RESUMO
This study investigates wireless power transfer for deep in-body receivers, determining the optimal frequency, power budget, and design for the transmitter and receiver. In particular, the focus is on small, in-body receivers at large depths up to 20 cm for obese patients. This enables long-term monitoring of the gastrointestinal tract for all body types. Numerical simulations are used to investigate power transfer and losses as a function of frequency and to find the optimal design at the selected frequency for an obese body model. From all ISM-frequencies in the investigated range (1 kHz-10 GHz), the value of 13.56 MHz yields the best performance. This optimum corresponds to the transition from dominant copper losses in conductors to dominant losses in conductive tissue. At this frequency, a transmitting and receiving coil are designed consisting of 12 and 23 windings, respectively. With a power transfer efficiency of 2.70×10-5, 18 µW can be received for an input power of 0.68 W while still satisfying exposure guidelines. The power transfer is validated by measurements. For the first time, efficiency values and the power budget are reported for WPT through 20 cm of tissue to mm sized receivers. Compared to WPT at higher frequencies, as commonly used for small receivers, the proposed system is more suitable for WPT to large depths in-body and comes with the advantage that no focusing is required, which can accommodate multiple receivers and uncertainty about receiver location more easily. The received power allows long-term sensing in the gastrointestinal tract by, e.g., temperature, pressure, and pH sensors, motility sensing, or even gastric stimulation.
Assuntos
Próteses e Implantes , Tecnologia sem Fio , Humanos , Fontes de Energia Elétrica , Desenho de Equipamento , Condutividade ElétricaRESUMO
An all-in-one battery powered low-power SoC for measuring multiple vital signs with wearables is proposed. All functionality needed in a typical wearable use case scenario, including dedicated readouts, power management circuitry, digital signal processing and wireless communication (BLE) is integrated in a single die. This high level of integration allows an unprecedented level of miniaturization leading to smaller component count which reduces cost and improves comfort and signal integrity. The SoC includes an ECG, Bio-Impedance and a fully differential PPG readout and can interface with external sensors (like an IMU). In a typical application scenario where all sensor readouts are enabled and key features (like heart rate) are calculated on the chip and streamed over the radio, the SoC consumes only 769 µW from the regulated 1.2 V supply.
Assuntos
Eletrocardiografia/instrumentação , Coração/fisiologia , Algoritmos , Impedância Elétrica , Desenho de Equipamento , Frequência Cardíaca , Humanos , Miniaturização , Processamento de Sinais Assistido por Computador , Dispositivos Eletrônicos Vestíveis , Tecnologia sem FioRESUMO
In May 2016, two separate clusters of febrile gastroenteritis caused by Listeria monocytogenes were detected by the local health authority in Piedmont, in northern Italy. We carried out epidemiological, microbiological and traceback investigations to identify the source. The people affected were students and staff members from two different schools in two different villages located in the Province of Turin; five of them were hospitalised. The epidemiological investigation identified a cooked beef ham served at the school canteens as the source of the food-borne outbreak. L. monocytogenes was isolated from the food, the stools of the hospitalised pupils and the environment of the factory producing the cooked beef ham. All isolates except one were serotype 1/2a, shared an indistinguishable PFGE pattern and were 100% identical by whole genome sequencing (WGS). By combining a classical epidemiological approach with both molecular subtyping and WGS techniques, we were able to identify and confirm a Listeria gastroenteritis outbreak associated with consumption of sliced cold beef ham.
Assuntos
Surtos de Doenças , Febre/etiologia , Doenças Transmitidas por Alimentos/epidemiologia , Gastroenterite/epidemiologia , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Carne Vermelha/microbiologia , Surtos de Doenças/estatística & dados numéricos , Fezes/microbiologia , Contaminação de Alimentos , Gastroenterite/diagnóstico , Gastroenterite/microbiologia , Humanos , Itália/epidemiologia , Listeria monocytogenes/genética , Listeriose/diagnóstico , Listeriose/microbiologia , Epidemiologia Molecular , Sequenciamento Completo do GenomaRESUMO
The Authors critically review three food poisoning episodes occurred within the coverage area of ASL NA2, and the related epidemiological researches carried out by the Prevention Department. Events, methodology, results, strength points, and criticalities are singularly described for each episode. Among the main criticalities: timeliness, the missed recovery of food samples and the absence of a reference head laboratory. In conclusion, the Authors insist on the need to select a central referral facility, responsible for coordinating services between the Department and all the other facilities within the coverage area.