43 research outputs found
Revisiting QRS detection methodologies for portable, wearable, battery-operated, and wireless ECG systems
Cardiovascular diseases are the number one cause of death worldwide. Currently, portable battery-operated systems such as mobile phones with wireless ECG sensors have the potential to be used in continuous cardiac function assessment that can be easily integrated into daily life. These portable point-of-care diagnostic systems can therefore help unveil and treat cardiovascular diseases. The basis for ECG analysis is a robust detection of the prominent QRS complex, as well as other ECG signal characteristics. However, it is not clear from the literature which ECG analysis algorithms are suited for an implementation on a mobile device. We investigate current QRS detection algorithms based on three assessment criteria: 1) robustness to noise, 2) parameter choice, and 3) numerical efficiency, in order to target a universal fast-robust detector. Furthermore, existing QRS detection algorithms may provide an acceptable solution only on small segments of ECG signals, within a certain amplitude range, or amid particular types of arrhythmia and/or noise. These issues are discussed in the context of a comparison with the most conventional algorithms, followed by future recommendations for developing reliable QRS detection schemes suitable for implementation on battery-operated mobile devices.Mohamed Elgendi, Björn Eskofier, Socrates Dokos, Derek Abbot
The VPLF method for vanishing point computation
Abstract A basic problem in computer vision is the extraction of 3D vanishing points (VP) out of 2D perspective projections. VP analysis provides strong cues for inferring the 3D structure of a scene from only a single view. In this work we present a novel method for VP computation based on a likelihood function that characterizes the plausibility of a point as VP. The performance of our method has been tested with a variety of arti®cial and real scenes and has been found very promising.