseter odgovorniji za protruzivnu izometričnu aktivnost, a temporalis za retruzivnu. U IP svi mišići znatno su smanjili aktivnost u odnosu prema Ml, što upućuje na refleksni inhibicijski input periodontalnih receptora frontalnih zuba na n. motorius n. trigemini.

Opisan je novi EMGa-1 uređaj, baziran na IBM kompatibilnom PC-u za preciznu analizu bioelektrične aktivnosti sa 6 kanala i analizu zvuka okluzije s 2 kanala. Ovo ispitivanje provedeno je s ciljem da se demonstriraju vrijednosti aparature u bazičnim eksperimentima i u kliničkoj evaluaciji funkcije. U njemu je sudjelovalo 10 ispitanika sa svim zubima i normalnom okluzijom. EMG signali registrirani su iz oba prednja temporalisa i iz oba masetera, simultano sa zvukom okluzije. Matematičke opcije, superponiranje signala i kursorska mjerenja omogućili su veliku raznolikost analize. Srednje vrijednosti mišićne aktivnosti u nekim funkcijskim položajima i za vrijeme mastikacije u suglasnosti su s rezultatima drugih autora. Moguće je mjeriti i tako kratkotrajne promjene kao što su mišićni refleksi. Neki parametri kao što su srednji mišićni naponi izotonične i izometrične aktivnosti i vremenski slijed zvučnih i/ili mišićnih signala izmjereni su prvi put, što su omogućile neke inovacije mjernog sustava EMGa-1 aparature (superponiranje grafičkih prozora mišićnih i/ili zvučnih signala i zoomin tehnika)., A new PC based system (EMGa-1) was developed for precise registration and analysis of bioelectrical muscle activity (from 6 channels) and sounds of occlusal contacts (from 2 channels). This study was performed to demonstrate its value for direct functional control during both basic experiments and clinical procedures. Ten individuals with normal occlusion and all teeth participated in the study. EMG signals were recorded from the anterior temporal and masseter muscles, together with the sounds of occlusal contacts in some experimental procedures. Mathematical options, cursor measurements and superimposing of various signals allowed a variety of analyses to be made. Mean voltages of muscle activity in some functional positions and mastication were in accordance with the results of other authors. It was also possible to measure such short-lasting events as muscle reflexes. Some parameters, such as the mean voltage during isotonic and isometric activity in an open-close-clench cycle and timing of the occlusal sounds from the left and the right side, were measured for the first time, due to some inovations of the EMGa-1 apparatus (superimposing of graphic windows and zoom technique).