Liam Kilmartin

Intra-Vehicle Networks: A Review

Automotive electronics is a rapidly expanding area with an increasing number of safety, driver assistance, and infotainment devices becoming standard in new vehicles. Current vehicles generally employ a number of different networking protocols to integrate these systems into the vehicle. The introduction of large numbers of sensors to provide driver assistance applications and the associated high-bandwidth requirements of these sensors have accelerated the demand for faster and more flexible network communication technologies within the vehicle. This paper presents a comprehensive overview of current research on advanced intra-vehicle networks and identifies outstanding research questions for the future.

Compressed Sensing for Bioelectric Signals: A Review

This paper provides a comprehensive review of compressed sensing or compressive sampling (CS) in bioelectric signal compression applications. The aim is to provide a detailed analysis of the current trends in CS, focusing on the advantages and disadvantages in compressing different biosignals and its suitability for deployment in embedded hardware. Performance metrics such as percent root-mean-squared difference (PRD), signal-to-noise ratio (SNR), and power consumption are used to objectively quantify the capabilities of CS. Furthermore, CS is compared to state-of-the-art compression algorithms in compressing electrocardiogram (ECG) and electroencephalography (EEG) as examples of typical biosignals. The main technical challenges associated with CS are discussed along with the predicted future trends.

Xilinx FPGA implementation of an image classifier for object detection applications

This paper describes an FPGA and distributed RAM architecture for an image classifier, implementing object classification stages of an object detection system. The system offers significant performance increase over current programmable DSP-based implementations. The paper shows that the considerable performance improvement using the FPGA solution results from the availability of high I/O resources and pipelined architecture. It also illustrates the suitability of an FPGA solution for tasks (such as real-time video processing) that have a large data throughput and require complex algorithmic manipulations. The system has been implemented using the RC1000-PP Virtex FPGA-based development platform and Handel-C hardware description language.

Performance analysis of secure session initiation protocol based VoIP networks

The commercial deployment of voice over internet protocol (VoIP) networks (and associated packet switching technologies) has gathered pace in the recent years. However, a major concern with such networks is the issue of the security of networks based on such open standards. Little research has been carried out into examining the options for securing VoIP networks and, more specifically, the impact which implementing such security architectures and protocols will have on the performance of such secure networks. This paper describes the research, which has been carried out into the development of a realistic model for carrying out simulations of the performance of secure session initiation protocol based VoIP networks. The results of the performance analysis obtained using this model are presented with a discussion of the implications of these results for designers considering implementation of real secure VoIP networks.

Accurate monitoring of human physical activity levels for medical diagnosis and monitoring using off-the-shelf cellular handsets

Numerous laboratory-based studies have been reported on the use of accelerometry for gait and activity analysis particularly among cohorts of elderly subjects. A drawback of such studies is the use of custom hardware platforms worn by subjects. This paper introduces a system solely utilizing accelerometers embedded in off-the-shelf cellular handsets that allow medical professionals and caregivers to remotely monitor the activity characteristics of elderly patients in the home or in the community. The use of ubiquitous cellular handsets makes the system far more acceptable to patients and enables the use of the system to be extended beyond healthcare facilities into the home environment. Mobile handset power consumption issues and other relevant handset and mobile handset application characteristics have been investigated in the context of the deployment of the proposed system.

Off-the-shelf mobile handset environments for deploying accelerometer based gait and activity analysis algorithms

Over the last decade, there has been substantial research interest in the application of accelerometry data for many forms of automated gait and activity analysis algorithms. This paper introduces a summary of new “of-the-shelf” mobile phone handset platforms containing embedded accelerometers which support the development of custom software to implement real time analysis of the accelerometer data. An overview of the main software programming environments which support the development of such software, including Java ME based JSR 256 API, C++ based Motion Sensor API and the Python based “aXYZ” module, is provided. Finally, a sample application is introduced and its performance evaluated in order to illustrate how a standard mobile phone can be used to detect gait activity using such a non-intrusive and easily accepted sensing platform.

Volume and shape analysis of subcortical brain structures and ventricles in euthymic bipolar I disorder.

Previous structural magnetic resonance imaging (S-MRI) studies of bipolar disorder have reported variable morphological changes in subcortical brain structures and ventricles. This study aimed to establish trait-related subcortical volumetric and shape abnormalities in a large, homogeneous sample of prospectively confirmed euthymic bipolar I disorder (BD-I) patients (n=60), compared with healthy volunteers (n=60). Participants were individually matched for age and gender. Volume and shape metrics were derived from manually segmented S-MR images for the hippocampus, amygdala, caudate nucleus, and lateral ventricles. Group differences were analysed, controlling for age, gender and intracranial volume. BD-I patients displayed significantly smaller left hippocampal volumes and significantly larger left lateral ventricle volumes compared with controls. Shape analysis revealed an area of contraction in the anterior head and medial border of the left hippocampus, as well as expansion in the right hippocampal tail medially, in patients compared with controls. There were no significant associations between volume or shape variation and lithium status or duration of use. A reduction in the head of the left hippocampus in BD-I patients is interesting, given this regions link to verbal memory. Shape analysis of lateral ventricular changes in patients indicated that these are not regionally specific.

Cortical thinning and caudate abnormalities in first episode psychosis and their association with clinical outcome.

First episode psychosis (FEP) has been associated with structural brain changes, largely identified by volumetric analyses. Advances in neuroimaging processing have made it possible to measure geometric properties that may identify subtle structural changes not appreciated by a measure of volume alone. In this study we adopt complementary methods of assessing the structural integrity of grey matter in FEP patients and assess whether these relate to patient clinical and functional outcome at 3 year follow-up. 1.5 Tesla T1-weighted Magnetic Resonance (MR) images were acquired for 46 patients experiencing their first episode of psychosis and 46 healthy controls. Cerebral cortical thickness and local gyrification index (LGI) were investigated using FreeSurfer software. Volume and shape of the hippocampus, caudate and lateral ventricles were assessed using manual tracing and spherical harmonics applied for shape description. A cluster of cortical thinning was identified in FEP compared to controls; this was located in the right superior temporal gyrus, sulcus, extended into the middle temporal gyrus (lateral temporal cortex - LTC). Bilateral caudate volumes were significantly lower in FEP relative to controls and the right caudate also displayed regions of shape deflation in the FEP group. No significant structural abnormalities were identified in cortical LGI or hippocampal or lateral ventricle volume/shape. Neither LTC nor caudate abnormalities were related to change in symptom severity or global functioning 3 years later. LTC and caudate abnormalities are present at the first episode of psychosis but do not appear to directly affect clinical or functional outcome.

Next generation wired intra-vehicle networks, a review

Automotive electronics is a rapidly expanding area with an increasing number of driver assistance and infotainment devices becoming standard in new vehicles. A review of current networking standards within vehicles reveals a fragmented and proprietary situation with several standards such as MOST, CAN and LVDS dominating, all of which are currently being used by various vehicle manufacturers. Due to the cost of employing a range of networking standards, there is a general desire within the automotive industry to converge on the use of the 802.3 Ethernet for all in-vehicle communication between devices. The introduction of in-vehicle cameras to provide driver assistance applications and the associated high bandwidth requirements of multi camera systems has accelerated the demand for a unifying automotive network architecture. This paper presents an overview of current research present in the literature and identifies trends in the field for the future.

Electrophysiological entropy in younger adults, older controls and older cognitively declined adults.

The current study examined electrophysiological entropy in younger adults, older adults, and older cognitively declined adults across four experimental conditions - eyes closed, eyes open, and during both encoding and recognition of words in a memory task. We hypothesised reduced entropy in older declined adults relative to both older controls and younger adults, with the largest group differences in entropy expected during the encoding and recognition phases of the experiment. We also hypothesised greater hemispheric asymmetry in younger adults compared with older controls and older declined adults. Results revealed significant increases in entropy from eyes closed to eyes open to task. Young adults showed higher entropy in the right relative to the left hemisphere in the temporal lobe and higher entropy in the left relative to the right hemisphere in the parietal lobe. Old cognitively declined adults showed no significant differences between right and left hemisphere entropy. There was a trend whereby older declined adults showed lower entropy than older controls in the frontal lobe, this difference being largest in the left hemisphere during the encoding phase of the experiment. Results indicate that measures of entropy are sensitive to information processing demands and that higher cognitive performance may not be a simple function of entropy level, but rather a combination of level and range, or differentiated range of entropy states across the brain.