Exhaled Levels Research Articles

Breath and plasma metabolomics to assess inflammation in acute stroke

Inflammation is strongly implicated in both injury and repair processes occurring after stroke. In this exploratory study we assessed the feasibility of repeated sampling of exhaled volatile organic compounds and performed an untargeted metabolomic analysis of plasma collected at multiple time periods after stroke. Metabolic profiles were compared with the time course of the inflammatory markers C-reactive protein (CRP) and interleukin-6 (IL-6). Serial breath sampling was well-tolerated by all patients and the measurement appears feasible in this group. We found that exhaled decanal tracks CRP and IL-6 levels post-stroke and correlates with several metabolic pathways associated with a post-stroke inflammatory response. This suggests that measurement of breath and blood metabolites could facilitate development of novel therapeutic and diagnostic strategies. Results are discussed in relation to the utility of breath analysis in stroke care, such as in monitoring recovery and complications including stroke associated infection.

Respiratory Aerosol Emissions from Vocalization: Age and Sex Differences Are Explained by Volume and Exhaled CO2

Evidence suggests that airborne transmission of infectious respiratory aerosol plays an important role for the SARS-CoV-2 virus. This work characterized respiratory aerosol emissions from a panel of healthy individuals of varying age and sex while talking and singing in a controlled laboratory setting. Particle number concentrations between 0.25 and 33 μm were measured from 63 participants aged 12–61 years with concurrent monitoring of voice volume and exhaled CO2 levels. On average, singing produced 77% (95% CI: 42,109%) more aerosol than talking, adults produced 62% (CI: 27,98%) more aerosol than minors, and males produced 34% (CI: 0,70%) more aerosol than females. After accounting for participant voice volume and exhaled CO2 (both of which were positively correlated with aerosol emissions) in linear models, the age and sex differences were attenuated and no longer statistically significant. These results support further investigation of voice volume and CO2 as indicators of infection risk indoors.

Continuous positive airway pressure affects mitochondrial function and exhaled PGC1-α levels in obstructive sleep apnea

Purpose: Subjects with obstructive sleep apnea (OSA) exhibit systemic and upper airway oxidative stress and inflammation, which cause mitochondrial dysfunction. The intend of this study is to estimate mitochondrial function (mitochondrial DNA/nuclear DNA [Mt/N] ratio) and protein levels of peroxisome proliferator-coactivated receptor gamma co-activator 1-alpha (PGC1-α) in the exhaled breath condensate (EBC) and plasma before and after continuous positive airway pressure (CPAP) treatment. Materials and methods: Twenty healthy individuals (control) and 40 subjects with severe or moderate OSA were recruited to undergo CPAP treatment and evaluation in a sleep study. The Mt/N ratio in the EBC and blood were assayed by quantitative real-time polymerase chain reaction. Enzyme-linked immunosorbent assay was used to measure the protein concentration of PGC1-α in the EBC and plasma. All experiments were performed after 3 months of CPAP treatment in subjects with OSA. Results: We observed no noteworthy differences between the control and treatment groups. Moreover, there were no differences in the Mt/N ratio in the blood and plasma levels of PGC1-α in subjects with OSA before and after treatment. However, the Mt/N ratio and protein levels of PGC1-α in the EBC of OSA subjects were higher than those in the control group and returned to normal levels after CPAP treatment. Conclusions: We successfully treated subjects with OSA by CPAP, which restored the Mt/N ratio and levels of PGC1-α in the EBC.

Investigating Radioactive Content in Various Commercially available Flour Samples in Local Iraqi Markets

The study was conducted to assess the radioactivity of alpha concentration of different samples of flour in Karbala mills and some samples in local Iraqi markets. Alpha sensitive CR-39 plastic paths detectors commonly know as "Solid State Nuclear paths Detectors" were used measuring the concentrations of uranium, efficaious radium content, and ratio of radon. The results indicate that the exhalation levels of mass and surface radon were between 0.214-0.549 mBq/kg.h, and 4.35 -11.185 mBq/m2.h, respectively, with an mediam of 0.385 mBq/kg.h and 7.691 mBq/m2.h. The effective radium content values range from 28 to 78 mBq/kg with an mediam value of 51.06 mBq/kg, respectively. The concentration of uranium values ranges from 0.334 to 0.858 Bq/kg, with a mean value of 0.602 Bq/kg. The measurements of the radon, radium, and uranium concentration in each sample are significant in terms of health safeguard point of view. Hence, easy, and accurate techniques of analysis are highly demanded.

HUBUNGAN TINGKAT PENGETAHUAN DENGAN KEPATUHAN PERAWAT DALAM MENJALANKAN EARLY WARNING SCORE DI RUMAH SAKIT BIMC KUTA

Early Warning Score (EWS) is an early warning system starting from early detection, making decisions before the patient experiences an emergency condition. The parameters in the EWS method are level of consciousness, respiration or exhalation, oxygen saturation, supplemental oxygen, temperature, pulse rate, and systolic blood pressure. The purpose of this study was to determine the correlation between knowledge level and nurse compliance of nurses in carrying out early warning score at BIMC Hospital Kuta. The EWS assessment is supported by nurses’ education level and work experience. This study used a cross-sectional approach correlation design with a total sampling technique of 58 nurses. In this study, it was found that the good knowledge level of nurses at BIMC Hospital Kuta was 86.2%, while the compliance level of nurses in carrying out the early warning score was found that the nurses obeyed in carrying out an early warning score of 86.2%. Data processing used the chi square statistical test. The results of the statistical test p value 0.000, which showed that there was a significant correlation between knowledge level and nurse compliance in carrying out the early warning score and r value = -0.619.

The Potential Role of Airways Periostin in the Clinical Practice of Patients Affected by Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic debilitating fibrotic lung disease leading to respiratory failure and ultimately to death. Noninvasive biomarkers, for the early diagnosis, differential diagnosis, prognosis, and prediction of therapeutic response, are needed. Previous studies support a role for periostin in lung fibrosis. The aim of our study was to analyze periostin levels in the airways of patients with IPF and to investigate its role as a useful predictive biomarker of the disease. We enrolled 30 IPF patients and 5 control subjects. All subjects underwent all standard radiological, functional, and biological examinations for IPF diagnosis and staging and exhaled breath condensate (EBC) collection. Periostin was assessed by an enzyme-linked immunosorbent assay kit on EBC. Periostin was dosable in the EBC of all subjects enrolled. We found higher exhaled periostin levels in IPF patients than healthy controls (65.5 ± 23.5 pg/mL vs. 33 ± 21.4 pg/mL, p < 0.05). Moreover, in receiver operating characteristic analysis, the clinical reference value of periostin was 37.88 pg/mL to discriminate patients with IPF from healthy subjects, with the area under the curve of 0.8815. There was no significant correlation between periostin levels and gender or pulmonary function tests. These preliminary results support our working hypothesis that periostin is dosable in the airways of patients with IPF. As the circulating periostin, also airways periostin may be a potential biomarker to support IPF diagnosis and to monitor disease progression during follow-up.

Diet and gut microbiome interactions of relevance for symptoms in irritable bowel syndrome

BackgroundWhile several studies have documented associations between dietary habits and microbiota composition and function in healthy individuals, no study explored these associations in patients with irritable bowel syndrome (IBS), and especially with symptoms.MethodsHere, we used a novel approach that combined data from a 4-day food diary, integrated into a food tree, together with gut microbiota (shotgun metagenomic) for individuals with IBS (N = 149) and healthy controls (N = 52). Paired microbiota and food-based trees allowed us to detect new associations between subspecies and diet. Combining co-inertia analysis and linear regression models, exhaled gas levels and symptom severity could be predicted from metagenomic and dietary data.ResultsWe showed that individuals with severe IBS are characterized by a higher intake of poorer-quality food items during their main meals. Our analysis suggested that covariations between gut microbiota at subspecies level and diet could be explained with IBS symptom severity, exhaled gas, glycan metabolism, and meat/plant ratio. We provided evidence that IBS severity is associated with altered gut microbiota hydrogen function in correlation with microbiota enzymes involved in animal carbohydrate metabolism.ConclusionsOur study provides an unprecedented resolution of diet-microbiota-symptom interactions and ultimately guides new interventional studies that aim to identify gut microbiome-based nutritional recommendations for the management of gastrointestinal symptoms.Trial registrationThis trial was registered on the ClinicalTrials.gov, with the registration number NCT01252550, on 3rd December 2010.93ov3mj-BC13x8K6khXmLQVideo abstract

Effect of submarine microclimate on respiratory physiology of submariners: An observational study

Introduction: A few personnel feel more tired staying and working inside submarine, as compared to ashore/outdoor spaces, or even onboard afloat platforms (ships). The microclimate onboard underwater platforms play a vital role in determining the respiratory physiology parameters of personnel onboard. There exists a felt need for deeper evidence in this regard. Aims and Objectives: This study is an effort to analyze if there exists any relationship between concentrations of respiratory gases (such as oxygen and carbon dioxide) and other parameters of submarine microclimate, on the respiratory physiology parameters (such as respiratory rate [RR] and SpO2) of personnel onboard underwater platforms. The difference in concentrations of oxygen and carbon dioxide in exhaled air of personnel both inside and outside submarine was also studied. Any difference between smokers and nonsmokers regarding this parameter was also evaluated. Materials and Methods: The study was carried out on thirty healthy volunteers posted onboard a submarine. Concentrations of oxygen and carbon dioxide in the atmosphere, as also the exhaled air, were measured using a digital gas analyzer. Humidity, temperature, and oxygen saturation were measured using digital meters. The values both inside and outside were recorded and compared. Results: There was a statistically significant difference in the temperature, humidity, and level of CO2 inside and outside the submarine. There was no statistically significant difference in level of oxygen in atmosphere, oxygen and carbon dioxide in exhaled air, RR, and SPO2 level inside and outside the submarine. Conclusion: The corrected effective temperature inside a submarine is to be measured periodically and maintained in the comfort zone. The level of CO2 should be maintained close to environmental levels.

Smoking regular and low-nicotine cigarettes results in comparable levels of volatile organic compounds in blood and exhaled breath

Smokers are exposed to more than 6000 (toxic) smoke components including volatile organic compounds (VOCs). In this study VOCs levels in headspace of blood and exhaled breath, in the mainstream smoke of three types of cigarettes of one brand varying in declared tar, nicotine and carbon monoxide (TNCO) yields are investigated. The objective was to identify whether VOC levels correlate with TNCO yields of cigarettes smoked according to ISO 3308. Our data show that smoking regular and low-TNCO cigarettes result in comparable levels of VOCs in blood and exhaled breath. Hence, declared TNCO-yields as determined with the ISO 3308 machine smoking protocol are irrelevant for predicting VOC exposure upon human smoking.Venous blood and exhaled breath were sampled from 12 male volunteers directly before and 10 min after smoking cigarettes on 3 d (day 1 Marlboro Red (regular), day 2 Marlboro Prime (highly ventilated, low-TNCO), day 3 Marlboro Prime with blocked filter ventilation (taped)). Upon smoking, the levels of toluene, ethylbenzene, m/p-xylene, o-xylene, and 2,5-dimethylfuran in both headspace of venous blood and exhaled breath increase within the same range for all three cigarette types smoked. However, no strong correlation was found between VOC levels in exhaled breath and VOC levels in headspace of blood because of variations between the individual smoking volunteers. More research is required in order to use exhaled breath sampling as a non-invasive quantitative marker for volatile toxicants from cigarette smoke exposure of different brands.

Measurement of Alpha Activity in Several Types of Iraqi Ceramic and Cement in the Iraqi Markets

In this study fifteen samples of ceramic and cement collected from Iraqi markets have been determined for the radium efficacy and radon exhalation rates using the CN-85 plastic track detectors. For the estimation of the effective radium content and exhale rate, these samples comprised 15 different Iraqi materials. The effective radium content values ranged from 2.108 to 21.689 Bq / kg to an average of 9.399 Bq / kg and standard devolution of 6.950. The mass exhalation levels for radon ranged from 0.106 to 1.092 mBq / kg.day, with an average value of 0.473 mBq / kg. day and standard deviation of 0.312 Bq / kg. The exhalation rate for the radon surfaces ranged from 1.889 to 19.44 mBq / kg.day. The mean radon exhalation levels, which are an effective radium element, were found to fall below the world average of 57600 Bq / m2 in the samples of ceramic and concrete materials and Soil: 35 Bq / kg, In addition, the study’s showed that the effective radium content in this study and the associated radon exhalation do not pose a human health risk when they are used in daily life in Iraqi markets.

Methane Exhalation Can Monitor the Microcirculatory Changes of the Intestinal Mucosa in a Large Animal Model of Hemorrhage and Fluid Resuscitation.

Background: Internal hemorrhage is a medical emergency, which requires immediate causal therapy, but the recognition may be difficult. The reactive changes of the mesenteric circulation may be part of the earliest hemodynamic responses to bleeding. Methane is present in the luminal atmosphere; thus, we hypothesized that it can track the intestinal circulatory changes, induced by hemorrhage, non-invasively. Our goal was to validate and compare the sensitivity of this method with an established technique using sublingual microcirculatory monitoring in a large animal model of controlled, graded hemorrhage and the early phase of following fluid resuscitation.Materials and Methods: The experiments were performed on anesthetized, ventilated Vietnamese minipigs (approval number: V/148/2013; n = 6). The animals were gradually bled seven times consecutively of 5% of their estimated blood volume (BV) each, followed by gradual fluid resuscitation with colloid (hydroxyethyl starch; 5% of the estimated BV/dose) until 80 mmHg mean arterial pressure was achieved. After each step, macrohemodynamic parameters were recorded, and exhaled methane level was monitored continuously with a custom-built photoacoustic laser-spectroscopy unit. The microcirculation of the sublingual area, ileal serosa, and mucosa was examined by intravital videomicroscopy (Cytocam-IDF, Braedius).Results: Mesenteric perfusion was significantly reduced by a 5% blood loss, whereas microperfusion in the oral cavity deteriorated after a 25% loss. A statistically significant correlation was found between exhaled methane levels, superior mesenteric artery flow (r = 0.93), or microcirculatory changes in the ileal serosa (ρ = 0.78) and mucosa (r = 0.77). After resuscitation, the ileal mucosal microcirculation increased rapidly [De Backer score (DBS): 2.36 ± 0.42 vs. 8.6 ± 2.1 mm−1], whereas serosal perfusion changed gradually and with a lower amplitude (DBS: 2.51 ± 0.48 vs. 5.73 ± 0.75). Sublingual perfusion correlated with mucosal (r = 0.74) and serosal (r = 0.66) mesenteric microperfusion during the hemorrhage phase but not during the resuscitation phase.Conclusion: Detection of exhaled methane levels is of diagnostic significance during experimental hemorrhage as it indicates blood loss earlier than sublingual microcirculatory changes and in the early phase of fluid resuscitation, the exhaled methane values change in association with the mesenteric perfusion and the microcirculation of the ileum.

Pathways in the Pathophysiology of Coronavirus 19 Lung Disease Accessible to Prevention and Treatment.

Background: In COVID 19 related lung disease, which is a leading cause of death from this disease, cytokines like tumor necrosis factor-alpha (TNF alpha) may be pivotal in the pathogenesis. TNF alpha reduces fluid absorption due to impairment of sodium and chloride transport required for building an osmotic gradient across epithelial cells, which in the airways maintains airway surface liquid helping to keep airways open and enabling bacterial clearance and aids water absorption from the alveolar spaces. TNF alpha can, through Rho-kinase, disintegrate the endothelial and epithelial cytoskeleton, and thus break up intercellular tight junctional proteins, breaching the intercellular barrier, which prevents flooding of the interstitial and alveolar spaces with fluid.Hypotheses: (1) Preservation and restoration of airway and alveolar epithelial sodium and chloride transport and the cytoskeleton dependent integrity of the cell barriers within the lung can prevent and treat COVID 19 lung disease. (2) TNF alpha is the key mediator of pulmonary edema in COVID 19 lung disease.Confirmation of hypothesis and implications: The role of a reduction in the function of epithelial sodium and chloride transport could with regards to chloride transport be tested by analysis of chloride levels in exhaled breath condensate and levels correlated with TNF alpha concentrations. Reduced levels would indicate a reduction of the function of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel and a correlation with TNF alpha levels indicative of its involvement. Anti-TNF alpha treatment with antibodies is already available and needs to be tested in randomized controlled trials of COVID 19 lung disease. TNF alpha levels could also be reduced by statins, aspirin, and curcumin. Chloride transport could be facilitated by CFTR activators, including curcumin and phosphodiesterase-5 inhibitors. Sodium and chloride transport could be further regulated to prevent accumulation of alveolar fluid by use of Na(+)/K(+)/2Cl(−) cotransporter type 1 inhibitors, which have been associated with improved outcome in adults ventilated for acute respiratory distress syndrome (ARDS) in randomized controlled trials. Primary prevention of coronavirus infection and TNF alpha release in response to it could be improved by induction of antimicrobial peptides LL-37 and human beta defensin-2 and reduction of TNF alpha production by vitamin D prophylaxis for the population as a whole.

Metabolic fate of newly developed nondigestible oligosaccharide, maltobionic acid, in rats and humans.

Maltobionic acid (MA), formed by a gluconic acid and glucose linked by an α‐1,4 bond, may have the properties of a nondigestible oligosaccharide. The objective of this study was to elucidate the bioavailability of MA in rats and humans by observing digestion of MA by small intestinal enzymes, the fermentation of MA by gut microbiota, and the effect of adaptation following prolonged ingestion of MA. MA digestion was assessed using brush border membrane vesicles (BBMV) from rat small intestine. A within‐subject repeated measures design was used for ingestion experiments in 10 healthy female participants. After MA ingestion, postprandial plasma glucose and insulin levels, breath hydrogen excretion, and urinary MA were measured. The effect of adaptation following prolonged MA ingestion was investigated in rats. MA was minimally hydrolyzed by BBMV. Ingestion of 10 g of MA by healthy females did not elevate postprandial plasma glucose and insulin levels. Breath hydrogen and urinary MA were negligibly excreted over 8 hr following ingestion. Adaptation to prolonged MA ingestion produced no significant difference in exhaled hydrogen levels over 8 hr following administration compared with controls. MA is a new food material that is highly resistant to digestion and fermentation. It expresses the characteristics of a nondigestible oligosaccharide, including being low energy, improving the flavor of food and juice, and mineral solubilization.

Fractional Exhaled Nitric Oxide and Nanomaterial Exposure in Workplaces.

The widespread application of engineered nanomaterials (ENMs) and the increasing likelihood of general and occupational exposure raised concerns on their possible human health impact. ENMs, in fact, may induce alterations in different organ systems, and particularly in the respiratory tract. This makes it important to identify possible biomarkers of early lung effect in exposed workers. In this regard, the possibility to use the fractional exhaled levels of nitric oxide (FENO) in biological monitoring has attracted considerable interest. To comprehensively assess the role of FENO as a possible biomarker of lung effect in ENM exposed workers. A systematic search was performed on Pubmed, Scopus, and ISI Web of Knowledge databases according to the PRISMA guidelines. Seven studies investigated FENO in workers exposed to different kinds of metal- (i.e. silver and gold), metal oxide- (titanium and silica dioxide), and carbon-based ENMs (carbon nanotubes). In general, no significant alterations were detected between exposed workers and controls. Definite conclusion on the function of FENO in occupational biological monitoring cannot be extrapolated due to the limited number of available studies and the small size of investigated populations. Additionally, the lack of environmental monitoring data and the fragmented knowledge on ENM modes of action prevent to establish dose-response relationships. Future research appears necessary to deeply define the possibility to employ FENO as an early biomarker of lung effects taking in consideration possible occupational exposure issues, i.e. differently characterized ENMs and work tasks, as well as individual influencing factors, i.e. smoking and atopy.

Impact of oral cleansing strategies on exhaled volatile organic compound levels.

The analysis of volatile organic compounds (VOCs) within exhaled breath potentially offers a non-invasive method for the detection and surveillance of human disease. Oral contamination of exhaled breath may influence the detection of systemic VOCs relevant to human disease. This study aims to assess the impact of oral cleansing strategies on exhaled VOC levels in order to standardise practice for breath sampling. Ten healthy volunteers consumed a nutrient challenge followed by four oral cleansing methods: (a) water, (b) saltwater, (c) toothbrushing, and (d) alcohol-free mouthwash. Direct breath sampling was performed using selected ion flow tube mass spectrometry after each intervention. Proposed reactions suggest that volatile fatty acid and alcohol levels (butanoic, pentanoic acid, ethanol) declined with oral cleansing interventions, predominantly after an initial oral rinse with water. Concentrations of aldehydes and phenols (acetaldehyde, menthone, p-cresol) declined with oral water rinse; however, they increased after toothbrushing and mouthwash use, secondary to flavoured ingredients within these products. No significant reductions were observed with sulphur compounds. Findings suggest that oral rinsing with water prior to breath sampling may reduce oral contamination of VOC levels, and further interventions for oral decontamination with flavoured products may compromise results. This intervention may serve as a simple and inexpensive method of standardisation within breath research.

Exhaled Carbon Monoxide Levels of Scavengers in Bantar Gebang Landfill, Bekasi

Background: Scavengers in landfills have high risk to pollution exposure. Carbon monoxide (CO) is one of important pollutants produced by burning process. Exhaled CO levels in scavengers is predicted to increase, caused by pollution exposure in workplace area. There has been no data on exhaled CO levels in scavengers, especially in Bantar Gebang, Bekasi.Methods: This study used cross-sectional design to the scavengers who work and live in Ciketing Udik, Bantar Gebang, Bekasi. This study was conducted in January - March 2015, by doing interviews and giving questionnaires, and conducted exhaled CO test.Results: Total sample was 108 subjects. Exhaled CO test result was 46 subjects (42.6%) had exhaled CO 5-10 ppm, 36 subjects (33.3%) &gt; 10 ppm, and 26 subjects (24.1%) ≤ 4 ppm. Multivariate analysis between exhaled CO levels with characteristics of the subjects found smoking habits were significantly correlated with CO exhalation levels (p=0,000).Conclusion: There were 33.3% scavengers who had exhaled CO &gt; 10 ppm. Smoking habits were the only factor that significantly correlated with CO in scavengers’ exhalation.

Respiratory health and inflammatory markers - Exposure to respirable dust and quartz and chemical binders in Swedish iron foundries.

PurposeTo study the relationship between respirable dust, quartz and chemical binders in Swedish iron foundries and respiratory symptoms, lung function (as forced expiratory volume FEV1 and vital capacity FVC), fraction of exhaled nitric oxide (FENO) and levels of club cell secretory protein 16 (CC16) and CRP.MethodsPersonal sampling of respirable dust and quartz was performed for 85 subjects in three Swedish iron foundries. Full shift sampling and examination were performed on the second or third day of a working week after a work free weekend, with additional sampling on the fourth or fifth day. Logistic, linear and mixed model analyses were performed including, gender, age, smoking, infections, sampling day, body mass index (BMI) and chemical binders as covariates.ResultsThe adjusted average respirable quartz and dust concentrations were 0.038 and 0.66 mg/m3, respectively. Statistically significant increases in levels of CC16 were associated with exposure to chemical binders (p = 0.05; p = 0.01) in the regression analysis of quartz and respirable dust, respectively. Non-significant exposure-responses were identified for cumulative quartz and the symptoms asthma and breathlessness. For cumulative chemical years, non-significant exposure–response were observed for all but two symptoms. FENO also exhibited a non significant exposure-response for both quartz and respirable dust. No exposure-response was determined for FEV1 or FVC, CRP and respirable dust and quartz.ConclusionsOur findings suggest that early markers of pulmonary effect, such as increased levels of CC16 and FENO, are more strongly associated with chemical binder exposure than respirable quartz and dust in foundry environments.

Air and breath analysis for the assessment of exposure to solvent emissions in university chemistry laboratories

In this study, ambient and biological monitoring, through the use of breath analysis, in different university laboratory environments have been performed and compared to assess whether breath analysis is an efficient alternative for exposure monitoring in non-acute conditions. 40 atmospheric samples from four laboratories were evaluated: three of the labs used solvents on a daily basis and the manipulation of solvents was forbidden in the other laboratory. 76 breath samples were analyzed from non-exposed people (n = 21) and researchers doing their regular daily routine in each of the tested laboratories (n = 55). It was found that ambient levels in the most contaminated laboratory reached values below the recommended occupational exposure limits for acute exposition. However, the levels found for some of the solvents tested were above the proposed inhalation minimum risk levels (MRL) and reference concentrations (RfC) associated with chronic health effects. The results obtained for exhaled breath tend to agree with the air levels detected in the most contaminated environments, but it was found that exhaled breath levels for people working in environments with low contamination levels were not always correlated with air levels. These results indicate that biological monitoring using breath analysis mirror more accurately the dose inhaled in non-acute conditions and may help to assess provable chronic health effects.

Monitoring Breathing Muscle Performance During Singing Noninvasively Using Mechanomyography and Electromyography

The aim of this study was to investigate the performance of mechanomyography (MMG) and electromyography (EMG) in monitoring the sternocleidomastoid (SCM) as accessory respiratory muscles when breathing during singing. MMG and EMG were used to record the activity of the SCM in 32 untrained singers reciting a monotonous text and a standard folk song. Their voices were recorded and their pitch, or fundamental frequency (FF), and intensity were derived using Praat software. Instants of inhale and exhales were identified during singing from their voice recordings and the corresponding SCM MMG and EMG activities were analysed. The SCM MMG, and EMG signals during breathing while singing were significantly different than breathing at rest (p < 0.001). On the other hand, MMG was relatively better correlated to voice intensity in both reading and singing than EMG. EMG was better, but not significantly, correlated with FF in both reading and singing as compared to MMG. This study established MMG and EMG as the quantitative measurement tool to monitor breathing activities during singing. This is useful for applications related to singing therapy performance measure including potentially pathologically effected population. While the MMG and EMG could not distinguish FF and intensity significantly, it is useful to serve as a proxy of inhalation and exhalation levels throughout a particular singing session. Further studies are required to determine its efficacy in a therapeutic setting.

A Prototype of a Portable Gas Analyzer for Exhaled Acetone Detection

The paper presents the development of a portable gas analyzer prototype for exhaled acetone detection, employing an application-suited gas sensor array and 3D printing technology. The device provides the functionality to monitor exhaled acetone levels, which could be used as a potential tool for non-invasive diabetes monitoring. The relationship between exhaled acetone concentrations and glucose in blood is confirmed in the literature, including research carried out by the authors. The design process is presented including a general consideration for the sensor array construction, which is the core for sensing gases, as well as requirements for the measurement chamber it is to be placed in. Moreover, the mechanical design of the 3D-printed housing is discussed to ensure the ergonomics of use as a hand-held device while keeping the hardware integrity. Also, the processing hardware is discussed to provide sufficient computing power to handle the stand-alone operation while being energy efficient, enabling long battery-powered operation. Finally, calibration and measurement, as well as the analyzer operation, are shown, validating the proposed class of exhaled acetone-detection capable meters.