Chris Heneghan

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The study of human cognition, and preoperative functional brain mapping, are facilitated through the use of magnetoencephalography (MEG). However, the noise present in such recordings is significant relative to the signals of interest. To circumvent this issue multiple trials are performed for the same task and an ensemble average is performed to increase(More)
Orthogonal frequency division multiplexed systems are particularly prone to errors due to clipping, since they typically have high peak-to-average power ratios. In this paper, we propose a more efficient clipping mitigation technique based on quasi maximum-likelihood detection which gives approximately 3 dB gain for the SER of 2 /spl times/ 10/sup -3/ and(More)
– The PR interval extracted from the surface electrocardiogram (ECG) may be used for the noninvasive assessment of autonomic nervous system (ANS) activity at the atrioventricular (AV) node. Accurate automated detection of the characteristic P wave onset and QRS complex onset is complicated by a number of factors including varying wave morphology, external(More)
The pathophysiological mechanisms of Atrial Fibri-llation (AF) are not entirely clear yet, and there is no full explanation for the development and evolution of the arrhythmia. The goal of this study is to find inter-atrium differences in electrophysiological behavior between persistent and paroxysmal AF. The database analyzed contains intra-cardiac records(More)
We present a technique for dimension reduction. The technique uses a gradient descent approach to attempt to sequentially find orthogonal vectors such that when the data is projected onto each vector the classification error is minimised. We make no assumptions about the structure of the data and the technique is independent of the classifier model used.(More)
—A method to elucidate PP and PR electrocardiogram variability during periods of obstructive apnea based on averaged interval length is considered. R and P peaks are extracted from 28 pediatric subjects' ECG signal using a Hilbert transform based technique. Visual analysis of phasic changes during obstructive events indicate that 21 of 28 of subjects(More)
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