Being able to rapidly detect a low air flow rate with high accuracy is essential for various applications in the automotive and biomedical industries. We have developed a thermal-based low air flow sensor with a low-power sensor readout for biomedical applications. The thermal-based air flow sensor comprises a heater and three pairs of temperature sensors that sense temperature differences due to laminar air flow. The thermal-based flow sensor was designed and simulated by using laminar flow, heat transfer in solids and fluids physics in COMSOL MultiPhysics software. The proposed sensor can detect air flow as low as 0.0064 m/sec. The readout circuit is based on a current- controlled ring oscillator in which the output frequency of the ring oscillator is proportional to the temperature differences of the sensors. The entire readout circuit was designed and simulated by using a 130-nm standard CMOS process. The sensor circuit features a small area and low-power consumption of about 22.6 µW with an 800 mV power supply. In the simulation, the output frequency of the ring oscillator and the change in thermistor resistance showed a high linearity with an R value of 0.9987. The low-power dissipation, high linearity and small dimensions of the proposed flow sensor and circuit make the system highly suitable for biomedical applications.
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http://dx.doi.org/10.1007/s10470-016-0848-4 | DOI Listing |
PLoS One
January 2025
Transfers, Interfaces and Processes, Université libre de Bruxelles, Brussels, Belgium.
In this paper, we present a new computational framework for the simulation of airway resistance, the fraction of exhaled nitric oxide, and the diffusion capacity for nitric oxide in healthy and unhealthy lungs. Our approach is firstly based on a realistic representation of the geometry of healthy lungs as a function of body mass, which compares well with data from the literature, particularly in terms of lung volume and alveolar surface area. The original way in which this geometry is created, including an individual definition of the airways in the first seven generations of the lungs, makes it possible to consider the heterogeneous nature of the lungs in terms of perfusion and ventilation.
View Article and Find Full Text PDFPulmonology
December 2025
Department of Emergency and Intensive Care, Fondazione IRCCS San Gerardo dei tintori, Monza, Italy.
Background: Non-invasive helmet respiratory support is suitable for several clinical conditions. Continuous-flow helmet CPAP systems equipped with HEPA filters have become popular during the recent Coronavirus pandemic. However, HEPA filters generate an overpressure above the set PEEP.
View Article and Find Full Text PDFAcc Mater Res
January 2025
School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30322, United States.
Increasing demand for high-purity fine chemicals and a drive for process intensification of large-scale separations have driven significant work on the development of highly engineered porous materials with promise for sorption-based separations. While sorptive separations in porous materials offer energy-efficient alternatives to longstanding thermal-based methods, the particulate nature of many of these sorbents has sometimes limited their large-scale deployment in high-throughput applications such as gas separations, for which the necessary high feed flow rates and gas velocities accrue prohibitive operational costs. These processability limitations have been historically addressed through powder shaping methods aimed at the fabrication of structured sorbent contactors based on pellets, beads or monoliths, commonly obtained as extrudates.
View Article and Find Full Text PDFFront Cardiovasc Med
January 2025
Department of Cardiovascular Medicine, Capital Medical University, Beijing LuHe Hospital, Beijing, China.
Objective: This meta-analysis elucidates the efficacy of the Transradial Band Device (TR Band) in minimizing complications like radial artery occlusion and hematoma, preserving heart health, and enhancing blood flow post-transradial catheterization.
Methods: A comprehensive literature search across databases including PubMed, Cochrane, and Embase examined the impact of radial artery compression techniques and decompression times on complications. Data from 13 studies were analyzed using R 4.
J Vasc Access
January 2025
EXPLOR! Center, Air Liquide Healthcare, Bagneux, France.
Background: Outpatient Parenteral Antibiotic Therapy (OPAT) services have expanded throughout the world thanks to elastomeric pumps (EP). Their flowrate is known to vary by ±15%. Treatment effectiveness and the organization of care at home may be impacted, especially with piperacillin/tazobactam infusion (TAZ).
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