Search results for "ventilation"

Comparing different processing methods in apple slice drying. Part 1. Performance of microwave, hot air and hybrid methods at constant temperatures

2019

The drying curves, energy efficiency and colour variations of sliced apples dried at various temperatures and using different techniques were evaluated, i.e. microwave (35, 55 and 65 °C), hot air (35, 55, 65 and 75 °C) and combination of both (65 °C). The microwave (MW) tests also included comparison between air recirculation and continuous inlet of fresh air. Each drying method was evaluated at a fixed temperature level by means of a control system based on infrared thermography. The time required to complete the drying process at 65 °C varied from about 44 min for MW with fresh air ventilation (double with air recirculation), to 122 min for hybrid heating and 238 min for hot air. Drying k…

Hyperpolarized helium-3 gas magnetic resonance imaging of the lung.

2003

3He magnetic resonance imaging (MRI) is capable of producing new and regional information on normal and abnormal lung ventilation. The basis of 3He MRI involves "optical pumping" to hyperpolarize the 3He nuclei by photon angular momentum transfer. The hyperpolarized gas is administered via inhalation. 3He is an inert, nontoxic noble gas and absorbed in less than 0.1%. Imaging consists of a four-step protocol. 1) Gas density 3He MRI with high spatial resolution displays the distribution of a 3He bolus in a 10-second breath-hold. An almost homogeneous distribution is regarded as normal. Patients with lung diseases show multiple ventilation defects. 3He MRI has been shown to be more sensitive …

Parked electric car's cabin heat management using photovoltaic powered ventilation system

2019

Abstract This paper explores the use of electric car roof mounted photovoltaic (PV) powered ventilation for cabin heat management/ventilation. A fully-functional Renault Zoe electric car has been used for performance evaluation of parked electric car ventilation directly powered by PV. This work has been part of a research project of testing electric cars in the urban environment and it has been conducted at the Edinburgh Napier University’s Transport Research Institute. In this work, parked electric car ventilation has been reported, when roof-mounted PV modules were used to operate DC powered fans for ventilation. It has been found that the DC motor-fan selection for removing the hot air …

2006

Introduction The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using highfrequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. Methods With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar …

Initiation of high-frequency oscillatory ventilation and its effects upon cerebral circulation in pigs: an experimental study

2006

BACKGROUND: Current practice at high-frequency oscillatory ventilation (HFOV) initiation is a stepwise increase of the constant applied airway pressure to achieve lung recruitment. We hypothesized that HFOV would lead to more adverse cerebral haemodynamics than does pressure controlled ventilation (PCV) in the presence of experimental intracranial hypertension (IH) and acute lung injury (ALI) in pigs with similar mean airway pressure settings. METHODS: In 12 anesthetized pigs (24-27 kg) with IH and ALI, mean airway pressure (P(mean)) was increased (to 20, 25, 30 cm H(2)O every 30 min), either with HFOV or with PCV. The order of the two ventilatory modes (cross-over) was randomized. Mean art…

Utilization of mechanical power and associations with clinical outcomes in brain injured patients: a secondary analysis of the extubation strategies …

2023

Background: There is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes. Methods: In this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale ≤ 12 before intubation) who required mechanical ventilation (MV) ≥ 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (H…

Ventilación mecánica no invasiva en el postoperatorio. Revisión clínica

2015

Non-invasive ventilation (NIV) is a method of ventilatory support that is increasing in importance day by day in the management of postoperative respiratory failure. Its role in the prevention and treatment of atelectasis is particularly important in the in the period after thoracic and abdominal surgeries. Similarly, in the transplanted patient, NIV can shorten the time of invasive mechanical ventilation, reducing the risk of infectious complications in these high-risk patients. It has been performed A systematic review of the literature has been performed, including examining the technical, clinical experiences and recommendations concerning the application of NIV in the postoperative per…

A Randomized Controlled Trial Comparing Inhaled Isoflurane Via the Anaesthetic Conserving Device (Sedaconda <sup>®</sup> ACD) with Propof…

2021

Background: Small studies indicate that isoflurane may be useful for sedation during invasive ventilation of ICU patients. There are no published large prospective efficacy trials. Methods: This phase 3, non-inferiority trial evaluated the efficacy and safety of ≤54 hours of isoflurane via the anaesthetic conserving device (ACD) compared with propofol in invasively ventilated ICU patients (30-day follow-up). Primary endpoint was percentage of time in Richmond Agitation–Sedation Scale (RASS) range –1 to –4; the predefined non-inferiority margin was 15% below the propofol mean. Secondary endpoints: opioid requirements, spontaneous breathing during sedation, time to wake-up and extubation, adv…

An Experimental Investigation on the Air Permeability of Passive Ventilation Grilles

2015

Abstract The need of increasing both energy saving and acoustic insulation has leaded to the design of lowest air permeability frames resulting in the worsening of indoor air quality. Moreover, sometime in several civil-use existing buildings (i.e. schools or houses, historical buildings) mechanical ventilation systems cannot be installed due to non-removable constraints. In these cases, passive ventilation grilles are a cheap and effective solution for the ventilation. This work deals with an in-depth experimental analysis about the air permeability values measured over a set of passive ventilation grilles available on the market. Obtained results often showed performances very far to thos…

Ventilating the newborn and child

2010

Summary The mechanical ventilation of neonates and children in operating theatres has always posed a challenge for anaesthesiologists. Firstly, the extreme physiological features of neonatal lungs make them very difficult to ventilate with an anaesthesia ventilator. Gattinoni's "baby lung" concept to describe ARDS lungs in adults comes from the physiological features of neonatal lungs (low dynamic compliance, low pulmonary time constant, low FRC, high closing volume, proneness to atelectasis, high inspiratory airway resistance). Secondly, the performance and technology (peak flow, insufflation power, trigger sensitivity, ventilation modes, etc.) of anaesthesia ventilators is still less adva…