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1.
Sensors (Basel) ; 20(7)2020 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-32260321

RESUMO

This paper describes the design of a two channels electrodermal activity (EDA) sensor and two channels electrocardiogram (ECG) sensor. The EDA sensors acquire data on the hands and transmit them to the ECG sensor with wireless WiFi communication for increased wearability. The sensors system acquires two EDA channels to improve the removal of motion artifacts that take place if EDA is measured on individuals who need to move their hands in their activities. The ECG channels are acquired on the chest and the ECG sensor is responsible for aligning the two ECG traces with the received packets from EDA sensors; the ECG sensor sends via WiFi the aligned packets to a laptop for real time plot and data storage. The metrological characterization showed high-level performances in terms of linearity and jitter; the delays introduced by the wireless transmission from EDA to ECG sensor have been proved to be negligible for the present application.


Assuntos
Eletrocardiografia , Tecnologia sem Fio , Bibliometria , Resposta Galvânica da Pele , Humanos
3.
Nat Med ; 26(3): 418-429, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32161411

RESUMO

Standard clinical care in neonatal and pediatric intensive-care units (NICUs and PICUs, respectively) involves continuous monitoring of vital signs with hard-wired devices that adhere to the skin and, in certain instances, can involve catheter-based pressure sensors inserted into the arteries. These systems entail risks of causing iatrogenic skin injuries, complicating clinical care and impeding skin-to-skin contact between parent and child. Here we present a wireless, non-invasive technology that not only offers measurement equivalency to existing clinical standards for heart rate, respiration rate, temperature and blood oxygenation, but also provides a range of important additional features, as supported by data from pilot clinical studies in both the NICU and PICU. These new modalities include tracking movements and body orientation, quantifying the physiological benefits of skin-to-skin care, capturing acoustic signatures of cardiac activity, recording vocal biomarkers associated with tonality and temporal characteristics of crying and monitoring a reliable surrogate for systolic blood pressure. These platforms have the potential to substantially enhance the quality of neonatal and pediatric critical care.


Assuntos
Técnicas Biossensoriais , Unidades de Terapia Intensiva Neonatal , Unidades de Terapia Intensiva Pediátrica , Monitorização Fisiológica , Pele/anatomia & histologia , Tecnologia sem Fio , Monitorização Ambulatorial da Pressão Arterial , Criança , Pré-Escolar , Eletrocardiografia , Desenho de Equipamento , Humanos , Recém-Nascido , Fotopletismografia , Fatores de Tempo
4.
Nat Biomed Eng ; 4(2): 207-222, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32076132

RESUMO

Clinically approved neural stimulators are limited by battery requirements, as well as by their large size compared with the stimulation targets. Here, we describe a wireless, leadless and battery-free implantable neural stimulator that is 1.7 mm3 and that incorporates a piezoceramic transducer, an energy-storage capacitor and an integrated circuit. An ultrasonic link and a hand-held external transceiver provide the stimulator with power and bidirectional communication. The stimulation protocols were wirelessly encoded on the fly, reducing power consumption and on-chip memory, and enabling protocol complexity with a high temporal resolution and low-latency feedback. Uplink data indicating whether stimulation occurs are encoded by the stimulator through backscatter modulation and are demodulated at the external transceiver. When embedded in ex vivo porcine tissue, the integrated circuit efficiently harvested ultrasonic power, decoded downlink data for the stimulation parameters and generated current-controlled stimulation pulses. When cuff-mounted and acutely implanted onto the sciatic nerve of anaesthetized rats, the device conferred repeatable stimulation across a range of physiological responses. The miniaturized neural stimulator may facilitate closed-loop neurostimulation for therapeutic interventions.


Assuntos
Neuroestimuladores Implantáveis , Tecnologia sem Fio , Animais , Fontes de Energia Elétrica , Desenho de Equipamento , Ratos , Nervo Isquiático/fisiologia , Processamento de Sinais Assistido por Computador , Ultrassom
5.
PLoS One ; 15(2): e0228861, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084146

RESUMO

A wireless photovoltaic retinal prosthesis is currently being studied with the aim of providing prosthetic vision to patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). The major challenge of a photovoltaic device is its limited power efficiency. Our retinal prosthetic design implements a unique divisional power supply scheme (DPSS) system that provides the electrical power generated by all of the solar cells to only a subset of electrodes at any moment in time. The aim of the present study was to systematically characterize the spatiotemporal integration performance of the system under various DPSS conditions using human subjects and a psychophysical approach. A 16x16 pixels LED array controlled by Arduino was used to simulate the output signal of the DPSS design, and human performance under different visual stimulations at various update frequencies was then used to assess the spatiotemporal capability of retinal prostheses. The results showed that the contrast polarity of the image, image brightness, and division number influenced the lower limit of the update frequency of the DPSS system, while, on the other hand, visual angle, ambient light level, and stimulation order did not affect performance significantly. Pattern recognition by visual persistence with spatiotemporal integration of multiple frames of sparse dots is a feasible approach in retinal prosthesis design. These findings provide an insight into how to optimize a photovoltaic retinal prosthesis using a DPSS design with an appropriate update frequency for reliable pattern recognition. This will help the development of a wireless device able to restore vision to RP and AMD patients in the future.


Assuntos
Fontes de Energia Elétrica , Próteses Visuais , Adulto , Sensibilidades de Contraste/fisiologia , Estimulação Elétrica , Eletrodos Implantados , Voluntários Saudáveis , Humanos , Degeneração Macular/fisiopatologia , Degeneração Macular/cirurgia , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Psicofísica , Retinite Pigmentosa/fisiopatologia , Retinite Pigmentosa/cirurgia , Energia Solar , Análise Espaço-Temporal , Percepção Visual/fisiologia , Tecnologia sem Fio , Adulto Jovem
6.
PLoS One ; 15(1): e0227982, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31978101

RESUMO

The rapid increase in the usage of the mobile internet has led to a great expansion of cellular data networks in order to provide better quality of service. However, the cost to expand the cellular network is high. One of the solutions to provide affordable wireless connectivity is the deployment of a WiFi access point to offload users' data usage. Nevertheless, the frequent and inefficient handover process between the WiFi AP and cellular network, especially when the mobile device is on the go, may degrade the network performance. Mobile devices do not have the intelligence to select the optimal network to enhance the quality of service (QoS). This paper presents an enhanced handover mechanism using mobility prediction (eHMP) to assist mobile devices in the handover process so that users can experience seamless connectivity. eHMP is tested in two wireless architectures, homogeneous and heterogeneous networks. The network performance significantly improved when eHMP is used in a homogeneous network, where the network throughput increases by 106% and the rate of retransmission decreases by 85%. When eHMP is used in a heterogeneous network, the network throughput increases by 55% and the retransmission rate decreases by 75%. The findings presented in this paper reveal that mobility prediction coupled with the multipath protocol can improve the QoS for mobile devices. These results will contribute to a better understanding of how the network service provider can offload traffic to the WiFi network without experiencing performance degradation.


Assuntos
Algoritmos , Redes de Comunicação de Computadores , Tecnologia sem Fio , Telefone Celular , Cadeias de Markov , Processamento de Sinais Assistido por Computador
7.
Zhonghua Wai Ke Za Zhi ; 58(1): 1-4, 2020 Jan 01.
Artigo em Chinês | MEDLINE | ID: mdl-31902160

RESUMO

The combination of network and medical field gave birth to telemedicine.The implementation of telemedicine can improve the uneven distribution of regional medical resources, reduce the working pressure of medical staff, shorten the distance between medical staff and patients and medical staff, and improve the timeliness of monitoring, diagnosis and treatment.The continuous development of telemedicine relies on the continuous innovation of network communication technology, the latest 5(th) generation wireless systems (5G) is bringing significant changes to mobile communication and other related industries by virtue of its advantages of high data rate and low latency. This paper reviews the development of telemedicine, introduces the characteristics of 5G technology, combines the research results of 5G technology applied in the medical field at home and abroad, and prospects the development of this field in the future.


Assuntos
Telemedicina , Tecnologia sem Fio , Humanos
8.
Nat Commun ; 11(1): 444, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974376

RESUMO

Networks of sensors placed on the skin can provide continuous measurement of human physiological signals for applications in clinical diagnostics, athletics and human-machine interfaces. Wireless and battery-free sensors are particularly desirable for reliable long-term monitoring, but current approaches for achieving this mode of operation rely on near-field technologies that require close proximity (at most a few centimetres) between each sensor and a wireless readout device. Here, we report near-field-enabled clothing capable of establishing wireless power and data connectivity between multiple distant points around the body to create a network of battery-free sensors interconnected by proximity to functional textile patterns. Using computer-controlled embroidery of conductive threads, we integrate clothing with near-field-responsive patterns that are completely fabric-based and free of fragile silicon components. We demonstrate the utility of the networked system for real-time, multi-node measurement of spinal posture as well as continuous sensing of temperature and gait during exercise.


Assuntos
Vestuário , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/métodos , Tecnologia sem Fio , Fontes de Energia Elétrica , Fenômenos Eletromagnéticos , Desenho de Equipamento , Exercício Físico/fisiologia , Humanos , Joelho , Postura/fisiologia , Coluna Vertebral/fisiologia , Temperatura , Caminhada/fisiologia , Tecnologia sem Fio/instrumentação
9.
PLoS One ; 15(1): e0227145, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31899768

RESUMO

Measurement of cardiac function is vital for the health of pediatric patients with heart disease. Standard tools to measure function including echocardiogram and magnetic residence imaging are time intensive, costly, and have limited accessibility. The Vivio is a novel, non-invasive, handheld device that screens for cardiac dysfunction by analyzing intrinsic frequencies (IF) ω1 and ω2 of carotid artery waveforms. Prior studies demonstrated that left ventricular ejection fraction can be derived from IFs in adults. This study 1) studies whether the Vivio can capture carotid arterial pulse waveform data in children ages 0-19 years old; 2) tests the performance of two sensor head geometries, one larger and smaller than the standard size used in adults, designed for the pediatric population; 3) compares the IFs between pediatric age groups and adults with normal function. The Vivio successfully measured a carotid artery waveform in all children over 5 years old and 28% of children under the age of five. The small head did not accurately measure a waveform in any age group. One-way analysis of variance (ANOVA) demonstrated a difference in the IF ω1 between the adult and pediatric cohorts (F = 7.3, Prob>F = 0.0001). Post host analysis demonstrated a difference between the adult cohort (ω1 = 99 +/- 5 bpm) and the cohorts ages 0-4 (ω1 = 111 +/- 2 bpm; p = 0.0006) and 15-19 years old (ω1 = 105 +/-5 bpm; p = 0.02). One-way ANOVA demonstrated a difference in the IF ω2 between the adult and pediatric cohorts (F = 4.8, Prob>F = 0.003), specifically between the adult (ω2 = 81 +/- 13 bpm) and age 0-4 cohorts (ω2 = 48 +/- 8 bpm; p = 0.002). These results suggest that the Vivio can be used to capture carotid pulse waveform data in pediatric populations and that the data produced can be used to measure intrinsic frequencies.


Assuntos
Determinação da Frequência Cardíaca/instrumentação , Monitorização Hemodinâmica/instrumentação , Estudo de Prova de Conceito , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Tecnologia sem Fio/instrumentação , Adolescente , Adulto , Artérias Carótidas/fisiologia , Cefalometria , Criança , Pré-Escolar , Estudos de Coortes , Estudos de Viabilidade , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Pulso Arterial , Adulto Jovem
10.
PLoS One ; 15(1): e0227270, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929560

RESUMO

With advances in technology, wireless and sensor technologies represent a method for continuously recording people's biomedical signals, which may enhance the diagnosis and treatment of users' everyday health conditions. These technologies mostly target older adults. In this study, we examine a smart clothing system targeting clinically high-risk patients, including older adults with cardiovascular disease (31 outpatients) and older adults in general (81 participants), to obtain an understanding of the patients' perception of using wearable healthcare technologies. Given that technology anxiety has been shown to affect users' resistance to using new technology and that perceived ubiquity is considered a characteristic of wearable devices and other mobile wireless technologies, we included three external variables: i.e., technology anxiety, perceived ubiquity, and resistance to change, in addition to the traditional components of the technology acceptance model (TAM). The results of the hypothesized model showed that among older adults in general, technology anxiety had a negative effect on the perceived ease of use and perceived ubiquity. The perceived ubiquity construct affects both user groups' perceived ease of use and perceived usefulness of wearing smart clothes. Most relationships among the original constructs of the TAM were validated in older adults in general. Interestingly, we found that perceived usefulness had an indirect effect on behavioral intention through attitude. These results further confirm the validity of the extended TAM in determining older users' technology acceptance behavior.


Assuntos
Ansiedade/psicologia , Doenças Cardiovasculares/diagnóstico , Modelos Psicológicos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Dispositivos Eletrônicos Vestíveis/psicologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Ansiedade/etiologia , Tecnologia Biomédica , Feminino , Humanos , Intenção , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/instrumentação , Monitorização Ambulatorial/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Preferência do Paciente , Taiwan , Telemedicina/instrumentação , Telemedicina/estatística & dados numéricos , Tecnologia sem Fio/instrumentação
11.
PLoS One ; 15(1): e0226649, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31910202

RESUMO

The fundamental utility of the Large-Scale Visual Sensor Networks (LVSNs) is to monitor specified events and to transmit the detected information back to the sink for achieving the data aggregation purpose. However, the events of interest are usually not uniformly distributed but frequently detected in certain regions in real-world applications. It implies that when the events frequently picked up by the sensors in the same region, the transmission load of LVSNs is unbalanced and potentially cause the energy hole problem. To overcome this kind of problem for network lifetime, a Comprehensive Visual Data Gathering Network Architecture (CDNA), which is the first comparatively integrated architecture for LVSNs is designed in this paper. In CDNA, a novel α-hull based event location algorithm, which is oriented from the geometric model of α-hull, is designed for accurately and efficiently detect the location of the event. In addition, the Chi-Square distribution event-driven gradient deployment method is proposed to reduce the unbalanced energy consumption for alleviating energy hole problem. Moreover, an energy hole repairing method containing an efficient data gathering tree and a movement algorithm is proposed to ensure the efficiency of transmitting and solving the energy hole problem. Simulations are made for examining the performance of the proposed architecture. The simulation results indicate that the performance of CDNA is better than the previous algorithms in the realistic LVSN environment, such as the significant improvement of the network lifetime.


Assuntos
Algoritmos , Redes de Comunicação de Computadores/instrumentação , Processamento Eletrônico de Dados/métodos , Interpretação de Imagem Assistida por Computador/métodos , Modelos Teóricos , Reconhecimento Automatizado de Padrão/métodos , Tecnologia sem Fio/instrumentação , Simulação por Computador , Processamento Eletrônico de Dados/instrumentação , Humanos , Percepção Visual
12.
PLoS One ; 15(1): e0220214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923185

RESUMO

BACKGROUND: Robotic surgery presents a challenge to effective teamwork and communication in the operating theatre (OR). Our objective was to evaluate the effect of using a wireless audio headset device on communication, efficiency and patient outcome in robotic surgery. METHODS AND FINDINGS: A prospective controlled trial of team members participating in gynecologic and urologic robotic procedures between January and March 2015. In the first phase, all surgeries were performed without headsets (control), followed by the intervention phase where all team members used the wireless headsets. Noise levels were measured during both phases. After each case, all team members evaluated the quality of communication, performance, teamwork and mental load using a validated 14-point questionnaire graded on a 1-10 scale. Higher overall scores indicated better communication and efficiency. Clinical and surgical data of all patients in the study were retrieved, analyzed and correlated with the survey results. The study included 137 procedures, yielding 843 questionnaires with an overall response rate of 89% (843/943). Self-reported communication quality was better in cases where headsets were used (113.0 ± 1.6 vs. 101.4 ± 1.6; p < .001). Use of headsets reduced the percentage of time with a noise level above 70 dB at the console (8.2% ± 0.6 vs. 5.3% ± 0.6, p < .001), but had no significant effect on length of surgery nor postoperative complications. CONCLUSIONS: The use of wireless headset devices improved quality of communication between team members and reduced the peak noise level in the robotic OR.


Assuntos
Recursos Audiovisuais , Procedimentos Cirúrgicos em Ginecologia/instrumentação , Laparoscopia/instrumentação , Procedimentos Cirúrgicos Robóticos/instrumentação , Procedimentos Cirúrgicos Urológicos/instrumentação , Tecnologia sem Fio/instrumentação , Idoso , Comunicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários
13.
Toxicol Lett ; 323: 35-40, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31991167

RESUMO

This article identifies adverse effects of non-ionizing non-visible radiation (hereafter called wireless radiation) reported in the premier biomedical literature. It emphasizes that most of the laboratory experiments conducted to date are not designed to identify the more severe adverse effects reflective of the real-life operating environment in which wireless radiation systems operate. Many experiments do not include pulsing and modulation of the carrier signal. The vast majority do not account for synergistic adverse effects of other toxic stimuli (such as chemical and biological) acting in concert with the wireless radiation. This article also presents evidence that the nascent 5G mobile networking technology will affect not only the skin and eyes, as commonly believed, but will have adverse systemic effects as well.


Assuntos
Campos Eletromagnéticos/efeitos adversos , Tecnologia sem Fio , Consenso , Humanos
14.
AJR Am J Roentgenol ; 214(2): 406-412, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31846373

RESUMO

OBJECTIVE. MRI is an imaging modality frequently ordered for patients with neuromodulation systems implanted for spinal cord stimulation. The purpose of this investigation was to evaluate MRI safety issues (magnetic field interactions, MRI-related heating, functional disturbances, and artifacts) for a new wirelessly powered lead with receiver used for SCS. MATERIALS AND METHODS. Lead samples underwent in vitro evaluation for MRI safety issues using standardized techniques. Magnetic field interactions (i.e., translational attraction and torque) and artifacts were tested at 3 T. MRI-related heating was performed at 1.5 T/64 MHz and 3 T/128 MHz using two different methods: numerical simulations with analytical modeling and physical testing. Possible functional disturbances were evaluated under exposures to 1.5-T/64-MHz and 3-T/128-MHz MRI conditions. RESULTS. The lead exhibited minor magnetic field interactions (22° deflection angle, no torque) at 3 T. The highest temperature change recorded at 1.5 T/64 MHz and 3 T/128 MHz was 3.8°C and 11.3°C, respectively. Exposures to MRI conditions did not damage or alter the functional aspects of the leads. The maximum artifact size seen on a gradient-echo pulse sequence extended approximately 10 mm relative to the size of the lead. CONCLUSION. The MRI tests performed on patients with the new lead with receiver revealed no substantial concerns with respect to the conditions that we provide in the safety guidelines that were based on the results of this investigation. Therefore, MRI examinations will result in acceptable heating when conducted at appropriate whole-body-averaged specific absorption rate levels (i.e., 2.0 W/kg at 1.5 T/64 MHz and 0.3 W/kg at 3 T/128 MHz, corresponding to adjusted temperature rises of 3.6°C and 1.2°C, respectively). Therefore, patients with this wirelessly powered lead and receiver implanted can safely undergo MRI examinations under specific conditions.


Assuntos
Segurança de Equipamentos , Imagem por Ressonância Magnética , Segurança do Paciente , Estimulação da Medula Espinal/instrumentação , Tecnologia sem Fio/instrumentação , Artefatos , Instalação Elétrica , Temperatura Alta , Humanos , Campos Magnéticos , Imagens de Fantasmas
16.
Bioelectromagnetics ; 41(1): 3-20, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31854006

RESUMO

Wireless wearable and implantable devices are continuing to grow in popularity, and as this growth occurs, so too does the need to consider the safety of such devices. Wearable and implantable devices require the transmitting and receiving of electromagnetic waves near and through the body, which at high enough exposure levels may damage proximate tissues. The specific absorption rate (SAR) is the quantity commonly used to enumerate exposure levels, and various national and international organizations have defined regulations limiting exposure to ensure safe operation. In this paper, we comprehensively review dosimetric studies reported in the literature up to the year 2019 for wearables and implants. We discuss antenna designs for wearables and implants as they relate to SAR values and field and thermal distributions in tissue, present designs that have made steps to reduce SAR, and then review SAR considerations as they relate to applied devices. As compared with previous review papers, this paper is the first review to focus on dosimetry aspects relative to wearable and implantable devices. Bioelectromagnetics. 2020;41:3-20 © 2019 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.


Assuntos
Radiometria/instrumentação , Tecnologia sem Fio/instrumentação , Campos Eletromagnéticos , Humanos , Músculo Esquelético/efeitos da radiação , Próteses e Implantes , Exposição à Radiação/análise , Temperatura , Dispositivos Eletrônicos Vestíveis
17.
Sensors (Basel) ; 19(24)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847216

RESUMO

We describe here a platform for autonomous hand rehabilitation and telemonitoring of young patients. A toy embedding the electronics required to sense fingers pressure in different grasping modalities is the core element of this platform. The system has been realized following the user-centered design methodology taking into account stakeholder needs from start: clinicians require reliable measurements and the ability to get a picture remotely on rehabilitation progression; children have asked to interact with a pleasant and comfortable object that is easy to use, safe, and rewarding. These requirements are not antithetic, and considering both since the design phase has allowed the realization of a platform reliable to clinicians and keen to be used by young children.


Assuntos
Força da Mão/fisiologia , Mãos/fisiologia , Jogos e Brinquedos , Técnicas Biossensoriais , Humanos , Pressão , Tecnologia sem Fio
18.
Sensors (Basel) ; 19(24)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847300

RESUMO

An intrabody nanonetwork (IBNN) is composed of nanoscale (NS) devices, implanted inside the human body for collecting diverse physiological information for diagnostic and treatment purposes. The unique constraints of these NS devices in terms of energy, storage and computational resources are the primary challenges in the effective designing of routing protocols in IBNNs. Our proposed work explicitly considers these limitations and introduces a novel energy-efficient routing scheme based on a fuzzy logic and bio-inspired firefly algorithm. Our proposed fuzzy logic-based correlation region selection and bio-inspired firefly algorithm based nano biosensors (NBSs) nomination jointly contribute to energy conservation by minimizing transmission of correlated spatial data. Our proposed fuzzy logic-based correlation region selection mechanism aims at selecting those correlated regions for data aggregation that are enriched in terms of energy and detected information. While, for the selection of NBSs, we proposed a new bio-inspired firefly algorithm fitness function. The fitness function considers the transmission history and residual energy of NBSs to avoid exhaustion of NBSs in transmitting invaluable information. We conduct extensive simulations using the Nano-SIM tool to validate the in-depth impact of our proposed scheme in saving energy resources, reducing end-to-end delay and improving packet delivery ratio. The detailed comparison of our proposed scheme with different scenarios and flooding scheme confirms the significance of the optimized selection of correlated regions and NBSs in improving network lifetime and packet delivery ratio while reducing the average end-to-end delay.


Assuntos
Tecnologia sem Fio , Algoritmos , Técnicas Biossensoriais , Lógica Fuzzy , Nanotecnologia/métodos
19.
Sensors (Basel) ; 20(1)2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31861505

RESUMO

Beekeeping is one of the widespread and traditional fields in agriculture, where Internet of Things (IoT)-based solutions and machine learning approaches can ease and improve beehive management significantly. A particularly important activity is bee swarming. A beehive monitoring system can be applied for digital farming to alert the user via a service about the beginning of swarming, which requires a response. An IoT-based bee activity acoustic classification system is proposed in this paper. The audio data needed for acoustic training was collected from the Open Source Beehives Project. The input audio signal was converted into feature vectors, using the Mel-Frequency Cepstral Coefficients (with cepstral mean normalization) and Linear Predictive Coding. The influence of the acoustic background noise and denoising procedure was evaluated in an additional step. Different Hidden Markov Models' and Gaussian Mixture Models' topologies were developed for acoustic modeling, with the objective being to determine the most suitable one for the proposed IoT-based solution. The evaluation was carried out with a separate test set, in order to successfully classify sound between the normal and swarming conditions in a beehive. The evaluation results showed that good acoustic classification performance can be achieved with the proposed system.


Assuntos
Abelhas/fisiologia , Som , Animais , Comportamento Animal , Fazendas , Aprendizado de Máquina , Cadeias de Markov , Distribuição Normal , Tecnologia sem Fio
20.
Sensors (Basel) ; 20(1)2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31861539

RESUMO

The coming years may see the advent of distributed implantable devices to support bioelectronic medicinal treatments. Communication between implantable components and between deep implants and the outside world can be challenging. Percutaneous wired connectivity is undesirable and both radiofrequency and optical methods are limited by tissue absorption and power safety limits. As such, there is a significant potential niche for ultrasound communications in this domain. In this paper, we present the design and testing of a reliable and efficient ultrasonic communication telemetry scheme using piezoelectric transducers that operate at 320 kHz frequency. A key challenge results from the multi-propagation path effect. Therefore, we present a method, using short pulse sequences with relaxation intervals. To counter an increasing bit, and thus packet, error rate with distance, we have incorporated an error correction encoding scheme. We then demonstrate how the communication scheme can scale to a network of implantable devices. We demonstrate that we can achieve an effective, error-free, data rate of 0.6 kbps, which is sufficient for low data rate bioelectronic medicine applications. Transmission can be achieved at an energy cost of 642 nJ per bit data packet using on/off power cycling in the electronics.


Assuntos
Telemetria/métodos , Humanos , Próteses e Implantes , Ondas de Rádio , Razão Sinal-Ruído , Telemedicina , Telemetria/instrumentação , Transdutores , Tecnologia sem Fio
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