Kai-Juan Wong

Emotion-aware technologies for consumer electronics

Emotions pervade in peoplepsilas daily lives. Recently, there is a trend of adding emotional characteristics as new features to electronic devices in order to provide more natural and intelligent interaction with human. Affective computing, a concept that combines computer science with psychology and cognitive science was brought forward to support the idea of making machines aware of humanpsilas affective states. This study focuses on differentiating peoplepsilas emotional states based on arousal and valence using physiological signals with the aim to improve human computer interaction for next generation consumer electronic devices.

An energy efficient MAC protocol for mobile in-vivo body sensor networks

Body sensor networks (BSNs) is a challenging research area that have attracted many researchers in recent times. Examples of BSN applications include those that are used to detect vital signs of the human body. As these body sensor devices are typically powered by batteries that are difficult to replace, energy efficient MAC protocols play an important role in BSNs. In this paper, we propose a novel TDMA-based energy efficient MAC protocol for in-vivo communications between mobile nodes in BSNs using an uplink/downlink asymmetric network architecture. A TDMA scheduling scheme and changeable frame formats are also proposed. An adaptive power control scheme is designed especially for the mobile sensor scenarios presented. Simulation results based on the random mobility pattern show that the power consumption of the proposed MAC protocol is much lesser than that of the star topology TDMA. Furthermore, it is also shown that the latency performance can be improved by reducing the data slot duration.

Using GA-based feature selection for emotion recognition from physiological signals

Emotion awareness is becoming an increasingly important field for human-computer interaction. Compare to audio-visual techniques, relying on physiological signals reveals a few advantages that inspired several research studies. By using various feature selection and classification algorithms, development on physiological signals based emotion recognition has been gradually broadened. This paper employed GA-based feature set searching algorithm combining with four classification methods for physiological signal based emotion recognition. GA is an optimization tool which has been proven to be quite effective for large-scale feature selection. The results in this paper will support a successful application of using GA-based feature selection.

In-vivo wireless capsule for health monitoring

The need for continuous and reliable health monitoring, especially for patients with diagnosed illnesses, is getting increasing attention from the consumers. The advancements in wireless communication and electronic technologies enable novel monitoring devices to be developed and deployed for in-vivo medical examination and treatment. One kind of device called in-vivo wireless capsule is introduced in recent years, which can examine the whole gastrointestinal tract with many kinds of sensors, and send the data outside the body wirelessly. This paper focuses on two research areas of the wireless capsule; localization and multi-capsule network. The different ways to realize position localization is discussed and compared. A new architecture for the multi-capsule network and a new power supply chain scheme are proposed.

Therapeutic Capsule Endoscopy: Opportunities and Challenges

The increasing demand for non-invasive (or less-invasive) monitoring and treatment of medical conditions has attracted both physicians and engineers to work together and investigate new methodologies. Wireless capsule endoscopy is a successful example of such techniques which has become an accepted routine for diagnostic inspection of the gastrointestinal tract. This method offers a non-invasive alternative to traditional endoscopy and provides the opportunity for exploring distal areas of the small intestine which are otherwise not accessible. Despite these advantages, wireless capsule endoscopy is still limited in functionality compared to traditional endoscopy. Wireless capsule endoscopes with advanced functionalities, such as biopsy or drug delivery, are highly desirable. In this article, the current status of wireless capsule endoscopy is reviewed together with some of its possible therapeutic applications as well as the existing challenges.

Modular “Plug-and-Play” capsules for multi-capsule environment in the gastrointestinal tract

The invention of wireless capsule endoscopy has opened new ways of diagnosing and treating diseases in the gastrointestinal tract. Current wireless capsules can perform simple operations such as imaging and data collection (like temperature, pressure, and pH) in the gastrointestinal tract. Researchers are now focusing on adding more sophisticated functions such as drug delivery, surgical clips/tags deployment, and tissue samples collection. The finite on-board power on these capsules is one of the factors that limits the functionalities of these wireless capsules. Thus multiple application-specific capsules would be needed to complete an endoscopic operation. This would give rise to a multi-capsule environment. Having a modular “plug-and-play” capsule design would facilitate doctors in configuring multiple application-specific capsules, e.g. tagging capsule, for use in the gastrointestinal tract. This multi-capsule environment also has the advantage of reducing power consumption through asymmetric multi-hop communication.

A novel TDMA-based MAC protocol for mobile in-vivo body sensor networks

With the development of sensor and wireless communication technologies, the concept of body sensor networks (BSNs) is proposed in recent years. BSNs are used to measure a large number of vital signs of the human body. Body sensor devices are typically powered by batteries and difficult to replace, so energy efficient medium access control (MAC) protocols, which can perform medium access mechanism with less energy are necessary. In this paper, we propose a novel energy saving MAC protocol for mobile BSNs based on time division multiple access (TDMA). An uplink, downlink asymmetric network architecture is introduced. A changeable access and sleep frame format as well as a routing algorithm are proposed. Simulation results show that the proposed MAC protocol achieves lower energy consumption than IEEE 802.15.6.

Evaluation of a TDMA-based energy efficient MAC protocol for multiple capsule networks

Wireless capsule endoscopy is a new kind of medical device, which monitors the gastrointestinal tract of the human body. It can be envisaged that in the future more than one capsule could be ingested by the patient and they operate collaboratively in the gastrointestinal (GI) tract to perform certain diagnostic and therapeutic tasks. These mobile capsules and the coordinator node, which is attached to the abdomen of the patient, form a wireless network. The capsule devices are typically powered by batteries, therefore, energy efficient medium access control (MAC) protocols for multiple capsule networks are necessary. This article proposes a novel energy efficient MAC protocol for multiple capsule networks based on time division multiple access (TDMA). An asymmetric up/down link network architecture is introduced. A novel TDMA slot assignment scheme is proposed and simulation results using Qualnet show that the proposed MAC protocol achieves lower energy consumption than B-MAC and star topology TDMA.

A Coverage-Based Adaptive Preamble Broadcasting Protocol for WSNs

Broadcasting is a fundamental operation in any wireless network, more so in wireless sensor networks, where each sensor node has limited transmission range as well as battery power. Broadcasting protocols for wireless sensor networks are required to simultaneously minimize resource usage and optimize performance metrics such as latency and reliability. Broadcasting becomes even more challenging, when nodes in the networks are duty cycled and sleep scheduling is asynchronous. In this paper, we propose a Coverage-based Adaptive Preamble Broadcasting (CAPB) Protocol, which utilizes the MAC layer preamble sending property before the data packet, counter-based approach with the area-based schemes in order to exploit the maximum advantage of these approaches. Our algorithm is compared against a fix probabilistic technique. CAPB maximizes the reach ability and rebroadcast saving while consuming the minimum possible power of the sensor nodes. CAPB also achieves higher throughput as compared to probability-based broadcasting scheme.

TDMA based MAC protocol for wireless capsule communications

Wireless capsule endoscopy (WCE) is getting more and more popular in recent years. Compared with the traditional push endoscopy, it gives patients little discomfort. Researchers are focusing on providing many advanced functionalities such as active locomotion, drug delivery. it can also imagined that more than one capsules are swallowed by patients and these capsules co-work to finish some common task. The capsules and data recorder form a wireless capsule network. This multiple capsule networks have some unique attributes which are different from wireless sensor networks and body sensor networks. A novel TDMA based asymmetric topology MAC protocol is proposed. The uplink and downlink data communications follow different topology. By this way the energy consumption can be reduced. The TDMA frame format is proposed. Simulation results using Qualnet 5.0 show that the proposed protocol outperforms star topology TDMA in terms of energy consumption.