Development of a Breath Sampler and proof of concept

Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2020-2021. Tutor/Director: Directori Tutor: Antonio Pardo MartínezIn the last few decades, there has been a pervading interest in non invasive technologies for diagnosis, monitoring as well as for treatment in the medical field. As part of this trend, breath analysis has emerged, and although very promising, there is a main issue this field’s development faces, the lack of reproducibility and reliability of protocols since there’s no standardization in the sampling process. This project aims to develop a Breath Sampler focused on achieving a protocolized sampling methodology that allows the collection of the fraction of exhaled air that has been in contact with the alveoli and therefore is rich in metabolites. To do so, different improvements of hardware and software are implemented on a first Breath Sampler prototype and a proof of concept is carried out to verify that itoperates as intended

Sensing Systems for Respiration Monitoring: A Technical Systematic Review

Respiratory monitoring is essential in sleep studies, sport training, patient monitoring, or health at work, among other applications. This paper presents a comprehensive systematic review of respiration sensing systems. After several systematic searches in scientific repositories, the 198 most relevant papers in this field were analyzed in detail. Different items were examined: sensing technique and sensor, respiration parameter, sensor location and size, general system setup, communication protocol, processing station, energy autonomy and power consumption, sensor validation, processing algorithm, performance evaluation, and analysis software. As a result, several trends and the remaining research challenges of respiration sensors were identified. Long-term evaluations and usability tests should be performed. Researchers designed custom experiments to validate the sensing systems, making it difficult to compare results. Therefore, another challenge is to have a common validation framework to fairly compare sensor performance. The implementation of energy-saving strategies, the incorporation of energy harvesting techniques, the calculation of volume parameters of breathing, or the effective integration of respiration sensors into clothing are other remaining research efforts. Addressing these and other challenges outlined in the paper is a required step to obtain a feasible, robust, affordable, and unobtrusive respiration sensing system

Mirror mirror on the wall... an unobtrusive intelligent multisensory mirror for well-being status self-assessment and visualization

A person’s well-being status is reflected by their face through a combination of facial expressions and physical signs. The SEMEOTICONS project translates the semeiotic code of the human face into measurements and computational descriptors that are automatically extracted from images, videos and 3D scans of the face. SEMEOTICONS developed a multisensory platform in the form of a smart mirror to identify signs related to cardio-metabolic risk. The aim was to enable users to self-monitor their well-being status over time and guide them to improve their lifestyle. Significant scientific and technological challenges have been addressed to build the multisensory mirror, from touchless data acquisition, to real-time processing and integration of multimodal data

NASA Tech Briefs, March 2013

Topics covered include: Remote Data Access with IDL Data Compression Algorithm Architecture for Large Depth-of-Field Particle Image Velocimeters Vectorized Rebinning Algorithm for Fast Data Down-Sampling Display Provides Pilots with Real-Time Sonic-Boom Information Onboard Algorithms for Data Prioritization and Summarization of Aerial Imagery Monitoring and Acquisition Real-time System (MARS) Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End Micro-Textured Black Silicon Wick for Silicon Heat Pipe Array Robust Multivariable Optimization and Performance Simulation for ASIC Design; Castable Amorphous Metal Mirrors and Mirror Assemblies; Sandwich Core Heat-Pipe Radiator for Power and Propulsion Systems; Apparatus for Pumping a Fluid; Cobra Fiber-Optic Positioner Upgrade; Improved Wide Operating Temperature Range of Li-Ion Cells; Non-Toxic, Non-Flammable, -80 C Phase Change Materials; Soft-Bake Purification of SWCNTs Produced by Pulsed Laser Vaporization; Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models; Hand-Based Biometric Analysis; The Next Generation of Cold Immersion Dry Suit Design Evolution for Hypothermia Prevention; Integrated Lunar Information Architecture for Decision Support Version 3.0 (ILIADS 3.0); Relay Forward-Link File Management Services (MaROS Phase 2); Two Mechanisms to Avoid Control Conflicts Resulting from Uncoordinated Intent; XTCE GOVSAT Tool Suite 1.0; Determining Temperature Differential to Prevent Hardware Cross-Contamination in a Vacuum Chamber; SequenceL: Automated Parallel Algorithms Derived from CSP-NT Computational Laws; Remote Data Exploration with the Interactive Data Language (IDL); Mixture-Tuned, Clutter Matched Filter for Remote Detection of Subpixel Spectral Signals; Partitioned-Interval Quantum Optical Communications Receiver; and Practical UAV Optical Sensor Bench with Minimal Adjustability

Development of a handheld breath analyser for the monitoring of energy expenditure

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

Applications of Proton Transfer Reaction and Selected Ion Flow Tube Mass Spectrometry in Health Monitoring

This thesis investigates the use of Volatile Organic Compounds (VOCs) in disease diagnosis and monitoring. VOCs may be found in the human body, in exhaled breath, faecal matter, urine, and skin. Analysis of the volatile profile produced in the human body can provide an indicator of metabolic status, allowing the screening and monitoring of different diseases and conditions, non-invasively and painlessly. In this thesis a range of highly sensitive analytical techniques have been adopted to measure such VOCs and demonstrate that such monitoring may be used as a disease diagnostic. For example breath samples may be analysed and calibrated against gas-phase standards prepared under physiologically representative concentrations as a tool for non-invasive disease monitoring, e.g. type 2 diabetes. Detailed faecal headspace analyses of two different mouse models of type 2 diabetes (Cushing´s mice and Afmid) were made. The mouse model of Cushing’s syndrome develop excessive circulating glucocorticoid concentrations, which are associated with obesity, hyperglycaemia and insulin resistance. The Afmid knockout mice suffer inactivation of Afmid genes, which in part regulates many functions including pancreatic secretion. These mice show impaired glucose tolerance. The gut microbiota of diabetic mice appear to have a different composition when compared to wild-type littermates, i.e. significantly increased levels of short-chain fatty acids (SCFAs), ketones, alcohols and aldehydes were found in the faecal headspace of diabetic mice, and a possible link between gut microbiota and type 2 diabetes is demonstrated. The use of VOCs as a screening tool of colorectal cancer was also explored. The current screening tools show lack of sensitivity and specificity for the screening of the disease. The volatile faecal profile of patients with colorectal cancer was investigated, and sulphide compounds, including hydrogen sulphide (H2S) are shown to have potential as biomarkers for screening of colorectal cancer

A low cost gas phase analysis system for the diagnosis of bacterial infection

Drug resistance is becoming a major concern in both the western world and in developing countries. The over use of common anti-bacterial drugs has resulted in a plethora of multi-drug resistant diseases and an ever reducing number of effective treatments - and is now of major concern to the UK government. One of the major reasons behind this is the difficulty in identifying bacterial infections from viral infections, especially in primary care where patients have an expectation of receiving medication. For most viral conditions, there is no effective treatment and the body fights off the disease, thus prescribing anti-bacterial drugs simply results in the proliferation of drugs within the community - increasing the rate of drug resistance. Increasing drug resistance contributed to the rise of superbugs (drug resistant bacteria) which are expected to kill an about 10 million people a year worldwide by the year 2050 and could result to an economic loss of $63 trillion. Increasing drug resistance contributed to the rise of superbugs (drug resistant bacteria) which are expected to kill an about 10 million people a year worldwide by the year 2050 and could result to an economic loss of$63 trillion. Therefore, there is a strong medical and economic need to develop tools that can diagnose bacterial diseases from viral infections, focused towards primary care. One means of achieving this is through the detection of gas-phase biomarkers IX of disease. It is well known that the metabolic activity of bacteria is significantly different from its host. Many studies have shown that it is possible to detect a bacterial infection, identify the strain and its current life-cycle stage simply by measuring bacterial metabolic emissions. In addition, the human body's response to a bacterial infection is significantly different from a viral infection the human body's response to a bacterial infection is significantly different from a viral infection, allowing human stress markers to also be used for differentiating these conditions. Thus, there is evidence that these bio-markers exist and could be detected. However, a major limiting factor inhibiting the wide-spread deployment of this concept is the unit cost of the analytical instrumentation required for gas analysis. Currently, the main preferred methods are GCMS (gas chromatography/mass spectrometry), TOF-MS (time of flight - MS) and SIFT-MS (selective ion flow tube - MS). Though excellent at undertaking this role, the typical unit cost of these instruments is in excess of $100k, making them out of reach of current GP budgets. Therefore, what is required is a low-cost, portable instrument that can detect bacterial infections from viral infections and be applicable to primary care

Advanced sensors technology survey

This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

Chemical characterization of human breath

In the present work analysis of exhaled breath has been proposed as a novel way to detect disease, to monitor disease progression, and to monitor clinical intervention. An analytical method of analysis based upon two stages thermal desorption capillary gas chromatography and mass spectrometry was developed for the analysis of breath samples. All the steps of the analytical procedure were evaluated, trying to identify the critical aspects in order to optimize the entire procedure. A novel breath collection media has been developed that is cheap, disposable and readily available. This material allows breath samples to be collected in a novel manner. After validation the procedure was applied to real samples and preliminary experiments were performed aimed at estimating the variability of the composition of breath as a function of time of day and the inter-subject variability. In particular the trend in time of the two principal compounds in breath, acetone and isoprene was observed. The data showed a wide inter-variability between different people and also confirmed that a meal can influence breath composition. For this reason if possible, it was better to collect a breath sample in the morning before eating. Single substances or sets and patterns of exhaled markers were also investigated in order to establish correlations between the chemical composition of breath and patients’ clinical conditions. Preliminary studies were performed on patients with end-stage renal disease. The results underlined the capacity of the analytical procedure to appreciate small variation in breath composition. In particularly in people under dialysis treatment two compounds were found to show significant differences in breath concentration between patients and healthy people before the dialysis and no important differences after. These two compounds should become an additional and important parameter to determine the end of the dialysis treatment. In parallel a breath collection system prototype has been designed that enables samples of dead space air to be separated from end tidal breath and be collected independently. This device is also novel and has a great potential in breath analysis field

Contribución al diseño de sensores vestibles y ambientales para medir la respiración y el salto vertical en adultos mayores y frágiles.

Con el avance de la tecnología, se ha popularizado entre la población el uso de dispositivos para medir su estado de salud. Para lograr esto, se suelen utilizar dispositivos vestibles como los smartwatch y smartbands, dispositivos ambientales embebidos en los alrededores, e incluso dispositivos conectados a aplicaciones móviles. El uso de estas tecnologías también se ha popularizado entre los profesionales de la salud.Esta tesis se centra en el desarrollo de dispositivos para monitorizar la salud de adultos mayores y adultos frágiles. Se desarrollaron dos líneas de trabajo: en la primera se diseñó e implementó un sistema vestible para monitorizar en tiempo real la respiración de los usuarios; en la segunda se desarrolló un sistema ambiental capaz de medir la altura del salto vertical efectuado por los usuarios sobre él.Sistema vestible para monitorizar la respiración:- Dentro de esta línea de trabajo se investigó un nuevo sensor de respiración que venía a cubrir algunas lagunas existentes en el estado de la técnica: la integración de todos los elementos electrónicos del sistema en un encapsulado compacto, la liberación del diseño para su reutilización y mejora por parte de otros investigadores y el bajo coste de los elementos que componen el sistema, entre otros. El sistema vestible consiste en un dispositivo que se coloca alrededor del pecho mediante una cinta ajustable. Este sistema funciona mediante un sensor piezoresistivo que detecta las variaciones en el diámetro del pecho ocasionadas al inhalar y exhalar; las variaciones detectadas son enviadas de forma inalámbrica mediante Bluetooth a una estación de visualización elegida por el usuario (PC, Tablet o Smartphone). El sistema se encuentra embebido en un armazón impreso en 3D. Para validar el funcionamiento de este sistema, se realizaron pruebas con 21 voluntarios que efectuaron diferentes ritmos de respiración. Para obtener los ritmos respiratorios de cada señal generada, se utilizaron dos algoritmos. Estos algoritmos calculan el ritmo respiratorio al segmentar la señal original en ventanas de tiempo desde 6 hasta 30 segundos. Los resultados obtenidos muestran que, con una ventana de tiempo de 27 segundos, se obtiene el menor error para cada algoritmo (4,02% y 3,40 %).Sistema ambiental para medir el salto vertical:- Dentro de esta segunda línea de trabajo se investigó en un novedoso sistema ambiental para medir la altura del salto, lo que supuso una innovación respecto a los sensores utilizados actualmente para este fin. El sistema ambiental consiste en una plataforma que detecta objetos sobre ella mediante la presión, y mide el tiempo transcurrido desde que un objeto se retira y se coloca de nuevo. El sistema detecta los objetos mediante una matriz de sensores piezoresitivos (Force Sensitive Resistors - FSR realizados con velostat). Las dimensiones de la plataforma son 30 cm x 30 cm, área sobre la cual se distribuyen un total de 256 sensores FSR. El salto vertical se calcula mediante la fórmula de tiempo de vuelo, y el resultado es enviado mediante Bluetooth a un PC o Smartphone. Se realizaron dos experimentos: en el primero participaron un total de 38 voluntarios, con el objetivo de validar el funcionamiento del sistema con una cámara de alta velocidad como referencia (120 fps); en el segundo experimento se capturaron los datos en crudo de 15 voluntarios, con estos datos se emularon 10 frecuencias de muestreo (desde 20 Hz hasta 200 Hz) y se analizaron los efectos de utilizar frecuencias más bajas. Del primer experimento se obtuvo un error relativo medio de 1.98% con un coeficiente de determinación r2= 0,996. Del segundo experimento se determinó que las frecuencias de muestreo de 200 Hz y 100 Hz muestran un desempeño similar al mantener un error relativo por debajo del 5% en el 95% de las mediciones.Finalmente, este trabajo de tesis concluye indicando las principales aportaciones realizadas para cada una de las dos líneas de trabajo, así como el trabajo futuro que podría desarrollarse en cada una de ellas.<br /