10 research outputs found
Unified physical DC model of staggered amorphous InGaZnO transistors
No full textIn this paper, we propose a unified physical model of InGaZnO [amorphous indium-gallium-zinc-oxide (a-IGZO)] thin-film transistors (TFTs) accounting for both charge injection at the contact and charge transport within the channel. We extract the current-voltage characteristics of the injecting contact from the measurements of a-IGZO TFTs fabricated on plastic foil. We show that the charge injection depends on both the drain and the gate voltages. We model the charge injection in staggered a-IGZO TFTs basing on the thermionic emission-diffusion theory including the charge carrier-dependent electron velocity due to the trap states in the subgap of the a-IGZO semiconductor. Combining the charge injection model with a charge transport model, we accurately and consistently describe the measurements of staggered a-IGZO TFTs with channel-length scaling from 200 μm to 15 μm. The proposed unified model is implemented in a circuit simulator and used to design unipolar inverters. The good agreement between simulations and measurements of the inverters further confirms the effectiveness of the proposed approach
Analogue Frontend Amplifiers for Bio-Potential Measurements Manufactured With a-IGZO TFTs on Flexible Substrate
No full textThree novel differential amplifier topologies using double gate a-IGZO TFTs on flexible substrate are presented in this paper. The designs exploit positive feedback and a load with self-biased top gate to achieve the highest static gain in single stage a-IGZO amplifiers reported to date. After fabrication, the three amplifiers exhibit respectively a static gain of 14 dB, 21.5 dB and 30 dB, with a bandwidth of 2 kHz, 400 Hz, and 150 Hz. Also, for each circuit the input referred noise has been measured to be 420 μVrms, 195 μVrms and 146 μVrms, respectively. Based on these results, the a-IGZO amplifier providing the highest gain is suitable as front-end for heart rate measurements and, with some further optimization verified in simulation, can also be used for other bio-potential applications, like electro hysterogram and electro cardiogram
Compact physical model of a-IGZO TFTs for circuit simulation
No full textAmorphous InGaZnO (a-IGZO) is a candidate material for thin-film transistors (TFTs) owing to its large electron mobility. The development of high functionality circuits requires accurate and efficient circuit simulation that, in turn, is based on compact physical a-IGZO TFTs models. Here we propose a compact physical-based and analytical model of the drain current of a-IGZO TFTs. The model accounts for both trapped and free charges by means of an effective density of states that accurately approximate the actual a-IGZO density of states in the energy range relevant for the TFT operation. The model is implemented in a circuit simulator and it is validated with the measurements of both coplanar and staggered a-IGZO TFTs fabricated on flexible substrates
Physical-based Analytical Model of Flexible a-IGZO TFTs Accounting for Both Charge Injection and Transport
No full textHere we show a new physical-based analytical model of a-IGZO TFTs. TFTs scaling from L=200 μm to L=15 μm and fabricated on plastic foil are accurately reproduced with a unique set of parameters. The model is used to design a zero-VGS inverter. It is a valuable tool for circuit design and technology characterization
Relevância das indicações de colonoscopia conforme os diagnósticos obtidos.
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Dapartamento de Clínica Cirúrgica
15.3 An a-IGZO asynchronous delta-sigma modulator on foil achieving up to 43dB SNR and 40dB SNDR in 300Hz bandwidth
No full textAmorphous IGZO (a-IGZO) TFTs fabricated on flexible large-area substrates provide better mobility than a-Si or organic counterparts and good uniformity. These features make a-IGZO TFTs an attractive technology for large-area sensing (e.g. strain, pressure, IR), low-cost RFIDs augmented with sensors and monitoring of biopotentials. In this context, it is crucial to accurately transform analogue sensor signals in a robust representation. The most common choice is a synchronous digital word, but a two-level PWM representation is another interesting possibility. Binary PWM can be transmitted on wire or via RF amplitude modulation with high immunity to noise and interferers
The state of knowledge on technologies and their use for fall detection: A scoping review
No full textBackground: Globally, populations are aging with increasing life spans. The normal aging process and the resulting disabilities increase fall risks. Falls are an important cause of injury, loss of independence and institutionalization. Technologies have been developed to detect falls and reduce their consequences but their use
and impact on quality of life remain debatable. Reviews on fall detection technologies exist but are not extensive.
A comprehensive literature review on the state of knowledge of fall detection technologies can inform research,
practice, and user adoption.
Objectives: To examine the extent and the diversity of current technologies for fall detection in older adults.
Methods: A scoping review design was used to search peer-reviewed literature on technologies to detect falls,
published in English, French or Spanish since 2006. Data from the studies were analyzed descriptively.
Results: The literature search identified 3202 studies of which 118 were included for analysis. Ten types of
technologies were identified ranging from wearable (e.g., inertial sensors) to ambient sensors (e.g., vision
sensors). Their Technology Readiness Level was low (mean 4.54 SD 1.25; 95% CI [4.31, 4.77] out of a maximum
of 9). Outcomes were typically evaluated on technological basis and in controlled environments. Few were
evaluated in home settings or care units with older adults. Acceptability, implementation cost and barriers were
seldom addressed.
Conclusions: Further research should focus on increasing Technology Readiness Levels of fall detection technologies by testing them in real-life settings with older adults.Antecedentes: A nivel mundial, las poblaciones están envejeciendo y la esperanza de vida aumenta. El proceso normal de envejecimiento y las discapacidades resultantes aumentan el riesgo de caídas. Las caídas son una causa importante de lesiones, pérdida de independencia e institucionalización. Se han desarrollado tecnologías para detectar caídas y reducir sus consecuencias pero su uso
y el impacto en la calidad de vida siguen siendo discutibles. Existen reseñas sobre tecnologías de detección de caídas, pero no son exhaustivas.
Una revisión exhaustiva de la literatura sobre el estado del conocimiento de las tecnologías de detección de caídas puede servir de base para la investigación,
práctica y adopción por parte de los usuarios.
Objetivos: Examinar el alcance y la diversidad de las tecnologías actuales para la detección de caídas en adultos mayores.
Métodos: Se utilizó un diseño de revisión de alcance para buscar literatura revisada por pares sobre tecnologías para detectar caídas,
publicados en inglés, francés o español desde 2006. Los datos de los estudios se analizaron descriptivamente.
Resultados: La búsqueda bibliográfica identificó 3202 estudios de los cuales 118 se incluyeron para el análisis. Diez tipos de
Se identificaron tecnologías que van desde dispositivos portátiles (por ejemplo, sensores inerciales) hasta sensores ambientales (por ejemplo, sensores de visión).
sensores). Su nivel de preparación tecnológica fue bajo (media 4,54 DE 1,25; IC del 95 % [4,31, 4,77] de un máximo
de 9). Los resultados generalmente se evaluaron sobre una base tecnológica y en entornos controlados. Pocos fueron
evaluados en ámbitos domiciliarios o unidades de atención con adultos mayores. Se evaluaron la aceptabilidad, el costo de implementación y las barreras.
rara vez abordado.
Conclusiones: La investigación adicional debería centrarse en aumentar los niveles de preparación tecnológica de las tecnologías de detección de caídas probándolas en entornos de la vida real con adultos mayores
