Predicting Pulmonary Function From the Analysis of Voice: A Machine Learning Approach.

INTRODUCTION: To self-monitor asthma symptoms, existing methods (e.g. peak flow metre, smart spirometer) require special equipment and are not always used by the patients. Voice recording has the potential to generate surrogate measures of lung function and this study aims to apply machine learning approaches to predict lung function and severity of abnormal lung function from recorded voice for asthma patients. METHODS: A threshold-based mechanism was designed to separate speech and breathing from 323 recordings. Features extracted from these were combined with biological factors to predict lung function. Three predictive models were developed using Random Forest (RF), Support Vector Machine (SVM), and linear regression algorithms: (a) regression models to predict lung function, (b) multi-class classification models to predict severity of lung function abnormality, and (c) binary classification models to predict lung function abnormality. Training and test samples were separated (70%:30%, using balanced portioning), features were normalised, 10-fold cross-validation was used and model performances were evaluated on the test samples. RESULTS: The RF-based regression model performed better with the lowest root mean square error of 10·86. To predict severity of lung function impairment, the SVM-based model performed best in multi-class classification (accuracy = 73.20%), whereas the RF-based model performed best in binary classification models for predicting abnormal lung function (accuracy = 85%). CONCLUSION: Our machine learning approaches can predict lung function, from recorded voice files, better than published approaches. This technique could be used to develop future telehealth solutions including smartphone-based applications which have potential to aid decision making and self-monitoring in asthma.

Monolithically-integrated cytometer for measuring particle diameter in the extracellular vesicle size range using multi-angle scattering.

Size measurement of extracellular vesicles is hampered by the high cost and measurement uncertainty of conventional flow cytometers which is mainly due to the use of non-specialised free space optics. Integrated cytometry, where the optics and fluidics are embedded in a monolithic chip shows promise for the production of low cost, micro-flow cytometers dedicated for extracellular vesicle (EV) analysis with improved size measurement accuracy and precision. This research demonstrates a unique integrated cytometer for sub-micron particle size measurement using multi-angle scattering analysis. A combination of three technologies is used: (i) Dean-based hydrodynamic focussing to deliver a tight sample core stream to the analysis region, (ii) integrated waveguides with multimode interference devices to focus a narrow excitation beam onto the sample stream, and (iii) an angular array of collection waveguides to measure particle scattering distribution and calculate diameter. Low index 200 nm liposomes could be detected and polystyrene size standards as small as 400 nm diameter could be measured with an uncertainty of ±21 nm (1/2 IQR) demonstrating a first step on the path to high performance integrated cytometry of EVs.

FCMPASS Software Aids Extracellular Vesicle Light Scatter Standardization.

The study of extracellular vesicles (EVs) is a rapidly growing field due to their great potential in many areas of clinical medicine including diagnostics, prognostics, theranostics, and therapeutics. Flow cytometry is currently one of the most popular methods of analyzing EVs due to it being a high-throughput, multiparametric technique, that is readily available in the majority of research labs. Despite its wide use, few commercial flow cytometers are designed specifically for the detection of EVs. Many flow cytometers used for EV analysis are working at their detection limits and are unable to detect the majority of EVs. Currently, very little standardization exists for EV flow cytometry, which is an issue because flow cytometers vary considerably in the way they collect scattered or fluorescent light from particles being interrogated. This makes published research hard to interpret, compare, and in some cases, impossible to reproduce. Here we demonstrate a method of flow cytometer light scatter standardization, utilizing flow cytometer postacquisition analysis software (FCMPASS ). FCMPASS is built upon Mie theory and enables the approximation of flow cytometer geometric parameters either by analyzing beads of known diameter and refractive index or by inputting the collection angle if known. The software is then able to create a scatter-diameter curve and scatter-refractive index curve that enables researchers to convert scattering data and instrument sensitivity into standardized units. Furthermore, with the correct controls, light scatter data can be converted to diameter distributions or refractive index distributions. FCMPASS therefore offers a freely available and ergonomic method of standardizing and further extending EV characterization using flow cytometry.

Upskilling healthcare professionals to manage clinical allergy.

It has long been recognised that given the high prevalence and considerable impact of allergic disease globally, there needs to be a focus on appropriate training for clinical professionals. The health-economic consequences of allergic disease are significant, with both direct healthcare costs (doctor, nurse and dietitian consultations, hospital admissions and prescribed medications) and indirect costs (lost school and work time, reduced productivity and over-the-counter medications). There is also a well-recognised impairment of quality of life, with less tangible costs including anxiety, distress, discomfort, disability and, occasionally, death. To help to mitigate these effects, there is a need to upskill the professional workforce at all levels, and also to equip those trained with the skills to become future healthare professional trainers. Upskilling the workforce from the grass-roots of undergraduate study in Medical, Nursing and Allied Health Professionals (AHP) through the entirety of training to senior consultant levels could have a major beneficial impact on the patient and their families, lead to a reduction in emergency use of clinical service, and help increase economic productivity.

The impact of a General Practitioner-led community paediatric allergy clinic: A service evaluation.

BACKGROUND: The NHS is not meeting the nation's allergy needs. There are insufficient allergy specialists, with variable care across the country. General practitioners (GPs) are lacking in allergy training. London's Whittington Hospital created a GP with Special Interest (GPwSI) community paediatric allergy clinic, running alongside pre-existing hospital clinics, to address local unmet needs, aiming to provide equity for patients, improve patient experience and decrease secondary care burden. OBJECTIVES: To establish whether improvements have occurred within the service by introducing a GPwSI-led community paediatric allergy clinic alongside providing GP education and referral pathways. This study asks: (a) Have allergy-related hospital attendances decreased with the provision of the community service? (b) Are patients seen in the appropriate clinic? (c) What proportion of patients require GPwSI follow-up? (d) Is there good patient satisfaction? (e) Have allergy clinic waiting times changed? METHODS: Numbers of allergy-related hospital attendances and waiting times in 2013, 2014 and 2016 were assessed. Data were analysed regarding proportions of patients requiring GPwSI follow-up or referral from the GPwSI community clinic to hospital. Patient satisfaction was assessed. RESULTS: Since introducing the GPwSI community service the burden on secondary care has decreased, with reduced hospital attendances for allergy clinic patients, although waiting times have increased. In 2013, 65% of allergy clinic patients attended other hospital services for allergy-related complaints prior to their first allergy clinic appointment. This was reduced to 27.3% (community) and 36.9% (hospital) in 2014 and maintained in 2016 (27.5% community and 37.5% hospital), P < 0.01. Patient satisfaction in the hospital and community clinics is very high. CLINICAL RELEVANCE: This integrated, multidisciplinary Paediatric Allergy Service could provide a model to improve the unmet allergy need both in the UK and beyond. This GPwSI model could also be applied to other chronic diseases in both adults and children, improving care beyond allergy.

Extracellular Vesicle Flow Cytometry Analysis and Standardization.

The term extracellular vesicles (EVs) describes membranous vesicles derived from cells, ranging in diameter from 30 to 1,000 nm with the majority thought to be in the region of 100-150 nm. Due to their small diameter and complex and variable composition, conventional techniques have struggled to accurately count and phenotype EVs. Currently, EV characterization using high-resolution flow cytometry is the most promising method when compared to other currently available techniques, due to it being a high-throughput, single particle, multi-parameter analysis technique capable of analyzing a large range of particle diameters. Whilst high resolution flow cytometry promises detection of the full EV diameter range, standardization of light scattering and fluorescence data between different flow cytometers remains an problem. In this mini review, we will discuss the advances in high-resolution flow cytometry development and future direction of EV scatter and fluorescence standardization. Standardization and therefore reproducibility between research groups and instrumentation is lacking, hindering the validation of EVs use as diagnostic biomarkers and therapeutics.

The development and implementation of a training package for dietitians on cow's milk protein allergy in infants and children based on UK RCPCH competencies for food allergies - a pilot study.

BACKGROUND: Many food allergy guidelines have been published worldwide over recent years. The United Kingdom National Institute of Health and Clinical Excellence guidelines and The Royal College of Paediatrics and Child Health food allergy care pathways require dietitians to assist with the diagnosis and management of food allergies, which highlighted the need for further education of dietitians to meet these competencies. The aim of this study was to design a competence based one day education course for dietitians on the diagnosis and management of cow's milk protein allergy in infants and children. METHODS: A one day training course was developed. Dietitians' knowledge was assessed via multiple choice questions before and on the day of the course and retention of knowledge was assessed one month after the course. Pre course reading was given once the first assessment was completed. RESULTS: Thirty seven dietitians attended the course and 32 completed all three assessments. A significant improvement in assessment scores was seen between the pre course and on the day assessments of 7.2% (p < 0.001) and between pre course and post course assessments of 8.9% (p < 0.001). In delegates who rated their perceived level of knowledge as high, a significant increase was seen between pre course and on the day and between pre course and post course (both p < 0.001). Actual increase in knowledge was seen alongside a significant increase in high rating of perceived level of confidence between pre course and on the day and between pre course and post course (both p < 0.001). CONCLUSIONS: Educating dietitians using the format of one day teaching with pre and post course assessment has improved both knowledge and competencies in the diagnosis and management of cow's milk protein allergy. Further courses in other areas of food allergy could be developed using this approach within the UK and worldwide.

Clinical assessment of speech correlates well with lung function during induced bronchoconstriction.

Clinical assessment of asthma often includes a crude assessment of speech, for example whether the patient can speak in full sentences. To date, this statement, despite appearing in national asthma guidelines, has not been related to lung function testing in asthma exacerbation. Seven asthmatics underwent a bronchial challenge and were then recorded reading a standardised text for 1 min. The recordings were played to 88 healthcare professionals who were asked to estimate FEV1% predicted. Health care professionals' estimations showed moderate correlation to FEV1% predicted (rho=0.61 P<0.01). There were no significant differences between professionals grouped by seniority or speciality. Speech can intuitively be estimated by health care professionals with moderate accuracy. This gives an evidence basis for the assessment in speech in acute asthma and may provide a new avenue for monitoring.

Paper-based colorimetric enzyme linked immunosorbent assay fabricated by laser induced forward transfer.

We report the Laser Induced Forward Transfer (LIFT) of antibodies from a liquid donor film onto paper receivers for application as point-of-care diagnostic sensors. To minimise the loss of functionality of the active biomolecules during transfer, a dynamic release layer was employed to shield the biomaterial from direct exposure to the pulsed laser source. Cellulose paper was chosen as the ideal receiver because of its inherent bio-compatibility, liquid transport properties, wide availability and low cost, all of which make it an efficient and suitable platform for point-of-care diagnostic sensors. Both enzyme-tagged and untagged IgG antibodies were LIFT-printed and their functionality was confirmed via a colorimetric enzyme-linked immunosorbent assay. Localisation of the printed antibodies was exhibited, which can allow the creation of complex 2-d patterns such as QR codes or letters for use in a final working device. Finally, a calibration curve was determined that related the intensity of the colour obtained to the concentration of active antibodies to enable quantitative assessment of the device performance. The motivation for this work was to implement a laser-based procedure for manufacturing low-cost, point-of-care diagnostic devices on paper.

The case for a children's multidisciplinary food allergy clinic.

In the UK, up to 6% of children are affected by food allergy. Accurate diagnosis, appropriate dietary management, family education, support and continuing follow up are essential to prevent further reactions and optimise the child's nutritional intake and growth. Setting up an improved, one- stop service to achieve these goals, which includes the multidisciplinary team, is feasible and cost neutral. This audit and service evaluation involved questionnaires with parents and staff focus groups to examine provision in one area of England. The views of children were not included. Practitioners involved should consider further training if necessary.

Comparison of venous and capillary differential leukocyte counts using a standard hematology analyzer and a novel microfluidic impedance cytometer.

Capillary blood sampling has been identified as a potentially suitable technique for use in diagnostic testing of the full blood count (FBC) at the point-of-care (POC), for which a recent need has been highlighted. In this study we assess the accuracy of capillary blood counts and evaluate the potential of a miniaturized cytometer developed for POC testing. Differential leukocyte counts in the normal clinical range from fingerprick (capillary) and venous blood samples were measured and compared using a standard hematology analyzer. The accuracy of our novel microfluidic impedance cytometer (MIC) was then tested by comparing same-site measurements to those obtained with the standard analyzer. The concordance between measurements of fingerprick and venous blood samples using the standard hematology analyzer was high, with no clinically relevant differences observed between the mean differential leukocyte counts. Concordance data between the MIC and the standard analyzer on same-site measurements presented significantly lower leukocyte counts determined by the MIC. This systematic undercount was consistent across the measured (normal) concentration range, suggesting that an internal correction factor could be applied. Differential leukocyte counts obtained from fingerprick samples accurately reflect those from venous blood, which confirms the potential of capillary blood sampling for POC testing of the FBC. Furthermore, the MIC device demonstrated here presents a realistic technology for the future development of FBC and related tests for use at the site of patient care.

What factors affect the carriage of epinephrine auto-injectors by teenagers?

BACKGROUND: Teenagers with allergies are at particular risk of severe and fatal reactions, but epinephrine auto-injectors are not always carried as prescribed. We investigated barriers to carriage. METHODS: Patients aged 12-18 years old under a specialist allergy clinic, who had previously been prescribed an auto-injector were invited to participate. Semi-structured interviews explored the factors that positively or negatively impacted on carriage. RESULTS: Twenty teenagers with food or venom allergies were interviewed. Only two patients had used their auto-injector in the community, although several had been treated for severe reactions in hospital. Most teenagers made complex risk assessments to determine whether to carry the auto-injector. Most but not all decisions were rational and were at least partially informed by knowledge. Factors affecting carriage included location, who else would be present, the attitudes of others and physical features of the auto-injector. Teenagers made frequent risk assessments when deciding whether to carry their auto-injectors, and generally wanted to remain safe. Their decisions were complex, multi-faceted and highly individualised. CONCLUSIONS: Rather than aiming for 100% carriage of auto-injectors, which remains an ambitious ideal, personalised education packages should aim to empower teenagers to make and act upon informed risk assessments.

Integrated systems for rapid point of care (PoC) blood cell analysis.

Counting the different subpopulations of cells in a fingerprick of human blood is important for a number of clinical point-of-care (PoC) applications. It is a challenge to demonstrate the integration of sample preparation and detection techniques in a single platform. In this paper we demonstrate a generic microfluidic platform that combines sample processing and characterisation and enumeration in a single, integrated system. Results of microfluidic 3-part differential leukocyte (granulocyte, lymphocyte and monocyte) counts, together with erythrocyte and thrombocyte (platelet) counts, in human blood are shown and corroborated with results from hospital clinical laboratory analysis.

On-chip epithelial barrier function assays using electrical impedance spectroscopy.

A bio-impedance chip has been developed for real-time monitoring of the kinetics of epithelial cell monolayers in vitro. The human bronchial epithelial cell line (16-HBE 14o-) was cultured in Transwells creating a sustainable and interactive model of the airway epithelium. Conducting polymer polypyrrole (PPy) doped with polystyrene sulfonate (PSS) was electrochemically deposited onto the surface of gold-plated electrodes to reduce the influence of the electrical double layer on the impedance measurements. Finite element and equivalent circuit models were used to model and determine the electrical properties of the epithelial cell monolayer from the impedance spectra. Electrically tight, confluent monolayers of 16 HBE 14o- cells were treated with increasing concentrations of either Triton X-100 to solubilize cell membranes or ethylene glycol-bis(2-aminoethyl-ether)-N,N,N'N'-tetraacetic acid (EGTA) to disrupt cell-cell adhesion. Experimental impedance data showed that disruption of epithelial barrier function in response to Triton X-100 and EGTA can be successfully measured by the bio-impedance chip. The results were consistent with the conventional hand-held trans-epithelial electrical resistance measurements. Immunofluorescent staining of the ZO-1 tight junction protein in the untreated and treated 16HBEs was performed to verify the disruption of the tight junctions by EGTA.

ADAM33 expression in atherosclerotic lesions and relationship of ADAM33 gene variation with atherosclerosis.

A-disintegrin-and-metalloproteinase-domains (ADAMs) are membrane-anchored glycoproteins involved in cell adhesion, cell migration and proteolysis. ADAM15 has been implicated in atherosclerosis, with an effect on vascular smooth muscle cell migration. We investigated whether ADAM33, which is evolutionally closely related to ADAM15, was expressed in atheromas and whether it had an effect on vascular smooth muscle migration. We also tested whether ADAM33 gene variation had an influence on the extent of atherosclerosis in patients with coronary artery disease. Immunohistochemical analyses showed that ADAM33 was expressed in smooth muscle cells in the arterial wall and that the expression was increased in smooth muscle cells in atheromas. ADAM33 immunostaining on inflammatory cells in atheromas was also observed. Primary vascular smooth muscle cells in culture were also found to express ADAM33. Boyden chamber assays showed that a neutralising antibody against ADAM33 increased the ability of arterial smooth muscle cells to migrate through a reconstituted basement membrane, suggesting that ADAM33 has an inhibitory effect on vascular smooth muscle migration. Moreover, we detected an association between ADAM33 genotype and the extent of atherosclerosis in a large cohort of coronary artery disease patients. These findings suggest that ADAM33 is implicated in the pathogenesis of atherosclerosis.

Leukocyte analysis and differentiation using high speed microfluidic single cell impedance cytometry.

Miniature high speed label-free cell analysis systems have yet to be developed, but have the potential to deliver fast, inexpensive and simple full blood cell analysis systems that could be used routinely in clinical practice. We demonstrate a microfluidic single cell impedance cytometer that performs a white blood cell differential count. The device consists of a microfluidic chip with micro-electrodes that measure the impedance of single cells at two frequencies. Human blood, treated with saponin/formic acid to lyse erythrocytes, flows through the device and a complete blood count is performed in a few minutes. Verification of cell dielectric parameters was performed by simultaneously measuring fluorescence from CD antibody-conjugated cells. This enabled direct correlation of impedance signals from individual cells with phenotype. Tests with patient samples showed 95% correlation against commercial (optical/Coulter) blood analysis equipment, demonstrating the potential clinical utility of the impedance microcytometer for a point-of-care blood analysis system.