Energy Efficiency and Reliability Considerations in Wireless Body Area Networks: A Survey.

In this paper, we have reviewed and presented a critical overview of "energy-efficient and reliable routing solutions" in the field of wireless body area networks (WBANs). In addition, we have theoretically analysed the importance of energy efficiency and reliability and how it affects the stability and lifetime of WBANs. WBAN is a type of wireless sensor network (WSN) that is unique, wherever energy-efficient operations are one of the prime challenges, because each sensor node operates on battery, and where an excessive amount of communication consumes more energy than perceiving. Moreover, timely and reliable data delivery is essential in all WBAN applications. Moreover, the most frequent types of energy-efficient routing protocols include crosslayer, thermal-aware, cluster-based, quality-of-service, and postural movement-based routing protocols. According to the literature review, clustering-based routing algorithms are the best choice for WBAhinwidth, and low memory WBAN, in terms of more computational overhead and complexity. Thus, the routing techniques used in WBAN should be capable of energy-efficient communication at desired reliability to ensure the improved stability period and network lifetime. Therefore, we have highlighted and critically analysed various performance issues of the existing "energy-efficient and reliable routing solutions" for WBANs. Furthermore, we identified and compiled a tabular representation of the reviewed solutions based on the most appropriate strategy and performance parameters for WBAN. Finally, concerning to reliability and energy efficiency in WBANs, we outlined a number of issues and challenges that needs further consideration while devising new solutions for clustered-based WBANs.

Miniaturized wireless, skin-integrated sensor networks for quantifying full-body movement behaviors and vital signs in infants.

Early identification of atypical infant movement behaviors consistent with underlying neuromotor pathologies can expedite timely enrollment in therapeutic interventions that exploit inherent neuroplasticity to promote recovery. Traditional neuromotor assessments rely on qualitative evaluations performed by specially trained personnel, mostly available in tertiary medical centers or specialized facilities. Such approaches are high in cost, require geographic proximity to advanced healthcare resources, and yield mostly qualitative insight. This paper introduces a simple, low-cost alternative in the form of a technology customized for quantitatively capturing continuous, full-body kinematics of infants during free living conditions at home or in clinical settings while simultaneously recording essential vital signs data. The system consists of a wireless network of small, flexible inertial sensors placed at strategic locations across the body and operated in a wide-bandwidth and time-synchronized fashion. The data serve as the basis for reconstructing three-dimensional motions in avatar form without the need for video recordings and associated privacy concerns, for remote visual assessments by experts. These quantitative measurements can also be presented in graphical format and analyzed with machine-learning techniques, with potential to automate and systematize traditional motor assessments. Clinical implementations with infants at low and at elevated risks for atypical neuromotor development illustrates application of this system in quantitative and semiquantitative assessments of patterns of gross motor skills, along with body temperature, heart rate, and respiratory rate, from long-term and follow-up measurements over a 3-mo period following birth. The engineering aspects are compatible for scaled deployment, with the potential to improve health outcomes for children worldwide via early, pragmatic detection methods.

Wearable Wireless Body Area Networks for Medical Applications.

In recent times, there has been a significant growth in networks known as the wireless body area networks (WBANs). A WBAN connects distributed nodes throughout the human body, which can be placed on the skin, under the skin, or on clothing and can use the human body's electromagnetic waves. An approach to reduce the size of different telecommunication equipment is constantly being sought; this allows these devices to be closer to the body or even glued and embedded within the skin without making the user feel uncomfortable or posing as a danger for the user. These networks promise new medical applications; however, these are always based on the freedom of movement and the comfort they offer. Among the advantages of these networks is that they can significantly increase user's quality of life. For example, a person can carry a WBAN with built-in sensors that calculate the user's heart rate at any given time and send these data over the internet to user's doctor. This study provides a systematic review of WBAN, describing the applications and trends that have been developed with this type of network and, in addition, the protocols and standards that must be considered.

Uso do sistema auxiliar de escuta com estudantes com deficiência auditiva: identificação de barreiras e facilitadores / Use of hearing assistance technology with students with hearing loss: identification of barriers and facilitators / Uso del sistema auxiliar de escucha com alunos com hipoacusia: identificación de barreras y facilitadores

Introdução: A relação sinal-ruído na sala de aula pode ser um vilão na inclusão na escola regular de alunos com deficiência auditiva, usuários de dispositivos eletrônicos, que utilizam a língua oral para se comunicar. Os recursos tecnológicos são determinantes para a melhor audibilidade de sons de fala em ambientes ruidosos e sua efetividade depende da adesão ao uso do dispositivo. Esse processo é determinado pela parceria entre profissionais da saúde, família e  escola. Objetivo: Identificar a relação entre a utilização consistente do sistema de microfone remoto (SMR) em estudantes com deficiência auditiva e o uso pelos professores, que favoreceram ou dificultaram sua adaptação e o desenvolvimento escolar desses estudantes. Método: Foram analisados 175 sujeitos entre 5 e 17 anos que receberam o SMR num serviço de saúde auditiva entre os anos de 2017 e 2018. Pais e professores de usuários também foram sujeitos do estudo. O funcionamento do SMR e a classificação quanto ao seu uso foram verificados. Resultado: Os indivíduos que mais 'usam' o SMR estão no ensino fundamental I, e os que 'não usam voluntariamente' estão no ensino médio e fundamental II. Considerando-se o tipo de escola, a maioria que 'não usa voluntariamente' o SMR está em escola ou sala para surdos com uso de libras e/ou tem intérprete na sala da escola regular. Conclusão: Houve associação entre uso do SMR e tipo de escola. Recomenda-se que o tipo de escola seja um critério de indicação do dispositivo. O nível educacional também foi uma variável determinante no uso do dispositivo na escola.

Introduction: The signal-to-noise ratio in the classroom can be a villain in the inclusion of hearing-impaired students in regular school, users of electronic devices, that use the oral language to communicate. The technological resources are determinant for better audibility of speech sounds in noisy environments and their effectiveness depends on adherence to the use of the device. This process is determined by the partnership between health professionals, family and school. Objective: Identify the relation between the use of remote microphone system (RMS) in hearing impaired students and the use by teachers, which favored or hindered their adaptation and the school development of hearing-impaired students. Method:175 subjects between 5 and 17 years of age who received the HAT in a hearing health service between the years 2017 and 2018 were analyzed. Parents and teachers of users were also subjects of the study. The functioning of the HAT and the classification regarding its use was verified. Result: Most of the individuals who 'use' HAT are in elementary school, and those who 'don't use it voluntarily' are in high school and middle school. Considering the type of school, most who 'don't use voluntarily' the HAT is in school or room for deaf students using sign language /or has interpreter in regular school. Conclusion:There was an association between the use of the HAT and the type of school. It is recommended that the type of school is a criterion for the indication of the device. The educational level was also a determinant variable in the use of the device at school.

Introducción: La relación señal-ruido en el aula puede ser un villano en la inclusión de estudiantes con discapacidad auditiva en la escuela normal, usuarios de dispositivos electrónicos que utilizan el lenguaje oral para comunicarse. Los recursos tecnológicos son cruciales para una mejor audibilidad de los sonidos del habla en ambientes ruidosos y su eficacia depende de la adherencia al uso del dispositivo. Este proceso está determinado por la asociación entre los profesionales de salud, familia y escuela. Objetivo: Identificar la relación entre el uso del sistema de micrófono remoto(SMR) en los alumnos con deficiencias auditivas y el uso por parte de los maestros, que han favorecido o dificultado su adaptación y el desarrollo escolar de los alumnos con deficiencias auditivas. Método: Se analizaron 175 sujetos de entre 5 y 17 años que recibieron el SMR en un servicio de salud auditiva entre los años 2017 y 2018. Los padres y maestros de los usuarios también fueron sujetos del estudio. Se ha comprobado el funcionamiento del SMR y la clasificación relativa a su uso. Resultado: Los individuos que "usan" más el SMR están en la escuela primaria, y los que "no usan voluntariamente" están en la secundaria. Considerando el tipo de escuela, la mayoría de los que "no usan voluntariamente" el SMR está en una escuela o sala para sordos con uso de libras y/o tiene un intérprete en la sala de la escuela regular. Conclusión: Hubo una asociación entre el uso del SMR y el tipo de la escuela. Se recomienda que el tipo de escuela sea un criterio para indicar el dispositivo. El nivel educativo, también fue una variable determinante en el uso del dispositivo en la escuela.

Social Distance Monitor with a Wearable Magnetic Field Proximity Sensor.

Social distancing and contact/exposure tracing are accepted to be critical strategies in the fight against the COVID-19 epidemic. They are both closely connected to the ability to reliably establish the degree of proximity between people in real-world environments. We proposed, implemented, and evaluated a wearable proximity sensing system based on an oscillating magnetic field that overcomes many of the weaknesses of the current state of the art Bluetooth based proximity detection. In this paper, we first described the underlying physical principle, proposed a protocol for the identification and coordination of the transmitter (which is compatible with the current smartphone-based exposure tracing protocols). Subsequently, the system architecture and implementation were described, finally an elaborate characterization and evaluation of the performance (both in systematic lab experiments and in real-world settings) were performed. Our work demonstrated that the proposed system is much more reliable than the widely-used Bluetooth-based approach, particularly when it comes to distinguishing between distances above and below the 2.0 m threshold due to the magnetic field's physical properties.

Automatic hoof-on and -off detection in horses using hoof-mounted inertial measurement unit sensors.

For gait classification, hoof-on and hoof-off events are fundamental locomotion characteristics of interest. These events can be measured with inertial measurement units (IMUs) which measure the acceleration and angular velocity in three directions. The aim of this study was to present two algorithms for automatic detection of hoof-events from the acceleration and angular velocity signals measured by hoof-mounted IMUs in walk and trot on a hard surface. Seven Warmblood horses were equipped with two wireless IMUs, which were attached to the lateral wall of the right front (RF) and hind (RH) hooves. Horses were walked and trotted on a lead over a force plate for internal validation. The agreement between the algorithms for the acceleration and angular velocity signals with the force plate was evaluated by Bland Altman analysis and linear mixed model analysis. These analyses were performed for both hoof-on and hoof-off detection and for both algorithms separately. For the hoof-on detection, the angular velocity algorithm was the most accurate with an accuracy between 2.39 and 12.22 ms and a precision of around 13.80 ms, depending on gait and hoof. For hoof-off detection, the acceleration algorithm was the most accurate with an accuracy of 3.20 ms and precision of 6.39 ms, independent of gait and hoof. These algorithms look highly promising for gait classification purposes although the applicability of these algorithms should be investigated under different circumstances, such as different surfaces and different hoof trimming conditions.

EVALUATING SHORT-TERM EXPOSURE TO WI-FI SIGNALS ON STUDENTS' REACTION TIME, SHORT-TERM MEMORY AND REASONING ABILITY.

This study investigated the effect of short-term exposure to Wi-Fi signals on the cognitive functions of the mind. After obtaining permission from the local Ethics Committee of Shiraz University of Medical Sciences and approval by the Iranian Registry of Clinical Trials (IRCT2017041233398N1), 45 male and female students from Shiraz University of Medical Sciences volunteered to participate in this study. They were exposed to Wi-Fi signals in two sham and exposure sessions, each for 2 hours. After completion, they took part in reaction time, short-term memory, and reasoning ability tests. After scoring, the data were analysed by SPSS software. In addition, the electric field strength and power density were calculated. The results showed no statistically significant differences between the mean scores of reaction time, short-term memory, and reasoning ability in sham and exposure. Also, the obtained values from the electric field strength and power density (E = 4.1 Vm-1, P = 0.446 Wm-2) were lower than that of threshold values by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Our results can greatly reduce concerns regarding the effects of short-term exposure to Wi-Fi waves on cognitive functions.

Evaluation of commercial, wireless dermal thermometers for surrogate measurements of core temperature.

Extensive research has been devoted to developing methods for assessing core body temperature, and to determine which method is most accurate. A number of wireless dermal thermometers for home use are presently available, but their relation to core body temperature and suitability for use in clinical research has hitherto not been assessed. The current study aimed to evaluate such thermometers by comparing them to the results of a rectal thermometer. Four wireless dermal thermometers for home use (FeverSmart, iThermonitor, Quest Temp Sitter, and Thermochron iButton) were applied to 15 patients during 24 h, and rectal temperature was measured at four occasions. Pearson correlation revealed moderate correlation for the Feversmart (r = 0.75), iThermonitor (r = 0.79), and Thermochron iButton (r = 0.71) systems. The Quest Temp Sitter system malfunctioned repeatedly, and the correlation (r = 0.29) for this method should therefore be assessed with caution. All dermal thermometers rendered lower average temperatures than Terumo c405 (Feversmart -0.70 ± 0.65 °C; iThermonitor -0.77 ± 0.53 °C, Quest Temp Sitter -1.18 ± 0.66 °C, and Thermochron iButton -0.87 ± 0.65 °C). Sensitivity of the dermal thermometers for detecting core temperatures ≥38.0 °C was low, ranging from 0.33 to 0.6, but improved to 0.60 to 0.80 after adjusting temperatures by the methods' average deviation from rectal temperature. The results from the dermal thermometers tested here showed an insufficient correlation to core temperature to be used for core temperature monitoring in clinical research and practice. Unfortunately, other options for non-invasive temperature measurements are few. The two thermometers with the least unsatisfactory performance profile in our evaluations were the Feversmart and iThermonitor systems.

An energy efficiency routing protocol for wireless body area networks.

The wireless body area networks (WBANs) play an important role in monitoring and minimising the duration of patients stays at the hospital. The aim of our study was to design an energy efficient routing protocol for WBANs taking into consideration the minimisation of energy and maximisation of the network lifetime, such as that the routing is recognised as a resource hungry operation. In this protocol, to confront the different constraints, we use the concept of the gateway body sensor which is responsible for sending data to the base station. Some biosensors transmit data directly while some use clustering technique to send data, it depends on the type of transferred information. Simulation results showed that clustering based routing protocol for wireless body area network (CRPBA) improves the quality of our network by minimising the energy consumption and enhances the stability period.

A home monitoring program including real-time wireless home spirometry in idiopathic pulmonary fibrosis: a pilot study on experiences and barriers.

In idiopathic pulmonary fibrosis (IPF), home monitoring experiences are limited, not yet real-time available nor implemented in daily care. We evaluated feasibility and potential barriers of a new home monitoring program with real-time wireless home spirometry in IPF. Ten patients with IPF were asked to test this home monitoring program, including daily home spirometry, for four weeks. Measurements of home and hospital spirometry showed good agreement. All patients considered real-time wireless spirometry useful and highly feasible. Both patients and researchers suggested relatively easy solutions for the identified potential barriers regarding real-time home monitoring in IPF.

Evaluation of a Novel Wireless Transmission System for Trauma Ultrasound Examinations From Moving Ambulances.

Objective: To determine if physicians trained in ultrasound interpretation perceive a difference in image quality and usefulness between Extended Focused Assessment with Sonography ultrasound examinations performed at bedside in a hospital vs. by emergency medical technicians minimally trained in medical ultrasound on a moving ambulance and transmitted to the hospital via a novel wireless system. In particular, we sought to demonstrate that useful images could be obtained from patients in less than optimal imaging conditions; that is, while they were in transport. Methods: Emergency medical technicians performed the examinations during transport of blunt trauma patients. Upon patient arrival at the hospital, a bedside Extended Focused Assessment with Sonography examination was performed by a physician. Both examinations were recorded and later reviewed by physicians trained in ultrasound interpretation. Results: Data were collected on 20 blunt trauma patients over a period of 13 mo. Twenty ultrasound-trained physicians blindly compared transmitted vs. bedside images using 11 Questionnaire for User Interaction Satisfaction scales. Four paired samples t-tests were conducted to assess mean differences between ratings for ambulatory and base images. Conclusion: Although there is a slight tendency for the average rating across all subjects and raters to be slightly higher in the base than in the ambulatory condition, none of these differences are statistically significant. These results suggest that the quality of the ambulatory images was viewed as essentially as good as the quality of the base images.

Analysis of channel uncertainty in ARQ relay networks.

Several power allocation algorithms for cooperative relay networks are presented in the literature. These contributions assume perfect channel knowledge and capacity achieving codes. However in practice, obtaining the channel state information at a relay or at the destination is an estimation problem and can generally not be error free. The investigation of the power allocation mechanism in a wireless network due to channel imperfections is important because it can severely degrade its performance regarding throughput and bit error rate. In this paper, the impact of imperfect channel state information on the power allocation of an adaptive relay network is investigated. Moreover, a framework including Automatic Repeat reQuest (ARQ) mechanism is provided to make the power allocation mechanism robust against these channel imperfections. For this framework, the end-to-end SNR is calculated considering imperfect channel knowledge using ARQ analytically. The goal is to emphasize the impact of imperfect channel knowledge on the power allocation mechanism. In this paper, the simulation results illustrate the impact of channel uncertainties on the average outage probability, throughput, and consumed sum power for different qualities of channel estimation. It is shown that the presented framework with ARQ is extremely robust against the channel imperfections.

Hearing Technology Use and Management in School-Age Children: Reports from Data Logs, Parents, and Teachers.

BACKGROUND: Consistency of hearing aid and remote microphone system use declines as school-age children with hearing loss age. One indicator of hearing aid use time is data logging, another is parent report. Recent data suggest that parents overestimate their children's hearing aid use time relative to data logging. The potential reasons for this disparity remain unclear. Because school-age children spend the majority of their day away from their parents and with their teachers, reports from teachers might serve as a valuable and additional tool for estimating hearing aid use time and management. PURPOSE: This study expands previous research on factors influencing hearing aid use time in school-age children using data logging records. Discrepancies between data logging records and parent reports were explored using custom surveys designed for parents and teachers. Responses from parents and teachers were used to examine hearing aid use, remote microphone system use, and hearing aid management in school-age children. STUDY SAMPLE: Thirteen children with mild-to-moderate hearing loss between the ages of 7 and 10 yr and their parents participated in this study. Teachers of ten of these children also participated. DATA COLLECTION AND ANALYSIS: Parents and teachers of children completed written surveys about each child's hearing aid use, remote microphone system use, and hearing aid management skills. Data logs were read from hearing aids using manufacturer's software. Multiple linear regression analysis and an intraclass correlation coefficient were used to examine factors influencing hearing aid use time and parent agreement with data logs. Parent report of hearing aid use time was compared across various activities and school and nonschool days. Survey responses from parents and teachers were compared to explore areas requiring potential improvement in audiological counseling. RESULTS: Average daily hearing aid use time was ∼6 hr per day as recorded with data logging technology. Children exhibiting greater degrees of hearing loss and those with poorer vocabulary were more likely to use hearing aids consistently than children with less hearing loss and better vocabulary. Parents overestimated hearing aid use by ∼1 hr per day relative to data logging records. Parent-reported use of hearing aids varied across activities but not across school and nonschool days. Overall, parents and teachers showed excellent agreement on hearing aid and remote microphone system use during school instruction but poor agreement when asked about the child's ability to manage their hearing devices independently. CONCLUSIONS: Parental reports of hearing aid use in young school-age children are largely consistent with data logging records and with teacher reports of hearing aid use in the classroom. Audiologists might find teacher reports helpful in learning more about children's hearing aid management and remote microphone system use during their time at school. This supplementary information can serve as an additional counseling tool to facilitate discussion about remote microphone system use and hearing aid management in school-age children with hearing loss.

Understanding Nurses' Strategies to Handle (Un)wanted Nurse Calls: A Resilience Perspective.

Nurse calls in a hospital can constitute either positive or negative (wanted or unwanted) interruptions depending on various factors. This study aims to understand nurses' strategies in facilitating the reception of wanted nurse calls and the restriction of unwanted nurse calls. Applying a resilience engineering perspective, nurses' performance variability is investigated as a basis to design appropriate computer support to enhance efficiency and patient safety. A qualitative case study was conducted for a period of 4 years with focus on nurses' use of a wireless nurse call system at a Norwegian university hospital. The study involved various data collection methods such as observations, interviews, and workshops. The collected data were then transcribed and analyzed using a combined inductive and deductive approach. Results indicate that nurses use four main strategies involving a large degree of collaboration to allow or avoid interruptions in the form of nurse calls depending on situation and circumstances. However, these strategies are not supported by the wireless nurse call system, which requires nurses to use suboptimal workarounds to enable the necessary performance variability. Interruptions have been largely perceived as a threat to patient safety. However, nurses' handling of calls illustrates that, when aiming to introduce interventions to manage interruptions, a detailed understanding of work as done is important. Nurses continuously make appropriate adjustments to cope with challenges that characterize hospital work to ensure efficient and safe operations. Hence, technology, in terms of a nurse call system, needs to be designed to afford the adjustments made to support a resilient practice and, as such, leverage patient safety.

INTRAOPERATIVE IMAGE NAVIGATION: EXPERIMENTAL STUDY OF THE FEASIBILITY AND SURGEON PREFERENCE BETWEEN A STERILE ENCASED NINTENDO WIITM REMOTE AND STANDARD WIRELESS COMPUTER MOUSE.

Diagnostic imaging plays an important role in the operating room, providing surgeons with a reference and surgical plan. Surgeon autonomy in the operating room has been suggested to decrease errors that stem from communication mistakes. A standard computer mouse was compared to a wireless remote-control style controller for computer game consoles (Wiimote) for the navigation of diagnostic imaging studies by sterile personnel in this prospective survey study. Participants were recruited from a cohort of residents and faculty that use the surgical suites at our institution. Outcome assessments were based on survey data completed by study participants following each use of either the mouse or Wiimote, and compared using an analysis of variance. The mouse was significantly preferred by the study participants in the categories of handling, accuracy and efficiency, and overall satisfaction (P <0.05). The mouse was preferred to both the Wiimote and to no device, when participants were asked to rank options for image navigation. This indicates the need for the implementation of intraoperative image navigation devices, to increase surgeon autonomy in the operating room.

Avoiding Biased-Feeding in the Scheduling of Collaborative Multipath TCP.

Smartphones have become the major communication and portable computing devices that access the Internet through Wi-Fi or mobile networks. Unfortunately, users without a mobile data subscription can only access the Internet at limited locations, such as hotspots. In this paper, we propose a collaborative bandwidth sharing protocol (CBSP) built on top of MultiPath TCP (MPTCP). CBSP enables users to buy bandwidth on demand from neighbors (called Helpers) and uses virtual interfaces to bind the subflows of MPTCP to avoid modifying the implementation of MPTCP. However, although MPTCP provides the required multi-homing functionality for bandwidth sharing, the current packet scheduling in collaborative MPTCP (e.g., Co-MPTCP) leads to the so-called biased-feeding problem. In this problem, the fastest link might always be selected to send packets whenever it has available cwnd, which results in other links not being fully utilized. In this work, we set out to design an algorithm, called Scheduled Window-based Transmission Control (SWTC), to improve the performance of packet scheduling in MPTCP, and we perform extensive simulations to evaluate its performance.

Evaluation of Miniature Wireless Vital Signs Monitor in a Trauma Intensive Care Unit.

A previous study demonstrated basic proof of principle of the value of a miniature wireless vital signs monitor (MWVSM, MiniMedic, Athena GTX, Des Moines, Iowa) for battlefield triage However, there were unanswered questions related to sensor reliability and uncontrolled conditions in the prehospital environment. This study determined whether MWVSM sensors track vital signs and allow for appropriate triage compared to a gold standard bedside monitor in trauma patients. This was a prospective study in 59 trauma intensive care unit patients. Systolic blood pressure, temperature, heart rate (HR), skin temperature, and pulse oximetry (SpO2) were displayed on a bedside monitor for 60 minutes. Shock index (SI) was calculated. A separate MWVSM monitor was attached to the forehead and finger of each patient. Data from each included pulse wave transit time (PWTT), temperature, HR, SpO2, and a summary status termed "Murphy Factor" (MF), which ranges from 0 to 5. Patients are classified as "routine" if MF = 0 to 1 or SI = 0 to 0.7, "priority" if MF = 2 to 3 or SI = 0.7 to 0.9, and "critical" if MF = 4 to 5 or SI ≥ 0.9. Forehead and finger MWVSM HRs both differed from the monitor (both p < 0.001), but the few beats per minute differences were clinically insignificant. Differences in MWVSM SpO2 (1-7%) and temperature (6-13°F) from the monitor were site specific (all p < 0.001). Forehead PWTT (271 ± 50 ms) was less (p < 0.001) than finger PWTT (315 ± 42 ms); both were dissociated from systolic blood pressure (r(2) < 0.05). The SI distributed patients about equally as "routine," "priority," and "critical," whereas MF overtriaged to "routine" and undertriaged to "critical" for both sensors (all p < 0.001). Our findings suggest that MF does not accurately predict the most critical patients, likely because erroneous PWTT values confound MF calculations. MF and the MWVSM are promising, but require fine-tuning before deployment.