IoT-Based Wireless System for Gait Kinetics Monitoring in Multi-Device Therapeutic Interventions.

This study presents an IoT-based gait analysis system employing insole pressure sensors to assess gait kinetics. The system integrates piezoresistive sensors within a left foot insole, with data acquisition managed using an ESP32 board that communicates via Wi-Fi through an MQTT IoT framework. In this initial protocol study, we conducted a comparative analysis using the Zeno system, supported by PKMAS as the gold standard, to explore the correlation and agreement of data obtained from the insole system. Four volunteers (two males and two females, aged 24-28, without gait disorders) participated by walking along a 10 m Zeno system path, equipped with pressure sensors, while wearing the insole system. Vertical ground reaction force (vGRF) data were collected over four gait cycles. The preliminary results indicated a strong positive correlation (r = 0.87) between the insole and the reference system measurements. A Bland-Altman analysis further demonstrated a mean difference of approximately (0.011) between the two systems, suggesting a minimal yet significant bias. These findings suggest that piezoresistive sensors may offer a promising and cost-effective solution for gait disorder assessment and monitoring. However, operational factors such as high temperatures and sensor placement within the footwear can introduce noise or unwanted signal activation. The communication framework proved functional and reliable during this protocol, with plans for future expansion to multi-device applications. It is important to note that additional validation studies with larger sample sizes are required to confirm the system's reliability and robustness for clinical and research applications.

Wireless electrocochleography in awake chinchillas: A model to study crossmodal modulations at the peripheral level.

The discovery and development of electrocochleography (ECochG) in animal models has been fundamental for its implementation in clinical audiology and neurotology. In our laboratory, the use of round-window ECochG recordings in chinchillas has allowed a better understanding of auditory efferent functioning. In previous works, we gave evidence of the corticofugal modulation of auditory-nerve and cochlear responses during visual attention and working memory. However, whether these cognitive top-down mechanisms to the most peripheral structures of the auditory pathway are also active during audiovisual crossmodal stimulation is unknown. Here, we introduce a new technique, wireless ECochG to record compound-action potentials of the auditory nerve (CAP), cochlear microphonics (CM), and round-window noise (RWN) in awake chinchillas during a paradigm of crossmodal (visual and auditory) stimulation. We compared ECochG data obtained from four awake chinchillas recorded with a wireless ECochG system with wired ECochG recordings from six anesthetized animals. Although ECochG experiments with the wireless system had a lower signal-to-noise ratio than wired recordings, their quality was sufficient to compare ECochG potentials in awake crossmodal conditions. We found non-significant differences in CAP and CM amplitudes in response to audiovisual stimulation compared to auditory stimulation alone (clicks and tones). On the other hand, spontaneous auditory-nerve activity (RWN) was modulated by visual crossmodal stimulation, suggesting that visual crossmodal simulation can modulate spontaneous but not evoked auditory-nerve activity. However, given the limited sample of 10 animals (4 wireless and 6 wired), these results should be interpreted cautiously. Future experiments are required to substantiate these conclusions. In addition, we introduce the use of wireless ECochG in animal models as a useful tool for translational research.

Wearable, battery-free, wireless multiplexed printed sensors for heat stroke prevention with mussel-inspired bio-adhesive membranes.

Wearable technologies are becoming pervasive in our society, and their development continues to accelerate the untapped potential of continuous and ubiquitous sensing, coupled with big data analysis and interpretation, has only just begun to unfold. However, existing wearable devices are still bulky (mainly due to batteries and electronics) and have suboptimal skin contact. In this work, we propose a novel approach based on a sensor network produced through inkjet printing of nanofunctional inks onto a semipermeable substrate. This network enables real-time monitoring of critical physiological parameters, including temperature, humidity, and muscle contraction. Remarkably, our system operates under battery-free and wireless near-field communication (NFC) technology for data readout via smartphones. Moreover, two of the three sensors were integrated onto a naturally adhesive bioinspired membrane. This membrane, developed using an eco-friendly, high-throughput process, draws inspiration from the remarkable adhesive properties of mussel-inspired molecules. The resulting ultra-conformable membrane adheres effortlessly to the skin, ensuring reliable and continuous data collection. The urgency of effective monitoring systems cannot be overstated, especially in the context of rising heat stroke incidents attributed to climate change and high-risk occupations. Heat stroke manifests as elevated skin temperature, lack of sweating, and seizures. Swift intervention is crucial to prevent progression to coma or fatality. Therefore, our proposed system holds immense promise for the monitoring of these parameters on the field, benefiting both the general population and high-risk workers, such as firefighters.

Efficacy of wireless sensors in assessing occlusal and bite forces: A systematic review.

BACKGROUND: The noteworthy correlation between bite force and masticatory performance emphasizes its significance as a meaningful and objective method for assessing oral function. Furthermore, in the study of bruxism, the measurement of intraoral bite force assumes critical importance. Given the importance of assessing occlusal forces and bite force, this systematic review aims to assess the efficacy of wireless sensors in measuring these forces. METHODS: The search methodology employed in this systematic review adhered to the guidelines outlined by PRISMA. The strategy involved the exploration of various databases, including PubMed/MEDLINE, SCOPUS and SCIELO. An assessment tool was employed to evaluate the bias risk and study quality. RESULTS: This systematic review encompassed six prospective clinical studies involving a total of 89 participants. Wireless sensors for measuring occlusal forces and bite forces were predominantly employed in healthy adults or individuals with bruxism, along with children undergoing orthodontic treatment. All wireless sensors employed in the studies underwent validation and reproducibility assessments, affirming their reliability. The findings indicated that all wireless sensors exhibited efficacy in detecting occlusal forces and bite forces. CONCLUSION: Wireless sensors offer real-time monitoring of occlusal and bite forces, aiding in understanding force distribution and identifying bruxism patterns. Despite limited studies on their application, these sensors contribute to evolving insights. Integration into clinical practice requires careful consideration of factors like calibration and patient compliance. Ongoing research is crucial to address limitations and enhance the efficacy of wireless sensors in measuring occlusal and bite forces and managing bruxism.

TBISTAT: An open-source, wireless portable, electrochemical impedance spectroscopy capable potentiostat for the point-of-care detection of S100B in plasma samples.

Point-of-Care (POC) testing for biomarker detection demands techniques that are easy to use, readily available, low-cost, and with rapid response times. This paper describes the development of a fully open-source, modular, wireless, battery-powered, smartphone-controlled, low-cost potentiostat capable of conducting electrochemical impedance spectroscopy for the electrochemical detection of the S100B protein captured in an ANTI-S100B functionalized thin-film gold interdigitated electrode platform to support traumatic brain injury diagnosis and treatment. EIS results from the developed potentiostat were validated with a commercial benchtop potentiostat by comparing impedance magnitude and phase values along the EIS frequency range. In addition, an experimental design was performed for detecting S100B in spiked human plasma samples with S100B concentrations of clinical utility, and a calibration curve was found for quantifying S100B detection. No statistically significant differences were found between EIS results from the developed potentiostat and the commercial potentiostat. Statistically significant differences in the changes in charge transfer resistance signal between each tested S100B concentration (p < 0.05) were found, with a limit of detection of 35.73 pg/mL. The modularity of the proposed potentiostat allows easier component changes according to the application demands in power, frequency excitation ranges, wireless communication protocol, signal amplification and transduction, precision, and sampling frequency of ADC, among others, when compared to state-of-the-art open-source EIS potentiostats. In addition, the use of minimal, easy acquirable open-source hardware and software, high-level filtering, accurate ADC, Fast Fourier Transform with low spectral leakage, wireless communication, and the simple user interface provides a framework for facilitating EIS analysis and developing new affordable instrumentation for POC biosensors integrated systems.

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.

Design of a Fully Integrated Inductive Coupling System: A Discrete Approach Towards Sensing Ventricular Pressure.

In this paper, an alternative strategy for the design of a bidirectional inductive power transfer (IPT) module, intended for the continuous monitoring of cardiac pressure, is presented. This new integrated implantable medical device (IMD) was designed including a precise ventricular pressure sensor, where the available implanting room is restricted to a 1.8 × 1.8 cm2 area. This work considers a robust magnetic coupling between an external reading coil and the implantable module: a three-dimensional inductor and a touch mode capacitive pressure sensor (TMCPS) set. In this approach, the coupling modules were modelled as RCL circuits tuned at a 13.56 MHz frequency. The analytical design was validated by means of Comsol Multiphysics, CoventorWare, and ANSYS HFSS software tools. A power transmission efficiency (PTE) of 94% was achieved through a 3.5 cm-thick biological tissue, based on high magnitudes for the inductance (L) and quality factor (Q) components. A specific absorption rate (SAR) of less than 1.6 W/Kg was attained, which suggests that this IPT system can be implemented in a safe way, according to IEEE C95.1 safety guidelines. The set of inductor and capacitor integrated arrays were designed over a very thin polyimide film, where the 3D coil was 18 mm in diameter and approximately 50% reduced in size, considering any conventional counterpart. Finally, this new approach for the IMD was under development using low-cost thin film manufacturing technologies for flexible electronics. Meanwhile, as an alternative test, this novel system was fabricated using a discrete printed circuit board (PCB) approach, where preliminary electromagnetic characterization demonstrates the viability of this bidirectional IPT design.

Perrogator: A Portable Energy-Efficient Interrogator for Dynamic Monitoring of Wavelength-Based Sensors in Wearable Applications.

In this paper, we report the development of a portable energy-efficient interrogator (Perrogator) for wavelength-based optical sensors. The interrogator is based on a compact solution encompassing a white light source and the spectral convolution between the sensor and a tunable filter, which is acquired by a photodetector, where a microcontroller has two functions: (i) To control the filter tuning and to (ii) acquire the photodetector signal. Then, the data is sent to a single-board computer for further signal processing. Furthermore, the employed single-board computer has a Wi-Fi module, which can be used to send the sensors data to the cloud. The proposed approach resulted in an interrogator with a resolution as high as 3.82 pm (for 15.64 nm sweeping range) and maximum acquisition frequency of about 210 Hz (with lower resolution ~15.30 pm). Perrogator was compared with a commercial fiber Bragg grating (FBG) interrogator for strain measurements and good agreement between both devices was found (1.226 pm/µÎµ for the commercial interrogator and 1.201 pm/µÎµ for the proposed approach with root mean square error of 0.0144 and 0.0153, respectively), where the Perrogator has the additional advantages of lower cost, higher portability and lower energy consumption. In order to demonstrate such advantages in conjunction with the high acquisition frequency allowed us to demonstrate two wearable applications using the proposed interrogation device over FBG and Fabry-Perot interferometer (FPI) sensors. In the first application, an FBG-embedded smart textile for knee angle assessment was used to analyze the gait of a healthy person. Due to the capability of reconstructing the FBG spectra, it was possible to employ a technique based on the FBG wavelength shift and reflectivity to decouple the effects of the bending angle and axial strain on the FBG response. The measurement of the knee angle as well as the estimation of the angular and axial displacements on the grating that can be correlated to the variations of the knee center of rotation were performed. In the second application, a FPI was embedded in a chest band for simultaneous measurement of breath and heart rates, where good agreement (error below 5%) was found with the reference sensors in all analyzed cases.

Video loss prediction model in wireless networks.

This work discusses video communications over wireless networks (IEEE 802.11ac standard). The videos are in three different resolutions: 720p, 1080p, and 2160p. It is essential to study the performance of these media in access technologies to enhance the current coding and communications techniques. This study sets out a video quality prediction model that includes the different resolutions that are based on wireless network terms and conditions, an approach that has not previously been adopted in the literature. The model involves obtaining Service and Experience Quality Metrics, such as PSNR (Peak Signal-to-Noise Ratio) and packet loss. This article outlines a methodology and mathematical model for video quality loss in the wireless network from simulated data and its accuracy is ensured through the use of performance metrics (RMSE and Standard Deviation). The methodology is based on two mathematical functions, (logarithmic and exponential), and their parameters are defined by linear regression. The model obtained RMSE values and standard deviation of 2.32 dB and 2.2 dB for the predicted values, respectively. The results should lead to a CODEC (Coder-Decoder) improvement and contribute to a better wireless networks design.

Reconfigurable Embedded System for Electrocardiogram Acquisition.

Smartphones include features that offers the chance to develop mobile systems in medical field, resulting in an area called mobile-health. One of the most common medical examinations is the electrocardiogram (ECG), which allows the diagnosis of various heart diseases, leading to preventative measures and preventing more serious problems. The objective of this study was to develop a wireless reconfigurable embedded system using a FPAA (Field Programmable Analog Array), for the acquisition of ECG signals, and an application showing and storing these signals on Android smartphones. The application also performs the partial FPAA reconfiguration in real time (adjustable gain). Previous studies using FPAA usually use the development boards provided by the manufacturer (high cost), do not allow the reconfiguration in real time, use no smartphone and communicate via cables. The parameters tested in the acquisition circuit and the quality of ECGs registered in an individual were satisfactory.

On the MAC/network/energy performance evaluation of Wireless Sensor Networks: Contrasting MPH, AODV, DSR and ZTR routing protocols.

Wireless Sensor Networks deliver valuable information for long periods, then it is desirable to have optimum performance, reduced delays, low overhead, and reliable delivery of information. In this work, proposed metrics that influence energy consumption are used for a performance comparison among our proposed routing protocol, called Multi-Parent Hierarchical (MPH), the well-known protocols for sensor networks, Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR), and Zigbee Tree Routing (ZTR), all of them working with the IEEE 802.15.4 MAC layer. Results show how some communication metrics affect performance, throughput, reliability and energy consumption. It can be concluded that MPH is an efficient protocol since it reaches the best performance against the other three protocols under evaluation, such as 19.3% reduction of packet retransmissions, 26.9% decrease of overhead, and 41.2% improvement on the capacity of the protocol for recovering the topology from failures with respect to AODV protocol. We implemented and tested MPH in a real network of 99 nodes during ten days and analyzed parameters as number of hops, connectivity and delay, in order to validate our Sensors 2014, 14 22812 simulator and obtain reliable results. Moreover, an energy model of CC2530 chip is proposed and used for simulations of the four aforementioned protocols, showing that MPH has 15.9% reduction of energy consumption with respect to AODV, 13.7% versus DSR, and 5% against ZTR.

A new crank arm-based load cell for the 3D analysis of the force applied by a cyclist.

This report describes a new crank arm-based force platform designed to evaluate the three-dimensional force applied to the pedals by cyclists in real conditions. The force platform was designed to be fitted on a conventional competition bicycle crankset while data is transmitted wirelessly through a Bluetooth™ module and also stored on a SD card. A 3D solid model is created in the SolidWorks (Dassault Systèmes SOLIDWORKS Corp.) to analyze the static and dynamic characteristics of the crank arm by using the finite elements technique. Each crankset arm is used as a load cell based on strain gauges configured as three Wheatstone bridges. The signals are conditioned on a printed circuit board attached directly to the structure. The load cell showed a maximum nonlinearity error between 0.36% and 0.61% and a maximum uncertainty of 2.3% referred to the sensitivity of each channel. A roller trainer equipped with an optical encoder was also developed, allowing the measurement of the wheel's instantaneous velocity.

Smart multi-level tool for remote patient monitoring based on a wireless sensor network and mobile augmented reality.

Technological innovations in the field of disease prevention and maintenance of patient health have enabled the evolution of fields such as monitoring systems. One of the main advances is the development of real-time monitors that use intelligent and wireless communication technology. In this paper, a system is presented for the remote monitoring of the body temperature and heart rate of a patient by means of a wireless sensor network (WSN) and mobile augmented reality (MAR). The combination of a WSN and MAR provides a novel alternative to remotely measure body temperature and heart rate in real time during patient care. The system is composed of (1) hardware such as Arduino microcontrollers (in the patient nodes), personal computers (for the nurse server), smartphones (for the mobile nurse monitor and the virtual patient file) and sensors (to measure body temperature and heart rate), (2) a network layer using WiFly technology, and (3) software such as LabView, Android SDK, and DroidAR. The results obtained from tests show that the system can perform effectively within a range of 20 m and requires ten minutes to stabilize the temperature sensor to detect hyperthermia, hypothermia or normal body temperature conditions. Additionally, the heart rate sensor can detect conditions of tachycardia and bradycardia.

Study of the effect of distance and misalignment between magnetically coupled coils for wireless power transfer in intraocular pressure measurement.

An analysis of the effect of distance and alignment between two magnetically coupled coils for wireless power transfer in intraocular pressure measurement is presented. For measurement purposes, a system was fabricated consisting of an external device, which is a Maxwell-Wien bridge circuit variation, in charge of transferring energy to a biomedical implant and reading data from it. The biomedical implant is an RLC tank circuit, encapsulated by a polyimide coating. Power transfer was done by magnetic induction coupling method, by placing one of the inductors of the Maxwell-Wien bridge circuit and the inductor of the implant in close proximity. The Maxwell-Wien bridge circuit was biased with a 10 MHz sinusoidal signal. The analysis presented in this paper proves that wireless transmission of power for intraocular pressure measurement is feasible with the measurement system proposed. In order to have a proper inductive coupling link, special care must be taken when placing the two coils in proximity to avoid misalignment between them.

Modeling IoT-based solutions using human-centric wireless sensor networks.

The Internet of Things (IoT) has inspired solutions that are already available for addressing problems in various application scenarios, such as healthcare, security, emergency support and tourism. However, there is no clear approach to modeling these systems and envisioning their capabilities at the design time. Therefore, the process of designing these systems is ad hoc and its real impact is evaluated once the solution is already implemented, which is risky and expensive. This paper proposes a modeling approach that uses human-centric wireless sensor networks to specify and evaluate models of IoT-based systems at the time of design, avoiding the need to spend time and effort on early implementations of immature designs. It allows designers to focus on the system design, leaving the implementation decisions for a next phase. The article illustrates the usefulness of this proposal through a running example, showing the design of an IoT-based solution to support the first responses during medium-sized or large urban incidents. The case study used in the proposal evaluation is based on a real train crash. The proposed modeling approach can be used to design IoT-based systems for other application scenarios, e.g., to support security operatives or monitor chronic patients in their homes.

Cooperation among wirelessly connected static and mobile sensor nodes for surveillance applications.

This paper presents a bio-inspired networking strategy to support the cooperation between static sensors on the ground and mobile sensors in the air to perform surveillance missions in large areas. The goal of the proposal is to provide low overhead in the communication among sensor nodes, while allocating the mobile sensors to perform sensing activities requested by the static ones. Simulations have shown that the strategy is efficient in maintaining low overhead and achieving the desired coordination.

A wearable mobile sensor platform to assist fruit grading.

Wearable computing is a form of ubiquitous computing that offers flexible and useful tools for users. Specifically, glove-based systems have been used in the last 30 years in a variety of applications, but mostly focusing on sensing people's attributes, such as finger bending and heart rate. In contrast, we propose in this work a novel flexible and reconfigurable instrumentation platform in the form of a glove, which can be used to analyze and measure attributes of fruits by just pointing or touching them with the proposed glove. An architecture for such a platform is designed and its application for intuitive fruit grading is also presented, including experimental results for several fruits.

Wireless medical sensor networks: design requirements and enabling technologies.

This article analyzes wireless communication protocols that could be used in healthcare environments (e.g., hospitals and small clinics) to transfer real-time medical information obtained from noninvasive sensors. For this purpose the features of the three currently most widely used protocols-namely, Bluetooth(®) (IEEE 802.15.1), ZigBee (IEEE 802.15.4), and Wi-Fi (IEEE 802.11)-are evaluated and compared. The important features under consideration include data bandwidth, frequency band, maximum transmission distance, encryption and authentication methods, power consumption, and current applications. In addition, an overview of network requirements with respect to medical sensor features, patient safety and patient data privacy, quality of service, and interoperability between other sensors is briefly presented. Sensor power consumption is also discussed because it is considered one of the main obstacles for wider adoption of wireless networks in medical applications. The outcome of this assessment will be a useful tool in the hands of biomedical engineering researchers. It will provide parameters to select the most effective combination of protocols to implement a specific wireless network of noninvasive medical sensors to monitor patients remotely in the hospital or at home.

Reliability and availability evaluation of Wireless Sensor Networks for industrial applications.

Wireless Sensor Networks (WSN) currently represent the best candidate to be adopted as the communication solution for the last mile connection in process control and monitoring applications in industrial environments. Most of these applications have stringent dependability (reliability and availability) requirements, as a system failure may result in economic losses, put people in danger or lead to environmental damages. Among the different type of faults that can lead to a system failure, permanent faults on network devices have a major impact. They can hamper communications over long periods of time and consequently disturb, or even disable, control algorithms. The lack of a structured approach enabling the evaluation of permanent faults, prevents system designers to optimize decisions that minimize these occurrences. In this work we propose a methodology based on an automatic generation of a fault tree to evaluate the reliability and availability of Wireless Sensor Networks, when permanent faults occur on network devices. The proposal supports any topology, different levels of redundancy, network reconfigurations, criticality of devices and arbitrary failure conditions. The proposed methodology is particularly suitable for the design and validation of Wireless Sensor Networks when trying to optimize its reliability and availability requirements.