| 1. |
- Flynn, M. J., et al.
(författare)
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Moving from Petaflops to Petadata
- 2013
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Ingår i: Communications of the ACM. - : Association for Computing Machinery (ACM). - 0001-0782 .- 1557-7317. ; 56:5, s. 39-42
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Forskningsöversikt (refereegranskat)abstract
- The race to build ever-faster supercomputers is on, with more contenders than ever before. However, the current goals set for this race may not lead to the fastest computation for particular applications. A creator of the TOP500 supercomputers list rightfully claimed the list sheds light on only one dimension of modern supercomputing, which is a relatively narrow one. This Viewpoint is intended to induce thinking about alternative performance measures for ranking, possibly ones with a much wider scope. This Viewpoint is not offering a solution. It is offering a theme for brainstorming. To demonstrate this need for such thinking, one will use the example of a particular type of systems, based on a kind of dataflow approach. The current era of supercomputing is referred to as the petascale era. The next big HPC challenge is to break the exascale barrier. However, due to technological limitations, there is growing agreement that reaching this goal will require a substantial shift toward hardware/software codesign.
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| 2. |
- Rashkovska, A., et al.
(författare)
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Medical-grade ECG sensor for long-term monitoring
- 2020
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 20:6
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Tidskriftsartikel (refereegranskat)abstract
- The recent trend in electrocardiogram (ECG) device development is towards wireless body sensors applied for patient monitoring. The ultimate goal is to develop a multi-functional body sensor that will provide synchronized vital bio-signs of the monitored user. In this paper, we present an ECG sensor for long-term monitoring, which measures the surface potential difference between proximal electrodes near the heart, called differential ECG lead or differential lead, in short. The sensor has been certified as a class IIa medical device and is available on the market under the trademark Savvy ECG. An improvement from the user’s perspective—immediate access to the measured data—is also implemented into the design. With appropriate placement of the device on the chest, a very clear distinction of all electrocardiographic waves can be achieved, allowing for ECG recording of high quality, sufficient for medical analysis. Experimental results that elucidate the measurements from a differential lead regarding sensors’ position, the impact of artifacts, and potential diagnostic value, are shown. We demonstrate the sensors’ potential by presenting results from its various areas of application: medicine, sports, veterinary, and some new fields of investigation, like hearth rate variability biofeedback assessment and biometric authentication.
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| 3. |
- Tomasic, Ivan, et al.
(författare)
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Can the regression trees be used to model relation between ECG leads?
- 2016
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Ingår i: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST. - Cham : Springer International Publishing. - 9783319470627 ; , s. 467-472
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Konferensbidrag (refereegranskat)abstract
- Presented is a preliminary study that investigates regression trees application for the purpose of mapping relationship between three differential ECG leads and leads of the 12-lead ECG. The approach was evaluated on a single ECG measurement on which it was superior to two syntheses performed by universal and personalized linear transformations, in terms of correlation coefficients between the synthesized and measured leads. A prominent imperfection however is that the regression trees can output only a limited number of values equal to the number of leaf nodes. The paper indicates some ideas on how to overcome this deficiency.
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| 4. |
- Tomasic, Ivan, et al.
(författare)
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Smart wireless sensor for physiological monitoring
- 2015
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Ingår i: Studies in Health Technology and Informatics, vol. 211. - 9781614995159 ; , s. 295-301
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Konferensbidrag (refereegranskat)abstract
- Presented is a wireless body sensor capable of measuring local potential differences on a body surface. By using on-sensor signal processing capabilities, and developed algorithms for off-line signal processing on a personal computing device, it is possible to record single channel ECG, heart rate, breathing rate, EMG, and when three sensors are applied, even the 12-lead ECG. The sensor is portable, unobtrusive, and suitable for both inpatient and outpatient monitoring. The paper presents the sensor's hardware and results of power consumption analysis. The sensor's capabilities of recording various physiological parameters are also presented and illustrated. The paper concludes with envisioned sensor's future developments and prospects.
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| 5. |
- Tomasic, Ivan, et al.
(författare)
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State-Space versus Linear Regression Models between ECG Leads
- 2021
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Ingår i: 2021 44th International Convention on Information, Communication and Electronic Technology, MIPRO 2021 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9789532331011 ; , s. 357-362
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Konferensbidrag (refereegranskat)abstract
- The first attempts to modeling relationships between electrocardiographic leads, were based on measuring lead vectors by using models of human torso (deterministic approach), and by estimating liner regression models between leads of interest (statistical models). Among the most recent attempts, one of the most prominent is the state-space models approach, because of better noise immunity compared to mean squared error estimated statistical models. This study uses state-space models to synthesize precordial leads and Frank leads, from leads I, II, and V1. The synthesis was evaluated with the linear correlation coefficient (CC) on 200 measurements from the Physionet's PTB diagnostic ECG database. The results show better performance of regression models (mean CC between 0.88 and 0.96) than the state-space models (mean CC between 0.78-0.86). The leads were not pre-aligned for the R-peaks, which can be the main cause for the lower performances of state-space models, as a previous study has also shown. Residual baseline wander (after filtering) was the dominant reason for not obtaining better synthesis results with both methods.
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| 6. |
- Tomasic, Ivan, et al.
(författare)
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The implications of the lead theory on the patch ECG devices positioning and measurement
- 2019
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Ingår i: IFMBE Proceedings. - Singapore : Springer Verlag. ; , s. 693-696
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Konferensbidrag (refereegranskat)abstract
- Currently we are witnessing fast development of patch ECG devices, some of which have already been extensively evaluated and shown to be useful for detecting arrhythmias. The research about using the patch ECG devices for purposes other than arrhythmia detection has been scarce. The efficiency of patch electrocardiography for a specific purpose can depend on the devices location on the body surface. It is still an open question where to position the ECG patch devices, and should the position depend on the specific purpose and perhaps even be personalized. We present the lead theory of differential leads (ECG leads obtained by patch ECG devices) and discuss its implications on the patch ECG devices positioning on the body surface.
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| 7. |
- Trobec, R., et al.
(författare)
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Commercial ECG systems
- 2018
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Ingår i: SpringerBriefs in Applied Sciences and Technology. - Cham : Springer Verlag. - 9783319593388 ; , s. 101-114
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Bokkapitel (refereegranskat)abstract
- Besides the standard 12-lead ECG and the Holter monitor, today the market offers a wide range of modern ECG devices and services supported by the latest developments in ICT. This chapter is devoted to the current state-of-the-art from the area of ECG with a reduced number of leads. We focus on ECG wireless body sensors, differentiating between those that measure only heart rate and are used just for entertainment or during sport activities, and those that actually measure and analyze the ECG signal, with all its waveforms. The latter are elaborated in more detail, particularly our differential ECG sensor and its commercial version Savvy, for which we provide also a comprehensive comparison to other state-of-the-art sensors in that field. It is, however, inevitable that the state-of-the art will change in the future. The constant progress in ICT will always drive the development of new and improved ECG devices.
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| 8. |
- Trobec, R., et al.
(författare)
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Detection and Treatment of Atrial Irregular Rhythm with Body Gadgets and 35-channel ECG
- 2019
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Ingår i: 2019 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics, MIPRO 2019 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9789532330984 ; , s. 301-308
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Konferensbidrag (refereegranskat)abstract
- The atrial irregular rhythm, often reflected in atrial fibrillation, undulation or flutter, is recognized as one of the major causes of brain stroke and entails an increased risk of thromboembolic events because it increases the likelihood of blood clots formation. Its early detection is becoming an increasingly important preventive measure. The paper presents a simple methodology for the detection of atrial irregular rhythm by ECG body gadget that can perform long-term measurements, e.g. several weeks or more. Multichannel ECG, on the body surface, gives a more detailed insight into the atrial activity in comparison to standard 12-lead ECG. The information from MECG is compared with single-channel patch ECG. The obtained results suggest that the proposed methodology could be useful in treatments of atrial irregular rhythm. One can obtain a reliable information about the time and duration of fibrillation events, or determine arrhythmic focuses and conductive pathways in heart atria, or study the effects of antiarrhythmic drugs on existing arrhythmias and on an eventual development of new types of arrhythmias.
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| 9. |
- Trobec, R., et al.
(författare)
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ECG pilot studies
- 2018
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Ingår i: SpringerBriefs in Applied Sciences and Technology. - Cham : Springer Verlag. - 9783319593388 ; , s. 61-75
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Bokkapitel (refereegranskat)abstract
- The use of wireless ECG body sensors in two pilot studies is presented. The first study, running at the Department of Cardiovascular Surgery of the University Medical Centre Ljubljana, is focused on the investigation of postoperative atrial fibrillation. The patients are monitored with wireless ECG body sensors one day before and five days after the surgery. The second study has been established at the primary care level in the Community Health Centre Ljubljana, with the intention to establish heart rhythm screening. As both studies are still in progress, we present just their setup and some interesting findings that emerged in their starting phase. Based on evidences from long-term ECG measurements, we identify several still open ECG research questions that could utilize the vast amount of long ECG recordings obtained from the pilot studies.
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| 10. |
- Trobec, R., et al.
(författare)
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Final remarks and conclusions
- 2018
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Ingår i: SpringerBriefs in Applied Sciences and Technology. - Cham : Springer Verlag. - 9783319593388 ; , s. 115-119
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Bokkapitel (refereegranskat)abstract
- The content of our book, devoted to body sensors and their implications to electrocardiography, is recapitulated with this chapter. The identified challenges in long-term ECG data analytics are discussed. Based on the presented material, the near future of mHealth perspectives is foreseen regarding the technology, the usability, and the potential of increased users’ awareness for their own health.
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