This study employs the transmitter part of an ultrasonic proximity sensor to generate a powerful ultrasonic field for medical humidification. This field is created using an arrangement of small ultrasonic transmitter transducers configured in an acoustic levitator-style setup. As droplets pass through this ultrasonic field, they undergo disintegration, leading to an accelerated evaporation process. The research findings highlight a significant change in droplet size distribution due to ultrasonics, resulting in a notable increase in the rate of evaporation. As a result, this study presents a conceptual framework for reimagining humidification devices for lung therapeutic purposes through the utilization of simple sensor technology.

Background/Objectives: Modern life is inconceivable without visual display terminal (VDT) work, including smartphones, computers, and games for both children and adults. VDT work under air conditioning and low humidity poses a high risk of dry eye and digital eye strain. Methods: Thirty-one participants were randomly divided into two groups using a desktop humidifier with photocatalytic technology, namely the \"with mist\" (humidifier) group and \"without mist\" (control) group. Participants performed VDT tasks using the humidifier with or without mist for 1 h. Ocular subjective symptoms and objective tear film parameters were assessed before, immediately after, and 1.5 h after the VDT task with or without mist. (Registry ID: UMIN000054379) Results: Ocular symptom scores improved significantly in the humidifier group immediately after the VDT task and up to 1.5 h later compared to before the task (p < 0.001, =0.006, respectively). Immediately after the VDT task, tear meniscus height was significantly higher and non-invasive breakup time was significantly longer in the humidifier group than in the control group (p < 0.001, =0.040, respectively). Plugging of the meibomian gland orifices was significantly reduced only in the humidifier group immediately after the VDT task compared to before the VDT task and remained significantly reduced up to 1.5 h later (p = 0.004, 0.016, respectively). Conclusions: The use of the photocatalytic desktop humidifier during VDT task resulted in significant improvements in the tear film parameters and subjective symptoms. The photocatalytic desktop humidifier could be effective in alleviating dry eye and eye strain in computer users in a modern office environment.

OBJECTIVE: No study has yet evaluated the degree of contamination after the total disassembly of continuous positive airway pressure (CPAP) devices. We investigated the extent of contamination of CPAP devices used daily by patients with obstructive sleep apnea (OSA) by disassembling the systems and identifying the factors that influenced the degree of CPAP contamination.
METHODS: We conducted a chart review of the medical records of patients with OSA for whom the CPAP devices were disassembled and cleaned. Two skilled technicians photographed the levels of contamination of each component and scored them using a visual analog scale. Patients\' clinical characteristics and records of CPAP device usage were statistically analyzed to identify characteristics that were significantly associated with the degree of CPAP device contamination.
RESULTS: Among the 55 participants, both the external components, including the mask and tube, and the internal components, such as the humidifier and the interior of the main body, showed a substantial degree of contamination. The total and average daily duration of usage of the CPAP device did not show significant associations with the degree of contamination. Age was most consistently associated with the degree of contamination, such as in masks, humidifiers, and interior and exterior main parts. The degree of contamination of the internal components of the device was significantly correlated with the degree of contamination of the external components.
CONCLUSIONS: Age-specific guidelines for managing the hygiene of external and internal CPAP components should be prepared.

Water transport in a hollow-fiber membrane depends on mass convection around the tube, mass convection inside the tube, and water diffusion through the membrane tube. The performance of water transport is then explained by the overall mass transfer coefficient in hollow-fiber membranes. This study presents the prediction of overall mass transfer coefficients of water transport in a hollow-fiber membrane module by an artificial neural network (ANN) that is used for a humidifier of a vehicular fuel cell system. The input variables of ANN are collected from water transport experiments of the hollow-fiber membrane module that is composed of inlet flow rates, inlet relative humidity, system pressures, and operating temperatures. The experimental mass transfer coefficients are the targets of the training model, which are determined via the effectiveness analysis. When unknown data are applied to the ANN model, the correlation of the overall mass transfer coefficient predicts precise results with R = 0.99 (correlation coefficient). The ANN model shows good prediction capability of water transport in membrane humidifiers.

The purpose of the study was to investigate the accuracy of mainstream EtCO2 measurements on the Y-piece (filtered) side of the heat and moisture exchanger filter (HMEF) in adult critically ill patients, compared to that on the patient (unfiltered) side of HMEF. We conducted a prospective observational method comparison study between July 2019 and December 2019. Critically ill adult patients receiving mechanical ventilation with HMEF were included. We performed a noninferiority comparison of the accuracy of EtCO2 measurements on the two sides of HMEF. The accuracy was measured by the absolute difference between PaCO2 and EtCO2. We set the non-inferiority margin at + 1 mmHg in accuracy difference between the two sides of HMEF. We also assessed the agreement between PaCO2 and EtCO2 using Bland-Altman analysis. Among thirty-seven patients, the accuracy difference was - 0.14 mmHg (two-sided 90% CI - 0.58 to 0.29), and the upper limit of the CI did not exceed the predefined margin of + 1 mmHg, establishing non-inferiority of EtCO2 on the Y-piece side of HMEF (P for non-inferiority < 0.001). In the Bland-Altman analyses, 95% limits of agreement between PaCO2 and EtCO2 were similar on both sides of HMEF (Y-piece side, - 8.67 to  + 10.65 mmHg; patient side, - 8.93 to  + 10.67 mmHg). The accuracy of mainstream EtCO2 measurements on the Y-piece side of HMEF was noninferior to that on the patient side in critically ill adults. Mechanically ventilated adult patients could be accurately monitored with mainstream EtCO2 on the Y-piece side of the HMEF unless their tidal volume was extremely low.

In times of the COVID-19 pandemic, wearing face masks is strongly recommended as a public health measure to stop the spread of the Sars Coronavirus. However, there are still people who ignore using this effective protective tool due to the lack of comfortable face masks on the market. Therefore, in the current study, we assessed commercially available face masks namely N95 masks, surgical masks, and cloth masks in order to find out their weakness. In addition, the identification needs of people from a face mask were collected by an online questionnaire. According to the information obtained; we achieved key factors required to design a new type of face mask using the Computer-Aided Design (CAD) and the final design was printed. Moreover, the long-term use of herbs in Iranian Traditional Medicine persuaded us to add a humidifier containing aromatic plants essential oils such as Eucalyptus globules Labill. and Rosa damascene Mill. with scientifically proven health benefits such as pain reliever, relaxing properties and antimicrobial activities. We are expected that these aromas would be an effective way to eliminate the problems of individuals suffering from air pollutants, respiratory disorders, and COVID which leads to encouraging more people to use face masks during pandemics or air pollution.

Recently, a novel humidifier that sprays water fine droplets equipped with a copolymer, poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT/PSS) was developed. PEDOT/PSS in the humidifier absorbs water from the environment and releases fine water droplets by heating. In the present study, the effect of hydration on the skin barrier, stratum corneum, was first determined by the application of fine water droplets using the humidifier. The skin-penetration enhancement effect of a model hydrophilic drug, caffeine, was also investigated using the humidifier and compared with a conventional water-evaporative humidifier. More prolonged skin hydration effect was observed after application of the fine water droplet release humidifier using PEDOT/PSS than that using a conventional humidifier. In addition, markedly higher skin permeation of caffeine was observed in both infinite and finite dose conditions. Furthermore, higher skin permeation of caffeine from oil/water emulsion containing caffeine was observed in finite dose conditions by pretreatment with the humidifier using PEDOT/PSS. This device can provide water droplets without replenishing water, so it is more convenient for enhancing the skin permeation of chemical compounds from topical drugs and cosmetic formulations.

A 46-year-old man visited our hospital with a fever and cough. The symptoms had started two months after continued use of an ultrasonic humidifier. He had hypoxemia on admission and late inspiratory crackles in both lungs on physical examination. The laboratory findings showed an increased white blood cell count and a C-reactive protein level, and his serum KL-6 level was slightly elevated, at 674 U/mL. Chest computed tomography showed diffuse ground-glass opacities, and histological examination of a transbronchial lung biopsy showed alveolitis without granulomas. The humidifier inhalation challenge test result was positive. Therefore, we diagnosed the patient with humidifier lung. His symptoms gradually improved after avoiding the humidifier without taking medication. The humidifier water was contaminated by various bacteria and fungi, as well as Mycobacterium gordonae and a high concentration of endotoxin. Unlike in those with typical hypersensitivity pneumonitis, the elevation of serum KL-6 levels in humidifier lung patients is mild, and granulomas are not apparent on histological examination, similar to our case. Furthermore, the endotoxin identified from the humidifier is one of the known pathogens of humidifier lung. Thus, humidifier lung seems to have different characteristics compared to other hypersensitivity pneumonitis phenotypes. The mechanism driven by the high concentration of endotoxin could be one of the main causes of humidifier lung.

With the industrialization and rapid development of technology that can measure the concentration of pollutants, studies on indoor atmosphere assessment focusing on occupants have been recently conducted. Pollutants that worsen indoor atmosphere include gaseous and particulate matter (PM), and the effects and diffusion characteristics that influence indoor atmosphere vary depending on the indoor and outdoor concentration. White dust is a PM generated from minerals in water used for humidifiers during winter. Therefore, studies on the impact of white dust on human health and its size distribution are being actively conducted. However, since the indoor PM concentration varies depending on the humidification method and water type used, relevant studies are needed. Accordingly, this study examined the change in the PM2.5 concentration and relative humidity on the basis of water types and humidification method. It was found that the indoor PM2.5 concentration varied from 16 to 350 ug/m3, depending on the water types used for an ultrasonic humidifier. Conversely, when using a natural evaporative humidifier, white dust did not increase the indoor PM2.5 concentration, regardless of the mineral content of the water used. Considering both humidification ability and continuous humidifier use indoors, water purifier with nano-trap filters must be utilized for ultrasonic humidifiers.

Household humidification is widely practiced to combat dry indoor air. While the benefits of household humidification are widely perceived, its implications to the indoor air have not been critically appraised. In particular, ultrasonic humidifiers are known to generate fine particulate matter (PM). In this study, we first conducted laboratory experiments to investigate the size, quantity, and chemical composition of PM generated by an ultrasonic humidifier. The mass of PM generated showed a correlation with the total alkalinity of charge water, suggesting that CaCO3 is likely making a major contribution to PM. Ion chromatography analysis revealed a large amount of SO4 2- in PM, representing a previously unrecognized indoor source. Preliminary results of organic compounds being present in humidifier PM are also presented. A whole-house experiment was further conducted at an actual residential house, with five low-cost sensors (AirBeam) monitoring PM in real time. Operation of a single ultrasonic humidifier resulted in PM2.5 concentrations up to hundreds of μg m-3 , and its influence extended across the entire household. The transport and loss of PM2.5 depended on the rate of air circulation and ventilation. This study emphasizes the need to further investigate the impact of humidifier operation, both on human health and on the indoor atmospheric chemistry, for example, partitioning of acidic and basic compounds.