Performance Evaluation of Wearable Sensor Systems: A Case Study in Moderate-Scale Deployment in Hospital Environment

A wearable sensor system enables continuous and remote health monitoring and is widely considered as the next generation of healthcare technology. The performance, the packet error rate (PER) in particular, of a wearable sensor system may deteriorate due to a number of factors, particularly the interference from the other wearable sensor systems in the vicinity. We systematically evaluate the performance of the wearable sensor system in terms of PER in the presence of such interference in this paper. The factors that affect the performance of the wearable sensor system, such as density, traffic load, and transmission power in a realistic moderate-scale deployment case in hospital are all considered. Simulation results show that with 20% duty cycle, only 68.5% of data transmission can achieve the targeted reliability requirement (PER is less than 0.05) even in the off-peak period in hospital. We then suggest some interference mitigation schemes based on the performance evaluation results in the case study

An investigation of extraocular and intraocular wireless communication techniques on a retinal prosthesis system

Retinitis Pigmentosa (RP) and Age-related Macular Degeneration (AMD) are two genetic ocular diseases that cause gradual visual impairments which will eventually lead to blindness as a result of damage in the retina. In the cases of people suffering from RP and AMD, it has been found out that 95% of the photoreceptors are damaged, while interestingly majority of the bipolar and ganglion cells that are responsible for the nerve stimulation remain intact. This is where a retinal prosthesis system comes into the picture. Retinal prosthesis is a prosthetic device that is aimed to assume the functionality of the damaged photoreceptors and produce stimulations to the bipolar and ganglion cells for a visual perception. Typically, a retinal prosthesis system comprises of two major components: an image capturing unit and an array of microelectrode. While a lot of studies have been conducted on each major component, the development of the wireless link between the two components has been mostly overlooked. It is clear that the two components are not physically connected and a data exchange is required between the two. This thesis aims to bridge the knowledge gap in this area by addressing the following research questions: “What is the most suitable frequency band for a wireless link in a retinal prosthesis system?” and “What kind of antenna would generate the most optimal performance under the constraints introduced by a retinal prosthesis system?

Developing a wireless implantable body sensor network in MICS band

Through an integration of wireless communication and sensing technologies, the concept of a body sensor network (BSN) was initially proposed in the early decade with the aim to provide an essential technology for wearable, ambulatory, and pervasive health monitoring for elderly people and chronic patients. It has become a hot research area due to big opportunities as well as great challenges it presents. Though the idea of an implantable BSN was proposed in parallel with the on-body sensor network, the development in this area is relatively slow due to the complexity of human body, safety concerns, and some technological bottlenecks such as the design of ultralow-power implantable RF transceiver. This paper describes a new wireless implantable BSN that operates in medical implant communication service (MICS) frequency band. This system innovatively incorporates both sensing and actuation nodes to form a closed-control loop for physiological monitoring and drug delivery for critically ill patients. The sensing node, which is designed using system-on-chip technologies, takes advantage of the newly available ultralow-power Zarlink MICS transceiver for wireless data transmission. Finally, the specific absorption rate distribution of the proposed system was simulated to determine the in vivo electromagnetic field absorption and the power safety limits

Implanted Antennas for Biomedical Applications

Body-Centric Wireless Communication (BCWC) is a central topic in the development of healthcare and biomedical technologies. Increasing healthcare quality, in addition to the continuous miniaturisation of sensors and the advancement in wearable electronics, embedded software, digital signal processing and biomedical technologies, has led to a new era of biomedical devices and increases possibility of continuous monitoring, diagnostic and/or treatment of many diseases. However, the major difference between BCWC, particularly implantable devices, and conventional wireless systems is the radio channel over which the communication takes place. The human body is a hostile environment from a radio propagation perspective. This environment is a highly lossy and has a high effect on the antenna elements, the radio channel parameters and, hence a dramatic drop in the implanted antenna performance. This thesis focuses on how to improve the gain of implanted antennas. In order to improve the gain and performance of implanted antennas, this thesis uses a combination of experimental and electromagnetic numerical investigations. Extensive simulation and experimental investigations are carried out to study the effects of various external elements on the performance improvement of implanted antennas. The thesis also shows the design, characterisation, simulation and measurements of four different antennas to work at ISM band and seventeen different scenarios for body wireless communication. A 3- layer (skin, fat and muscle) and a liquid homogenise phantom were used for human body modelling in both simulation and measurements. The results shows that a length of printed line and a grid can be used on top of the human skin in order enhance the performance of the implanted antennas. Moreover, a ring and a hemispherical lens can be used externally in order to enhance the performance of the implanted antenna. This approach yields a significant improvement in the antenna gain and reduces the specific absorption rate (SAR) in most cases and the obtained gain varies between 2 dB and 8 dB

System design and performance analysis of wireless body area networks

One key solution to provide affordable and proactive healthcare facilities to overcome the fast world population growth and a shortage of medical professionals is through health monitoring systems capable of early disease detection and real-time data transmission leading to considerable improvements in the quality of human life. Wireless body area networks (WBANs) are proposed as promising approaches to providing better mobility and flexibility experience than traditional wired medical systems by using low-power, miniaturised sensors inside, around, or off the human body and are employed to monitor physiological signals. However, the design of reliable and energy efficient in-body communication systems is still a major research challenge since implant devices are characterised by strict requirements on size, energy consumption and safety. Moreover, there is still no agreement regarding QoS support in WBANs. The first part of this work concentrates on the design and performance evaluation of WBAN communication systems involving the ‘in-body to in-body’ and ‘in-body to on-body’ scenarios. The essential step is to derive the statistical WBAN path loss (PL) models, which characterise the signal propagation energy loss transmitting via intra-body region. Moreover, from the point of view of human body safety evaluation, the obtained specific absorption rate (SAR) values are compared with the latest Institute of Electrical and Electronics Engineers (IEEE) 802.15.6 Task Group technical standard and the International Commission on Non-Ionizing Radiation Protection (ICNIRP) safety guidelines. Link budget analysis is then presented using a range of energy-efficient modulation schemes, and the results are given including the transmission distance, data rate and transmitting power in individual sections. On the other hand, major quality of service (QoS) support challenges in WBANs are discussed and investigated. To achieve higher lifetime and lower network energy consumption, different data routing protocol methods, including incremental relaying and the two-relay based routing technique are taken into account. A set of key QoS metrics for linear mathematical models is given along with the related subjective functions. The incremental relaying routing protocol promises significant enhancements in in-body WBAN network lifetime by minimising the overall communication distance while the two-relay based routing method achieves better performance in terms of emergency data transmission and high traffic condition, QoS-aware WBANs design. Moreover, to handle real-time high data transmission applications such as capsule endoscope image transmission, a flexible QoS-aware wireless body area sensor networks (WBASNs) model is proposed and evaluated that can bring novel solutions for a realistic multi-user hospital environment regarding information packet collision probability, manageable numbers of sensor nodes and a wide range of data rates

Robots, Cyborgs, and Humans. A Model of Consumer Behavior in Services: A Study in the Healthcare Services Sector

La present tesi es basa en una investigació que proposa un ús futurista de l'robot i el cyborg com cirurgians oculars. El model desenvolupat investiga la intenció de l'consumidor per elegir cada cirurgià (és a dir: cirurgià robot, cirurgià cyborg o cirurgià humà). Les dades es van analitzar utilitzant la tècnica PLS-SEM. Els resultats de la investigació mostren que l'expectativa d'esforç, l'expectativa de rendiment, el risc percebut i la influència social van mostrar un impacte significatiu en la intenció d'utilitzar els serveis de l'robot cirurgià. Els resultats de el model per al cyborg cirurgià van confirmar l'impacte significatiu de l'expectativa d'esforç, l'excitació, l'expectativa de rendiment i la influència social en la intenció d'utilitzar els seus serveis. L'expectativa d'esforç i la influència social van confirmar un impacte significatiu en la intenció d'utilitzar els serveis de l'cirurgià humà. Els resultats mostren que en els tres models les variables influència social i expectativa d'esforç afecten significativament a la intenció d'utilitzar aquests serveis de cirurgia i que amb diferent intensitat entre els models per expectativa de esforç-. L'impacte de la influència social dóna una idea general sobre la naturalesa de el sector de la salut a Jordània, on una part de la societat presta més atenció a les recomanacions dels altres a l'elegir els seus cirurgians. A més, l'impacte de l'expectativa d'esforç contribueix a les expectatives per la simplicitat de l'servei dels pacients, en termes d'ús i interacció amb els cirurgians proposats. L'anàlisi multigrup va confirmar que les variables dels models estan afectant de la mateixa manera a l'comparar la intenció d'usar cyborgs i humans, i a l'comparar cyborgs i robots. No obstant això, sí que hi ha diferències significatives a l'comparar l'elecció entre robots i humans en l'impacte de l'expectativa d'esforç per utilitzar els serveis de cirurgia. D'altra banda, els participants van mostrar la seva preferència pel cirurgià humà sobre els cirurgians cyborg i robot, respectivament. Com a resultat, l'acceptació de les tecnologies de robot i cyborg per part de la societat podria donar una idea sobre la lluita esperada en el futur entre el desenvolupament de robots i la millora de les capacitats humanes.La presente tesis se basa en una investigación que propone un uso futurista del robot y el cyborg como cirujanos oculares. El modelo desarrollado investiga la intención del consumidor para elegir a cada cirujano (es decir: cirujano robot, cirujano cyborg o cirujano humano). Los datos se analizaron utilizando la técnica PLS-SEM. Los resultados de la investigación muestran que la expectativa de esfuerzo, la expectativa de rendimiento, el riesgo percibido y la influencia social mostraron un impacto significativo en la intención de utilizar los servicios del robot cirujano. Los resultados del modelo para el cyborg cirujano confirmaron el impacto significativo de la expectativa de esfuerzo, la excitación, la expectativa de rendimiento y la influencia social en la intención de usar sus servicios. La expectativa de esfuerzo y la influencia social confirmaron un impacto significativo en la intención de utilizar los servicios del cirujano humano. Los resultados muestran que en los tres modelos las variables influencia social y expectativa de esfuerzo afectan significativamente a la intención de usar esos servicios de cirugía –aunque con distinta intensidad entre los modelos para expectativa de esfuerzo-. El impacto de la influencia social da una idea general sobre la naturaleza del sector de la salud en Jordania, donde una parte de la sociedad presta más atención a las recomendaciones de los demás al elegir a sus cirujanos. Además, el impacto de la expectativa de esfuerzo contribuye a las expectativas por la simplicidad del servicio de los pacientes, en términos de uso e interacción con los cirujanos propuestos. El análisis multigrupo confirmó que las variables de los modelos están afectando de la misma manera al comparar la intención de usar cyborgs y humanos, y al comparar cyborgs y robots. Sin embargo, sí que existen diferencias significativas al comparar la elección entre robots y humanos en el impacto de la expectativa de esfuerzo para utilizar los servicios de cirugía. Por otro lado, los participantes mostraron su preferencia por el cirujano humano sobre los cirujanos cyborg y robot, respectivamente. Como resultado, la aceptación de las tecnologías de robot y cyborg por parte de la sociedad podría dar una idea sobre la lucha esperada en el futuro entre el desarrollo de robots y la mejora de las capacidades humanThe research proposes a futuristic use of robot and cyborg as surgeons in an eye surgery. Thereafter, the developed model has been applied to investigate the intention to use each surgeon (i.e. robot surgeon, cyborg surgeon, and human surgeon). The data was analyzed using the PLS-SEM technique. According to the research results, effort expectancy, performance expectancy, perceived risk, and social influence showed a significant impact on intention to use robot services. However, the results of the cyborg service model confirmed the significant impact of effort expectancy, arousal, performance expectancy, and social influence on the intention to use cyborg services. Furthermore, effort expectancy and social influence confirmed their significant impact on the intention to use human services. The results of the three models showed that the variables social influence and effort expectancy significantly affected the intention to use these surgical services, with a different intensity between the models for effort expectancy. The social influence impact gives a general idea about the nature of the healthcare sector in Jordan, where a part of society gives more attention to the recommendation from others while choosing their surgeons. Also, the effort expectancy impact contributes to patients' expectations of simplicity, in terms of use and interaction with the proposed surgeons. The multigroup analysis confirmed that the models' variables are affecting the intention to use cyborg and human service, and cyborg and robots in the same way. However, the differences were confirmed between robot and human cyborgs in terms of the impact of effort expectancy on the intention to use these services. On the other side, the participants showed their preference of the human surgeon over the cyborg and robot surgeons, respectively. As a result, the acceptance of the robot and cyborg technologies by a part of the society could give an idea about the expected struggle in the future among developing robots and enhancing human capabilities