The Library
Development of a handheld breath analyser for the monitoring of energy expenditure
Tools
Vincent, Timothy A. (2017) Development of a handheld breath analyser for the monitoring of energy expenditure. PhD thesis, University of Warwick.
|
PDF
WRAP_Theses_Vincent_2017.pdf - Submitted Version - Requires a PDF viewer. Download (13Mb) | Preview |
Official URL: http://webcat.warwick.ac.uk/record=b3104834~S15
Abstract
Metabolic rate is not routinely assessed in healthcare for the general population, nor is it a measure commonly recorded for in-patients (incorrect feeding can slow post-operation recovery rate). For the general community, this lack of knowledge prevents the accurate determination of calorific need and is a factor contributing towards the onset of an overweight and an increasingly obese population. In the UK alone, obesity costs the National Health Service a staggering £5 billion annually. In this thesis a novel low-cost hand-held breath analyser is presented in order to measure human energy expenditure (EE). A unique optical CO2 sensor was developed, capable of sampling exhaled breath with a fast response time ~1 s and resilience to a humidity range of ~30 % to near saturated. The device was tested in a laboratory gas testing rig and a detection limit of ~25 ppm CO2 was measured. A low power metal oxide sensor (~100 mW) was developed to detect volatile organic compounds (VOCs) in the breath, for disease detection and investigation of the variation of inter-individual metabolism processes. The device was sensitive to acetone (100 to 300 ppm, which is a biomarker for type-I diabetes). Other VOCs, such as NO2 were tested (10 to 250 ppb). Further work includes investigating the inter-individual variance of metabolism processes, for which the metal oxide sensor would be well-suited. Software was developed to operate the gas testing rig and acquire sensor output data in real-time. An application was written for smartphones to enable EE measurements with the breath analyser, outside of a laboratory environment. Three hand-held analysers were constructed and tested with a trial of 10 subjects. A counterpart (benchmark) unit with medical grade commercial sensors (cost of ~£2500) and hospital respiratory rooms (reference) were included in the trial. The newly developed analysers improved upon the performance of the benchmark system (average EE measurement error +2.4 % compared to +7.9 %). The affordable device offered far greater accuracy than the traditional method often used by practitioners (predictive equations, error +41.4%). It is proposed a set of periodic (hourly) breath measurements could be used to determine daily EE. The EE analyser and associated low-cost sensors developed in this work offer a potential solution to halt the growing cost of an obese population and provide point-of-care health management.
Item Type: | Thesis (PhD) | ||||
---|---|---|---|---|---|
Subjects: | R Medicine > R Medicine (General) T Technology > TA Engineering (General). Civil engineering (General) |
||||
Library of Congress Subject Headings (LCSH): | Metabolism -- Testing, Breath tests, Carbon dioxide -- Measurement, Medical instruments and apparatus -- Design and construction, Obesity -- Prevention | ||||
Official Date: | May 2017 | ||||
Dates: |
|
||||
Institution: | University of Warwick | ||||
Theses Department: | School of Engineering | ||||
Thesis Type: | PhD | ||||
Publication Status: | Unpublished | ||||
Supervisor(s)/Advisor: | Gardner, J. W. (Julian W.), 1958- | ||||
Sponsors: | University of Warwick. School of Engineering ; University Hospitals Coventry and Warwickshire NHS Trust | ||||
Format of File: | |||||
Extent: | xxix, 372 leaves : illustrations, charts | ||||
Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year