Browsing by Author "Soares, Salviano"
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- An implantable microsystem for electrical resistance and temperature measurements in cows with wireless capabilities suitable for reproductive managementPublication . Morais, R.; Valente, António; Almeida, José Carlos; Silva, Amélia M.; Soares, Salviano; Valentim, Ramiro; Azevedo, JorgeIn the cattle breeding industry, where artificial insemination techniques are employed, the successful detection of oestrus onset leads to considerable cost saving in herd management. One of the most reliable approaches is based on the determination of progesterone concentration in milk. However, these methods rely on the biosensor concept where a biological substrate is used in a chemical binding reaction to, directly or indirectly; produce some effect (electrical or light) that is used at the transducer level. These methods present several drawbacks concerning real-time measurements due to the complexity of the reactions involved and reagent/waste handling. Another approach is to combine measurements of electrical resistance of vaginal mucus and temperature to predict estrus. Using a low-power microsystem with wireless capabilities it is possible to take these measurements in-situ and more frequently. The proposed microsystem comprises a second-order delta-sigma modulator for analog to digital conversion and a class-E radio-frequency (RF) transmitter operating in the ISM-band of 433 MHz to transfer acquired data to a collar. Electrical resistance is measured by using a modified Wenner array and temperature by the on-chip temperature sensor. System (including battery and antenna) package is made of a tissue compatible material to allow implantation in the cow vulvar muscle.
- Concept study of an implantable microsystem for electrical resistance and temperature measurements in dairy cows, suitable for estrus detectionPublication . Morais, Raul; Valente, António; Almeida, José Carlos; Silva, Amélia M.; Soares, Salviano; Reis, Manuel José Cabral dos Santos; Valentim, Ramiro; Azevedo, JorgeIn cattle breeding industry, where artificial insemination techniques are employed, the successful detection of estrus onset leads to considerable cost-saving in herd management. One of the most reliable approaches is based on the determination of progesterone concentration in milk. However, these methods rely on the biosensor concept where a biological substrate is used in a chemical-binding reaction to directly or indirectly produce some effect (electrical or light) that is used at the transducer level. These methods present several drawbacks concerning real-time measurements due to the complexity of the reactions involved and reagent/waste handling. Another approach is to combine measurements of temperature and electrical resistance of reproductive tissues to predict estrus. Using a low-power microsystem with wireless capabilities it is possible to take these measurements in situ and more frequently. The proposed microsystem comprises a second-order delta–sigma modulator for analog-to-digital conversion and a class-E radio-frequency (RF) transmitter operating in the ISM-band of 433MHz to transfer acquired data to a collar. Electrical resistance is measured by using a modifiedWenner array and temperature by the on-chip temperature sensor. System (including battery and antenna) package is made of a tissue-compatible material to allow implantation in the cow’s vulvar muscle. Since estrus prediction is based on relative changes of the two correlated parameters, calibration is not necessary. Some preliminary results regarding the measuring concept are presented.
- Evaluation of LP-WAN technologies for fire forest detection systemsPublication . Adorno, Daniel; Soares, Salviano; Lima, José; Valente, AntónioLow Power Wide Area Networks (LP-WAN) are receiving a lot of attention because of their ability to communicate using radio frequency in long distances, with low-power consumption and low-cost devices. In this paper, we provide a comparison between the two LP-WAN platforms that are leading the market, the Sigfox and the LoRaWAN, based on the literature. Both platforms are analyzed considering the context of the forest fire detection and verification systems. Many aspects are being considered to identify which LP-WAN is more adequate to be used in this kind of systems, such as battery lifetime, coverage range, business model and costs. The comparison shows that both platforms are very similar in most of the aspects, although LoRaWAN is more flexible than Sigfox on the deployment and management of the network infrastructure. LoRaWAN allows customers to implement and manage their own infrastructure network, which is essential in systems which monitor vast forest areas.
- F0, LPC, and MFCC analysis for emotion recognition based on speechPublication . Teixeira, Felipe; Teixeira, João Paulo; Soares, Salviano; Abreu, J.L. PioIn this work, research was done to understand what is needed to build a database to recognise emotions through speech. Some features that can highlight a good success rate for emotion recognition through speech were investigated. Also studied were some characteristics (symptoms) that can be associated with a specific emotional state. On the other hand, we also studied some features that can be used to identify some emotional states. A System Emotion Recognition (SER) was built with SVM, and the binary analysis was compared with a multi-category analysis. The binary analysis achieved an accuracy of 87.5% and the multi-class 42.6%. The parameters Fundamental Frequency-F0, Linear Predictive Coefficients (LPC), and Mel Frequency Cepstral Coeficients (MFCC) were used. The modest accuracy of this work was achieved using only F0, LPC and MFCC features.
- High-resolution portable bluetooth module for ECG and EMG acquisitionPublication . Luiz, Luiz E.; Soares, Salviano; Valente, Antonio; Barroso, João; Leitão, Paulo; Teixeira, João PauloPortable ECG/sEMG acquisition systems for telemedicine often lack application flexibility (e.g., limited configurability, signal validation) and efficient wireless data handling. A modular biosignal acquisition system with up to 8 channels, 24-bit resolution and configurable sampling (1–4 kHz) is proposed, featuring per-channel gain/source adjustments, internal MUX-based reference drive, and visual electrode integrity monitoring; Bluetooth® transmits data via a bit-wise packet structure (83.92% smaller than JSON, 7.28 times faster decoding with linear complexity based on input size). Results: maximum 6.7 μVrms input-referred noise; harmonic signal correlations >99.99%, worst-case THD of -53.03 dBc, and pulse wave correlation >99.68% in frequency-domain with maximum NMSE% of 6e-6%; and 22.3-hour operation (3.3 Ah battery @ 150 mA). The system enables high-fidelity, power-efficient acquisition with validated signal integrity and adaptable multi-channel acquisition, addressing gaps in portable biosensing.
- A LoRaWAN IoT system for smart agriculture for vine water status determinationPublication . Valente, António; Costa, Carlos M.; Pereira, Leonor Sousa; Soares, Bruno; Lima, José; Soares, SalvianoIn view of the actual climate change scenario felt across the globe, resource management is crucial, especially with regard to water. In this sense, continuous monitoring of plant water status is essential to optimise not only crop management but also water resources. Currently, monitoring of vine water status is done through expensive and time-consuming methods that do not allow continuous monitoring, which is especially inconvenient in places with difficult access. The aim of the developed work was to install three groups of sensors (Environmental, Plant and Soil) in a vineyard and connect them through LoRaWAN protocol for data transmission. The results demonstrate that the implemented system is capable of continuous data communication without data loss. The reduced cost and superior range of LoRaWAN compared to WiFi or Bluetooth is especially important for applications in remote areas where cellular networks have little coverage. Altogether, this methodology provides a remote, continuous and more effective method to monitor plant water status and is capable of supporting producers in more efficient management of their farms and water resources.
- A narrative review of speech and EEG features for schizophrenia detection: progress and challengesPublication . Teixeira, Felipe; Costa, Miguel Rocha; Abreu, J.L. Pio; Cabral, Manuel; Soares, Salviano; Teixeira, João PauloSchizophrenia is a mental illness that affects an estimated 21 million people worldwide. The literature establishes that electroencephalography (EEG) is a well-implemented means of studying and diagnosing mental disorders. However, it is known that speech and language provide unique and essential information about human thought. Semantic and emotional content, semantic coherence, syntactic structure, and complexity can thus be combined in a machine learning process to detect schizophrenia. Several studies show that early identification is crucial to prevent the onset of illness or mitigate possible complications. Therefore, it is necessary to identify disease-specific biomarkers for an early diagnosis support system. This work contributes to improving our knowledge about schizophrenia and the features that can identify this mental illness via speech and EEG. The emotional state is a specific characteristic of schizophrenia that can be identified with speech emotion analysis. The most used features of speech found in the literature review are fundamental frequency (F0), intensity/loudness (I), frequency formants (F1, F2, and F3), Mel-frequency cepstral coefficients (MFCC's), the duration of pauses and sentences (SD), and the duration of silence between words. Combining at least two feature categories achieved high accuracy in the schizophrenia classification. Prosodic and spectral or temporal features achieved the highest accuracy. The work with higher accuracy used the prosodic and spectral features QEVA, SDVV, and SSDL, which were derived from the F0 and spectrogram. The emotional state can be identified with most of the features previously mentioned (F0, I, F1, F2, F3, MFCCs, and SD), linear prediction cepstral coefficients (LPCC), linear spectral features (LSF), and the pause rate. Using the event-related potentials (ERP), the most promissory features found in the literature are mismatch negativity (MMN), P2, P3, P50, N1, and N2. The EEG features with higher accuracy in schizophrenia classification subjects are the nonlinear features, such as Cx, HFD, and Lya.
- Portable system and user interface for ECG and EMG acquisition, conditioning, and parameters extractionPublication . Luiz, Luiz E.; Silva, Wilson J. da; Soares, Salviano; Leitão, Paulo; Teixeira, João PauloElectrical signals from the human body are constantly the focus of research, searching for a better understanding of physiological events, discovering early signs of disease, and improving life quality. Developing devices that allow research beyond the usual requirements and allow easy adaptation regarding the system's acquisition, conditioning, and processing parts could be a step toward better understanding some behaviours. Therefore, this work focused on designing a system that goes from the discrete components to a graphical interface, allowing user control of parameters to set the acquisition in a way that favours the specific signal of interest. The resulting system allows the user to change parameters regarding the analogue and digital filtering, sampling frequency and events detection, namely R-peaks, in the electrocardiogram, to estimate heart rate and its frequency fluctuation, and muscle contraction in electromyogram, to analyse contraction strength and muscle fatigue. The system also allows the data to be stored, aiming to generate datasets to further process the data in AI-based algorithms.
- Resistência ao fogo de blocos de betão leve à base de caroço de espiga de milhoPublication . Faustino, Jorge; Alves, Nuno; Piloto, P.A.G.; Ferreira, Débora; Fonseca, E.M.M.; Silva, Elisabete Cristina Cruz; Soares, Salviano; Pinto, JorgeEstudos recentes indicam que o caroço da espiga de milho tem algumas propriedades interessantes, das quais se destacam a leveza e o bom desempenho em termos de capacidade de isolamento térmico e acústico. Neste trabalho de investigação, o caroço da espiga de milho é proposto como agregado no fabrico de blocos de betão leve. Para o efeito, o caroço da espiga de milho é granulado previamente. Posteriormente, as partículas de milho são envoltas numa pasta de cimento para reduzir a capacidade de absorção de água e melhorar a aderência. A aplicação preferencial, dos blocos de espiga de milho, será a construção de paredes divisórias, pelo que o estudo da sua capacidade resistente ao fogo é o objetivo fundamental a alcançar neste trabalho de investigação.
- Robot-assisted rehabilitation architecture supported by a distributed data acquisition systemPublication . Chellal, Arezki Abderrahim; Lima, José; Gonçalves, José; Fernandes, Florbela P.; Pacheco, Maria F.; Monteiro, Fernando C.; Brito, Thadeu; Soares, SalvianoRehabilitation robotics aims to facilitate the rehabilitation procedure for patients and physical therapists. This field has a relatively long history dating back to the 1990s; however, their implementation and the standardisation of their application in the medical field does not follow the same pace, mainly due to their complexity of reproduction and the need for their approval by the authorities. This paper aims to describe architecture that can be applied to industrial robots and promote their application in healthcare ecosystems. The control of the robotic arm is performed using the software called SmartHealth, offering a 2 Degree of Autonomy (DOA). Data are gathered through electromyography (EMG) and force sensors at a frequency of 45 Hz. It also proves the capabilities of such small robots in performing such medical procedures. Four exercises focused on shoulder rehabilitation (passive, restricted active-assisted, free active-assisted and Activities of Daily Living (ADL)) were carried out and confirmed the viability of the proposed architecture and the potential of small robots (i.e., the UR3) in rehabilitation procedure accomplishment. This robot can perform the majority of the default exercises in addition to ADLs but, nevertheless, their limits were also uncovered, mainly due to their limited Range of Motion (ROM) and cost.