| 1. |
- Barile, Gianluca, et al.
(författare)
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A standard CMOS bridge-based analog interface for differential capacitive sensors
- 2017
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Ingår i: PRIME 2017 - 13th Conference on PhD Research in Microelectronics and Electronics, Proceedings. - : IEEE. - 9781509065073 ; , s. 281-284
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Konferensbidrag (refereegranskat)abstract
- This work describes an analog electronic interface, based on a modified De Sauty AC bridge, performing a differential capacitive sensor estimation. A suitable feedback loop tunes a Voltage Controlled Resistor to balance the bridge. The electronic circuit has been designed in a standard integrated CMOS technology (AMS 0.35μm) with a low supply voltage (±1.5 V) and a reduced power consumption (lower than 4mW). PSpice simulation results show a very good agreement with theoretical expectations. The output voltage accuracy shows a 0.03V maximum absolute error for a range of ±50% of sensor variations from its baseline value. Very small baseline values are allowed (tens of μF).
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| 2. |
- Barile, Gianluca, et al.
(författare)
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Linear Integrated Interface for Automatic Differential Capacitive Sensing
- 2017
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Ingår i: Proceedings, Volume 1, Eurosensors 2017. - Basel Switzerland : MDPI.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work, the authors introduce a new full-analog front-end for differential capacitance sensors which provides a DC output voltage, directly proportional to the measurand variations. The readout circuit architecture is based on a De Sauty bridge as core of the capacitive sensing whereas the feedback circuitry performs the bridge autobalancing operation by means of changes in a multiplier output. The circuit is designed in a standard CMOS technology (AMS 0.35 µm) so is suitable for portable systems. Simulated results have shown a good agreement with the theoretical model being the percentage relative error less than 2.5%. Interface sensitivity is constant and values around 0.055 V/mm for the considered application.
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| 3. |
- Bonafini, Federico, et al.
(författare)
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Exploiting localization systems for LoRaWAN transmission scheduling in industrial applications
- 2019
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Ingår i: 2019 15th IEEE International Workshop on Factory Communication Systems (WFCS). - : IEEE. - 9781728112688
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Konferensbidrag (refereegranskat)abstract
- The Internet of Things (IoT) paradigm contaminated industrial world, allowing for innovative services. The wireless communications seem to be particularly attracting, especially when complement indoor and outdoor Real Time Location Systems (RTLS) for geo-referencing smart objects (e.g. for asset tracking). In this paper, the LoRaWAN solution is considered for transmitting RTLS data. LoRaWAN is an example of Low Power Wide Area Network: it tradeoffs throughput with coverage and power consumption. However, performance can be greatly improved with limited changes to the standard specifications. In this work, a scheduling layer is suggested above the regular stack for allocating communication resources in a time slot channel hopping medium access strategy. The main innovation is the time synchronization, which is obtained opportunistically from the ranging devices belonging to the RTLSs. The experimental testbed, based on commercially available solutions, demonstrates the affordability and feasibility of the proposed approach. When low-cost GPS (outdoor) and UWB (indoor) ranging devices are considered, synchronization error of few microseconds can be easily obtained. The experimental results show the that time reference pulses disciplined by GPS have a maximum jitter of 180 ns and a standard deviation of 40 ns whereas, if time reference pulses disciplined by UWB are considered, the maximum jitter is 3.3 μs and the standard deviation is 0.7 μs.
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| 4. |
- Crema, Claudio, et al.
(författare)
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Virtual Respiratory Rate Sensors : An Example of A Smartphone-Based Integrated and Multiparametric mHealth Gateway
- 2017
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 66:9, s. 2456-2463
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Tidskriftsartikel (refereegranskat)abstract
- In the last few years, several wearables appeared in the market, for fitness and healthcare applications. Such smart devices have been proposed as a possible solution for lowering the costs of healthcare, leading to the mHealth revolution. In the typical scenario, each wearable, embedding sensors, processing units and communication modules, adopts a smartphone for data collection, data displaying, and remote communication. In this paper, authors modify this paradigm simplifying the wearables (e.g., relying only on simple analog front ends and communication interfaces) and exploiting the (relatively large) computational capability of the smartphone, not only for implementing gateway features but also for processing raw biosignals as well. Several experiments verify the feasibility of the proposed approach and demonstrate that 'local' biosensor virtualization is possible, expanding possibilities of mHealth. In particular, tests have been carried out to evaluate the performance of hearth rate computation and respiratory rate virtual sensor, starting from a single-lead electrocardiogram signal.
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