Biomedical Engineering and Bioengineering Commons^™

A Robust Lpc Filtering Method For Time-Resolved Morphology Of Eeg Activity Analysis, Jin Xu, Mark Davis, Ruairí De Fréin

Conference Papers

This paper introduces a new time-resolved spectral analysis method based on Linear Prediction Coding (LPC) method that is particularly suited to the study of the dynamics of EEG (Electroencephalogram) activity. The spectral dynamic of EEG signals can be challenging to analyse as they contain multiple frequency components and are often heavily corrupted by noise. Furthermore, the temporal and spectral resolution that can be achieved is limited by the Heisenberg-Gabor uncertainty principle [1]. The method described here is based on a z-plane analysis of the poles of the LPC which allows us to identify and estimate the frequency of the dominant …

Quantized Nonnegative Matrix Factorization, Ruairí De Fréin

Conference papers

Even though Nonnegative Matrix Factorization (NMF) in its original form performs rank reduction and signal compaction implicitly, it does not explicitly consider storage or transmission constraints. We propose a Frobenius-norm Quantized Nonnegative Matrix Factorization algorithm that is 1) almost as precise as traditional NMF for decomposition ranks of interest (with in 1-4dB), 2) admits to practical encoding techniques by learning a factorization which is simpler than NMF’s (by a factor of 20-70) and 3) exhibits a complexity which is comparable with state-of-the-art NMF methods. These properties are achieved by considering the quantization residual via an outer quantization optimization step, in …

Multimodal Wearable Sensors For Human-Machine Interfaces, Mark Nolan

Doctoral

Certain areas of the body, such as the hands, eyes and organs of speech production, provide high-bandwidth information channels from the conscious mind to the outside world. The objective of this research was to develop an innovative wearable sensor device that records signals from these areas more conveniently than has previously been possible, so that they can be harnessed for communication. A novel bioelectrical and biomechanical sensing device, the wearable endogenous biosignal sensor (WEBS), was developed and tested in various communication and clinical measurement applications.

One ground-breaking feature of the WEBS system is that it digitises biopotentials almost …

Novel Bioelectrical Measurement Using A Digital Biopotential Monode, Mark Nolan, Edward Burke, Eugene Coyle

Conference Papers

In conventional biopotential recording, two or more electrodes are placed on the body. A unipolar lead records the time-varying electrical potential at a single point (relative to a reference potential) via one signal electrode. A bipolar lead records the time-varying potential difference between two points via two signal electrodes. In each case, the signal electrodes are connected to high impedance amplifier inputs, while an additional electrode provides a low-impedance path between the amplifier and human subject. Bipolar leads are usually preferred since interference appearing at both signal electrodes can be eliminated using an instrumentation amplifier with high CMRR. A drawback …

An Investigation Of The Use Of A High Resolution Adc As A Digital Biopotential Amplifier, Damon Berry, Frank Duignan, Richard Hayes

Conference Papers

Sigma delta analogue to digital converters have been used in many signal processing applications including some commercially available systems for sampling of bio-signals Bio-potential amplifiers have traditionally utilised specialised highquality analogue components to amplify bio-signals.

The central aim of this work is to investigate the benefits of using high-resolution sigma delta conversion as a digital amplification stage in the signal path of a bio-potential amplifier. A number of system arrangements specific to bio-potential measurement are presented and discussed. These arrangements are designed to use the high resolution capacity of the sigma delta converter in different ways, providing different benefits. To …