Reduced Graphene Oxide-Metalloporphyrin Sensors for Human Breath Screening

The objective of this study is to validate reduced graphene oxide (RGO)-based volatile organic compounds (VOC) sensors, assembled by simple and low-cost manufacturing, for the detection of disease-related VOCs in human breath using machine learning (ML) algorithms. RGO films were functionalized by four different metalloporphryins to assemble cross-sensitive chemiresistive sensors with different sensing properties. This work demonstrated how different ML algorithms affect the discrimination capabilities of RGO–based VOC sensors. In addition, an ML-based disease classifier was derived to discriminate healthy vs. unhealthy individuals based on breath sample data. The results show that our ML models could predict the presence of disease-related VOC compounds of interest with a minimum accuracy and F1-score of 91.7% and 83.3%, respectively, and discriminate chronic kidney disease breath with a high accuracy, 91.7%.

Volatile organic breath components and exercise induced bronchoconstriction in asthmatic children

Introduction Asthma is one of the most common chronic diseases in childhood and is generally characterized by exercise induced bronchoconstriction (EIB). Assessing EIB is time consuming and expensive as it requires a fully equipped pulmonary function laboratory. Analysis of volatile organic compounds (VOCs) in breath is a novel technique for examining biomarkers which may associate with asthma features. The aim of this pilot study was to identify potential markers in the relationship between EIB and VOCs. Methods Children between four and 14 years old were asked to provide a breath sample prior to undergoing an exercise challenge test to assess for EIB. Results Breath samples were collected and analyzed in 46 asthmatic children, 21 with EIB and 25 without EIB (NO-EIB). Molecular features (MFs) were not significantly different between EIB and NO-EIB controls. 29 of the 46 children were corticosteroid naïve, 10 with EIB and 13 without. In the corticosteroid naïve group EIB was associated with increased MF23 and MF14 in the lower breath sample (p-value < 0.05). Conclusion This pilot study shows that EIB was related to an increased MF14 and MF23 in corticosteroid naïve children. The tentative identities of these compounds are octanal and dodecane/tetradecane respectively. These candidate biomarkers have a potential to enable non-invasive diagnosis of EIB in steroid-naïve children. Trial registration This study is registered in the Netherlands trial register (trial no. NL6087) at 14 February 2017.

Handwashing Results in Incomplete Nicotine Removal from Fingers of Individuals who Smoke: A Randomized Controlled Experiment

Objective: Tobacco residue, also known as third-hand smoke (THS), contains toxicants and lingers in dust and on surfaces and clothes. THS also remains on hands of individuals who smoke, with potential transfer to infants during visitation while infants are hospitalized in neonatal intensive care units (NICUs), raising concerns (e.g., hindered respiratory development) for vulnerable infants. Previously unexplored, this study tested handwashing (HW) and sanitization efficacy for finger-nicotine removal in a sample of adults who smoked and were visiting infants in an NICU. Study Design: A cross-sectional sample was recruited to complete an interview, carbon monoxide breath samples, and three nicotine wipes of separate fingers (thumb, index, and middle). Eligible participants (n = 14) reported current smoking (verified with breath samples) and were randomly assigned to 30 seconds of HW (n = 7) or alcohol-based sanitization (n = 7), with the order of finger wipes both counterbalanced and randomly assigned. After randomization, the first finger was wiped for nicotine. Participants then washed or sanitized their hands and finger two was wiped 5 minutes later. An interview assessing tobacco/nicotine use and exposure was then administered, followed by a second breath sample and the final finger wipe (40–60 minutes after washing/sanitizing). Results: Generalized linear mixed models found that HW was more effective than sanitizer for nicotine removal but failed to completely remove nicotine. Conclusions: Without proper protections (e.g., wearing gloves and gowns), NICU visitors who smoke may inadvertently expose infants to THS. Research on cleaning protocols are needed to protect vulnerable medical populations from THS and associated risks. Key Points

A Pilot Study for the Prediction of Liver Function Related Scores Using Breath Biomarkers and Machine Learning

Liver function test is the first step to diagnose various liver diseases by measuring certain proteins and liver enzymes from the blood sample. After getting the required data of the clinical parameters from the blood test it is possible to calculate Child-Pugh (CTP), AST to PLT ratio (APRI) and Model for end-stage liver disease (MELD) clinical scores that help the doctors about the severity of the disease progression. Volatile organic compounds (VOCs) found in-breath and monitoring their concentration may be a prevailing method for disease diagnosis. In this work, Isoprene, Limonene, and Dimethyl sulphide (DMS) are considered as a potential breath biomarker related to liver disease. A dataset is designed, that includes the biomarkers concentration analysed from the breath sample before and after study subjects performed an exercise. Four regression methods are performed to predict the clinical scores using breath biomarkers data as features set by the machine learning techniques. Regression methods on the dataset for prediction are evaluated by mean absolute error and root mean square error. A significant difference observed for isoprene concentration (p<0.01) and for DMS concentration (p<0.0001) between liver patients and healthy subjects breath sample. Ensemble regression methods are found best suited for the dataset. The mean absolute error for CTP score is 0.07, for APRI score 0.1 and for MELD score 0.7. The R-square value between actual clinical score and predicted clinical score is found to be 0.78, 0.95, and 0.85 for CTP score, APRI score, and MELD score, respectively. These results suggest that breath biomarkers hold a promising approach for non-invasive test and mass screening related to liver disease.

Characteristics of oxygen concentration and the role of correction factor in real-time GI breath test

ObjectiveA high quality end-expiratory breath sample is required for a reliable gastrointestinal breath test result. Oxygen (O2) concentration in the breath sample can be used as a quality marker. This study investigated the characteristics of O2 concentration in the breath sample and the impact of using a correction factor in real-time breath measurement.DesignThis study includes two separate groups of patient data. Part 1 of the study analysed the patient’s ability to deliver end-expiratory breath samples over a 2-year period (n=564). Part 2 of the study analysed a separate group of patients (n=47) with additional data to investigate the O2 characteristics and the role of correction factor in breath test.ResultsThe results indicated 95.4% of 564 patients were able to achieve an O2 concentration below 14% in their end-expiratory breath. Part 2 of the study revealed that the distribution of O2 concentration was between 9.5% and 16.2%. Applying a correction factor to predict the end-expiratory H2 and CH4 values led to an average measurement error of −36.4% and −12.8%, respectively.ConclusionThe majority of patients are able to deliver a high quality end-expiratory breath sample, regardless of age or gender. The correction factor algorithm is unreliable when predicting the end-expiratory result at 15% O2 and it would have resulted in false negative result for 50% of the positive cases in this study. It has also indicated that the continuous O2 measurement is essential to ensure breath sample quality by preventing secondary breathing during real-time breath collection.

Efficacy of Arabic Coffee and Black Tea in Reducing Halitosis: A Randomized, Double-Blind, Controlled, Crossover Clinical Trial

The aim of the study was to objectively evaluate the short-term effect of Arabic coffee and black tea on oral halitosis. This study was a single-center, randomized, double-blind, placebo-controlled, crossover clinical trial on 17 healthy individuals. During the initial visit, pre-treatment breath samples were collected from each subject and analyzed using portable gas chromatography (OralChroma™). Four interventions were evaluated, with Arabic coffee and black tea as the test intervention tools, mouthwash containing a solution (0.05% chlorhexidine, 0.05% cetylpyridinium chloride, and 0.14% zinc lactate (CHX-CPC-Zn)) as a positive control, and drinking water as a negative control. Halitosis was induced by rinsing with 10 mL solution of L-cysteine for 30 s. Twenty minutes later, a breath sample was taken to record the baseline volatile sulfur compounds (VSC) levels (T0). Then, the participants were asked to rinse with 10 mL of a randomly-assigned solution for 30 s. Sixty minutes later, another breath sample was recorded (T1). Finally, after 120 min, the final breath sample was recorded (T2). It was found that rinsing with Arabic coffee decreased the level of H2S both in the first hour (T1) and the second hour (T2). The reduction was significantly greater at T1 (p = 0.017). There was a similar result after the volunteers rinsed with black tea. At T2, Arabic coffee showed a substantially greater reduction in H2S (p < 0.001). On the contrary, using CHX-CPC-Zn showed a significant and continuous decrease in H2S values in the breath throughout the experiment (p < 0.001). Water showed no significant impact on the level of VSC (p = 0.71). This study demonstrates that black tea and Arabic coffee had inhibitory effects on halitosis that was greater in the first hour and was not sustained over a long period. Additionally, Arabic coffee had a greater inhibitory effect on halitosis than black tea.

Halitosis in Children Undergoing Full Mouth Rehabilitation under General Anesthesia

Interventions and management modalities of pediatric halitosis have been suggested in the literature, however, the effect of full mouth rehabilitation (FMR) under general anesthesia (GA) on pediatric halitosis was not reported. Therefore, the present study was conducted to investigate parents’ perceptions of their child’s halitosis before and after FMR under GA; and to evaluate the effect of FMR on clinical halitosis. Fifty-seven children between 3–8 years old, scheduled for FMR under GA, were included after satisfying the inclusion criteria and upon parental consent. Parents’ perception of halitosis in their children was evaluated using a standardized questionnaire and a breath sample was collected to assess the level of volatile sulfur compounds (VSCs) using OralChromaTM before and after FMR under GA. Sixty percent (n = 34) of the parents perceived halitosis in their children before FMR and about 80% (n = 27) of them reported improvement in halitosis after FMR. Clinical halitosis was detected in 84.2% (n = 48) of the sample before treatment. A statistically significant reduction in halitosis was found in 56.3% (n = 27) of the children after treatment (p < 0.001). In conclusion, majority of parents perceived an absence or reduction of halitosis in their children following FMR and significant improvement of clinical halitosis.

The characteristics of oxygen concentration and the role of correction factor in real-time GI Breath Test

ABSTRACTA high quality end-expiratory breath sample is required for a reliable GI breath test result. Oxygen (O2) concentration in the breath sample can be used as a quality marker. This study investigated the characteristics of oxygen concentration in breath sample and the issues with using a correction factor in real-time breath test. The results indicated 95.4% of 564 patients were able to achieve an O2 concentration below 14% in their end-expiratory breath. A further 228 samples were studied and revealed that the distribution of O2 concentration was between 16.5% and 9.5%. Applying a correction factor to predict the end-expiratory H2 and CH4 values led to an error of −28.0% and −15.2% respectively. The correction factor algorithm based on limiting O2 at 14% has resulted in a false negative diagnosis in one case. This study has also indicated the continuous O2 measurement is essential to ensure breath sample quality by preventing secondary breathing during real-time breath collection.

P01.03 VOC pattern recognition of lung cancer: a comparative evaluation of different dog- and eNose-based strategies using different sampling materials

BackgroundIt has been reported that canine scent tests offer the possibility to screen for cancer. Assuming that breath samples can be collected with carrier materials, we tested the practicability of different carrier materials to be presented to dogs, and validated and compared results with an eNose. Moreover, we hypothesised that cancer detection ability of dogs differs according to their working experience.Materials and MethodsIn a methodological approach two dog teams participated, one using experienced working dogs and the other ordinary household dogs to find discover which dogs were better qualified and the best training method. To find best carrier material for breath sampling we compared charcoal containing glass tubes with fleece masks. In a second validating part, experienced working dogs were trained with improved training strategies. For breath sampling two different, previously successfully tested fleece-based carrier materials were used: one was used with the dog team and both materials were compared with eNose.ResultsIn the first part of the study it was shown overall that experienced working dogs performed better to family dogs and the dogs achieved a sensitivity of 45–59% and a specificity of 45–69%. Charcoal based breath sample carrier materials did not qualify for detection of VOC by dogs. In the second part of the study, the dogs achieved a specificity of 83% and a sensitivity of 56%, but with considerable differences between individual dogs. The eNose provided a specificity of 97% for both fleece based carrier materials and a sensitivity of 89% for fleece filled glass tubes and 100% for earloop masks. Measurements of breath samples collected directly in respiratory bags as reference measurements achieved a sensitivity and specificity of 100%.ConclusionsOur data confirmed that diagnostic accuracy of dogs depended on the type of dog training and on the carrier materials. A comparison of breath samples analysis with an eNose achieved better results for both, sensitivity and specificity, than for dogs. The use of fleece masks or fleeces in glass tubes as a sampling material can be recommended as successful VOC carriers, encouraging their use for clinical screenings.Disclosure InformationW. Biehl: None. H. Schmetzer: None. R. Koczulla: None. A. Hattesohl: None. R. Jörres: None. T. Duell: None. U. Althöhn: None.