Automatic Ventilation Research Articles

АЛГОРИТМІЗАЦІЯ ПРОЦЕСІВ РОБОТИ СИСТЕМИ АВТОМАТИЧНОЇ ВЕНТИЛЯЦІЇ КУЗОВА АВТОМОБІЛЯ

The switching scheme of components of the car body ventilation system with an electronic control unit based on Arduino Uno is presented. This scheme provides a fully autonomous ventilation of the car body, independent of engine, and eliminates the influence of the human factor. The design of components of the scheme is selected. The linear algorithm for the program of control by the system of automatic ventilation of the car body is developed which ensures its energy efficiency and efficiency of accumulated heat removal from the cabin at any time of the day. The presented scheme allows to prevent heat accumulation, which will provide comfortable conditions for staying of children and animals in the cabin when the car is parked under the sun

Durable UV-protective cotton fabric by deposition of multilayer TiO2 nanoparticles films on the surface

Durable ultraviolet (UV)-protective cotton fabric has great application potential in outdoor cotton clothing. In this study, oppositely charged TiO2 nanoparticles were deposited onto cotton fabric through the layer-by-layer self-assembly technique, resulting in multilayer films with UV-protective properties. The mechanism of the technology has been investigated through characterization of the structure and properties using different techniques including FTIR, UV–Vis spectroscopy, and a scanning electron microscope with an energy-dispersive X-ray spectrum. The results showed that TiO2 nanoparticles distributed uniformly on the surface of cotton fibers. The TGA results indicated that the TiO2 nanoparticles deposit on cotton fabrics had little effect on the thermal stability of cotton fabrics. The tensile strength and air permeability of the cotton samples were tested by a universal material testing machine and automatic ventilation instrument. The UV protection property of cotton fabric after assembled multilayer films was measured by an ultraviolet transmittance analyzer, and the laundering experiments were carried out to determine the durability of TiO2 nanoparticles on cotton fabric. The results showed that the UV protection property of cotton fabrics after assembled TiO2 nanoparticles was still maintained at a high level after five launderings.

Wearable Sweat Rate Sensors for Human Thermal Comfort Monitoring

We propose watch-type sweat rate sensors capable of automatic natural ventilation by integrating miniaturized thermo-pneumatic actuators, and experimentally verify their performances and applicability. Previous sensors using natural ventilation require manual ventilation process or high-power bulky thermo-pneumatic actuators to lift sweat rate detection chambers above skin for continuous measurement. The proposed watch-type sweat rate sensors reduce operation power by minimizing expansion fluid volume to 0.4 ml through heat circuit modeling. The proposed sensors reduce operation power to 12.8% and weight to 47.6% compared to previous portable sensors, operating for 4 hours at 6 V batteries. Human experiment for thermal comfort monitoring is performed by using the proposed sensors having sensitivity of 0.039 (pF/s)/(g/m2h) and linearity of 97.9% in human sweat rate range. Average sweat rate difference for each thermal status measured in three subjects shows (32.06 ± 27.19) g/m2h in thermal statuses including ‘comfortable’, ‘slightly warm’, ‘warm’, and ‘hot’. The proposed sensors thereby can discriminate and compare four stages of thermal status. Sweat rate measurement error of the proposed sensors is less than 10% under air velocity of 1.5 m/s corresponding to human walking speed. The proposed sensors are applicable for wearable and portable use, having potentials for daily thermal comfort monitoring applications.

OCCUPATIONAL GENOTOXIC EFFECTS AMONG A GROUP OF NURSES EXPOSED TO ANESTHETIC GASES IN OPERATING ROOMS AT ZAGAZIG UNIVERSITY HOSPITALS

from the patient’s anesthetic breathing circuit into the air of operating rooms during delivery of anesthesia. Personnel who are working in operating rooms are most likely to be exposed to waste anesthetic gases with no or bad automatic ventilation or scavenging systems. Aim of the work: The current study aimed to assess the level of biological marker of anesthetic gases and identify genotoxic effects among operating room nurses in Zagazig University Hospitals. Materials and methods: This study was conducted in Zagazig University Hospitals on 64 nurses who were divided into two groups: operating room nurses as exposed group, matched with outpatient clinic nurses as non exposed group. The data were collected using a questionnaire including demographic data, occupational, medical, family histories and complaints. Laboratory investigations done including Karyotyping of the chromosomes to assess genotoxic effects and assessment of urinary isoflurane. Results: Our study showed that there were highly statistical significant difference between both groups regarding occurrence of threatened and spontaneous abortion, repeated abortion> 2 times, congenital anomalies and symptoms during work as headache and dizziness. Also this work showed that chromosomal aberrations were present among about 59% of the exposed group, compared to 12.5% of non-exposed with highly statistically significant difference . The most common form of abnormalities were breaks of chromosomes (31.3%), fragments (18.8%) and polyploidy (6.2%). There were statistical significant difference between exposed and non-exposed in number of abnormal chromosomes and urinary isoflurane. Conclusion: Exposure to some anesthetic gases is associated with genotoxic effects among operating room personnel, leading to increased morbidity.

Mechanical ventilation. Part I: Physiology and pathophysiology

Despite the fact that mechanical ventilation is an integral part of anaesthesia practice, its widespread use in veterinary medicine has yet to be established. The increasing needs and advances in animal pain management, being associated with anaesthetic protocols that can cause hypoventilation, make the use of mechanical ventilation more necessary than ever. Although mechanically ventilating the patient is not pivotal in a substantial number of surgical techniques, inability to do so precludes certain anaesthetic protocols from being used, making the choice of the drugs to be employed troubleshooting. Successful mechanical ventilation requires a thorough understanding of the physiology and pathophysiology of respiration, as well as the way mechanical ventilation affects them. Before any attempt to describe mechanical ventilation, a glossary of technical terms has to be accepted, as long as consensus between the authors has not been found in the literature. Lung elasticity, resistance to flow, inspiration time and the ratio of inspiration to expiration time interact during mechanical ventilation affecting the final result on the patient. Volutrauma, barotrauma, ventilation-perfusion mismatch and cardiac output decrease are some of the adverse effects of mechanical ventilation. The choice of whether or not to use automatic ventilators, the choice of the right equipment and setting the variables correctly on the control panel need a thorough understanding of patient pathology. This article reviews respiration under normal and pathologic conditions and the effects mechanical ventilation exerts on different organ systems. Guidelines for the application of mechanical ventilation under various pathologic conditions are provided.

Mechanical ventilation. Part II: Basic principles and function of ventilators.

Mechanical ventilation is the process of supporting respiration by manual or mechanical means. When normal breathing is inefficient or has stopped, mechanical ventilation is life-saving and should be applied at once. The ventilator increases the patient's ventilation by inflating the lungs with oxygen or a mixture of air and oxygen. Ventilators play an important role in the anaesthetic management of patients, as well as in the treatment of patients in the ICU. However, there are differences between the anaesthetic ventilators and the ventilators in ICU. The main indication for mechanical ventilation is difficulty in ventilation and/or oxygenation of the patient because of any respiratory or other disease. The aims of mechanical ventilation are to supply adequate oxygen to patients with a limited vital capacity, to treat ventilatory failure, to reduce dyspnoea and to facilitate rest of fatigued breathing muscles. Depression of the central nervous system function is a pre-requirement for mechanical ventilation. Some times, opioids or muscle relaxants can be used in order to depress patient's breathing. Mechanical ventilation can be applied using many different modes: assisted ventilation, controlled ventilation, continuous positive pressure ventilation, intermittent positive pressure ventilation and jet ventilation. Furthermore, there are different types of automatic ventilators built to provide positive pressure ventilation in anaesthetized or heavily sedated or comatose patients: manual ventilators (Ambu-bag), volumecontrolled ventilators with pressure cycling, volume-controlled ventilators with time cycling and pressure-controlled ventilators. In veterinary practice, the ventilator should be portable, compact and easy to operate. The controls on most anaesthetic ventilators include settings for tidal volume, inspiratory time, inspiratory pressure, respiratory rate and inspiration: expiration (I:E) ratio. The initial settings should be between 10-20 ml/kg for tidal volume, 12-30 cmH2 0 for the inspiratory pressure and 8-15 breaths/min for the respiratory rate. Mechanical ventilation is a very important part of treatment in the ICU, but many problems may arise during application of mechanical ventilation in critically ill patients. All connections should be checked in advance and periodically for mechanical problems like leaks. Moreover, complications like lung injury, pneumonia, pneumothorax, myopathy and respiratory failure can occur during the course of mechanical ventilation causing difficulty in weaning.

Development of an Indoor Photovoltaic Energy Harvesting Module for Autonomous Sensors in Building Air Quality Applications

A 50 mm ${\times } \,\, 20$ mm ${\times } \,\, 15$ mm indoor photovoltaic (PV) energy harvesting power module (IPEHPM) has been developed for powering an Internet of Things (IoT) sensor node containing a low-power CO2 sensor for automatic building ventilation. It is composed of a high efficiency PV energy harvesting module and a supercapacitor to produce 3.6–4.2 V output voltage with 100 mA pulse current for up to 600 ms. Storage efficiency analysis and storage efficiency tests of the IPEHPM have demonstrated that with the adopted simple power management scheme, which exempts the commonly used power management blocks of the voltage regulator and the maximum power point tracking to save power, 88.7% average storage efficiency has been achieved at 200 lux. With the newly established PV powering model, the power consumption requirements of an IoT node can be directly converted into the illumination requirements of the PV energy harvester, making the IPEHPM easy to use. IPEHPM powered IoT experiments with a low-power CO2 gas sensor have demonstrated that the IPEHPM is suitable for IoT-based building ventilation applications, where the CO2 concentration level is measured every 150 s at the indoor lighting condition down to 200 lux.

Ventilatory choices for intubated patients during helicopter stretcher winching

The winching of intubated patients on a stretcher into a helicopter is a rare event. Intermittent positive pressure ventilation is mandatory, which can either be performed manually with a self-inflating bag, or automatically using a portable ventilator. Theoretically automatic ventilation would provide improved oxygenation, more stable arterial carbon dioxide levels and a reduced risk of airway disconnection. Furthermore, the stretcher attendant may better perform winching procedures with higher situational awareness, contributing to crew and patient safety. However ventilator failure, and the diagnosis and management of such, is of concern. The aim of this study is to compare automatic against manual ventilation during intubated helicopter stretcher winching. The trial had two phases. Initially a static winch on a hoist simulator was performed, followed by live winching into a helicopter. All stretcher attendants performed two winches with an intubated manikin. During one winch, the manikin was manually ventilated, and an automatic ventilator was used for the other. Airway pressures were measured. Automatic ventilation did not fail. Compared with automatic ventilation, manual ventilation displayed significant pauses, inconsistent rates and both high and low airway pressures. Automatic ventilation permitted better situational awareness and performance in winching manoeuvres. One airway disconnection occurred during manual ventilation. During helicopter winching, automatic ventilation is superior in providing controlled, consistent and reliable ventilation for intubated patients. The stretcher attendant is also able to provide more attention to the winching manoeuvres with subsequent safety gains. The risk of automatic ventilator failure is low.

Energy Consumption and Energy Saving Measures in Poultry

Livestock buildings are energy consumers and aggravate the environment directly through their emissions and indirectly through the natural sources consumption. The contribution of energy consumption in the total production cost increases as the mechanization level and the conventional energy cost arises. In the present work the total energy consumption in poultries and its distribution according to the type of energy and the type of application is approached in two ways: a) The operational rating through the process of energy audit and, b) The asset rating where the thermal needs of the chambers are calculated using a source analytical explicit model in hourly time step. In terms of final energy consumption the energy per unit area ranges between 30 and 130 kWh/m2 and in terms of primary energy between 70 and 180 kWh/m2, depended on the chamber insulation, location and automation level. The insulation can contribute mostly in mountainous area and the automation level in lowland units. An insulation thickness of 4 to 5cm is recommended for lowland farms and 6cm for mountainous farms. Further insulation cannot offer benefit since ventilation heat losses represent significant percentage of the total heat losses and can be reduced with automatic ventilation control.

Feasibility of the capnogram to monitor ventilation rate during cardiopulmonary resuscitation

AimThe rates of chest compressions (CCs) and ventilations are both important metrics to monitor the quality of cardiopulmonary resuscitation (CPR). Capnography permits monitoring ventilation, but the CCs provided during CPR corrupt the capnogram and compromise the accuracy of automatic ventilation detectors. The aim of this study was to evaluate the feasibility of an automatic algorithm based on the capnogram to detect ventilations and provide feedback on ventilation rate during CPR, specifically addressing intervals where CCs are delivered. MethodsThe dataset used to develop and test the algorithm contained in-hospital and out-of-hospital cardiac arrest episodes. The method relies on adaptive thresholding to detect ventilations in the first derivative of the capnogram. The performance of the detector was reported in terms of sensitivity (SE) and Positive Predictive Value (PPV). The overall performance was reported in terms of the rate error and errors in the hyperventilation alarms. Results were given separately for the intervals with CCs. ResultsA total of 83 episodes were considered, resulting in 4880min and 46,740 ventilations (8741 during CCs). The method showed an overall SE/PPV above 99% and 97% respectively, even in intervals with CCs. The error for the ventilation rate was below 1.8min−1 in any group, and >99% of the ventilation alarms were correctly detected. ConclusionA method to provide accurate feedback on ventilation rate using only the capnogram is proposed. Its accuracy was proven even in intervals where canpography signal was severely corrupted by CCs. This algorithm could be integrated into monitor/defibrillators to provide reliable feedback on ventilation rate during CPR.

Down to the Wire? Ventilation during Intubated Stretcher Helicopter Winching

The stretcher winching of intubated patients into a helicopter is an uncommon procedure. Positive pressure ventilation is required, which can be performed either manually with a self-inflating bag or automatically using a mechanical ventilator. The optimal method of ventilation has not been studied. Automatic ventilation has theoretical advantages in maintaining better oxygenation and stable arterial carbon dioxide levels, with less risk of airway disconnection. There is also likely to be better performance and situational awareness of the stretcher attendant during the winch, contributing to crew and patient safety. However, the ability to diagnose and manage airway disconnections and ventilator failure is of concern. To compare automatic vs manual ventilation during intubated stretcher helicopter winching. There were 2 phases to the trial. An initial static winch with a hoisting simulator was performed with 10 stretcher attendants, followed by a live helicopter winch at 30 feet into a Bell 412 with 5 attendants. Each attendant performed 2 separate winches with an intubated mannequin. During one winch the mannequin was ventilated with manual (bag) ventilation; an automatic ventilator was used for the other. Airway pressures were measured. The results showed no failure of automatic ventilation. Automatic ventilation was superior to manual ventilation. Automatic ventilation allowed for better situational awareness and perceived performance in winching maneuvers. There was one airway disconnection during a manual ventilation winch into the aircraft. Automatic ventilation is superior in providing stable, reliable, uninterrupted ventilation during simulated helicopter winching. The risk of ventilator failure and disconnection is low. Medical retrieval organizations should develop standard operating procedures, equipment, and training to facilitate automatic ventilation during helicopter winching.

Portable sweat rate sensors integrated with air ventilation actuators

A portable sweat rate sensor integrated with a thermo-pneumatic actuator for automatic ventilation has been proposed and experimentally verified its performance. The previous forced ventilation sweat rate sensors using external ventilating devices had the problem of the bulky size with the lack of portability. The previous natural ventilation sweat rate sensors with portable sizes meanwhile required a manual ventilation per each measurement. The total weight of the present portable sweat rate sensor is 6.2% of that of the previous forced ventilation sweat rate sensors. The integrated thermo-pneumatic actuator lifts the humidity measuring chamber above the skin for automatic natural ventilation. The portable sweat rate sensor, having a size of 38±0.5mm×41±0.5mm×29±0.5mm with a total weight of 63±1g, is capable of lifting the humidity chamber 1.91±0.27mm above the skin in a movement cycle period of 3min. The portable sweat rate sensor measures the sweat rate with a sensitivity of 0.056 (pF/s)/(g/m2h) and a linearity of 99.1% in a sweat rate range of 3.76–137.68g/m2h. The portable sweat rate sensor is insensitive to the environmental air flow, and thus demonstrates high potential for mobile human thermoregulatory status monitoring applications, such as human monitoring jackets and cognitive air-conditioning systems based on human sweat.

Bio-inspired, Moisture-Powered Hybrid Carbon Nanotube Yarn Muscles.

Hygromorph artificial muscles are attractive as self-powered actuators driven by moisture from the ambient environment. Previously reported hygromorph muscles have been largely limited to bending or torsional motions or as tensile actuators with low work and energy densities. Herein, we developed a hybrid yarn artificial muscle with a unique coiled and wrinkled structure, which can be actuated by either changing relative humidity or contact with water. The muscle provides a large tensile stroke (up to 78%) and a high maximum gravimetric work capacity during contraction (2.17 kJ kg−1), which is over 50 times that of the same weight human muscle and 5.5 times higher than for the same weight spider silk, which is the previous record holder for a moisture driven muscle. We demonstrate an automatic ventilation system that is operated by the tensile actuation of the hybrid muscles caused by dew condensing on the hybrid yarn. This self-powered humidity-controlled ventilation system could be adapted to automatically control the desired relative humidity of an enclosed space.

In-Vitro Characterization of the Aerosolized Dose During Non-Invasive Automatic Continuous Positive Airway Pressure Ventilation

Many devices (e.g., nebulizers and spacers) are used to deliver aerosol in a non-invasive ventilation circuit (NIV) without any special recommendation. The aim of the present work was to compare the doses delivered from seven different aerosol delivery systems when placed in the NIV using automatic continuous positive airway pressure (Auto-CPAP). Three spacers and three vibrating mesh nebulizers were compared to a Sidestream jet nebulizer (SIDE). Each device was placed proximal to a breathing simulator in a standard NIV circuit with a 500 ml tidal volume, 15 breaths/min and a 1:3 inspiratory-expiratory ratio. Two ml of salbutamol solution containing 10,000 μg was nebulized using Aerogen Pro (PRO), Aerogen Solo (SOLO), NIVO and SIDE. Twelve metered dose inhaler doses, containing 100 μg salbutamol each, were delivered using AeroChamber MV (AC), AeroChamber Vent (VC) and AeroChamber Mini (MC). Total emitted dose (TED) and its percentage were determined. Aerodynamic droplet characteristics were measured using cooled Andersen Cascade Impactor. The vibrating mesh nebulizers used had significantly more (p < 0.001) TED compared to the jet nebulizer. The spacers used had higher TED % (p < 0.001) compared to the nebulizers. The fine particle fraction of SIDE was the highest (p = 0.021) and mass median aerodynamic diameter of the spacers was the smallest (p = 0.001). The fine particle dose from vibrating mesh nebulizers was the greatest (p = 0.02). Aerosol delivery in Auto-CPAP NIV is feasible; however, aerosol delivery method should be chosen or substituted with care. 2 mg delivered from a spacer would be equivalent to 3 mg nebulized from a vibrating mesh nebulizer and 5 mg nebulized from a Sidestream.

Automatic Tube Compensation Versus Pressure Support Ventilation as a Weaning Mode, Does It Make a Difference?

Automatic Tube Compensation Versus Pressure Support Ventilation as a Weaning Mode, Does It Make a Difference?

Automated respiratory therapy system based on the ARDSNet protocol with systemic perfusion control

Abstract A medical expert system of automatic artificial ventilation is set up in a star topology with additional closed-loop hemodynamic control. Arterial blood pressure (MAP) is controlled by noradrenaline (NA) as a controlling variable. The overall patient-in-the-loop expert system can intensively and intelligently perform a long-term treatment based on the Acute Respiratory Distress Syndrome Network (ARDSNet) protocol. Three main goals are actively carried out, namely the stabilization and regulation of oxygenation, plateau pressure and blood pH value. The developed system shows a distinctive experimental result based on a 31.5-kg pig, in order to fulfil the ventilatory goals and to ensure proper systemic perfusion. Hence, this system has enormous potentials to realize a commercial system for individual patient with ARDS.

Providers with Limited Experience Perform Better in Advanced Life Support with Assistance Using an Interactive Device with an Automated External Defibrillator Linked to a Ventilator

BackgroundMedical teams with limited experience in performing advanced life support (ALS) or with a low frequency of cardiopulmonary resuscitation (CPR) while on duty, often have difficulty complying with CPR guidelines. ObjectiveThis study evaluated whether the quality of CPR of trained medical students, who served as an example of teams with limited experience in ALS, could be improved with device assistance. The primary outcome was the hands-off time (i.e., the percentage of the entire CPR time without chest compressions). The secondary outcome was seven time intervals, which should be as short as possible, and the quality of ventilations and chest compressions on the mannequin. MethodsWe compared standard CPR equipment to an interactive device with visual and acoustic instructions for ALS workflow measures to guide briefly trained medical students through the ALS algorithm in a full-scale mannequin simulation study with a randomized crossover study design. The study equipment consisted of an automatic external defibrillator and ventilator that were electronically linked and communicating as a single system. Included were regular medical students in the third to sixth years of medical school of one class who provided written informed consent for voluntary participation and for the analysis of their CPR performance data. No exclusion criteria were applied. For statistical measures of evaluation we used an analysis of variance for crossover trials accounting for treatment effect, sequence effect, and carry-over effect, with adjustment for prior practical experience of the participants. ResultsForty-two medical students participated in 21 CPR sessions, each using the standard and study equipment. Regarding the primary end point, the study equipment reduced the hands-off time from 40.1% (95% confidence interval [CI] 36.9–43.4%) to 35.6% (95% CI 32.4–38.9%, p = 0.031) compared with the standard equipment. Within the prespecified secondary end points, study equipment reduced the time interval until the first rescuer changeover from 273 s (95% CI 244–302 s) to 223 s (95% CI 194–253 s, p = 0.001) and increased the percentage of ventilations with a correct tidal volume of 400–600 mL from 34.3% (95% CI 19.0–49.6%) to 60.9% (95% CI 45.6–76.2%, p = 0.018). ConclusionsThe assist device increased the rescuers' CPR quality. CPR providers with limited experience or a limited frequency of CPR performance (i.e., rural Emergency Medical Services crew) may potentially benefit from this assist device.

Dynamic real-time monitoring of chloroform in an indoor swimming pool air using open-path Fourier transform infrared spectroscopy.

This study used open-path Fourier transform infrared (OP-FTIR) spectroscopy to continuously assess the variation in chloroform concentrations in the air of an indoor swimming pool. Variables affecting the concentrations of chloroform in air were also monitored. The results showed that chloroform concentrations in air varied significantly during the time of operation of the swimming pool and that there were two peaks in chloroform concentration during the time of operation of the pool. The highest concentration was at 17:30, which is coincident with the time with the highest number of swimmers in the pool in a day. The swimmer load was one of the most important factors influencing the chloroform concentration in the air. When the number of swimmers surpassed 40, the concentrations of chloroform were on average 4.4 times higher than the concentration measured without swimmers in the pool. According to the results of this study, we suggest that those who swim regularly should avoid times with highest number of swimmers, in order to decrease the risk of exposure to high concentrations of chloroform. It is also recommended that an automatic mechanical ventilation system is installed to increase the ventilation rate during times of high swimmer load.

フルオープン型および谷部自動開閉型ビニールハウスに生じるプラスチックフィルムの損傷の考察とその実験的シミュレーション

フルオープン型および谷部自動開閉型ビニールハウスに生じるプラスチックフィルムの損傷の考察とその実験的シミュレーション

PPC fixe ou autopilotée : la question est-elle encore d’actualité ?

Automatic constant positive airway pressure ventilation (AutoCPAP) is a commercial success in the management of the obstructive sleep disorders (OSD). Nevertheless, several studies have questioned their reliability in terms of recognition and correction of respiratory events depisted by polysomnography. Moreover, all devices tend to invent eventswhen submitted to a healthy subject. Fixed CPAP must remain the first-choice treatment for the management of the OSD.