Non‐invasive exhaled breath diagnostic and monitoring technologies

Abstract Blood glucose monitoring (BGM) is the most important part of diabetes management. In classical BGM, glucose measurement by test strips involves invasive finger pricking. We present results of a clinical study that focused on a non-invasive approach based on volatile organic compounds (VOCs) in exhaled breath. Main objective was the discovery of markers for prediction of blood glucose levels (BGL) in diabetic patients. Exhaled breath was measured repeatedly in 60 diabetic patients (30 type 1, 30 type 2) in fasting state and after a standardized meal. Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR-ToF-MS) was used to sample breath every 15 minutes for a total of six hours. BGLs were tested in parallel via BGM test strips. VOC signals were plotted against glucose trends for each subject to identify correlations. Exhaled indole (a bacterial metabolite of tryptophan) showed significant mean correlation to BGL (with negative trend) and significant individual correlation in 36 patients. The type of diabetes did not affect this result. Additional experiments of one healthy male subject by ingestion of lactulose and 13C-labeled glucose (n=3) revealed that exhaled indole does not directly originate from food digestion by intestinal microbiota. As indole has been linked to human glucose metabolism, it might be a tentative marker in breath for non-invasive BGM. Clinical studies with greater diversity are required for confirmation of such results and further investigation of metabolic pathways.

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Exhaled Breath Condensate pH as a Non-invasive Measure of Inflammation in Non-CF Bronchiectasis

ISRN Pulmonology ◽

10.5402/2011/169080 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

A. Shoemark ◽

R. Wilson

Keyword(s):

Repeated Measures ◽

Ex Vivo ◽

Exhaled Breath Condensate ◽

Exhaled Breath ◽

Noninvasive Test ◽

Need For Treatment ◽

Non Invasive ◽

Bronchial Inflammation ◽

Breath Condensate ◽

Ciliary Dyskinesia

Bronchiectasis is characterised by neutrophilic bronchial inflammation. Direct measurement of lung inflammation would be useful to assess disease activity, guide need for treatment, and monitor response. The aim of this study was to test whether exhaled breath condensate (EBC) pH, a simple noninvasive test, provides a clinically useful measure of inflammation in the lungs of patients with bronchiectasis. 96 consecutively referred patients were studied when clinically stable, 20 followed up over two years, and a further 22 patients seen during an exacerbation. Subjects breathed tidally for 10 minutes into a condensing chamber (Ecoscreen, Erich Jaeger, Hoechberg, Germany). pH in EBC was measured immediately using a pH probe. In a representative group of 25 patients samples were deaerated with argon gas. This was to control for variations in pH ex vivo by removing CO2. EBC was acidic in bronchiectasis patients () compared to controls () and primary ciliary dyskinesia patients (). pH was related to lung volume but not disease severity. Repeated measures show EBC pH changes with symptoms. EBC is further acidified during an exacerbation of bronchiectasis (), this acidification persists following treatment (). EBC pH is not sufficiently sensitive or specific to monitor patients' health status or provide information to inform acute treatment decisions.

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A Sensor Platform for Athletes’ Training Supervision: A Proof of Concept Study

Sensors ◽

10.3390/s19183948 ◽

2019 ◽

Vol 19 (18) ◽

pp. 3948 ◽

Cited By ~ 2

Author(s):

Zompanti ◽

Sabatini ◽

Santonico ◽

Grasso ◽

Gianfelici ◽

...

Keyword(s):

Least Squares Method ◽

Maximal Oxygen Consumption ◽

Lactate Concentration ◽

Carbon Dioxide Production ◽

Exhaled Breath ◽

Non Invasive ◽

Sport Practice ◽

Novel Approach ◽

Respiratory Parameters ◽

Partial Least Squares Method

One of the basic needs of professional athletes is the real-time and non-invasive monitoring of their activities. The use of these kind of data is necessary to develop strategies for specific tailored training in order to improve performances. The sensor system presented in this work has the aim to adopt a novel approach for the monitoring of physiological parameters, and athletes’ performances, during their training. The anaerobic threshold is herein identified with the monitoring of the lactate concentration and the respiratory parameters. The data collected by the sensor are used to build a model using a supervised method (based on the partial least squares method, PLS) to predict the values of the parameters of interest. The sensor is able to measure the lactate concentration from a sample of saliva and it can estimate a respiratory parameter, such as maximal oxygen consumption, maximal carbon dioxide production and respiratory rate from a sample of exhaled breath. The main advantages of the device are the low power; the wireless communication; and the non-invasive sampling method, which allow its use in a real context of sport practice.

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Validity of a Portable Breath Analyser (AIRE) for the Assessment of Lactose Malabsorption

Nutrients ◽

10.3390/nu11071636 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1636 ◽

Cited By ~ 1

Author(s):

Aahana Shrestha ◽

Utpal K. Prodhan ◽

Sarah M. Mitchell ◽

Pankaja Sharma ◽

Matthew P.G. Barnett ◽

...

Keyword(s):

Significant Positive Correlation ◽

Self Management ◽

Exhaled Breath ◽

Post Challenge ◽

Lactose Malabsorption ◽

Maximum Score ◽

Non Invasive ◽

Upper Limit ◽

Invasive Method ◽

Digestive Health

Hydrogen (H2) measurement in exhaled breath is a reliable and non-invasive method to diagnose carbohydrate malabsorption. Currently, breath H2 measurement is typically limited to clinic-based equipment. A portable breath analyser (AIRE, FoodMarble Digestive Health Limited, Dublin, Ireland) is a personalised device marketed for the detection and self-management of food intolerances, including lactose malabsorption (LM). Currently, the validity of this device for breath H2 analysis is unknown. Individuals self-reporting dairy intolerance (six males and six females) undertook a lactose challenge and a further seven individuals (all females) underwent a milk challenge. Breath samples were collected prior to and at frequent intervals post-challenge for up to 5 h with analysis using both the AIRE and a calibrated breath hydrogen analyser (BreathTracker, QuinTron Instrument Company Inc., Milwaukee, WI, USA). A significant positive correlation (p < 0.001, r > 0.8) was demonstrated between AIRE and BreathTracker H2 values, after both lactose and milk challenges, although 26% of the AIRE readings demonstrated the maximum score of 10.0 AU. Based on our data, the cut-off value for LM diagnosis (25 ppm H2) using AIRE is 3.0 AU and it is effective for the identification of a response to lactose-containing foods in individuals experiencing LM, although its upper limit is only 81 ppm.

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